tag:blogger.com,1999:blog-59001232818439211682024-02-18T22:59:40.157-08:00No Spin Science -- NeuroscienceJohn Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-5900123281843921168.post-41878553511546537672018-01-16T10:32:00.001-08:002018-05-06T07:26:00.412-07:00My Genetics<br />
( Accompaniment to Part I - Mitochondrial Genetics; published here; https://medicalxpress.com/news/2018-05-genome-imitochondrial-dna.html )<br />
<br />
mtDNA variants (homoplasmy) result haplogroup H56<br />
<br />
<pre style="white-space: pre-wrap; word-wrap: break-word;">ID POS MUT FWD REV Locus AAC MutPred SelectionScore HaploGrepWeight
A18-0020_S2_L001_R1_001.gz_rCRS 11788 C>T 905 / 909 853 / 856 MT-ND4 . . . 8.8
A18-0020_S2_L001_R1_001.gz_rCRS 1438 A>G 808 / 808 769 / 769 MT-CYB . . . 10.0
A18-0020_S2_L001_R1_001.gz_rCRS 15326 A>G 1086 / 1086 838 / 839 MT-CYB T194A 0.452 0.395 10.0
A18-0020_S2_L001_R1_001.gz_rCRS 16519 T>C 864 / 866 933 / 934 MT-DLOOP1 . . . n.d.
A18-0020_S2_L001_R1_001.gz_rCRS 263 A>G 896 / 896 841 / 842 MT-DLOOP2 . . . 8.8
A18-0020_S2_L001_R1_001.gz_rCRS 4769 A>G 965 / 967 898 / 898 MT-ND2 . . . 8.8
A18-0020_S2_L001_R1_001.gz_rCRS 750 A>G 882 / 882 777 / 777 MT-RNR1 . . . 10.0
A18-0020_S2_L001_R1_001.gz_rCRS 8860 A>G 1064 / 1068 855 / 857 MT-ATP6 T112A 0.369 0.287 10.0</pre>
<br />
detected heteroplasmies;<br />
<br />
A18-0020_S2_L001_R1_001.gz_rCRS1977T0.0118T/C3352 / 3571125A18-0020_S2_L001_R1_001.gz_rCRS2005C0.0127C/T3030 / 351915A18-0020_S2_L001_R1_001.gz_rCRS2523C0.0129C/T1103 / 1455134A18-0020_S2_L001_R1_001.gz_rCRS2541C0.0119C/T978 / 1453126A18-0020_S2_L001_R1_001.gz_rCRS2557C0.0166C/T884 / 1468134A18-0020_S2_L001_R1_001.gz_rCRS2563T0.0147T/C836 / 1472124A18-0020_S2_L001_R1_001.gz_rCRS2571G0.0103G/A762 / 1463113A18-0020_S2_L001_R1_001.gz_rCRS2572C0.0063C/T765 / 1463110A18-0020_S2_L001_R1_001.gz_rCRS2577C0.0129C/T728 / 1446126A18-0020_S2_L001_R1_001.gz_rCRS2581A0.0155A/G715 / 1473128<br />
<br />
from mtDNA-server<br />
<br />
23AndMe results; Paternal <span style="background-color: white; color: #333435; font-family: "avenir next" , "helvetica" , "roboto" , "arial" , sans-serif; font-size: 16px;">Haplogroup I-M253, can be found at levels of 10% and higher in many parts of Europe</span><br />
<span style="background-color: white; color: #333435; font-family: "avenir next" , "helvetica" , "roboto" , "arial" , sans-serif; font-size: 16px;"><br /></span>
for 15326 variant -<br />
<h2 class="citation__title" style="background-color: white; box-sizing: border-box; color: #1c1d1e; font-family: "Open Sans", sans-serif, icomoon; line-height: 30px; margin: 10px 0px 15px;">
<span style="font-weight: normal;"><span style="font-size: small;"><i style="box-sizing: border-box;">MT‐CYB</i> mutations in hypertrophic cardiomyopathy</span></span></h2>
<div>
https://onlinelibrary.wiley.com/doi/full/10.1002/mgg3.5</div>
<br />
SNPedia<br />
<br />
SNPs rsID http://howirecovered.com/my-genetics/#mitochondrial<br />
<br />
MitoMap https://mitomap.org/MITOMAP<br />
<br />
Mitogenome MitoCarta https://www.broadinstitute.org/scientific-community/science/programs/metabolic-disease-program/publications/mitocarta/mitocarta-in-0<br />
http://bioinfo.nist.gov/<br />
<br />
<span style="font-family: "arial"; font-size: 11pt; white-space: pre;">Genomics to brain; personal journey</span><span id="docs-internal-guid-5fa1f299-4da8-1d29-6cab-ebdec8343efa"></span><br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre;">- folate-B12 pathays, methylation, mitochondria, nucleic acid metablosim</span><br />
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre;"><br /></span><span style="background-color: transparent; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre;">https://www.greatplainslaboratory.com/organic-acids-test/</span><br />
<span style="background-color: transparent; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre;"><br /></span>
<span style="background-color: transparent; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre;"><br /></span>
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre;"><br /></span></div>
John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com3tag:blogger.com,1999:blog-5900123281843921168.post-74184138892480862682017-07-20T10:49:00.000-07:002018-09-24T11:31:30.402-07:00Future of Medicine - draft<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<b id="docs-internal-guid-b4c48c79-58ab-53fc-db2a-392a73563b1b" style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
( Forthcoming paper )</div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The pursuit of an indefinite healthy lifespan, or healthspan, is the most noble challenge put before mankind. To get there, many bold technologies have been proposed and are now being explored. Among them are two seemingly unique approaches that many believe have already achieved some preliminary measure of success: The first is to eliminate cellular senescence using ‘senolytic’ drugs. The second is to ‘fix’ mitochondria by ‘allotopically expressing’’ reserve copies of untarnished mitochondrial genes into the nuclear DNA. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Regrettably, neither of these methods stands a chance, for reasons I will detail in this essay. Fortunately, at the confluence of these seemingly isolate approaches to conquering aging there is a way forward. This interface, namely, the mitochondrial control of cellular senescence offers deep promise. The idea idea that mitochondria have a hand in controlling cell senescence is nothing new (1). For example, by toggling energy production in the cell between mitochondrial respiration and cytosolic glycolysis with various drugs or genetic manipulations we can tweak cellular metabolism and fate to our liking. At least for cells in a dish.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">What I will offer here that is entirely new, is an incite into the surprising way in which mitochondrial control of cell senescence is exacted across the entire organism. Furthermore, I will describe how we can exploit these natural mechanisms to control the rate of aging at a systems level. Perhaps even more encouraging than mere talk, is that the bleeding edge in medicine has already pushed beyond drug and genetic therapies to devise optimal methods to therapeutically transform ailing tissue by introducing whole mitochondria.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The clear implication here is that the molecule or gene is not the fundamental medicinal unit of measure we will need in order to to out-engineer the ultimate malady; going forward, the ‘quantum of aging’ is the mitochondrion. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Many of the new techniques for artificial mitochondrial transfection, or mitoception, have only been applied in-vitro. One is a ‘photothermal nanoblade’ that uses laser pulses to induce bubble cavitation and mitochondrial uptake. Another, termed magnetomitotransfer, outfits mitochondria with magnetic beads and directs them via magnetic fields (2). But getting mitochondria into cells does not seem to be the problem. Whether they are injected into culture dishes or into whole organs, blood, or cerebrospinal fluid, cells naturally scoop them up faster than fish flakes sprinkled into an aquarium. In other words, </span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">uptake of mitochondria seems to be universal (3).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Cells will use any and all manner of endocytotic mechanisms to get them. Cells will also build elaborate ‘membrane tunneling nanotubes’ reinforced with actin or tubulin to siphon them up when scarce, or unload them during excess. The interesting part for us is discovering the rules of the game -- who transfers to who, and when? Which cell types are the most needy and which the most generous? What really drives the epithelial-mesenchymal transition, or maturation in the bone marrow stem cell population? The answers have been coming in, and a lot of them have been coming from the biology of cancer (4).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Current clinical efforts to deploy mitochondria aim to treat everything from the whole body, by making three-parent embryos, to treating specific regions of damaged hearts by brute force arterial or muscular injection. (4a) What’s missing in all these efforts is an overarching theory to guide them. A theory encompassing how mitochondrial pools are endogenously created, mined, selected, and eliminated. Perhaps more importantly, how they naturally MOVE throughout the body. We hinted at such a theory last year in Part I of the story where we focused on excitability and the nervous system (5). In particular, how the directional transfer of mitochondria can establish polarized neurons and circuits. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Since that time, several advancements in our understanding of how the nervous system controls stem cells, tumors, and cell senescence have suggested we were on the right track. Before getting to some of these advances, let's dispense with those two outdated ideas mentioned above that now occupy and beleaguer much of aging research.</span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">What’s wrong with senolytics?</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Cellular senescence refers to cells that can no longer divide. The flip side of the senescence coin is that these cells don’t die either. Instead, they limp along in a crippled limbo lacking the most basic drive inherent in peaceful multicellularity. That drive is a willingness to self-destruct gracefully through apoptosis when you have outlived your useful lifespan. There are many ways cells become senescent. Neurons and heart cells are senescent by design -- they quiescently rest in the permanent </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">G</span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 8.4pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: sub; white-space: pre-wrap;">0 </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">growth phase.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A more insidious cellular fate is something known as replicative senescence. This occurs when cells reach their so-called Hayflick limit. At this stage, the telomeres at the ends of the chromosomes have been eroded to the point where cell division is no longer possible. When this phenomenon was initially discovered, it appeared that artificial activation of telomerase genes might be used to rebuild telomeres. This would circumvent the built in limitations of the telomere counting mechanism and extend the division cycles of expired cells. Later on, it was found that some 85% of tumors evade senescence by doing exactly this. Researchers eventually admitted to themselves that an indiscriminate reactivation of telomerase would be folly.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Other common varieties of senescence include oncogene-induced, DNA damage, and stress induced senescence. There is also immunosenescence, where hematopoiesis declines with age resulting in a diminished adaptive immune response. This is a double whammy because a healthy immune system will eliminate not only cancer cells but also senescent cells. In other instances, senescence results when precancerous cells manage to halt potential runaway replication only to fall short of deploying the full apoptotic program that normally would remove them from the body.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The rapidly exploding new field of ‘senolytics’ aims to eliminate cells in these various debilitated states using senolytic drugs. Success so far hinges on several assumptions. The main one is that senescent cells possess something in common which can be used both to identify them, and also target some therapy towards them. Typically this would be either the expression of a very specific biomarker, or some defined pathway or sequence of protein operations that could be blocked or activated. The first major problem with senolytics is the underlying assumptions are simply invalid. There is no unique marker only expressed by senescent cells, and there is no pathway that can be uniquely targeted in just these cells. Fake news. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The second major problem is that the drugs that have been promoted as senolytics invariably turn out to have significant toxicity. There is a reason for this. The only way that any of them have managed to gain any traction in the medical or anti-aging communities is by virtue of the fact that they have been previously tested and approved by the FDA -- no small feat for any treatment in today’s regulatory pipeline. Generally speaking, we are dealing chemotherapies or anti-viral drugs. The kicker here, is that these drugs end up being promoted as senolytics only because their side effects proved TOO toxic to continue to justify their use in killing tumors.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Let that sink in for a moment. As it turns out, cutting edge senolytics are largely just unemployed layabouts in need of a job. This is madness.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To put some meat on this sweeping dismissal, we should probably consider some specifics in more detail. One recent paper in Nature recently hit the news cycle with considerable fanfare (6). The authors imply that we might clear senescent cells from auricular cartilage to cure osteoarthritis by injecting the mystery compound UBX0101 into joints. </span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">What exactly is UBX0101 I wonder? If you can somehow manage to get access to their locked-down paper, you can see that they are using the expression of the molecule p16INKa as a proxy for ‘senescent cells’. As mentioned, this is already suspect -- all ‘biomarkers’ are flawed. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The references in the paper for this UBX0101 indicate that the compound is actually ABT-263. This changing of getaway cars in the tunnel does not engender confidence, particular when we google ABT-263 and find out it is actually navitoclax. Although navitoclax does specifically induce apoptosis in senescent cells, it wreaks havoc on your platelets. </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Navitoclax was already on the radar of the extremely diligent anti-aging community as something many of them might want to experiment with. It had previously been billed as a safer successor to more indiscriminate cancer-killing drugs like obatoclax, or to natural flavanoids like quercetin and dasantinib which act similar molecular pathways that promote survival in senescent of cancer cells.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As it turns out, a contributor to one noteworthy and excellent blog, ‘Fight Aging’ (7), was at a conference where he spoke with someone from with the maker of the drug, Unity Biotechnology. This representative apparently indicated that UBX0101 wasn’t ABT-263 after all. Furthermore, they related that after the first review of the paper the actual name and structure was removed! Obviously people don’t expect as much these days from published ‘science’ as they used to. At least to me, this whole business sounds more like some kind of senolytic weed killer a company like Monsanto might market; Its actual chemical formulation changes from time to time when needed, but it is still offered to the public under a trade name like ‘RoundUp’.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">What’s wrong with allotopic expression? </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Allotopic expression is a great idea on paper. It was proposed decades ago almost as soon as people realized our mitochondria are in fact endosymbiont proteobacteria that were engulfed by an archaebacterial host eons ago at the dawn of the eukaryotes. For all the recent talk of the importance of bacterial ‘microbiome’, meaning all the bacteria that crawl through our guts and on our skin, we should probably confess that our primary microbiome is our mitochondria. The mitochondriome, if you will. A most curious feature of this eukaryotic merger is that nearly all of the genes of the original symbiont were copied into nuclear DNA. As the story goes, they then somehow acquired laser-like mitochondrial localization sequences (MLS’s) to get the proteins back to the mitochondria. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Once mitochondria had a steady source of nuclear mitoproteins, their own genes were dropped from the mtDNA. In many mammals, for example, all that remains in the mtDNA is 13 protein subunits and a minimal set of tRNA and rRNA genes to translate them. These select proteins form the critical hydrophobic membrane spanning portions of various respiratory complexes. Proponents of allotopic expression fancy their mission as a man-made speedup that completes a natural evolutionary process. Namely, a world where copies of ALL the mitochondrial genes have been carted off and encoded in nuclear DNA. Rest assured, this is big government of the highest order. It is also a complete fiction. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Why might someone want this? The logic behind allotopic expression is that once safely ensconced away in the nucleus, mitogenes would be immune to corruption from the free radicals generated by respiration. The evolution of the nuclear versions of these genes would effectively be decoupled from the high substitution and deletion rates of their brethren still in the mtDNA. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The success of this strategy depends on the ability to re-target the proteins made by these genes back to the mitochondria. First they must be recoded to use the nuclear codon system. Then the hydrophobicity of the proteins themselves needs to be dialed back so that they don’t fold up prior to import. This sequence optimization step may also require adding code for translocator and protease recognition, and for proper insertion in the inner membrane, The mRNA code itself may also need to be optimized so that it is translated by cytosolic ribosomes localized at the mitochondrial surface. Getting this process to work for those few remaining proteins that nature herself had the most difficulty with would seem to be a tall order.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It is now known that cytosolic ribosomes conveniently bind to mitochondria at their TOM (Translocator on the Outer Membrane) complexes, typically right above crista junctions (7a). If some of the energy supplied to the nascent peptide elongated by the ribosome is also used to cotranslationally import the newly made proteins through TOMs, much of this whole idea of MLS 'sequence' starts to look like an artifact. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Remarkably, researchers at the SENS Institute reported that they had achieved some signs of successful allotopic expression for the ATP6 and ATP8 subunits of complex V. (8) Another group at Gensight has similarly reported success for the ND4 subunit of complex I. If these studies pan out it is possible that some very sick people with major mitochondrial dysfunction, and their offspring, could see some benefit. Perhaps it should not be too surprising that some functional complexes can be built by saturating cells with nuclear copies of missing subunits. The problem, is in trying to extrapolate these findings into something that can improve normal people.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">For one thing, if you alter the sequence away from naturally evolved ideal in order to pull off nuclear expression, your subunits just won’t be as good. For example, some bugs and many single celled protists manage to get by with far fewer genes in their mitochondria. Some have even offloaded their tRNAs or mRNAs to the nucleus and import them as well. For example, trypanosomes get all of their tRNA from the nucleus and must use the same TOM importers for both tRNAs and proteins. (8a). These creatures only manage to pull this off by making qualitative sacrifices in every product they jettison off the nucleus for cytosolic manufacture. Typically for proteins, this means making them less hydrophobic, as has been intentionally done by researchers to get allotopic expression. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Even more problematic, is that there will be no regulation of genes that are haphazardly integrated into the nuclear DNA. Protists have been playing this game for millions of years and have achieved some level of nuclear regulation, but there is a cost to giving up local on site regulation in the mitochondria. Namely, these creatures are still just protists. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There has been a complete failure in the field to distinguish between what I would call ‘soft’ and ‘hard’ allotopic expression. Soft expression would be putting copies of just one or two genes into the nucleus, while hard expression would be all the genes. Similarly, there has been a failure to distinguish between ‘duplicating’ mtDNA in the nucleus and ‘replacing’ mtDNA. There is a reason for this: DUPLICATING mtDNA into the nucleus is REPLACING mtDNA, and when you replace mtDNA, you have no mitochondria left. Instead you have something else -- a mitosome or perhaps a hydrogenosome -- if that.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The nucleoid that contains the mtDNA is the heart of the mitochondria. Researchers have found that mitochochondrial ribosomes, or mitoribosomes, are assembled right on the nucleoid. Proteins made by these mitoribosomes are in turn co-translationally inserted right into the overlying inner membrane, leaving little wiggle room for wasted motions. By analogy to the nucleolus of the cell nucleus, this larger machine is now called the mitochondriolus (9).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">While there are many good reasons why organelles retain this private genome, the mac daddy of all them is CoRR hypothesis. It stands for ‘colocation (of gene and gene product) for Redox Regulation of Gene Expression’ (10). In a nutshell, it says that organelles with elaborate electron transport chains need to have a direct vote in the expression of its major components in order to maintain redox balance in the bioenergetic membrane. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The initial evidence for the CoRR hypothesis came from observing how photosynthetic organelles tune the rates of electron transport through Photosystem I and II in response to changes in light quality. </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The redox state of electron carriers directly controls various protein modifications which ultimately determine how energy is distributed between the two photosystems. Local redox regulation of transcription adjusts the stoichiometry of photosystem components within the chloroplasts. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Similar redox regulation occurs in mitochondria, where the generation of radicals, direction of electron transport, and stoichiometry of individual respiratory complexes within supercomplexes is tightly controlled. When researchers first started to try allotopic expression little was understood about how these macro complexes were assembled. That situation has changed. For example, the precise location and sequence of assembly for individual submodules of complex I has recently been worked out for several species. Similar to the need for mito-encoded RNAs to seed assembly of mitoribosomes, the mito-encoded membrane protein subunits are critical control points for assembly of the complexes. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The academic community has been critical of private efforts to do allotopic expression to the point that they now mutually ignore each other. I asked Leo Nijtmans, the researcher who cracked the human complex I assembly process, to present the SENS paper to his peers at the recent EuroMit conference. Although still somewhat noncommittal, he did eventually get back to me with a list of questions and criticisms in the appendix section (11). </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There seems to be little doubt that </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">restriction or loss of organelle respiratory bioenergetics is accompanied by reduction or loss of organelle DNA. The prediction of the CoRR hypothesis is borne out in nature in the relic mitosomes and hydrogenosomes that have no genomes left. The converse, that loss of genome leads to loss of functional oxidative respiration would seem inevitable, the only question is how quickly things would unravel. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The apparent speed at which mutant mitochondria with naturally occurring major deletions to their genome can clonally expand to take over cells, organs, or bodies has been a main motivator of the allotopic expression initiative. Yet allotopic expression itself would in fact be a major mtDNA deletion by design. Not only would this be a public relations disaster for mitochondria, their reason to be would vanish.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The original deletion studies were done a fairly long time ago in a restricted class of cells. More recent studies have revealed more details regarding large deletions that deletions that result directly from transient ischemia. One common deletion takes out a 7.3 kb chunk that includes 11 proteins. The breakpoints occur in the ATP synthase eight and cytochrome b genes near direct repeat sequences and other hotspots of mutation. While allotopic expression, or even direct germline editing could theoretically be useful here, it seems that a simple mitochondrial transplantation is all that is necessary to fix things (11a). </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The seemingly massive and disproportionate overhead of carrying nearly twice as many tRNAs as proteins is actually a primary feature of mitochondria rather than a bug. As genetic hybrids, these organelles exploit two completely separate and uniquely optimized transcription and translation systems. (In some species, there are even three or four separate genetic systems that have been retained within different organelles.) This meta-genetic cooperative works in tandem to simultaneously construct the respiratory complexes with the mitoribosomes cranking away in the matrix while the ribosomes work at the outer membrane facing the cytosol.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">-Maybe add picture of dual ribosome system?, </span><a href="https://pbs.twimg.com/media/DCw4bqxWsAAmV0V.jpg" style="text-decoration: none;"><span style="background-color: transparent; color: #2163a0; font-family: "arial"; font-size: 11.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://pbs.twimg.com/media/DCw4bqxWsAAmV0V.jpg</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Eukaryotes, which posses a bacterially-derived glycolytic pathway, use ribosomes that ultimately root from an archeal lineage. Mitoribosomes, on the other hand, stem from bacterial ribosomes. There is only one reported instance in the literature of mitoribosomes naturally translating nuclear RNAs, and that is for some sperm mitochondria (12) There is a marvellous new theory that explains how the composition of different kinds of ribosomes is precisely tailored to what they need to accomplish. The authors note that cytosolic ribosomes are autocatalytic in the sense that they beget other ribosomes. Except for a couple of rRNAs, mitoribosome parts are made by cytosolic ribosomes.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It was realized that the ribosome doubling time imposes significant constraints on the cell doubling time. The smallest and fastest translating ribosomes are those of bacteria which are under the most selective pressure for fast biogenesis. Their ribosomes, which contain the shortest ribosomal proteins and the highest mass percentage of rRNA (70%), require only six minutes to make a new set of ribosomal proteins. While their rRNAs vary greatly in size, the short proteins all turn out to be roughly the same length. The length of the rRNAs does not matter so much, only that they are made in the proper stoichiometry. Like the respiratory subunits encoded in mitochondria, this is ensured making single long transcripts which are later cleaved into final products.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Eukaryotic ribosomes are somewhere in the middle of the ribosome world -- they have more proteins, each of longer length, and have less of a need for rapidly synthesized rRNA content. At the far end of the spectrum are the mitoribosomes, which have the largest protein mass (80%) and the highest number of ribosomal protein subunits (~80), each with longer average length. The authors came up with a theory that neatly accounts these distributions. Specifically, a formula for the</span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> minimum fraction of time ribosomes spend on their own generation as a function of cell doubling time, number of proteins in a ribosome, and the time it takes a ribosome to make a new set of those proteins (13).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If theory can accurately predict how mitochondria should outfit and apportion their mitoribosomes, we need not consign these kinds of details to ’frozen accidents’. Perhaps we can generate theories for how mitochondria should conduct other business. In particular we should like similar theories of operation for each respiratory complex. Ribosomes may be more structurally complicated, but they are still basically enzymes -- enzymes which take the concept of cofactors to an extreme; The prosthetic groups of ribosomes are not iron-sulfur clusters, cytochromes, or flavins, but rather, a singular exchangeable system of virtualized cofactors (the tRNAs), that are in turn charged by a massive arsenal of tRNA synthetase enzymes. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Eventually we would desire that the respiratory and metabolic theory somehow adds up to a morphological theory of how mitochondria choose to fuse, fizz, die, and amble through different compartments in the cell. Beyond that, a budget to account for net creation and dissolution in the mitochondrial population as it migrates across cells and through the body at large. A couple things we know we should probably include at a fundamental level, are oxygen, the associated generation of radicals like superoxide, and perhaps a few nitrogen radicals.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To fully comprehend what mitochondria do it is instructive to examine how they get pressed into service in some of the unique anatomical specializations found across the animal kingdom. Whether it is the pit organs of vipers, shock box of the eel, or paracrystalline lens of the planarian eye, invariably these sensory exotica are packed to the hilt with unusual forms of mitochondria. In familiar organs, like hearts, cell-wide networks of mitchondria some 8000 strong fill 30 percent of the volume of the cell and tightly control contractility. They do this by rapidly uncoupling their intermitochondrial junctions when their own membranes are depolarized (13a). When forming a network, their individual cristae line up into a continuous reticulum that spans the double membranes that separate them (13b). Incredibly, temperatures inside active mitochondria have apparently been apparently measured to hover around a scorching 50 degrees celsius (13c).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To look at one example in slightly more detail, consider constructing a theory of operation for the firefly light mantle (14). </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To turn on, the firefly needs to send boatloads of oxygen to peroxisomes where the luciferin based light reaction happens. This oxygen is freed up by shutting down mitochondria with nitric oxide (NO). Nerves release the transmitter octopamine onto nearby tracheal cells which form branching channels that penetrate the light mantle. The subsequent signal cascade leads to the generation of NO which effectively diffuses to mitochondria some 20um away in the cytoplasm of photocytes. Here NO shuts down oxygen use at cytochrome c oxidase (complex IV) by binding to its</span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> hemoprotein.</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Removal of this inhibition requires electron transfer from haem. Curiously, the firefly flash itself may supply the off signal because inhibition of complex IV can be reversed by white light.</span><span style="background-color: transparent; color: #231f20; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> The basic behavior of this relatively simple transduction pathway could be captured by static compartmental models involving O2, NO, and perhaps a few other molecules. If, however, we consider autonomous mitochondria capable of moving toward or away from peroxisomes, the situation gets complicated quickly. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #121212; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There have been several intriguing attempts to capture global mitochondrial performance in terms of just a few parameters, in particular with regards to oxygen use and formation of radicals. One notable idea is that the crucial determinant of radical formation is something called the F/N ratio. This is ratio</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> of electrons entering the respiratory chain via FADH</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> vs. those from NADH. This ratio, along with radical formation, would be low during glucose breakdown and high during fatty acid breakdown. The longer the fatty acid, the higher the F/N. Ideally then, the longest fatty acids should be broken down in a separate place where the extra FADH2 won’t lead to excess mitochondrial radical formation.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If the power of a theory is what it can explain, we might say its usefulness would be what it can predict. In this case the theory offers an explanation both for the evolution of peroxisomes, and for the absence of fatty acid oxidation in long lived cells like neurons. It may also explain several eclectic mitochondrial refinements like carnitine shuttles, uncoupling proteins, and multiple antioxidant mechanisms linked to fatty acid oxidation. Depending on the species and tissue, peroxisomes perform many unique functions for the cell. One thing the theory predicts is that β-oxidation would be the most conserved and most ancient pathway across all peroxisomes. </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">(15) </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Another attempt to define mitochondrial performance has been to split operation into </span><span style="background-color: transparent; color: #121212; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">three primary operating modes for the purpose of quantifying how radical production, particularly superoxide anion (</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">O</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2•−)</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">, occurs in each. In the first case mitochondria are in a normal mode of making ATP resulting in a more oxidized NADH pool, reduced membrane potential (</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Δp ), and consequently a negligible O</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2•−</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> production. In a second mode, mitochondria are not making ATP and consequently have a high Δp, a reduced CoQ (coenzyme Q) pool and CoQH</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">/CoQ ratio. This results in reverse electron transport through complex I and significant generation of O</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2•−</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">. In the third mode, O</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2•−</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> is also high, in this case resulting from a reduced NADH pool or high NADH/NAD</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">+</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> ratio in the matrix(16)</span><span style="background-color: transparent; color: #121212; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">.</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> The ability to accurately measure O</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 8.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2•−</span><span style="background-color: white; color: #121212; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> in vivo, perhaps via EPR measurements would be vital to testing these kinds of theories (16).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Return to reality</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A curious thing has unfolded in aging research that seems to have caught many off guard. That thing is the realization that free radicals (like dual genetic systems) are actually features rather than just bugs. What was the response of the allotopic community and SENS Foundation to this newsflash? I have not heard, but I can tell you what I think their response should have been. I would argue that rather than trying to allotopically diminish the role of our mitochondria, what we should be doing instead is trying to enhance them. In other words, give them more genes and more powers where it might make sense. This is something we can already do. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Genetic engineering of mitochondria is not as advanced as for the nucleus. There are not as many good restriction enzymes available, and advanced methods like CRISPR will not work for nucleoids because mitochondria lack the ability to do many kinds of DNA repair taken for granted in the nucleus. In particular, mitochondria do not do non-homologous end joining. But there are many new methods now in the pipeline to modify the mitochondrial genome that do not need the repair machinery (17). It is also possible to get new proteins to mitochondria without doing full blown allotopic expression. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">For example, one group recently reported the ability to optically control mitochondrial membrane potential and ATP generation by transfecting cells with cDNAs for optically gated channels. (18) In this case it was just a matter of getting the right leader sequences so that the proteins would be put into the mitochondria instead of the plasma membrane. This is heady stuff. For one thing, it should also be possible to transfect mitochondria with optical indicators (18a). If we might briefly opine, the ‘Brain Machine Interfaces’ (BMIs) we have now are basically gimmicks (18b). On the other hand, an all-optical BMI using specially modified mitochondria would be the real deal.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Similarly enticing, would be the ability to swap out a few mitochondria to better match your metabolism to your environment. There are specific mitochondrial haplotypes that are ideally suited for different temperatures and altitudes. Need to burn brown fat in a warm sea-level location? There’s a hap for that. In particular, the mtDNA ‘uncoupling’ variants U5a and U4 that are common in Northern Europe reportedly give you greater on-demand fat burning ability. The downside is they may have a higher Parkinson’s risk associated with them (18c).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Today researchers and clinicians alike invariably still speak of ‘heteroplasmy’ (having more than one brand or haplotype of mitochondria in a cell or body) as a negative thing. This doesn’t have to be the case. There is no evidence that two heterogeneous populations of mitochondria cannot peacefully coexist and complement each other. The fate of mitochondria with a few artificial optoproteins inside the body would be unknown. Fortunately, we could watch them. We can even watch endogenous mitochondria that have not been modified in any way. For example, two-photon-excited fluorescence of NADH in mitochondria has been used to image mitochondrial reorganization in the skin, and distinguish basal cell carcinoma and melanoma (18d).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Charlie Gard</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Charlie Gard was a child with severe mitochondrial depletion syndrome. He was made famous this past July after Donald Trump and Pope Francis made compassionate pleas on his behalf to an English hospital where he was being held. Eerily similar to the case of Justina Pelletier, a patient with mitochondrial disease at a Boston hospital, he was for all intents and purposes being kept as a medical prisoner. When Charlie’s parents wanted him to see an American doctor and try a seemingly rational (if a long shot) therapy to replace the nucleosides his mitochondria could not make, a court had to intervene to stop the English hospital from pulling the plug on his respirator. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Charlie had the misfortune of inheriting two mutated copies of a </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Ribonucleoside-diphosphate reductase (</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">RRM2B) gene from his parents. </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">RRM2B is needed in senescent cells for DNA repair and for mtDNA synthesis. Another form of ribonucleoside reductase is used in dividing cells.</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Unable to make enough mtDNA, what Charlie really needed was an infusion of good mitochondria.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The conventional wisdom has been that you can’t just inject extra mitochondria into your bloodstream like you would in a transfusion. For one thing, mitochondria are highly immunogenic by virtue of their bacteria-style formylated peptides and undermethylated CpG islands. CpG islands are regions of their genome that can be given extra methyl group tags by epigenetic regulatory enzymes. In fact, our immune system exploits this immunogenic property of mitochondria in order to self-activate (19).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Notwithstanding this settled science, a Chinese group recently found evidence that bloodstream injection of mitochondria in rodents can apparently fix certain kinds of brain damage (20). They reported zero immune activation in the acute phase for the first 2 hrs after injection. Intriguingly they discovered that cells from many different organs had taken up functional mitochondria from the initial injection stock. A likely explanation is that blood or endothelial cells absorb the mitochondria right after injection and pass them on to other distribution channels. I asked the researchers if they had found evidence of immune reaction in the longer chronic phase, and also suggested that they might try injecting mitochondria directly into the ventricular system of the brain. Both experiments are now planned.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If the mitochondria can pass the blood brain barrier, or alternatively can be supplied more directly to key access points in the nervous system, then many new possibilities open up. For one, like the testes, the nervous system is immunoprivileged. The peripheral immune system rarely gains access to the brain. Another advantage is that nerves reach out and touch many exclusive locations that capillary beds only reach by diffusion. For example, they directly contact sensory corpuscles, hair follicles, bone marrow sites of hematopoiesis, and niche stem cell populations in the epithelial sheets lining many organs in the body.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">An important finding in these stem cell populations is that mitochondria directly control the fate and senescence of daughter cells. One way they do this is by sorting themselves out inside the cell according to age, membrane potential, and other indicators of status. The daughter cell that differentiates into a post-mitotic state asymmetrically receives more and younger mitochondria while the daughter that retains stem cell character retains fewer but older mitochondria (21). When cells or their progeny turn cancerous, it is frequently because their mitochondrial function has been compromised in some way. Furthermore, what often transforms a quiescence tumor into an invasive cancer after the initial metabolic pivot away from mitochondrial respiration is donation of fresh mitochondria from nearby cells (22). </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The other major element that controls cell fate, and particularly cancer, is nerves. The list of nerve-controlled tumors has expanded to include multiple cancer types in multiple organs. Cholinergic innervation of stem cell crypts times the maturation, proliferation, and tumorigenicity of cells in the gut. Nerves specializing in other factors, like GDNF, control pancreatic cancers. Still other nerve channels feed basal cell carcinomas or melanomas in the skin. The control of cell senescence and cancer by nerves has several things in common with the control of tissue regeneration by nerves. Salamander digits and tadpole limbs readily regrow when when cut off, but all regenerating tissues seem to require something from nerves in order to do this. Take away the nerves, and regeneration stalls.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">In order to tie these observations together we need to consider one further fact. That fact is that nerves take the donation and absorption of mitochondria to an extreme. As we will see shortly, we might say it is their bread and butter. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">With that in mind, the full Monty is now laid bare; </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The nervous system controls the rate of aging throughout the body, and maintains its populations of cells in various states of senescence and proliferation by apportioning mitochondria. In this light, cell senescence is not quite so irreversible as one might assume (23).</span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">John McCain</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">What about cancers of the brain itself? By one count there are now at least 80 treatments in various stages of testing and trial to defeat glioblastoma. Many of them use viruses like herpes, HIV, or polio, or even combinations of viruses, drugs, and immunotherapies against the tumor. A unique feature of glioblastoma is its resistance to all forms of treatment. When it is knocked down by drug, surgery, and radiation, it reorganizes and returns with a vengeance. Whether these gliomas originate from neural stem cells, glial progenitors, or astrocytes, the feature that defines them is their formation of one continuous syncytium (24).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">By watching these networks evolve on timescales from minutes to years it was discovered that nuclei and mitochondria constantly scan the entire glioma through the membranous tubes that interconnect it. It has been shown that when cells are irradiated, mitochondria bear the brunt of the damage. (25) Incidentally, mitochondria may be the primary targets of damage by excessive ultrasound. It is believed that one source of the remarkable resistance of gliomas to radiation is the ability to rapidly repopulate and energize the network with fresh mitochondria. Something that advocates of allotopic expression might want to keep in mind, is that should they ever succeed in installing their nuclear backup copies of mtDNA, their tumors may not be as susceptible to radiation therapies.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As far as John McCain’s prognosis, one thing that could be in his favor would be for his brand of tumor to be an isocitrate dehydrogenase (IDH) mutant version. IDH mutants typically respond better to treatment and patients have longer mean survival, but they are a less common form of glioma. A related finding is that tumors with a certain deletion, the 1p/19q codeleted tumors, are invariably also IDH mutated. The interesting thing about these tumors is that they lack the elaborate intercellular membrane tubes, and do not form radiotherapy-resistant astrocytoma networks. Many of the behind the scenes links between nuclear alterations and mitochondrial dysfunction, and vice-versa, are now coming to light. One crafty mechanism the nucleus employs to sense mitochondrial status is to attach mitochondrial localization sequences to the front end of a dual purpose transcription factor, and nuclear localization sequences to the back end.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">For example, if the nucleus reels off copies of a transcription factor known as ATFS1, but the mitochondrial can’t import it because their membrane potential is too weak for uptake, it will eventually find its way back to the nucleus where it can regulate genes to rev respiration back up (26). This level of feedback would be difficult to install in artificial allotopic expression.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">While we lack a complete understanding of mito-nuclear regulatory crosstalk in cancers like glioblastoma, some inferences are now possible. The regular migration of nuclei and mitochondria within the gliomal syncytium might be considered to be a throwback to a much earlier time. One theory, due to Garg and Martin (27), places the</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: white; color: black; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">symbiotic association with mitochondria at the founding of a multinucleated eukaryotic cell. They propose that eukaryotic chromosome division arose in a filamentous, syncytial ancestor. Individual nuclei inside the proto-syncytium with insufficient chromosome numbers could complement each other through mRNA in the cytosol, and generate new chromosome combinations through nuclear fusion (karyogamy). The theory explains why the mechanisms for eukaryotic chromosome separation are more conserved than those for cell division. It also explains the origin of sex, and accounts for sequence of the evolutionary appearance of meiosis and mitosis.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: black; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The authors show that the energy provided by mitochondria relieved a major constraint on the ability to produce tubulin for chromosome separation. The ability to make tubulin in sufficient quantities to nucleate microtubules also made things like neurons, axons, and organelle transport possible. </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A remarkable feature of the methods used to transmit mitochondria, namely cytoskeleton infused membrane nanotubes and endo/exocytosis, is that they look a lot like those features the brain normally employs in its daily operation. That is to say, axons, dendrites, and vesicle-mediated synaptic transmission.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It is not to difficult to imagine that in the early evolution of nervous system mitochondria began to push out these neuritic proto-appendages in order to escape predation and degradation by the lysosomes in the locale of the nucleus. Fully arborized neurons eventually rectified themselves into polarized circuits transmitting from dendrite to axon, with mitochondria along for the ride. One predictable side effect of this would be that neurons became selectors of mitochondria (28).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Much of the basic allometry of nervous systems (like relative lengths and branching patterns of dendrites and axons, or thickness and gyrification of cortex and cerebellum) can not be adequately explained by the electrotonic computational theory that traditional neuroscience continues to offer. Instead, these features may have been shaped more by what mitochondria within those neurons and circuits needed to accomplish. In the view, rapid signal transduction and ‘computation’ would have arose as a side effect of this primal function.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If neurons are devices to select mitochondria, we might ask when they require net creation and transmission of mitochondria, and when their sequestration and removal? Under what circumstances are whole mitochondria transferred, and when just their nucleoids? Similarly, neurons with distinct phenotypes may select the particular transmitter systems they use in successive legs of a neural circuit based on the metabolic needs of their mitochondria. This entails certain advantages and vulnerabilities for synapses competing for real estate within the brain. The immediate result of this transmitter specialization and competition for survival can be seen directly in the microstructure of grey matter; The thorny excrescences, synaptic ribbons, and spiney involutions of neuropil accrete into nested triads and glomeruli around their core sources, directionally passing different metabolites between center and periphery. In the grey matter, this source is often a single apical dendrite or capillary, and in the white matter, a node or hillock.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Consider cells which use the transmitter dopamine. They are uniquely susceptible to loss of their mitochondria, particularly in Parkinson’s disease or when certain drugs are imported into their nerve terminals. While Parkinson’s is a blanket term, different forms of the disease can be distinguished by detection of mitochondria vented into the CSF. Incidentally, mitochondria are also found in the CSF during stroke (29). Stroke is interesting here because it is now known that astrocytes can rescue ailing neurons after their blood supply is interrupted by donating mitochondria (30). In idiopathic Parkinson’s disease, a high concentration of mtDNA in the CSF has been found in patients that carry the LRRK2G2019S mutation (31). To replenish mitochondria in a disease that uniquely targets certain transmitter systems like dopamine, one thing we would want is a circuit diagram for mitochondrial flow through the striatum.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">How do we create mitochondrial maps for the body?</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A significant problem with many common chemotherapies is they take a huge toll on the hematopoietic system that generates new blood cells. It turns out that the drugs destroy the adrenergic nerve endings that contact stem cells niches in the bone marrow to promote their survival. Without these sympathetic nerves, </span><span style="background-color: white; color: #333333; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">proliferation and differentiation of hemotpoietic cells grinds to a halt (32). In acute myeloid leukemia (AML) the bone marrow is infiltrated by a clonally expanding population poorly differentiated blast cells. Compared to normal CD34+ hematopoetic stem cell progenitors, these cells are overloaded with mitochondria and rely on their oxidative phosphorylation to generate ATP. This contrasts with most common tumors which generate their ATP by ’aerobic glycolysis’ in accordance with the Warburg hypothesis.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It was recently discovered that the mitochondria responsible for transforming malignant AML blasts are supplied by bone marrow stromal cells (BMSCs). This heterogenous population of local stromal cells includes precursors of endothelial cells, osteoclasts, osteoblasts, adipocytes, and fibroblasts. The way the AML blasts get the mitochondria is by extending tunneling nanotubes to the BMSCs. The way that blasts make the nanotubes is by generating superoxide radical with NADPH oxidase (33).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">We just described how sympathetic nerves trophically support the marrow stem cell pool, and how the marrow cells support AML blasts. What do we get when when put these two observations together? One exemplary possibility we can infer is a multi-hop mitochondrial transfer circuit from nerve to marrow cell to AML blast. </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Better living by defeating male pattern baldness</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Under the Warburg effect, cancer cells oxidize a decreased fraction of the pyruvate (generated by glycolysis) in their mitochondria. Instead they ferment it to lactate to generate NAD to rerun glycolysis. The lactate then fuels other pathways or is excreted. One strategy against colon and prostate cancers has been to re-express or upregulate various carriers that ferry pyruvate into mitochondria (34).</span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Hair follicle stem cells (HFSCs) utilize glycolytic metabolism to produce significantly more lactate than other cells in the epidermis. This lactate appears critical for HFSC activation because deleting lactate dehydrogenase blocks their activation while deleting mitochondrial pyruvate carriers accelerates it. Mitochondria would therefore directly influence the unique pattern of oscillation between proliferation and quiescence that is seen in follicular cells. Balding men everywhere recently got some very good news; Blocking mitochondrial pyruvate carriers with a molecule called UK-5099 regrows hair (35).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Nerves like to feed on lactate. During aerobic exercise the brain acts largely as a processor for muscle released lactate. Axons use a monocarboxylate transporter called MCT2, and astrocytes a different one called MCT1. Both work similarly to the mitochondrial pyruvate carriers, but the direction of transport depends on local conditions. Evidence from the optic nerve suggests that astrocytes release lactate and axons gobble it up (36). This trophic pathway parallels a reciprocal transexudation of mitochondria from axon to glial cell in the optic nerve head (37).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As with the above example for bone marrow stem cells, we might pool these observations about hair and nerves to infer another potential mitochondrial circuit from nerve to follicle. In this circuit nerves would be attracted to follicles by the abundant lactate they produce, and control their cycle of activation via mitochondria. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Where does all this leave aging?</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">For people with serious mitochondrial dysfunction or depletion, knowing the status of their mitochondriome is of vital importance. It is difficult to tell what is going on in the entire body just by sampling the blood, but it is the easiest place to begin. It has not escaped the notice of many people in the anti-aging community that the status of the mitochondriome might be of considerable interest to anyone. This information would not simply be the amount of mitochondria in your blood cells and a static sequence of your mtDNA. Rather, it would be a living sequence database that is continually updated from many sources to document how heteroplasmy evolves in the body. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Heteroplasmy is a woefully neglected issue in medicine. Consider current efforts to make transplantable organs from pigs. To make them compatible with humans, researchers have gone to great lengths to delete sequences known as PERVs (porcine porcine endogenous retroviruses) from the pigs (38). Little mention is made that putting a pig liver into a human would introduce a bucketload of pig mitochondria. Experiments done a couple of decades ago have given some indication that human cells may do okay with heteroplasmic mitochondria from other species. One researcher from Advanced Cell Technology created hybrid cow-human embryos by fusing his own cells with cow eggs that had their nuclei removed. The cells, which retained cow mitochondria along with the human nucleus were in fact quite viable (39). </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To get an idea how the mitochondriome is evaluated with our current technology, consider some recent advances in understanding and treating Friedrich’s ataxia. This neurodegenerative disease caused by inherited deficiency of the mitochondrial protein Frataxin. Frataxin makes the iron-sulfur clusters that are needed by respiratory complexes I,II, and III. These clusters are also needed for DNA replication and repair. By measuring </span><span style="background-color: white; color: #555555; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">nucleoid copy number as ratio of mtDNA over nuclear DNA by quantitative PCR it was found that frataxin mutations cause deficiencies in mitochondrial biogenesis (40).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #555555; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A second study showed that a drug now used to treat multiple sclerosis called dimethyl fumarate (DMF), could boost mitochondrial numbers. The authors suggest that DMF might be used to treat a broad class of mitochondrial deficiencies. If so, this would probably the first actual mitochondria-boosting drug, despite the claims of many supplements on the market. To see if it is actually working, one might simply count mitochondria in bone marrow derived platelets in the blood (41). </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #555555; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Ultimately any drug given to the body at large is going to affect metabolisms all throughout it. As far as dealing with cell senescence and aging there simply has been no drug that has been unambiguously proven to be worth the trouble -- there are always significant side effects. Controlling the life cycle of cells, tissues, and the body itself will require controlling the nervous system and mitochondria distributed by it.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #555555; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">References</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">1) </span><span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Mitochondria in Cell Senescence: Is Mitophagy the Weakest Link?</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.ebiomedicine.com/article/S2352-3964(17)30116-0/fulltext" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.ebiomedicine.com/article/S2352-3964(17)30116-0/fulltext</span></a></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Mitochondrial Dysfunction Meets Senescence</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.cell.com/trends/biochemical-sciences/pdf/S0968-0004(16)00020-7.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/trends/biochemical-sciences/pdf/S0968-0004(16)00020-7.pdf</span></a></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">An attempt to prevent senescence: A mitochondrial approach </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.sciencedirect.com/science/article/pii/S0005272808007573" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.sciencedirect.com/science/article/pii/S0005272808007573</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2) Artificial Mitochondria Transfer: Current Challenges, Advances, and Future Applications</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> https://www.hindawi.com/journals/sci/2017/7610414/</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">3) Mitochondria Know No Boundaries: Mechanisms and Functions of Intercellular Mitochondrial Transfer </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5039171/" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5039171/</span></a><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">4) Nerve Dependence: From Regeneration to Cancer</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.cell.com/cancer-cell/fulltext/S1535-6108(17)30048-X" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cancer-cell/fulltext/S1535-6108(17)30048-X</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">4a) </span><span style="background-color: transparent; color: #111111; font-family: "georgia"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Myocardial Rescue with Autologous Mitochondrial Transplantation in a Porcine Model of Ischemia/Reperfusion</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="https://www.researchgate.net/publication/310431730_Myocardial_Rescue_with_Autologous_Mitochondrial_Transplantation_in_a_Porcine_Model_of_IschemiaReperfusion" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.researchgate.net/publication/310431730_Myocardial_Rescue_with_Autologous_Mitochondrial_Transplantation_in_a_Porcine_Model_of_IschemiaReperfusion</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">5) The excitable mitochondria </span><a href="http://inference-review.com/article/the-excitable-mitochondria" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://inference-review.com/article/the-excitable-mitochondria</span></a></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Critically reviewed on hacker News </span><a href="https://news.ycombinator.com/item?id=13088772" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://news.ycombinator.com/item?id=13088772</span></a><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">6) </span><span style="background-color: transparent; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Local clearance of senescent cells attenuates the development of post-traumatic osteoarthritis and creates a pro-regenerative environment</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">https://www.nature.com/nm/journal/v23/n6/full/nm.4324.html</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">7)</span><span style="background-color: white; color: black; font-family: "times new roman"; font-size: 12pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Fight Aging blog </span><a href="https://www.fightaging.org/archives/2017/04/more-evidence-for-senescent-cells-as-a-significant-cause-of-osteoarthritis/#comments" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.fightaging.org/archives/2017/04/more-evidence-for-senescent-cells-as-a-significant-cause-of-osteoarthritis/#comments</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">7a) </span><span style="background-color: white; color: #646464; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Visualization of cytosolic ribosomes on the surface of mitochondria by electron cryo‐tomography </span><span style="background-color: white; color: #646464; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">http://embor.embopress.org/content/early/2017/08/21/embr.201744261</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">8) </span><span style="background-color: white; color: #545454; font-family: "roboto"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Stable nuclear expression of ATP8 and ATP6 genes rescues a mtDNA Complex V null mutant </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Stable+nuclear+expression+of+ATP8+and+ATP6+genes+rescues+a+mtDNA+Complex+V+null+mutant" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "roboto"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pubmed/?term=Stable+nuclear+expression+of+ATP8+and+ATP6+genes+rescues+a+mtDNA+Complex+V+null+mutant</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #545454; font-family: "roboto"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">8a) </span><span style="background-color: white; color: #202020; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">tRNAs and proteins use the same import channel for translocation across the mitochondrial outer membrane of trypanosomes </span><a href="http://www.pnas.org/content/early/2017/08/22/1711430114" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.pnas.org/content/early/2017/08/22/1711430114</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">9) The Mitochondriolus: assembling mitoribosomes </span><a href="http://mbi-umiami.org/wp-content/uploads/2016/06/Barrientos-A.-Mitochondriolus-assembling-ribosomes-Oncotarget-2015.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://mbi-umiami.org/wp-content/uploads/2016/06/Barrientos-A.-Mitochondriolus-assembling-ribosomes-Oncotarget-2015.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #202020; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">10) Why chloroplasts and mitochondria retain their own genomes and genetic systems: Colocation for redox regulation of gene expression</span></div>
<div dir="ltr" style="line-height: 1.3800000000000001; margin-bottom: 0pt; margin-top: 0pt;">
<a href="http://www.pnas.org/content/112/33/10231.abstract" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.pnas.org/content/112/33/10231.abstract</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">11) The Assembly Pathway of Mitochondrial Respiratory Chain Complex I </span><a href="http://www.cell.com/cell-metabolism/pdf/S1550-4131(16)30480-6.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cell-metabolism/pdf/S1550-4131(16)30480-6.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<h1 dir="ltr" style="background-color: white; line-height: 1.38; margin-bottom: 2pt; margin-top: 4pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Regulation of Mitochondrial Complex I Biogenesis in </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Drosophila</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Flight Muscles</span></h1>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="http://www.cell.com/cell-reports/fulltext/S2211-1247(17)30812-4" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cell-reports/fulltext/S2211-1247(17)30812-4</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Leo Nijtman’s criticisms to the SENS allotopic paper </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">1. What are the specific tricks they did to improve the allotopic expression (compared to earlier work).</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">2. Why did they only use the ATP8 mutant for the allotropic (stable?). Why not also wt cells, rho zero, or NARP (8993) cybrids?</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">3. I think that it would be elegant to use classical import assays to show the import of the allotopic gene. Perhaps also Prot K treatment to show that the proteins are really imported.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">4. Blue native gels show co-migration with HMW complexes (not necessarily CV). It would have been good if they had also used other approaches to show the incorporation of the allotopic protein. e.g co-IP or complexome profiling could be informative.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">5. I was also surprised that there was no low molecular weight species of A8 (unincorporated in the complex) in the BN gels.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 9pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">6. Also why does the stable expressed allotopic gene does not show a unprocessed species (uncleaved presequence).</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">11a) Mitochondrial transplantation for therapeutic use</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851669/</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">12) Mammalian sperm translate nuclear-encoded proteins by mitochondrial-type ribosomes </span><a href="http://genesdev.cshlp.org/content/20/4/411.full.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://genesdev.cshlp.org/content/20/4/411.full.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">13) </span><span style="background-color: transparent; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Ribosomes are optimized for autocatalytic production</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="https://www.nature.com/nature/journal/v547/n7663/full/nature22998.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.nature.com/nature/journal/v547/n7663/full/nature22998.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">13a) Power Grid Protection of the Muscle Mitochondrial Reticulum</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="http://www.cell.com/cell-reports/pdf/S2211-1247(17)30424-2.pdf" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cell-reports/pdf/S2211-1247(17)30424-2.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "times new roman"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">13b) Trans-mitochondrial coordination of cristae at regulated membrane junctions</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://www.nature.com/articles/ncomms7259" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.nature.com/articles/ncomms7259</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #131313; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">13c) Mitochondria Are Physiologically Maintained At Close To 50 C </span><a href="http://www.biorxiv.org/content/early/2017/05/02/133223" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.biorxiv.org/content/early/2017/05/02/133223</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">14) </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Nitric oxide and control of firefly flashing</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> http://science.sciencemag.org/content/292/5526/2486.full</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">15) </span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">On being the right Q: Shaping Eukaryotic evolution'</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="http://www.biochemj.org/content/473/22/4103" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.biochemj.org/content/473/22/4103</span></a><span style="background-color: white; color: #500050; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #333333; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">16) How mitochondria produce reactive oxygen species </span><a href="http://www.biochemj.org/content/417/1/1?ijkey=8f94df7bae97f641d7c650baa88f1e81cfebcabc&keytype2=tf_ipsecsha" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.biochemj.org/content/417/1/1?ijkey=8f94df7bae97f641d7c650baa88f1e81cfebcabc&keytype2=tf_ipsecsha</span></a><span style="background-color: transparent; color: #500050; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">17) </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Modifying the mitochondrial genome </span><a href="http://www.cell.com/cell-metabolism/pdf/S1550-4131%2816%2930155-3.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cell-metabolism/pdf/S1550-4131%2816%2930155-3.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18) </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Optogenetic control of mitochondrial metabolism and Ca2+signaling by mitochondria-targeted opsins </span><a href="http://www.pnas.org/content/114/26/E5167.abstract" style="text-decoration: none;"><span style="background-color: white; color: #2163a0; font-family: "arial"; font-size: 11.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.pnas.org/content/114/26/E5167.abstract</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<h1 dir="ltr" style="background-color: white; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18b) Pure optical detection of spikes for the ultimate brain machine interface</span></h1>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://phys.org/news/2017-08-pure-optical-spikes-ultimate-brain.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://phys.org/news/2017-08-pure-optical-spikes-ultimate-brain.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18a) Multibeam femtosecond optical transfection for the ultimate brain interface </span><a href="https://medicalxpress.com/news/2013-11-multibeam-femtosecond-optical-transfection-ultimate.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://medicalxpress.com/news/2013-11-multibeam-femtosecond-optical-transfection-ultimate.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18b) Pure optical detection of spikes for the ultimate brain machine interface </span><a href="https://phys.org/news/2017-08-pure-optical-spikes-ultimate-brain.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://phys.org/news/2017-08-pure-optical-spikes-ultimate-brain.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18c) The Impact of Mitochondrial DNA and Nuclear Genes Related to Mitochondrial Functioning on the Risk of Parkinson’s Disease</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3924249/" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3924249/</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">18d) I</span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">maging mitochondrial dynamics in human skin reveals depth-dependent hypoxia and malignant potential for diagnosis</span><a href="https://t.co/oL7tuPxSAW" style="text-decoration: none;"><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: white; color: #2b7bb9; font-family: "arial"; font-size: 10.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">stm.sciencemag.org/content/8/367/</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">19) </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Platelets release mitochondria serving as substrate for bactericidal group IIA-secreted phospholipase A2 to promote inflammation </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260364/" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260364/</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Mesenchymal stem cells use extracellular vesicles to outsource mitophagy and shuttle microRNAs https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4598952/</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">20</span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">)</span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Intravenous administration of mitochondria for treating experimental Parkinson's disease</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> https://www.ncbi.nlm.nih.gov/pubmed/28242362</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #2a2a2a; font-family: "merriweather"; font-size: 10pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Isolated Mitochondria Transfer Improves Neuronal Differentiation of Schizophrenia-Derived Induced Pluripotent Stem Cells and Rescues Deficits in a Rat Model of the Disorder</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">https://academic.oup.com/schizophreniabulletin/article-abstract/doi/10.1093/schbul/sbx077/3861669/Isolated-Mitochondria-Transfer-Improves-Neuronal?redirectedFrom=fulltext</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">21) Asymmetric apportioning of aged mitochondria between daughter cells is required for stemness</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405120/" style="text-decoration: none;"><span style="background-color: white; color: #2163a0; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405120/</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">22) Horizontal transfer of mitochondria in sickness and in health https://medicalxpress.com/news/2015-08-horizontal-mitochondria-sickness-health.html</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">23) How the nervous system controls tumor growth </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="https://medicalxpress.com/news/2017-03-nervous-tumor-growth.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://medicalxpress.com/news/2017-03-nervous-tumor-growth.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">24)</span><span style="background-color: white; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Brain tumour cells interconnect to a functional and resistant network.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/26536111" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pubmed/26536111</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> A malignant cellular network in gliomas: potential clinical implications </span><a href="https://academic.oup.com/neuro-oncology/article/18/4/479/2509372/A-malignant-cellular-network-in-gliomas-potential" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://academic.oup.com/neuro-oncology/article/18/4/479/2509372/A-malignant-cellular-network-in-gliomas-potential</span></a><span style="background-color: white; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292b31; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Mitoception: Transferring Isolated Human MSC Mitochondria to Glioblastoma Stem Cells. </span><a href="https://www.ncbi.nlm.nih.gov/pubmed/28287607" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pubmed/28287607</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">25) </span><span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Effects of ionizing radiation on mitochondria</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> http://www.sciencedirect.com/science/article/pii/S0891584913003687</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">26)Mitochondrial and Nuclear Accumulation of the Transcription Factor ATFS-1 Promotes OXPHOS Recovery during the UPRmt</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt; text-align: justify;">
<a href="http://www.cell.com/molecular-cell/fulltext/S1097-2765(15)00100-8" style="text-decoration: none;"><span style="background-color: white; color: #2163a0; font-family: "arial"; font-size: 11.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/molecular-cell/fulltext/S1097-2765(15)00100-8</span></a><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 11.5pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">27) Mitochondria, the Cell Cycle, and the Origin of Sex via a Syncytial Eukaryote Common Ancestor </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390555/" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390555/</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">28) The Origins of Polarized Nervous Systems https://phys.org/news/2015-03-polarized-nervous.html</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">29) Extracellular Mitochondria in Cerebrospinal Fluid and Neurological Recovery After Subarachnoid Hemorrhage</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">http://stroke.ahajournals.org/content/48/8/2231</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">30) Transfer from astrocytes to axon in stroke http://www.nature.com/nature/journal/v535/n7613/full/nature18928.html?elqTrackId=6065b51923c041e7b1d568338bdeceda&elq=d18a525516ef4a5ab861916f9ab12978&elqaid=16324&elqat=1&elqCampaignId=17</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">31) </span><span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Mitochondrial DNA in CSF distinguishes </span><span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: italic; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">LRRK2</span><span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> from idiopathic Parkinson's disease</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.sciencedirect.com/science/article/pii/S096999611630122X" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.sciencedirect.com/science/article/pii/S096999611630122X</span></a><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Leucine-rich repeat kinase 2 (LRRK2) also called dardarin, from the Basque word ‘dardara’, which means trembling</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">32) </span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Chemotherapy-induced bone marrow nerve injury impairs hematopoietic regeneration. </span><a href="https://www.nature.com/nm/journal/v19/n6/full/nm.3155.html" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.nature.com/nm/journal/v19/n6/full/nm.3155.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">33) NADPH oxidase-2 derived superoxide drives mitochondrial transfer from bone marrow stromal cells to leukemic blasts </span><a href="http://www.bloodjournal.org/content/early/2017/07/21/blood-2017-03-772939" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.bloodjournal.org/content/early/2017/07/21/blood-2017-03-772939</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">34) Inhibition of pyruvate carrier widely explored in cancer, prostate, colon cancer, and warburg effect repessor in general </span><a href="http://www.cell.com/molecular-cell/fulltext/S1097-2765(14)00783-7" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/molecular-cell/fulltext/S1097-2765(14)00783-7</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">35) </span><span style="background-color: whitesmoke; color: #222222; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Lactate dehydrogenase activity drives hair follicle stem cell activation </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://www.nature.com/ncb/journal/vaop/ncurrent/full/ncb3575.html" style="text-decoration: none;"><span style="background-color: whitesmoke; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.nature.com/ncb/journal/vaop/ncurrent/full/ncb3575.html</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">36) Transfer of glycogen-derived lactate from astrocytes to axons via specific monocarboxylate transporters supports mouse optic nerve activity.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pubmed/16015619</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">37) Transcellular degradation of axonal mitochondria </span><a href="http://www.pnas.org/content/111/26/9633.full.pdf" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.pnas.org/content/111/26/9633.full.pdf</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">38) </span><span style="background-color: transparent; color: #333333; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Inactivation of porcine endogenous retrovirus in pigs using CRISPR-Cas9</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="http://science.sciencemag.org/content/early/2017/08/09/science.aan4187" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://science.sciencemag.org/content/early/2017/08/09/science.aan4187</span></a></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #505050; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">39) Researchers claim embryonic mix of human and cow http://www.nytimes.com/1998/11/12/us/researchers-claim-embryonic-cell-mix-of-human-and-cow.html</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">40) </span><span style="background-color: transparent; color: #2a2a2a; font-family: "merriweather"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Frataxin deficiency impairs mitochondrial biogenesis in cells, mice and humans</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">https://academic.oup.com/hmg/article-abstract/26/14/2627/3746878/Frataxin-deficiency-impairs-mitochondrial?redirectedFrom=fulltext</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">41) Dimethyl Fumarate Mediates Nrf2-dependent Mitochondrial Biogenesis in Mice and Humans.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<a href="https://www.ncbi.nlm.nih.gov/pubmed/28460056" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: "arial"; font-size: 11pt; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://www.ncbi.nlm.nih.gov/pubmed/28460056</span></a></div>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<br /></div>
</div>
John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com2tag:blogger.com,1999:blog-5900123281843921168.post-81445962380318752982017-07-13T14:18:00.000-07:002017-08-09T08:31:11.936-07:00Caloric restriction for anti-aging<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">A recent paper <a href="https://link.springer.com/article/10.1007/s11357-017-9976-8" target="_blank">published in GeroScience</a> by researchers at the University of Oklahoma provides some much needed food for thought for the field of caloric restriction. The title, ‘</span><span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Role of DNA methylation in the dietary restriction mediated cellular memory’ suggests some underlying mechanisms have been uncovered which can explain the presumed healthful benefits of dietary restriction (DR). If so, then what exactly is the nature of these apparent relationships and what are their benefits?</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Somewhere in the nebulous aether filling the void between correlation and causality lies the frequently employed dictum of ‘plays a role in’. The way I read things here there are at least 3 or 4 variables at play upon which we might imposed a natural sequence or order. Namely we have in the following scheme (1 >2 > 3 >4):</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Dietary Restriction > Decreased Methylation Of Certain Promoters > Increased Expression Of The Genes Under Control Of Those Promoters > Cell Memory In The Form Persistent Changes To Parts 2 And 3. </span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<br /></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">While several genes (</span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Pomc</span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">, </span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Hsph1</span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">, and </span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Nts1</span><span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">) and their inclusive islands of methylation were clearly operated on by dietary restriction, the most important findings were found within the Nts1 gene. Nts1 encodes the Neurotensin Receptor 1. This G-protein transduces whatever message it is that the 13 amino acid long neuropeptide neurotensin signal locally supplies. This message intimately depends on cell type, and where the cells are found. </span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<br /></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Centrally, neurotensin functions in the hypothalamus, a place where each nuclei contains unique neuronal subtypes specializing in the production of a few eclectic signal molecules. Perception of hunger and satiety are believed to be integrated there, as is the nutrient-dependent control of subsequent food- sensing and food-seeking behaviors. It is therefore a logical place to further explore the many established links between nutrients and epigenetic changes like methylation.</span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<br /></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: #fcfcfc; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">N</span><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">eurotensin acts to </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Hypotension&source=gmail&ust=1500066956581000&usg=AFQjCNFwWjuUcygbPKkKwQtBiKRhuSc5zg" href="https://en.wikipedia.org/wiki/Hypotension" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">lower blood pressure</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">, raise</span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Hyperglycemia&source=gmail&ust=1500066956581000&usg=AFQjCNFXbccgWfrvE9OEP_hUINyAwnjzHw" href="https://en.wikipedia.org/wiki/Hyperglycemia" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;"> blood sugar</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">, </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Hypothermia&source=gmail&ust=1500066956581000&usg=AFQjCNFfpAi-kB4TYOUeO7i-guU12g2Ilg" href="https://en.wikipedia.org/wiki/Hypothermia" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">lower body temperature</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">, and confer antinociception. Another pathway leads to the release of prolactin and </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Luteinizing_hormone&source=gmail&ust=1500066956581000&usg=AFQjCNEPaag5mCxXoAt71RjnKEooAl8EGA" href="https://en.wikipedia.org/wiki/Luteinizing_hormone" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">luteinizing hormone</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">s, ultimately through activity in the arcuate nucleus (where the Pomc neurons are also found) via its own set of tediously constructed peptides. The hypothalamus in turn is supplied with signals, nutrient, and even mitochondrial product from the rest of the brain via the thick fiber bundle from the hippocampus known as the fornix.</span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">It has been argued that these diverse hypothalamic and pituitary mediators represent so-called reliable or ‘honest’ signals conforming to the ‘handicap principle’ -- otherwise popularly known as the ‘peacock effect’. One example of this would be the arduous steroid and vitamin D synthesis chains whose rate-limiting steps are frequently resident in the mitochondria. These expensive and rare (ie. difficult to replicate and active at very low concentration) signals of metabolic state get funneled to the body at large through individual kingpin neurons residing at apex positions in the brain. </span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">In peripheral regions, neurotensin’s major local effects are in the small intestine where it leads to </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Secretion&source=gmail&ust=1500066956581000&usg=AFQjCNEbeg-BAWXSkQAN5WcDZnF4a-C8YQ" href="https://en.wikipedia.org/wiki/Secretion" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">secretion</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;"> and </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Smooth_muscle&source=gmail&ust=1500066956581000&usg=AFQjCNGSyKFJtxgqQCKQhOZ9nkFh4wELMQ" href="https://en.wikipedia.org/wiki/Smooth_muscle" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">smooth muscle</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;"> contraction via </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=https://en.wikipedia.org/wiki/Enteroendocrine_cell&source=gmail&ust=1500066956581000&usg=AFQjCNHmaggCy5ljIJPv_3QaSux0AGjXMQ" href="https://en.wikipedia.org/wiki/Enteroendocrine_cell" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="color: #0b0080; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">enteroendocrine cells</span></a><span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">. It also acts to preserve intestinal stem pool which is why the authors make special mention that memory effects in methylation of the Nts gene may be critical there. </span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">The primary experimental manipulation performed here was to place mice on a DR diet for a few months and then return them to a normal diet for another few months and see what happens. Perhaps not surprisingly significant changes in gene expression were noted within one month of the initial DR. After normal feeding was done the authors found both reduced methylation at three key CG sites in the Nts gene promoter using standard bisulfite amplicon sequencing, and also an overall increase in expression of Nts1 transcripts using RNA-Seq techniques. This confirms their initial hypothesis flowing from DR to a cell memory effect.</span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<br /></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">While these expression and methylation findings are all </span><span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">well and good, I think at this point we need to ask a question that might be on the minds of any red-blooded American:</span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<br /></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;"> How on Earth does Herschel Walker, top mixed-martial arts competitor today at age 55 and still widely regarded as the greatest college running back of all time, manage to crank out over 1500 push-ups, 1500 sit-ups, 1500 pull-ups, followed up by a grueling sprint and long distance workout, each day, every day, while eating nothing but a small dinner of salad, soup, and bread?</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">I am not presenting Hershel’s claims above as facts to be swallowed whole by the reader, but rather offering them up for consumption as something we must potentially account for. Putting up those kinds of numbers, ie. physical work produced from calories burned, is simply not possible by any known man-made machine, and is just barely imaginable for one of flesh and blood. So how does he maintain a stout 225 lb frame where mere mortals attempting to subsist on lumpy green shakes would rapidly shrivel and etiolate? In other words, what exactly is his nuclear DNA, mitochondrial DNA, and epigenetic state?</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">To answer that we would probably need to do more than a quick cheek swab and sequencing from somebody like 23andMe. In fact we’d have to do a lot more to attempt to understand something so fickle as epigenetics, something that can purportedly respond to any given sandwich with a cascading butterfly effect of changes. In many instances these changes are not limited to simple cell memory, but rather can be experimentally extended into heritability and beyond.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">So we must dive deep into our evolutionary roots to uncover the origins, and thereby implications of what methylation really is. It is widely held that methylation in its most ancient incarnation first arose in bacteria for purposes of transposon control. Regarding transmission of acquired characteristics, like diet, it should not escape notice that bacteria are essentially full blown Lamarckian creatures -- their immediate daughter fission products directly feel the full metabolic life history of the parent.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">The transposon idea may have some substance to it because methylation is a powerful transcriptional repressor in animals plants and protists that at least in CpG environments can ensure permanent silencing of rogue transposable elements. Furthermore, methylation tends to repress genes of multicellular organisms that need to be silenced in most but not all differentiated tissues.</span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Yet bacteria do not take methylation to the extent that higher mammals like ourselves do. In fact, one of the ways in which our immune system recognizes and deploys our own bacterial endosymbionts, aka the mitochondria, is by the very absence of any methylated mtDNA should their nucleoids get released into blood. </span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Another major clue we have is that between generations in mammals, DNA methylation patterns, including many imprinting and X-inactivation marks, are largely erased and then re-created to various levels of fidelity at several key stages. The first is a ‘genetic reboot’ consisting of deliberate demethylation and remethylation during gametogenesis. The next two happen first in pre-implantation period of the zygote and then in the blastula stage where the CpG islands are shielding from a bulk methylation wave so that a global repression phase allows housekeeping genes to be deployed through the entire blastula. After that, methylation patterns become tissue and cell type specific to permit stable differentiation.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">At the most basic level many aspects of genome-wide methylation are quite predictable. For example, it has been suggested that the use of thymine in DNA as opposed to uracil in RNA evolved for error-control purposes because any deleterious uracils generated by spontaneous deamination of cytosine could be more easily recognized and removed. 5-methylcytosine has its methyl group at the same spot thymine does, which is the only thing that distinguished thymine from uracil. CpG methylation is evolutionarily costly because over time methylated cytosine spontaneously deaminate to thymine. </span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">The maxim that hypermethylated CpG in promoters leads to repression of gene expression is not always the case. In a paper published in Science last week </span><a data-saferedirecturl="https://www.google.com/url?hl=en&q=http://science.sciencemag.org/content/356/6337/eaaj2239&source=gmail&ust=1500066956581000&usg=AFQjCNF_0oIAHte9YWXs_1rk-pJRZJHZzQ" href="http://science.sciencemag.org/content/356/6337/eaaj2239" style="color: #1155cc; text-decoration-line: none;" target="_blank"><span style="background-color: transparent; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">http://science.sciencemag.org/<wbr></wbr>content/356/6337/eaaj2239</span></a></div>
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">authors looked at 542 human transcription factors and found that for many, particularly homeodomain proteins active during development, methylated promoters enhanced transcription. </span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<span style="font-family: "arial"; font-size: 11pt; vertical-align: baseline; white-space: pre-wrap;">Another study revealed that a reliable biomarker of chronological aging can be extracted by looking at methylation at 353 sites in the human genome. This perhaps is the kind of data we might seek to answer the question we posed above. Namely, how Herschel Walker can look like he does by basically running on fumes while many top powerlifters and bodybuilders with comparable physiques claim to require anywhere from 5000-10000 calories a day.</span>John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com0tag:blogger.com,1999:blog-5900123281843921168.post-45867543242739982452017-07-13T14:12:00.002-07:002017-07-13T14:12:54.611-07:00Complete evulsion of right proximal outer bicep tendon head, bug or feature?Dear Doc,<br />
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.5pt; white-space: pre-wrap;"><br /></span>
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.5pt; white-space: pre-wrap;">I wanted to let you know what I decided to do regarding my right proximal outer bicep tendon tear. First of all, I want to thank you for making the time to see me, and for your excellent consultation and advice. Having watched a couple youtube videos now, I am very impressed with the the surgical tools now available to re-attach tendons, and also the skill with which surgeons like yourself can wield them. I have no doubt you are among the best, and would have every confidence in your abilities if you did surgery on my arm.</span><br />
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="color: #292f33; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">When I saw you a couple weeks ago I had fairly severe cramping in the bicep, which I hoped would soon subside, and also had real concerns it was still in the process of some further tearing throughout the muscle because of the way it felt. For the most part the cramping is gone now. Although I have not had any MRI, mainly because I do not like being stuffed in the tunnel (particularly without any chance to do any kind a quick ‘dry run’ ahead of time to get acclimatized and relieve anxiety), I am sure you were right that the proximal tendon tore completely.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="color: #292f33; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">Looking back, I think the tendon must have been pretty much gone for some time and was merely hanging on uselessly by a thread that served to do nothing for me save keep the bicep from crumpling up like it is now, and causing me intense pain for two years. I think that because when it finally went, there was absolutely no blood or bruising (like both of us expected) in the arm at large afterwards, and also because for the last two years that I had the shoulder pain, and also mid bicep cramping (like when I took long jogs), I could notice the slightest little droop in the right bicep relative to left. </span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="color: #292f33; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">I must say I am elated that I can now throw footballs, shoot hoops, and lift weights without the pain I had grown accustomed to and that going through a surgery and the associated recovery time is the furthest thing from my mind right now. My expectation now for surgical reattachment to the humerus somewhere at this point would really only be to serve a cosmetic purpose, and that alone cannot justify surgery given my personal aversion to what I see as the endemic and unavoidable risks to general anesthesia (and intubation). I am not an expert in upper arm anatomy but my impression is that the ideal attachment point to give the muscle any actual purpose for generating additional supination force would be high up in an area where real estate is already expensive -- in other words, I imagine you would have to make space by taking it from somewhere else.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="color: #292f33; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">Yes the bicep still looks a little strange, but having tested things now, the arm as a whole somehow seems to have full strength. I know the conventional wisdom is the tendon does not sprout and reattach, but as I mentioned, my experience with other injured parts of my body and eventual recovery suggests I should give natural healing processes a shot and see what my own rehabilitation efforts might accomplish. I must agree with Leonardo Da Vinci who apparently was the first to say that the biceps is only a minor playing in elbow flexion and really acts primarily to assist in supination. My baseline test for that is that I used to do 10 pullups with a 60lb weight vest on; if I can do that again eventually I will be content. As far as supination, I have not tested things yet by trying to torque down a bolt or open a big bottle of tightly corked Belgian beer, but soon will.</span></div>
<br style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;" />
<div dir="ltr" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="color: #292f33; font-family: "arial"; font-size: 10.5pt; vertical-align: baseline; white-space: pre-wrap;">I was curious that in your experience the preferred method of reattachment was a titanium screw as opposed to something that would eventually degrade away, but understand that surgery is not an a-la-carte affair where the patient picks what they imagine might work and the surgeon complies. One last comment. In looking at the curious structure of the tendon and the way it winds around to eventually form the labrum, it is not surprising to me that this thing eventually frays in many men who do evolutionarily odd things like throw balls. If I had to guess I would imagine this kind of structure formerly was a good way to stabilize and provide feedback for walking on four limbs, something of little use to me now, and that my own self pruning has essentially acted more as a feature than a bug.</span></div>
John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com0tag:blogger.com,1999:blog-5900123281843921168.post-882012467267225752017-03-14T08:51:00.002-07:002017-03-14T09:05:58.461-07:00Taxpayer funded research woes<div>
<br /></div>
<div>
<div class="m_-3156362060331962400gE m_-3156362060331962400iv m_-3156362060331962400gt" style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 13px; padding: 12px 0px 3px;">
<table cellpadding="0" class="m_-3156362060331962400cf m_-3156362060331962400gJ" style="border-collapse: collapse; margin-top: 0px; width: auto;"><tbody>
<tr class="m_-3156362060331962400acZ" style="height: 16px;"><td class="m_-3156362060331962400gF m_-3156362060331962400gK" style="margin: 0px; padding-right: 8px; padding-top: 0px; vertical-align: top; white-space: nowrap; width: 1035px;"><table cellpadding="0" class="m_-3156362060331962400cf m_-3156362060331962400ix" style="border-collapse: collapse; table-layout: fixed; width: 1035px;"><tbody>
<tr><td style="margin: 0px;"><div class="m_-3156362060331962400iw" style="display: inline-block; max-width: 92%; overflow: hidden; white-space: nowrap;">
<span class="m_-3156362060331962400gD" name="Sullenberger, Diane" style="color: #222222; display: inline; font-size: 13px; font-weight: bold; vertical-align: top;">Sullenberger, Diane</span> <span class="m_-3156362060331962400go" style="color: #555555; vertical-align: top;"><<a href="mailto:DSullenb@nas.edu" style="color: #1155cc;" target="_blank">DSullenb@nas.edu</a>></span></div>
</td></tr>
</tbody></table>
</td><td class="m_-3156362060331962400gH" style="color: #222222; margin: 0px; text-align: right; vertical-align: top; white-space: nowrap;"><div class="m_-3156362060331962400gK" style="padding-right: 2px; padding-top: 0px;">
<span alt="Fri, Jun 25, 2010 at 3:58 PM" class="m_-3156362060331962400g3" id="m_-3156362060331962400:zn" style="margin-right: 3px; vertical-align: top;" title="Fri, Jun 25, 2010 at 3:58 PM">6/25/10</span><br />
<div class="m_-3156362060331962400zd" style="display: inline-block; height: 20px; outline: 0px;">
<span class="m_-3156362060331962400T-KT" style="display: inline-block; height: 19px; padding: 2px; text-align: center; width: 19px;"><img alt="" class="m_-3156362060331962400f m_-3156362060331962400T-KT-JX CToWUd" src="https://blogger.googleusercontent.com/img/proxy/AVvXsEi8QXjvn4hvIcIJfr4QhlXwHKEYzXOX9v0qMSqwl3yX6qWrHQRDywgxJMfo1TOR0NGancGnR0CRAMLaUMob941_nOtXPPwyBPSS60nK69C82rJ8Mtf8J0r9u0TNeX0PxspreWgjO-zDa2o6mObm1aMvxVfBLw=s0-d-e1-ft" style="margin-top: 0px; vertical-align: top;" /></span></div>
</div>
</td><td class="m_-3156362060331962400gH" style="color: #222222; margin: 0px; text-align: right; vertical-align: top; white-space: nowrap;"></td><td class="m_-3156362060331962400gH m_-3156362060331962400acX" rowspan="2" style="color: #222222; margin: 0px; text-align: right; vertical-align: top; white-space: nowrap;"><div class="m_-3156362060331962400T-I m_-3156362060331962400J-J5-Ji m_-3156362060331962400T-I-Js-IF m_-3156362060331962400aaq m_-3156362060331962400T-I-ax7 m_-3156362060331962400L3" style="background-color: whitesmoke; background-image: -webkit-linear-gradient(top, rgb(245, 245, 245), rgb(241, 241, 241)); border-radius: 2px 0px 0px 2px; border: 1px solid rgba(0, 0, 0, 0.0980392); color: #444444; display: inline-block; font-size: 11px; font-weight: bold; height: 27px; line-height: 27px; margin-right: 0px; min-width: 32px; outline: 0px; padding: 0px 8px; text-align: center;" title="Reply">
<img alt="" class="m_-3156362060331962400hB m_-3156362060331962400T-I-J3 CToWUd" src="https://blogger.googleusercontent.com/img/proxy/AVvXsEi8QXjvn4hvIcIJfr4QhlXwHKEYzXOX9v0qMSqwl3yX6qWrHQRDywgxJMfo1TOR0NGancGnR0CRAMLaUMob941_nOtXPPwyBPSS60nK69C82rJ8Mtf8J0r9u0TNeX0PxspreWgjO-zDa2o6mObm1aMvxVfBLw=s0-d-e1-ft" style="background-image: url("https://blogger.googleusercontent.com/img/proxy/AVvXsEixz1AMayvYNiaEY50MFmMMwhJjJlEsDMfJB6kWTWKeIA5y1nDzlNJhIBwnkL0fDlGUtP8lmdgjTEYcHBYGT2QxPZkoJL0i9AGMUWgil4-eIxHfjT6VUK-ztb4OECVOnbxZbADFT8YLfFpPJu9VAQnjfDlOh4senbDdGE1Xiu6XCgQm7rb7761va_RCqEvh7350=s0-d-e1-ft"); background-position: 0px -462px; background-repeat: no-repeat; height: 21px; opacity: 0.55; vertical-align: middle; width: 21px;" /></div>
<br />
<div class="m_-3156362060331962400T-I m_-3156362060331962400J-J5-Ji m_-3156362060331962400T-I-Js-Gs m_-3156362060331962400aap m_-3156362060331962400T-I-awG m_-3156362060331962400T-I-ax7 m_-3156362060331962400L3" id="m_-3156362060331962400:10m" style="background-color: whitesmoke; background-image: -webkit-linear-gradient(top, rgb(245, 245, 245), rgb(241, 241, 241)); border-radius: 0px 2px 2px 0px; border: 1px solid rgba(0, 0, 0, 0.0980392); color: #444444; display: inline-block; font-size: 11px; font-weight: bold; height: 27px; line-height: 27px; margin-right: 0px; min-width: 21px; outline: 0px; padding: 0px; text-align: center;" title="More">
<img alt="" class="m_-3156362060331962400hA m_-3156362060331962400T-I-J3 CToWUd" src="https://blogger.googleusercontent.com/img/proxy/AVvXsEi8QXjvn4hvIcIJfr4QhlXwHKEYzXOX9v0qMSqwl3yX6qWrHQRDywgxJMfo1TOR0NGancGnR0CRAMLaUMob941_nOtXPPwyBPSS60nK69C82rJ8Mtf8J0r9u0TNeX0PxspreWgjO-zDa2o6mObm1aMvxVfBLw=s0-d-e1-ft" style="background-image: url("https://blogger.googleusercontent.com/img/proxy/AVvXsEixz1AMayvYNiaEY50MFmMMwhJjJlEsDMfJB6kWTWKeIA5y1nDzlNJhIBwnkL0fDlGUtP8lmdgjTEYcHBYGT2QxPZkoJL0i9AGMUWgil4-eIxHfjT6VUK-ztb4OECVOnbxZbADFT8YLfFpPJu9VAQnjfDlOh4senbDdGE1Xiu6XCgQm7rb7761va_RCqEvh7350=s0-d-e1-ft"); background-position: 0px -22px; background-repeat: no-repeat; height: 21px; opacity: 0.55; vertical-align: middle; width: 21px;" /></div>
</td></tr>
<tr class="m_-3156362060331962400acZ m_-3156362060331962400xD" style="height: 16px;"><td colspan="3" style="margin: 0px;"><table cellpadding="0" class="m_-3156362060331962400cf m_-3156362060331962400adz" style="border-collapse: collapse; table-layout: fixed; white-space: nowrap; width: 1114px;"><tbody>
<tr><td class="m_-3156362060331962400ady" style="margin: 0px; overflow: hidden;"><div class="m_-3156362060331962400iw m_-3156362060331962400ajw" style="display: inline-block; max-width: 92%; overflow: hidden;">
<span class="m_-3156362060331962400hb" style="color: #777777; vertical-align: top;">to <span class="m_-3156362060331962400g2" name="me" style="vertical-align: top;">me</span></span></div>
<br />
<div class="m_-3156362060331962400ajy" style="display: inline-block; margin-left: 5px; vertical-align: top;">
<img alt="" class="m_-3156362060331962400ajz CToWUd" id="m_-3156362060331962400:12g" src="https://blogger.googleusercontent.com/img/proxy/AVvXsEi8QXjvn4hvIcIJfr4QhlXwHKEYzXOX9v0qMSqwl3yX6qWrHQRDywgxJMfo1TOR0NGancGnR0CRAMLaUMob941_nOtXPPwyBPSS60nK69C82rJ8Mtf8J0r9u0TNeX0PxspreWgjO-zDa2o6mObm1aMvxVfBLw=s0-d-e1-ft" style="background-image: url("https://blogger.googleusercontent.com/img/proxy/AVvXsEjLUbKuM-le7dxD4x7JIJp_Nn5kz_AZUMa96NxV28UCiHi5nIaaZE-u1DYVZvxCHuXgowIRM4OmzC4ACe3bNkRe1Y6kQAe2Er7arxSCydyw6FNyIDoXZeG5cs0tLqOvS9FDQH0JvDNrczfNJi46ViPMnKiM_EdLr7kkGck25yianKIfHux2bA=s0-d-e1-ft&view=dim&iv=19jjsiul4qg7l&it=ic"); background-position: -60px -100px; background-repeat: no-repeat; height: 12px !important; padding: 0px 0px 1px; vertical-align: bottom; width: 12px !important;" /></div>
</td></tr>
</tbody></table>
</td></tr>
</tbody></table>
</div>
<div class="m_-3156362060331962400utdU2e" style="background-color: white; color: #222222; font-family: arial, sans-serif;">
</div>
<div class="m_-3156362060331962400tx78Ic" style="background-color: white; color: #222222; font-family: arial, sans-serif;">
</div>
<div class="m_-3156362060331962400aHl" style="background-color: white; color: #222222; font-family: arial, sans-serif;">
</div>
<div id="m_-3156362060331962400:116" style="background-color: white; color: #222222; font-family: arial, sans-serif;">
</div>
<div class="m_-3156362060331962400ii m_-3156362060331962400gt m_-3156362060331962400adP m_-3156362060331962400adO" id="m_-3156362060331962400:129" style="background-color: white; color: #222222; direction: ltr; font-family: arial, sans-serif; font-size: 13px; margin: 5px 15px 0px 0px; padding-bottom: 5px;">
<div id="m_-3156362060331962400:128">
Dear John Hewitt,<br />
<br />
Thank you for your email to the journal. <span class="m_-3156362060331962400il" style="background-color: #ffffcc;"><span class="il">PNAS</span></span> is a self-sustaining operation of the National Academy of Sciences and the journal operates on a breakeven basis, receiving no direct funds from the Academy or from the government. <span class="m_-3156362060331962400il" style="background-color: #ffffcc;"><span class="il">PNAS</span></span> relies on two main <span class="m_-3156362060331962400il" style="background-color: #ffffcc;">sources</span> of funding, author charges and subscriptions.<br />
<br />
All of our articles dating back to 1915 are free online after 6 months, 27% are immediately free under our <span class="m_-3156362060331962400il" style="background-color: #ffffcc;">open</span> access option, and all articles are immediately free to more than 140 developing countries.<br />
<br />
We hope this clarifies our operations.<br />
<br />
Regards,<br />
Diane Sullenberger<br />
Executive Editor<br />
<br />
<br />
-----Original Message----- <br />
(Highly didacted)<br />
From: john hewitt [mailto:<a href="mailto:john@hewitt123.com" style="color: #1155cc;" target="_blank">john@hewitt123.com</a>]<br />
Sent: Wednesday, June 23, 2010 5:44 PM<br />
To: <a href="mailto:pnas-feedback@highwire.stanford.edu" style="color: #1155cc;" target="_blank"><span class="m_-3156362060331962400il" style="background-color: #ffffcc; color: #222222;"><span class="il">pnas</span></span>-feedback@highwire.<wbr></wbr>stanford.edu</a><br />
Subject: my tax money (<span class="m_-3156362060331962400il" style="background-color: #ffffcc;"><span class="il">PNAS</span></span> Feedback Form)<br />
<br />
<br />
<br />
<span style="font-size: 12.8px;">Comments sent via PNAS Feedback Page</span><br />
<span style="font-size: 12.8px;">------------------------------</span><wbr style="font-size: 12.8px;"></wbr><span style="font-size: 12.8px;">------------------------------</span><br />
<span style="font-size: 12.8px;"> NAME: john hewitt</span><br />
<span style="font-size: 12.8px;"> EMAIL: </span><a href="mailto:john@hewitt123.com" style="color: #1155cc; font-size: 12.8px;">john@hewitt123.com</a><br />
<span style="font-size: 12.8px;"> </span><span style="font-size: 12.8px;">PROMOTIONAL USE: Granted</span><br />
<span style="font-size: 12.8px;"> </span><br />
<span style="font-size: 12.8px;">------------------------------</span><wbr style="font-size: 12.8px;"></wbr><span style="font-size: 12.8px;">------------------------------</span><br />
<span style="font-size: 12.8px;">COMMENTS:</span><br />
<span style="font-size: 12.8px;">I bust my ___ every day and pay my taxes. You take that tax money and fund research. Great, but that is my research and frankly, I would like to see it. I demand access to the work I fund. Your magazine has the ___ to charge researchers who use my money to pay you to publish their research, and you then try to extort from me further money to see that research. Enough, that model is done. We won't except it anymore. Show me the money.</span></div>
</div>
</div>
John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com0tag:blogger.com,1999:blog-5900123281843921168.post-76739042118020186562017-03-01T12:43:00.001-08:002017-03-01T12:43:36.433-08:00Hoverboard hack for electric skateboard
Hoverboard hubmotor ZRT Raspberry Pi Board
Just finished a hoverboard hack into a skateboard and need to find better controllers.
Has anyone built a ZRT board, or hacked the hoverboard, or used 2 Vescs with two remotes, or one combo remote for zeroT? Has anyone actually done position control with a BLDC motor with the Vesc controller?
If anyone is useing a raspberry Pi on board I was wondering if they have figured out how to run the Vesc software on it? Also I now use 2 Pi's since I can't figure out how to reliably make one Pi be both a WiFi hotspot and a client at the same time. Right now, one Pi is the hotspot and gets internet via a short ethernet from the second Pi which is a WiFi client. Anyone interested in this please let me know and I will upload more details.
thanks
John@hewitt123.com
some pics before adding second Pi, and casters for ZRT
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7eQmnQdVQGP8eXo_3vAoGnrUTr497yxgxzxmfMgqufImxfSWsEpkIfRL1FfIpe-9g7WPY4MYIObYH4LYU_pofVNTqMgu0L0nuz1pz6wsIXqV8aIq0GJA-RSG2AlRacbXUT3lIl-ACrc6x/s1600/20170125_081933.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7eQmnQdVQGP8eXo_3vAoGnrUTr497yxgxzxmfMgqufImxfSWsEpkIfRL1FfIpe-9g7WPY4MYIObYH4LYU_pofVNTqMgu0L0nuz1pz6wsIXqV8aIq0GJA-RSG2AlRacbXUT3lIl-ACrc6x/s400/20170125_081933.jpg" width="400" height="225" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpg9ro2ZQE0a_qDdKiH9tjub5QpfqvTdf5nsGOQNTA3jssGfidKripwDmRTJjCj0tPkbsQk0uZMqtMUUeEM8WUJX0uRoDNIeG53L8ASG_-JP60K6uCGiTFzW1fJGQG5Mpsc1_HzN1H3o1h/s1600/20170125_081944.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpg9ro2ZQE0a_qDdKiH9tjub5QpfqvTdf5nsGOQNTA3jssGfidKripwDmRTJjCj0tPkbsQk0uZMqtMUUeEM8WUJX0uRoDNIeG53L8ASG_-JP60K6uCGiTFzW1fJGQG5Mpsc1_HzN1H3o1h/s400/20170125_081944.jpg" width="400" height="225" /></a>John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com15tag:blogger.com,1999:blog-5900123281843921168.post-10031584127832331642016-10-26T05:52:00.000-07:002016-10-26T05:52:22.670-07:00 <span style="font-size: large;"><a href="http://neurowritings.blogspot.com/" target="_blank">No Spin Science -- Publications</a></span><br />
<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
<br />
<b><br /></b><b>Links to author index for places I publish:</b><br />
<br />
<a href="http://phys.org/search/?search=author%3A%28John+Hewitt%29" target="_blank">Physorg</a><br />
<a href="http://inference-review.com/article/the-excitable-mitochondria" target="_blank">Inference: International Review of Science</a><br />
<a href="http://phys.org/search/?search=author%3A%28John+Hewitt%29" target="_blank">MedicalXpress</a><br />
<a href="http://www.extremetech.com/author/jhewitt" target="_blank">ExtremeTech</a><br />
<a href="http://www.medgadget.com/author/jhewitt" target="_blank">Medgadget</a><br />
<br />
<b>Books, chapters:</b><br />
<br />
T<a href="http://goertzel.org/End_of_the_Beginning_July_2015.pdf" target="_blank">he Beginning of the End: Chapter 4</a><br />
<div>
<br /></div>
John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com0tag:blogger.com,1999:blog-5900123281843921168.post-39194007249832666672016-09-27T05:57:00.000-07:002017-11-10T06:31:46.807-08:00Medical Genetics Reports -- Jackson<span style="font-family: "arial"; font-size: 14.6667px; white-space: pre-wrap;">Jackson Report 9/16/16</span><br />
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Emily, thanks for sharing the results of Jackson’s genetic studies, particularly the exome sequencing and the four genes with variants of interest that were found. I want to summarize the significant results here (at least as I understand them), and then generate a few lines of inquiry to present to any experts that might help. I don’t want it to be a whole genetics course, but I want to add enough detail so that both ourselves, and any geneticist, protein experimentalist or modeler, neurologist, neurobiologist, or radiologist clinician can get the fuller picture.</span><br />
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Jackson is the person the geneticists designate as the ‘proband’, meaning the one who initiated the study, in this case a one year old boy. Four variants in four genes were noted:</span></div>
<span style="font-family: "arial"; font-size: 14.6667px; white-space: pre-wrap;">NEB (nebulin) c.11450G>A; p.S3817N</span><br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">PLP1 (proteolipid protein 1) c.194T>G; p.I65S</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">ERCC6 (</span><span style="background-color: white; color: #666666; font-family: "arial"; font-size: 15.333333333333332px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">excision repair cross-complementation group 1</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">) c.2924G>A; p.R975Q</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">PGAP1 (</span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">post-GPI attachment to proteins 1</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">) c.2525+4C>T</span><br />
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<a name='more'></a><br />
<span style="font-family: "arial"; font-size: 14.6667px; white-space: pre-wrap;">The docs logically focused on the PLP1 gene (and initially diagnosed the associated Pelizaeus-Merzbacher disease - PMD) because it is X-linked (homozygous) and therefore Jackson only has the one copy of the gene. The other three genes are on ‘autosomal chromosomes’, heterozygous, and would therefore not immediately be prime suspects by virtue of the fact that another functioning copy of the gene is present. That is not to say the other genes can be fully discounted, particularly given the absence of a full genome sequence which would contain any potential exome regions not analyzed in the exome sequence, including regulatory regions generally at the beginning of genes. It is also possible that one gene copy simply does not supply a required threshold level of the protein, or that the defective protein itself causing some new pathology.</span><br />
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It appears that the parental origin of all genes was determined (the so-called ‘phase’ analysis) but I do not know if that analysis determines whether the presumed ‘good’ copy of the gene could also have the same (and therefore undetected) variant.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Quite a bit is already known about the NEB gene and protein from many prior animal studies and although it is expressed in brains generally (in addition to the muscle regions where it is fairly critical), results from animals studies suggest there islargely normal cognitive function and neural structure in the presence of disabled nebulin genes.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">PGAP1, technically heterozygous here, would only be an immediate red flag if there was also something like an undetected ‘compound heterozygous’ mutation (a second bad variant or polymorphism); in other words, the gene originating from the other presumed healthy parent has a different mutation, in which case serious neurologic issues are known to be a possible effect. PGAP1 is required </span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">for the production of GPI </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">(</span><span style="background-color: white; color: black; font-family: "times new roman"; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">glycosylphosphatidylinositol) </span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">that is attached to some proteins, and </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">myelinating oligodendrocytes direct significant amounts these GPI proteins to the myelin sheath.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">ERCC6 is involved in transcription coupled repair and similarly, it is typically associated with severe neurologic conditions only when both genes are affected (like in Cockayne syndrome). I only want to note here its </span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">implication in some microcephalic outcomes, including microcephalin and ATR (Seckle syndrome). If any significant question arises here one test for faulty ERCC6 repair capability might be a radiation sensitivity of skin fibroblasts, though I don’t know how accurate and informative it would be.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">In order to look closer at the specific case of Jackson’s PLP1 variant we first need to decode and disambiguate the genetic notation for the variant; ‘c.194T>G; p.I65S’. I will need to verify what I write here because errors are readily made.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The initial ‘c.’ indicates that we are looking at cDNA or complementary DNA, as we are dealing with exome sequencing info. It refers to an </span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">mRNA transcript's sequence expressed as DNA (GCAT) bases rather than as RNA (GCAU) bases.</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Having a ‘genomic sequencing’ reference (g.) would be a little more informative here for many reasons, namely, the presence of multiple transcription initiation sites (promoters), alternative splicing, the use of different poly-A addition signals, multiple translation initiation sites (ATG-codons), and the occurrence of length variations. </span><span style="background-color: transparent; color: #333333; font-family: "georgia"; font-size: 15.333333333333332px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Potentially, if exome sequencing draws on mRNAs after they are edited, (either in nucleus-specific or cytosol-specific editing), this would be an issue too, although RNA editing (post-transcriptional modification of bases, mostly A to G or A to I substitutions in humans) is quite rare.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As I understand the notation 194T>G, the 194th base pair position in Jackson’s cDNA for PLP1 has a G while most normal cDNAs would have a T. Because G (like A) is a purine and T (like C) is a pyrimidine, this substitution is called a ‘transversion’ as opposed to a ‘transition’ (which would occur in the case of a purine to purine or pyrimidine to pyrimidine switch). Since there are natural mechanisms in the cell which more readily convert one-ring purines to other purines, or convert two-ring pyrimidines to other pyrimidines, transitions are significantly more common than transversions. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To get a better idea of how this T>G could have arisen I spoke with cell biologist Carl Smythe, a professor in the </span><span style="background-color: transparent; color: #414042; font-family: "georgia"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Department of Biomedical Science at University of Sheffield, and also geneticist Shane McKee, clinical director of the Belfast Health & Social Care Trust.The ‘</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">T>G’ doesn’t necessarily mean that a G has been directly changed into a T in the gene. For example, such a transversion could arise as a consequence of a mutation from a C to A on the non-coding strand. G-A bases can pair quite well (as do some others, although normal pairing is A to T and G to C) without causing major structural issues between the coding (sense) and noncoding (antisense) strands. </span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As a consequence of this, the A would have a T inserted in opposite strand in the next round of synthesis.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Either strand could have had the original mutation, and the DNA replication process will give rise to two distinct coding sequences for a single locus. One can therefore end up with two cells each with complex phenotypes. After a non coding strand C to A mutation you get the stable G-A base pair, which after duplication gives a G-C pair and a T-A pair, where the latter corresponds to Jackson's mutation. This may have occurred during meiosis and have been in a sperm, or it may have occurred during development in whoever had the original mutation.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Because Jackson would have inherited his X chromosome with the variant PLP1 from his mom, the grandparents were checked and it was found that gramps had the same variant. Because gramps is asymptomatic the docs more or less recanted the PMD diagnosis. One possible explanation of this situation is that gramps could be a ‘mosaic’. In other words the mutation was not present at the level of the sperm but rather arose later in development (as a somatic mutation), in which case it is possible that the cells that gave rise to gramps’ nervous system have a normal copy of PLP1, and he is therefore quite normal. Another possibility is that gramps himself inherited the variant but none the less was able to repair it in the cells of his nervous system. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Although it would be rare, it is also conceivable that Jackson has the same mutation as gramps but it was independently gained, ie. it arose again in the bloodline as de novo variant in Jackson. Perhaps not totally inconceivable when you imagine that whatever genetic or metabolic background the gramps mutation originated in, a similar background would be expected to be present in Jackson. More typically the conventional thinking is that ‘spontaneous’ mutations arise more or less randomly during events like DNA synthesis when there is some non-negligible error rate during copying that escapes proofreading mechanisms.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #222222; font-family: "arial"; font-size: 12.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It is also possible that the mutation does not have much effect in gramps’ genetic background, but does have significant effect when occurring in the context of Jackson’s genetic profile, ie. a 'facilitative' mutation necessary but not sufficient for PMD. One curious feature of PMD is that up to 70% of the patients have a duplicated PLP1 gene -- an extra copy. It looks like this was explicitly checked for with Jackson, as exome sequencing wouldn’t see it, but he did not have a duplication. His mitochondria were also sequenced and found to be normal, however in the face of not uncommon mitochondrial heteroplasmy (more than one unique set of mtDNA), we might also be curious what mitochondrial source was actually sampled here.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">An important related question here is what tissue source got sequenced in the exome analysis -- was it blood, skin, or epithelium? Because the same gene is typically spliced differently in different tissues it would also give different cDNAs in exome analysis of different tissues.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To get past this looming diagnostic roadblock, and in addition to whole sequence analysis, a functional protein study could be done to try and determine possible effects of the variant PLP1 substitution. This can include using software tools to model the structure and function of the protein, and actually constructing the variant protein in the lab and expressing it in animals to look for effects. </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 12.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">For example, by creating what is called a conditional knock-in mouse line,</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">To start this kind of protein analysis one would need to look at the second part of the variant notation -- the ‘</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">p.I65S’. Here the ‘p’ indicates we are talking about the amino acid sequence of the protein that corresponds to the cDNA or mRNA sequence. It says that Jackson’s PLP1 will have a serine (S) substituted in at position 65 in place of the normal isoleucine. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If</span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> the possible isoleucine DNA codons (sense) are ATT, ATC, ATA, and the new variant possible serine codons are TCT, TCC, TCA, TCG, AGT, AGC, we can assume by process of elimination that it was the middle codon spot in either the ATT or ATC threonine that was changed into the AGT or AGC serine codon. I think it makes sense to presume that any b</span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">ase pair substitution generally originates and/or remains unrepaired in cells for some reason (even if that reason is excessive solar radiation applied to a skin cell), and that reason will typically reflect what is going on in the larger background metabolism and environment of the cell, and as it may happen, the organism.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Isoleucine is a hydrophobic amino acid and serine is a polar and uncharged amino acid. These are fairly different animals altogether and it is normally assumed that this kind substitution should have some significant effect on protein structure or function. The question is what effect? In checking some of the common software tools and databases for this kind of thing we find that ‘PolyPhen2’ says the substitution is probably damaging, ‘MutationTaster’ isn’t happy with it either, and it is not recorded in either ExAC or 1000G. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The canonical membrane structures of some of the various splice variants of the normal PLP1 protein have been determined well over a decade ago. It is a highly conserved protein that is virtually identical in several species from mouse to man. More recently, a few 3D protein conformations, the actual crystal structures, have also been determined, sometimes in combination with other bound proteins. The presumptive membrane topology is four transmembrane helices, with the position 65 serine (or thereabouts depending on where the amino acid start count is done) lying at the extracellular apex of the first membrane helix. While serine can be phosphorylated in various proteins this may not be likely in the observed position.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As alternative splicing of the PLP gene yields four products — the classic PLP and DM20 proteolipids, and the more recently described proteolipids, srPLP and srDM20, it is important to try to understand how much of these various products are getting made by various kinds of cells in the nervous system, and their effects on those cells. A lot is already known, and more information is now acquired fairly continuously. Additionally, the (subcellular) localization of these products to various compartments within the cell is an important point (some get put into the myelin sheath, others get localized to the mitochondria, while other stay in the endoplasmic reticulum). The main question I think, at each instance, is whether there too much of this protein or not enough, and then also what is the effect of a poorly functioning, nonfunctioning or otherwise obstructive protein in each case? To this point, it is known that while transgenic mice that overexpress the PLP gene exhibit neuronal degeneration and axonal disintegration, perhaps paradoxically, the absence of PLP/DM20 in PLP null mice also causes axonal swellings. Because this protein is normally so abundant, around 50% of the total myelin protein, small changes can have large effects.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It is not known if the serine spot should affect splicing (but note nearby splice site in picture below), or affect any of the protein’s cross-linked cysteines, or alternatively affect any critical cysteine palmitoylations, but further study would be needed. As the protein is also known to form dimers and maybe even higher older multimers, likely linking up to each other to across layers of compacted myelin, the effect of serine on such oligomerization may be an important question. Although most of those cysteines are closer to the beginning of the protein so to speak, they are a bit of an enigma these days because they can do so many things for the protein by virtue of their sulfur group. When cross linked or unlinked they change protein conformation, and also transduce ox-redox signals. When palmitoylated they target and localize the protein to the myelin sheath, and when spaced in various well defined ‘localization sequences or motifs (like C-3xC, or C-10X, as here) they are also targeted to the mitochondria to participate in all kinds of functions. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It is critical I think to circulate Jackson’s details to any doctors and researchers who might be poised to help, namely, experts in the various ‘orphan’ progressive degenerative neurologic disease. This class would include experts in various leukodystrophies and lysosomal storage diseases that affect myelin, and also those that ultimately affect mitochondria and their role in energy production and other key metabolic processes. Two guys who come immediately to mind, and who I have spoken to in the past for various articles are </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Bruno Benitez </span><span style="background-color: #f5f8fa; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Washington University in St. Louis, and Doug Wallace at CHOP.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I will not delve into the other variants found in the genetic testing other than to note that the one for PGAP1 has a slightly different notation from the others, given as </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> c.2525+4C>T. T</span><span style="background-color: white; color: #1f497d; font-family: "calibri" , sans-serif; font-size: 11pt;">his annotation c.2525+4C>T suggests that this variant is located +4 nucleotides apart from the last exonic nucleotide. This variant is predicted to be a “splice donor” which means that can alter the length of the resulting protein, a different transcript.</span><br />
<span style="background-color: white; color: #1f497d; font-family: "calibri" , sans-serif; font-size: 11pt;"> </span><span style="background-color: white; color: #292f33; font-family: "arial" , "verdana" , sans-serif; font-size: 14px; white-space: pre-wrap;">PGAP1 has 22 exons and at least 11 splice variants. This variant has a mutation in the intron downstream of nucleotide position 2525. This creates a splice junction failure where the intron will not be spliced out and thus the variant will include protein sequence corresponding to the intron. Uncertain about whether that affects enzyme activity of PGAP1. It will generate a protein of unexpected length. The precise number of splice variants affected by this mutation would need careful analysis, and the tissue sampled is likely to have a different spectrum of PGAP1 variants compared to brain. Worth noting that PGAP mutations are associated with developmental defects, although can't find anything with this mutation though.</span><br />
<br />
<div class="MsoNormal" style="background-color: white; color: #222222; font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;">
Note, this blog post later published at:<br />
<div style="color: black; font-family: "Times New Roman"; font-size: medium;">
<span style="font-family: "arial"; font-size: 14.6667px; white-space: pre-wrap;">https://medicalxpress.com/news/2016-11-diagnosis-brave-world-genetics-based-medicine.html</span></div>
</div>
</div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><b>Presumptive PLP1 membrane topology.</b></span><br />
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img height="317" src="https://lh5.googleusercontent.com/MWFvaXwhBG6ZLpU8Kl3rGAPoHEXo3bL31YE9WH8_Xv1cOe7t5fduZB5GIwiiNC6T_OUwLNOV_g0CBg_gvm7W-x-GoW_TTh3Ah6h-yyvxUHymr44zu-K7EaICaaYXnn6JfDReGu8_" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="417" /></span></div>
<b style="font-weight: normal;"><br /><br /><br /></b><br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><b>A 3D structure of PLP1.</b></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img height="397" src="https://lh4.googleusercontent.com/1l5OkmE-ZVlRMHTZ1huntmcW9kILU8hmlQWYpwGC-9Z1WBUMkpfydTfMd2gTfWXY_TiHI1J3ZhF-9uq6pg41C-_5suM7_vCREtxuXuPYR_gjVUK_tgC952OQX9QhQjM8v3VwO2hY" style="border: none; transform: rotate(0rad);" width="397" /></span></div>
<br />
<b>Jackson.</b><br />
<br />
<br />
<img alt="image1.JPG" height="400" src="https://mail.google.com/mail/u/0/?ui=2&ik=d4aa546f8c&view=fimg&th=157d2c59c7ca19f7&attid=0.1.1&disp=emb&attbid=ANGjdJ-16XJ6l1O_Vc_SWB4pSuujIDEFkgPjq6kvJXcdARG4WHztOWoFykT0MzTyL5TMliqNOg98u8hLvyfNQ4KixKesBx--1fu14cIPNQHzl4wW66rY2pYj497sYNU&sz=s0-l75-ft&ats=1476709977296&rm=157d2c59c7ca19f7&zw&atsh=1" width="300" /><br />
<br />
<br />
<br />
<br />
<br />
<br />John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com2tag:blogger.com,1999:blog-5900123281843921168.post-867059696028809792016-09-27T05:47:00.000-07:002018-05-06T07:23:24.057-07:00The Future of Neuroscience (preprint)<br />
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150"></span>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150"><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">( Later published in highly redacted form in 'Inference; International Review of Science, http://inference-review.com/article/the-excitable-mitochondria, and publicly reviewed on Hacker News / YCombinator; https://news.ycombinator.com/item?id=13088772 )</span></span><br />
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br /></span>
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Plunging an electrode deep into the brain is one way to ablate hundreds of voxels of white matter. Unfortunately, there is no ‘before and after’ imaging study that could possibly tell you where in the cortex you would find the actual neuron bodies that had their axons clipped. Pyramidal cell axons project out of the cortex and branch in the white matter to contact many potential targets -- the spinal cord, deep brain stem nuclei, and contralateral hemisphere to name a few. Compromising the business end of a few thousand random neurons might be an acceptable side effect for giving a voice to the locked-in, an arm to the paraplegic, or steadiness to the tremoring hand of a Parkinson’s victim, however, for the elective augmentative procedures many future healthy subjects will eventually want and need, it may be a deal breaker.</span></div>
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150">
</span>
<br />
<div>
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150"><br /></span></div>
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150">
</span>
<br />
<a name='more'></a><span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150"><br /></span>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150"><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Ideally, surgeons would come to the table with a full engineering CAD model of their patient’s brain. In addition to modeling the relevant neural compartments, a thorough preoperative workup would also simulate the behavior of the local microvasculature (now known as the ‘angiome’), and the larger topology of CSF flow (the so-called ‘glymphatic’ system). Included in this package would be a dropdown menu of ‘brain physics’ modules that capture not only electrical conduction, but also parameters like thermal conductivity, bulk moduli and pressures, and the diffusion and convection of fluids flowing through various foramina, ventricles, and vessels. </span></span></div>
<span id="docs-internal-guid-afc1eddd-6bb5-a066-f644-79de21531150">
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">While it is often noted that the brain has around 100,000 miles of glial-insulated axon tract, there is also over 100,000 miles of capillaries insulated by glial cell endfeet in the brain. When looked at from above, the brain appears to be as much a machine built to artfully distribute fluids as it does one to transport electrical signals. For comparison’s sake, if we look at how the muscles in the legs are powered, we find an informative dichotomy: delivery of a pressurized nutrient broth of glucose and oxygen, and removal of lactic acid and carbon dioxide only requires a femoral artery about a half an inch wide. But the more ethereal, ‘information-bearing’ electrical energy is supplied to the same muscle through a massive sciatic nerve some three-quarters of an inch wide.</span><span style="background-color: white; font-family: "arial"; font-size: 16px; vertical-align: baseline; white-space: pre-wrap;"> (1)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">While software that keeps tabs on the fluid amenities of the nervous system would help insure a patient can get up off the table after a radical cerebral installation or deletion, the real bread and butter of the operation would be simulating what happens to their mind. Consider a patient request to eliminate some immaterial mental malady -- maybe it is a desire to squelch an intrusive internal voice, or perhaps to subdue the burning phantom of a supernumerary limb that quizzically appeared after a stroke. Traditionally, doctors would beat these bugbears over the head with mind-numbing drugs. Today however, many might presume that the ability to directly eliminate any offending neural elements using minimally invasive ablation with directed energy beams should just around the corner. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">In order to do this while sparing surrounding friendly fire we would not only need pinpoint accuracy in our instruments, but also point-to-point knowledge of the brain. Without something like a high resolution ‘connectome’ on hand to trace projections through a 3D model, any outcome would be hard to predict. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">While the main focus of the current and proposed brain megaprojects in Europe and the US is to understand how the brain works through simulation, connectomes, and animal brain activity maps (BAMs), I would argue that these approaches are naive and hopeless. Yes, I think we need these software tools to probe and visualize brains, but the reason for building these tools is not be that they will magically delivery any understanding. What they will do is help us build and place more powerful implants. While these implants will in turn lead to better maps, it is only through their direct and personal use -- the first and second hand human experience of implant interaction at the level consciousness -- that the understanding of the brain we seek will be gained. (2)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Brains by design</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Neuroscience now supplies an open-ended stream of ever-finely scaled cellular and molecular detail. Marshalling this divergent fount of knowledge into CAD form presents several challenges. For one, nobody seems to have a plan for creating these whimsical software packages, let alone selecting what data to feed it. Electrical engineers, by comparison, have plenty of CAD-like options for creating their circuit board connectomes. They call these diagrams of the connections within or between individual chips, ‘netlists’. Once the logic performance of a circuit is verified, and its corresponding netlist generated, the designer performs the ‘layout’ or the place and route step, to position all the components in space. Simulation tools then probe worst case scenarios to see how the behavior varies from the ideal ‘perfect connections’ of the netlist. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">As is the case for brains, there are many possible layouts that correspond to the same netlist. To flesh out a netlist using real world constraints the circuit engineer has a marvelous program called ’autoroute’. In addition to optimizing timing, and which paths wires should take, it can also specify how wide and how much copper should be laid to meet restrictions on capacitance and inductance imposed by high frequency signals. Similarly, for low power applications a little extra extra copper can be specified in order to decrease path resistance and save battery life. For something like a seven-layer board with hundreds of thru hole ‘vias’ linking different planes, the layout can get fairly complicated. In the layout of nervous systems, much these same considerations apply for wiring and myelination. In general, you want to minimize wire and power requirements while maximizing speed by placing high traffic links close to each other using the fattest, low resistance paths for carrying the highest rate or time sensitive signals.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">For the task of safely and reversibly implanting brains with hardware want we really want is a detailed ‘parametric’ CAD model of the kind normally used by mechanical engineers. In CAD design you generally work from the ground up building your parts from completely-defined one dimensional sketches. The parts are then hierarchically mated together to form an sub-assemblies, and ultimately, the top-level assembly model. Mechanical realism is algorithmically ensured by not letting the build/rebuild step (essentially the compile step) continue in the presence of physical impossibilities. Interference fits, collisions, loose parts, or stuck parts will pop out when you grab the model with the mouse and shake it. The offending members are highlighted with ominous red ‘X’s’ in the annotations menu off to the side making it easy to supply the appropriate code equivalents of duct tape or WD-40.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Nothing in the model is considered complete until its scale and operation are fully constrained. In practice this means that every feature either needs an explicitly declared dimension, or else a relation to a declared dimension that dictates how the part model will change when those primary dimensions are tweaked. This is the whole point of the model -- to have something where the global form and behavior can be controlled by simply toggling a few critical design points. In practice, these relations are are typically scaling and transformation functions embedded at the base level into the sketches. The ‘mates’ that describe how parts interact are canned elementary descriptors like ‘mirror symmetric to’, ‘co-planar with’, ‘concentric with’, or slightly more advanced user-defined operations. This ‘easy to vary’ way of capturing the essential elements of a complex system makes it practical to explore many closely related designs, or for that matter, brains. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Where is our engineering CAD model of the brain?</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">At the heart of this question lies an ineluctable paradox. The field’s undisputed founding father, Santiago Ramón y Cajal, single-handedly sketched every major variety of cell and observable feature of the nervous system, in exacting detail, well over a century ago. Yet today, despite astounding advances in genetics and cell biology, there is still no practical blueprint to guide the implantation any type of hardware in the brain. Similarly, there is also nothing available to guide implantation of stem cells into the brain, let alone guide their integration into the site of a simply bone reconstructive surgery. When stem cells are used during surgery, they are not integrated as ‘structural’ materials at all. Instead, they are literally just dumped in with no more expectation that the provisioning of the one or two special chemical products they synthesize and secrete.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">I’d argue that in order to go forward in building the engineering model of the brain we so sorely need, neuroscience as a whole will need to retrace its steps and address the many critical loose ends that were simply glossed over -- those basic things that the field collectively thinks it must know, but in fact does not. By that I mean all those tiny anatomical intangibles that the forefathers clearly encountered, puzzled over in the literature, and often theorized about, but were not yet equipped to answer. Many early conundrums were geometrical in nature; For example, why neurons adopt a polarized axo-dendritic form and why their axon is chiral; which direction myelin spirals going down the axon, and across adjacent axons geared together in nerves, and among the many arms of a single oligodendrocyte; why Schwann cells are single use items while oligodendrocytes are multiplexed; and how whole axon tracts warped and decussated as the the genetic body plan twisted and inverted during evolution of vertebrates.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Many of the brains signature functions have also been incorrectly or insufficiently explained -- the full multiphysical nature of the action potential(3); how receptors detect odorants(4), how receptors detect anything(5); how outer hair cells mechanically oscillate upwards of 40kh on nanometer scales, how bats could possibly detect features with nanosecond timing differences; how chemomagnetic sensation works, and why neurons use the transmitters they do -- for example, why invertebrates retained a highly enriched glutamate blend to fuel their neuromuscular junctions while vertebrates modified their transmitter mix to nearly pure acetylcholine?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">In the face of all this ignorance there is hope. Imaginative answers, or at least good guesses to each of these questions can be supplied if you have the right vantage point. For example, if you were to start modeling a Schwann cell you would reach one inescapable conclusion as soon as you added the first dimension -- they are massive. Operating near its theoretical metabolic maximum during peak development a single Schwann cell </span><span style="background-color: white; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;">15um in diameter x 1500um long with 150 turns must rapidly crank out enough lipid-protein mortar to fill a single-unit myelinating volume of 150,000um^3. On the other hand, an oligodendrocyte only 500um-long x 5um and 50 turns per arm with similar synthesis capacity might be able to put out a whopping 50 myelinated units. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;">If you were to then begin adding myelinating compartments to axons in a CAD model, and bundle them in a nerve fascicle or tract, the question of how they should mate and slide together spawns its own potential answers: does the actual force driving the spiralling inner myelin tongues derive from beyond the myelin itself, perhaps from tiny chiral torques mechanically supplied by the axon spiking away inside it? ie. that axons wrap up their own myelin. Yeah I said it, neurobiologists have no idea HOW myelin wraps, and there will be no realistic CAD model till they do. The experts in the field are aware of these truths, and they have been documented.(6)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Connectomes, Brain Activity Maps, Molecular Tickertapes, and Neural Barcodes</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">In 2013 Jeff Lichtman hit peak connectomics with his fantastic 1-terabyte in-silico recreation of a tiny grain of mouse cortex. One of his particularly compelling reconstructions contained a cylindrical patch of tissue surrounding a single apical dendrite of a pyramidal cell. Lichtman’s team exhaustively mapped every mitochondria, every postsynaptic density, and nearly every vesicle in 774 synapses made onto the dendrite by some 680 surrounding local nerve fibers. With this approach they also managed to extract the complete membrane topology for this one-billionth volume of a mouse brain. The few advances made since have only served to pound home the obvious state of affairs in connectomics -- it would take of lot of CAD rendered terabyte ‘Lichtman cubes’ to scale up to something the size of our brains. (7)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 13.3333px; vertical-align: baseline; white-space: pre-wrap;">In fact, at the height of this connectomania there was even a paper devoted solely to evaluating the economic impact of pursuing a full brain connectome, a field the authors whimsically dubbed </span><span style="background-color: white; color: #545454; font-family: "arial"; font-size: 13.3333px; vertical-align: baseline; white-space: pre-wrap;">Conneconomics. These authors had also previously produced a fantastical paper entitled ‘Physical Principles for scalable Neural Recording’ where they calculated the ultimate limits (namely space, power transmission, and heat dissipation) by neural recording, stimulation, and communication hardware that would be used in brain mapping. This was then followed by a their equally evocative paper entitled, ‘Rosetta Brains: A Strategy for Molecularly-Annotated Connectomics’. In it they detailed how molecular scale ‘barcodes’ written by tract-tracing viruses and bulk nucleic acid sequencing could be scaled up to generate whole-brain connectomes(8).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; color: #545454; font-family: "arial"; font-size: 13.3333px; vertical-align: baseline; white-space: pre-wrap;">At the height of the mad scramble for BRAINI initiative funds these guys, mainly together with genetics pioneer George Church, also envisioned and patented related techniques to create ‘molecular tickertapes’ that would use a modified polymerase to write brain activity maps into DNA. Presumably, these extrachromosomal DNA nucleoids would later be amplified, read out, and decoded. Now there is no doubt that this still mostly theoretical work is completely awesome. However, there is in my mind a major oversight in all this. Namely, if anyone was actually serious about generating connectomes and maps they wouldn’t be talking about grey matter connectomes at all at this point, they would be talking about white matter connectomes. Furthermore, if the brain contains as much vascular wire as axonal wire, and both are fully vested by a composite intermeshed network of glial cells, one might wonder why nobody has called for a glial connectome(9)?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 13.3333px; vertical-align: baseline; white-space: pre-wrap;">A case in point here is popular Eyewire project which seeks to map every miniscule leaf of every dendritic tree in the retina. Mind you, this is the same retina that routinely rewrites whole swaths of physical connectivity on 5 or 10 minute timescales during dark adaption. This same anatomical trick was apparently appreciated by pirates who were rumored to have kept one eye patched and ready to spot enemies at night when they came out to the deck from a well lit room below. The only reason that neuroscientists go for the grey matter is that they happen to be really good at making detailed EM sections that provide a lot of information about extremely tiny pieces of brain. Trying to map the white matter pathways this way is like bringing a magnifying glass to take see the Grand Canyon; they are simply too big to analyze whole by EM. Unfortunately, they are still too small to accurately resolve using mapping techniques like diffusion MRI tractography. That’s a bit of shame because while the grey matter is highly labile, the thickly myelinated white matter is highly stabile. If we ever hope to have something we might call a ‘living connectome’ -- a connectome that does not require destroying the brain and replacing it with a sparsified ghost -- let alone a fossil one, we are going to have to be a bit more creative. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 13.3333px; vertical-align: baseline; white-space: pre-wrap;">The </span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">full scale membrane topology Einstein’s grey matter might be great attraction at a museum, but it probably wouldn’t be of much use to Einstein. Aside from the obvious data problem such a file would present, a living grey matter netlist is something that is physically impossible. You can never step into the same brain twice because neural connections change much faster than the time it would take to read them all out by any method constrained by the laws of physics. The white matter, on the other hand, would not. White matter is also highly predictable; Neighboring axons surrounding any given axon tend to signal in much the same direction, lie in much the same orientation, and are likely to be wrapped by arms from the same oligodendrocyte. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">If one was writing an actual white matter connectome they might forsake a neurocentric description altogether and instead use the coordinates of each oligodendrocyte together with the fifty or so minion axons wrapped up by its arms. As far as file formats for crunching a neural netlist go, there is no mad rush to standardize because the gray matter connectomists haven’t even figured out what constitutes a ‘connection’.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Fundamental Principles and Neuroscience’s ‘Missing Link’</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">For several decades Eric Kandel’s ‘Principles of Neural Science’ has served as the de facto entry point to all things neuro. It is both a crash course for intrepid cross-disciplinary dilettantes, and rite of passage for its primary students. Although the bulk of this text has remained fairly solid, improvements to its foundation have been incremental. In 2015 the field got what is arguably its second great learned tome in the form of Sterling and Laughlin’s ‘Principles of Neural Design’. While descriptive, a gaping void still persists at its conclusion: from whence does all this complexity arise?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The once heretical but now seemingly endemic finding that organelles, notably mitochondria, are transferred whole or piecemeal from neuron to neuron presents a unique challenge to any ‘neuron doctrine’ touting discrete parts -- namely, if organelles don’t belong to cells, what’s a cell(10)? In cancer, several organ systems partake of a curious mitochondrial dynamic in which they initially become tumorigenic as a result of losing respirative power, and then subsequently lose the ability to repair their DNA. This ‘metabolic origins’ view of cancer throws a bit of a monkey wrench into the old nuclear DNA ‘mutations first’ oncogenic tumor-suppressor paradigm. A mind-numbing finding is that after reaching an uneasy steady-state truce with the efforts of the body and doctors to contain it, the seemingly quiescent cancer cells can suddenly go rogue and become metastatic upon donation of fresh mitochondria from the nearby healthy cells(11). One might ask, what kind of way to run a ship is that? This hither-to-now underappreciated mitochondrial plasticity is but the tip of the iceberg.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">More pertinent for us here is the question of how plastic whole nervous systems can actually get? In other words, how labile is the constitution and form of neurons? Turning high resolution microscopes to the brain with a keen eye for anomaly researchers have found that the hallowed zone known as the ‘axon initial segment’ -- the place where the axon roots itself at the cell and its organizing centriole -- moves around the cell quite alarmingly. For example, in up to 10% of cells in parts of the hippocampus the axon migrates far afield of its ‘normal’ location and roots itself on a proximal dendrite(12). Needless to say, these kinds of findings are a bit awkward. Looking further afield with better imaging techniques for delineating axons via the chiral cytoskeletal hooks attached to their tubulin this kind of behavior will likely be found to be quite common. One might wager a neuron with two axons could be theoretically possible. Or maybe not.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">It was not until Ramon Cajal’s famous inaugural Neuron Doctrine that it was fully accepted that nervous systems were actually made from discrete parts. Although other pioneer’s like Czech anatomist Jan Purkinje made early forward contributions, Cajal was the first to declare that the neuron, with all its dendrites acting together to feed a single polar axon, is the fundamental unit of the nervous system. Prior to Cajal, the so-called ‘continuous syncytium’ model espoused by Camillo Golgi’s reticular theory had held sway(13).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">What I want to suggest is that the fundamental discrete units of nervous systems, and for that matter every organ, are not neurons or other cells, but rather the mitochondria.</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Furthermore, if neurons routinely compete for, harvest, or otherwise exchange synaptic and other structural wetware, possibly even whole axons, than the differences between the old synticial and the newer discrete model would seem significantly less sharp. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">In a word, the primary feature we expect for an irreducible neural component -- and similarly seek of mitochondria -- is excitability. As we’ll see below, mitochondria take excitability to an extreme.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">From a strictly mechanical point of view, the brain really is a kind of a syncytium. While the electrical component of a spike that invades the synapse is chemically transformed according to some only vaguely understood transfer function into a vesicle message, the mechanical portion of the spike is transformed and propagated into and across the synapse in a way dictated by the mechanical impedance of local membrane, cytoskeleton, and synaptic matrix(14).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">If mitochondria are actually the fundamental units of the nervous systems, then the parts to which the most care and attention need be applied in a CAD model should be the mitochondria. The immediate question then, of “where is our brain model?”, for all intents and purposes is significantly reduced to the question of “where is our mitochondria model”? In the now beleaguered Eurobrain project, from which visionary founder Henry Markram was recently deposed, we might opine that there was not a single mitochondria to be found everywhere.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Can we construct model brains from principles?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Sterling and Laughlin’s ‘Principles‘ propose at least a partial explanation for why things look like they do in any given cube of tissue. Specifically, their cost saving analysis of different neural circuits suggest that there is some underlying logic to why neural connections have the precise diameters, numbers of vesicles, vesicle release probability, and spontaneous and maximum firing rates that they do. They also espouse ‘computing with chemistry’ rather than neural circuits whenever possible, ‘minimizing wire’ in converging and diverging circuits, and optimally locating cell bodies within the folded layers of various cortices and nuclei.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Unfortunately, their principles also suffer from narrow perspective. By that I mean that are they are derived entirely from electrical considerations; primarily how much energy it takes to generate an electrical spike in an axon, how much ATP it takes to pump the ions back out, and how noisy the channels and receptors are. If asked to sum up their musings on why brains look like they do in a single parameter that sets everything else in stone it would simply be ‘the electrical resistance of cytoplasm’. However, in contrast to the purely electrical model, the full mechanical nature of the pulse propagation in neurites, particularly in those where myelin participates in carrying some of the energy of the signal, suggests that sending spikes appreciable distances may be much more efficient than has been previously assumed.</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">With these forebearances in minds, where else might we look for the underlying principles for constructing neural networks that are even more general than those Sterling and Laughlin? Another famous Czech, the late neurosurgeon Karl Pribram, spent a lot of time trying to characterize exactly what it is that brains do, and how they do it. He famously came up with the four ‘F’s of evolutionary biology; feeding, fleeing, fighting, and fornicating. These top level behaviors are leagues above the crude functions, algorithms, or computations that neural modelers might seek to embed in their artificial networks. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Although simulated networks attempt to connect and integrate signals like real networks, they invariably ignore a couple important features of actual neurons that are only rarely mentioned. First, neurons connect to themselves. These ‘autapses’ may represent a minor portion of their overall synaptic budget, but they are tightly controlled by a suite of recognition molecules. The second fact, is that when neurons do connect to another neuron, they hit it in spades with a large bloom of synapses that would defy any characterization by the single ‘synaptic weights’ used for artificial neural network connections. Cajal’s drawings in his ‘Butterflies of the Soul’, show retinal cells dedicating nearly their entire axonal or dendritic arbor to just one or two vertically adjacent partners. I think these are design features rather than bugs, perhaps they are even principles.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">There is another, much more nasty paradox lurking behind theoretical efforts to establish laws by which networks of cells might create complex behavior. The hideous riddle that Pribram’s four ‘F‘s’ present, is that while the network modeler seeks complex functions from the interactions of approximated neural units, each real neuron -- essentially a domesticated and docile protist -- already contains each behavior in full. In fact, if you accept the horizontal transfer of genetic material as part and parcel of the copying and reproductive behavior, then not only protists, but far simpler bacteria display all four evolutionary motivators as well.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">In other words, the real conundrum we face is not figuring out how brains are wired to solve problems, but rather to first figure out how single cells solve problems — i.e. where is their brain?</span><span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">When single cells reigned, there was no brain. Any computation was presumably ‘done with chemistry’ in accordance with the platonic ideals of Sterling and Laughlin. In their conception, this computation occurs at the level of receptors and the associated signalling pathways inside individual cells. Perhaps one way we might intuit how complex nervous systems later materialized from this base is to interpret their detailed network structures as spatial optimizations of the specific metabolic pathways used generate the unique transmitters completing each leg of the circuit. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Neuroscience has a lot to say about receptors and channels, but little about why neurons use the transmitters they do. At the ground floor level, I would suggest that transmitter chemistry must be ideally suited to whatever computational task it is that needs to be done at a given synapse. Some transmitter molecules might best be likened to brute force irritants used to create a little synaptic breathing room. Others transmitters might be metabolic dead ends that are simply expressed into the synaptic space as wastes. Still others might best be likened as expensive gifts or metabolic candies plied to attract.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">These transmitters are generally not shuttled whole through each junction, but rather it is their parts and physical influence -- their functional groups, protons, electrons, and free energy -- that is ultimately what is transduced. In some circuits, these parts are directly rendered upon enzymatic transformation and receptor activity in the synaptic cleft. Others (like the glutamate/glutamine transmitter cycle), require uptake of the largely complete molecule by the postsynaptic cell, or other glial hosts, in order to actuate their functional groups. One thing many transmitters seem to have in common is that their metabolites are key participants in the signature transport shuttles that control the metabolism of mitochondria. These organelles are invariably concentrated and closely apposed to each other at active presynaptic and postsynaptic sites giving one the direct impression that they are there to communicate. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Clues as to how cells use mitochondria, and conversely how mitochondria might use cells to communicate beyond their borders are now most succinctly emerging from the improbable haunts of our immune and hematopoietic systems. White blood cells not only utilize mitochondria for the killing power of their oxidants, but they actually sort and translocate them to the plasma membrane according to their depolarization states, and then dangle them as immunogenic lures in the bloodstream to recruit defenses against invaders in the body(15). The reason this strategy works is because ailing mitochondria have a penchant for exposing their bacterial-style formylated peptides, cardiolipin, and DNA (mainly oxidized methylguanosine) on their surfaces.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">When bloodstream is breached somewhere, thrombin and other factors transform quiescent platelets first into prickly amoeboids, and then into giant kamikaze ‘superplatelet’ balls within seconds. They do this by FM modulations to the base carrier frequency of calcium oscillations in their mitochondria, which together with a sudden reversal of proton pumping in their ATPase machinery irreversibly sets these cells upon their supernova fate(16). In the brain itself, astrocytes have co-opted these peripheral immune system actuators, like glycoprotein CD38 for example, in order to initiate the programmed transfer of mitochondria from astrocytes to neurons to repair damage after stroke(17). Conversely, the two main mitochondrial proteins implicated in controlly mitochondrial dynamics in the brain in Parkinson’s disease (Pink1 and Parkin), are actually the key regulators in the peripheral adaptive immune system which inhibit mitochondrial antigen presentation. The fact that mitochondria are so intimately involved with presenting antigens is somewhat astonishing and reflects their full integration into every cell function.(18)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The point of listing these recent findings is that the underlying activators can in each case be traced down to base level self-excitations occurring deep within the cristae of mitochondria. These nonlinear ‘mitoflashes’ are now known to be proton-triggered and sensitive to just a small number of protons persisting less than 2 ns and diffusing just 2nm in the matrix(19). Although mitochondria can not generally slew their mitoflash potentials around or repeat them at a rate anywhere near what neurons can do(), they do have a few tricks of their sleeves. When watched by parametric imaging these mitoflashes follow up their local proton and membrane voltage fluxes with a predictable sequence of calcium and redox ‘sparks’. What’s particularly interesting is that mitoflashes and spontaneous oxidative bursts have been found to be accompanied by significant mitochondrial shape changes -- namely, reversible contractions. Although the mechanical aspect of mitoflash was only initiated at a rate of 0.6 per hour in a given mitochondria, there are thousands, sometimes tens of thousands of mitochondria in each neuron(20).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">If neurons are packing this kind of excitatory power then certainly a large army of these mitochondrial ‘one-shots’ (even if they take a while to recompose themselves) should influence the excitability of the neuron itself. It is not such an enormous logical leap to then suppose that mitoflash, particularly when occurring near membranes with high channel densities could initiate neural spikes, and similarly, that neural spikes could initiate mitoflash.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">As mentioned, it has long been appreciated that the familiar ‘action potentials’ of neurons are multiphysical phenomena whose mechanical displacement, pressure, and counterintuitive heat absorption and release each follow their own predictable time course and spread. The electrical blimps amplified on oscilloscopes, or the narrowly prescribed wave of inrushing sodium ions and outrushing potassium ions one might see in a drawing are a bit misleading. When axons fire, there is no spatially localized pulse; the whole axon depolarizes. For example, if the spike lasts for a millisecond, and its expanding front travels at 100 meter/second, then we are talking about a physical disturbance that would extend some 10cm. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">To the dismay of neurophysiologists who have been using the so-called ‘antidromic collision technique’ to trace axonal connections (this includes myself), real spikes travelling in opposite directions on axons can pass right through each other. If these observations, originally discovered in worms, hold true more generally then the neuroscience literature is likely riddled with spurious results. These persistent spikes would be more reflective of mechanical soliton-like waves then of the annihilating electrical spikes one would get with the inactivating ion channels and mandatory refractory periods of the Hodgkin Huxley model. Oops(21).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">What is the Brain?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">One of the most astounding revelations of modern genetics and the comparative phylogeny it enables has been tracing the origins of mitochondria in the symbiosis of two different bacteria with complementary metabolisms. The details of different theories vary a bit, but the main idea is that as the genome of one bacteria shrunk (the presumptive mitochondrial precursor), the genome of the other grew (the host) and established the nucleus of the first Eukaryote(22). After eukaryogenesis, mitochondria turned their attention to driving cell differentiation and multicellularity (and the accompanying transformation to gender binary sexual reproduction), and then ultimately to crafting the nervous system. </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Sterling and Laughlin’s original cover art was a typical EM image of a section of grey matter. Like so many other neurobiology texts that offer much the same familiar images, they never get around to adequately explaining this highly recognizable structure. What we see is very clear; it’s mitochondria, as thick as weeds in an unkempt field. They’re all nestled inside a convoluted system of narrow tubes -- passageways that they themselves construct by power of their own respiration along with the strategic deployment of a cache of genes long since offloaded to centralized nuclear storehouses.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">In other words, we are looking at an elaborate antfarm. If you watch ants moving about in a typical ant trail you might notice a peculiar thing. They don’t seem to be bulk migrating in either direction with any particular order or purpose. Rather than trying to avoid each other, they instead run smack into each other. After butting heads to exchange chemical status bits, they change heading, and repeat. From this simple back and forth they manage to tap out remarkably adaptive colonies. In other words, the commute itself is the computation, a dead reckoning where each step and about face is intimately composed via on board molecular Fit-bits.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">When you actually look at the brain with time-lapse microscopy this is more-or-less what you see the mitochondria doing. The main difference is that mitochondria have an extra trick up their sleeve that ants do not. This additional ‘F’ behavior is fusion. If you watch a neuron for any length of time, you will invariably see two mitochondria coming together and forming one. Normally this process is constrained by eventual fission back into two new mitochondria. By fine tuning fusion and fission rates, each cell maintains a large centralized mitochondrial syncytium that dispatches and recalls punctate mitochondrial quanta to different parts of the cell as needed. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The spatial extent of this syncytial mitochondrial fluid both controls, and is in turn controlled by, the phase of the cycle cycle. As most neurons are postmitotic, their mitochondria are essentially decoupled from cell state, freeing them up to pursue other things, like driving their axon far out into parts unknown. Integral to this function is the responsibility of each mitochondria both for policing its own health, and that of the host cell. When coupled with the ability to deliberately self-destruct via a process known as mitophagy, and to subvert their host cell via autophagy, fusion/fission provides a competitive mechanism to promote desirable mtDNA, purge oxidatively damaged DNA, and ensure that the required host cell proteins are properly distributed. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Exactly why mitochondria form syncytia is not yet completely understood, but several ideas emerging from the analogous aggregation of slime molds during times of stress (and from other schooling, flocking, or swarming behaviors) have already gotten molecular backing. The kicker here, is that it isn’t just mitochondria that routinely fuse, but whole cells fuse, often quite predictably. For example, bone resorbing osteoclasts, developing muscle cells, placental cells, fly embryos, and worm germ cells all form multinucleated syncytia by one mechanism or another. Furthermore, when foreign stem cells containing heteroplasmic mitochondria (mitochondria with some mtDNA different from those of the host) are introduced into the brain they have the curious habit of fusing with the local population of neurons. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">If whole neurons or their parts habitually fuse it should not be lost on anyone that we have a powerful new mechanism to help explain how the observed structure of the brain could arise. Fusion anastomoses, like those so common in the circulatory system, could dissolve borders across pre- and postsynaptic sites to yoke neurons together while de novo creation of synapses in the middle of a bare neurite could isolate them again as needed. Developmental curiosities and anatomical enigmas, like the finely interleaved stria of the basal ganglia where descending pyramidal cells of the internal capsule penetrate, or the illusive dorsal fornix collaterals that span the corpus callosum may no longer seem quite so inexplicable.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Where do mitochondria come from and where are they going?</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Genetic sequence analysis has tagged mitochondria as the direct descendants of a class of bacteria known as alphaproteobacteria. In particular, the pathways involved in </span><a href="https://en.wikipedia.org/wiki/Adenosine_triphosphate" style="text-decoration: none;"><span style="background-color: white; color: #0b0080; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;">ATP</span></a><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;"> production in certain subgroups like </span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Rickettsia</span><span style="background-color: white; color: #252525; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;"> are fairly similar to those in present day mitochondria</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">(23). Against the backdrop of this broad consensus, it should be noted that there are lots of very different, very diverse, bacteria that hail from any given bacterial subgroup -- and all of them have very different metabolisms from present day mitochondria. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">One indication that some uncertainty still permeates this arena is that within certain geophysics communities (and they are often the real innovators here) the idea that the original protomitochondrion emerged from the class of magnetotactic bacteria still floats about relatively unscathed since it was proposed a few decades ago. This curious theory persists despite the fact that modern mitochondria show virtually no hint of having ever had magnetosomes or magnetotactic behavior, save perhaps for the primal and ubiquitous FeS cluster remnants ensconced away in the heart of their enzymes. (24)</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Precursors to the magnetite (Fe304) and greigite (Fe3S4) assemblies used to build magnetosomes appear to have originally played critical roles as terminal electron acceptors in various electron transport circuits where oxygen now fulfils that function in the oxidative phosphorylation of mitochondria. Whether catalytic FeS clusters ‘came first’, ie. before our many other critical metal cofactors, or even before the iconic tetrapyrrole cofactors so critical in every metabolism, may seem like a remote ‘origin of life’ type question. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">However, I would argue that these very questions are critical in defining the instinctual behaviors and functions of mitochondria which later guided their construction of nervous systems. </span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The reason for delving into the many idiosyncratic bedside manners of mitochondria above, is that the intracellular and trans-cellular mitochondrial networks provide a way to explain things about the structure of neurons and nervous systems that purely electrical considerations can not. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">For example, the elaborate dendritic trees of cerebellar Purkinje cells contain tens of thousands of synaptic inputs all funneling down into the soma via single dendritic shafts. Sterling and Laughlin give a great account of the firing rates, vesicle release probabilities, material investments and placement of different parts of the cerebellar circuit. What they don’t do, is explain the huge information loss -- the blatant squandering energy and resource, that is witnessed if the fractally converging Purkinje tree is operated purely as an electrical machine(). In other words, unless things are really quiet on almost all of the dendrite’s synapses, there will simply be no bandwidth available to convey messages to the soma. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Whatever combinatorial logic it is that neural modelers imagine occurs at the dendritic bifurcation points, it appears that most of it gets throttled. Conversely, if almost all synapses are really quiet, and signals really sparse, then this design would seem to be an inefficient allocation of resource. Complementary arguments also apply at the output end of the cell, the axon. Here, a presumably identical spike signal is redundantly sent to hundreds or thousands of divergent synaptic endpoints where it is mixed in with local information resident at each synapse. By any measure this would be appear to be a strange computer architecture.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">If neuroscientists still fancy the idea of brains and neurons performing computations, then where do they occur? Is it all simply ‘compute with chemistry’ using receptors and intracellular signals, or is it something more nebulous still, like ‘compute with physics’, or perhaps even ‘compute with respiration’? Could the purely energetic process of respiration, namely the electron transport chain, have been harnessed by neurons for computation in a way that parallels how electricity, originally used in bulk form for lights, motors, and solenoid switches was later refined into modern electronics? While no one expects to find the orderly transistor arrays of memory chips or logic gates chips inside neurons, one might expect that the hardware solutions brains eventually hit upon should be fairly endemic to their structure, perhaps even recognizable to us at this point in the game.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Although we cannot directly see the hardware of respiration when we look at EM images, it is now possible to infer much of what must actually be there. For example, the folds and pits which concentrate and funnel metabolites between cristae take the precise forms mandated by the many oxidation, translocation, and junctional assembly complexes embedded in their membranes. One might note in this vein that the dimers forming the ATP synthase of Complex IV are offset by 90 degrees into a ‘V’ shape not entirely unlike the pistons in an engine. They bend the local membrane geometry to orient themselves in rows at the bottom of a deep proton well(26). That Nature has full access to fine tune ATPase assembly can be seen in the unique dimerization structures found in other organisms. For example, the helical tubular arrays of cristae in paramecium mitochondria are based on a unique ‘U’ shaped dimer that offests in a precise zig-zag pattern(27).</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The placement of these ATPase dimers sets the floorplan for the other three major complexes of respiration. Complex II, which includes the succinate dehydrogenase ensemble, is a critical point of convergence in the respirative logic because it is also one of the legs of the citric acid cycle around which the entire metabolism of the mitochondria is constructed. As with the other complexes, electrons in Complex II tunnel through multiple cofactor centers possessing precisely tuned redox potentials. The Complex II pipeline includes several varieties of iron-sulfur clusters, each with a geometry and stoichiometry ideally suited to function. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Curiously, one of these clusters is analogous to the greigite thiocubane Fe3S4 unit that is preferentially incorporated into magnetosomes by magnetotactic bacteria when oxygen is scarce. It is now widely held that life as we know it took root when these clusters were further metalized with nickel or molybdenum on the surfaces of certain minerals(). Electrons evolved at Complex II eventually drain to Complex III where they are gated together with those from the Complex I electron circuit. Complex III then lowers the electrons the rest of the way down to oxygen, while raising up additional protons to power ATP synthesis at Complex IV.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Laughlin and other ATP neuroaccountants tell us that both spikes and synapses are expensive in terms of energy requirements. Beyond that there is little accounting for how a given cell should apportion the two. One thing electrophysiologists seem to know with some confidence is that the probability of release of least one vesicle after a spike is received at a release zone is roughly ½, on average, throughout the brain. Does this probability merely reflect some kind of natural balance struck between sending spikes and sending vesicles for each cell? In other words, is the energy spent in structurally maintaining axons and pumping ions back out after sending spikes roughly proportional to the total energy spent in provisioning vesicles and resynthesizing transmitter at the sum total of all of an axon’s synapses? </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">With these details in tow we can now offer a better explanation for the elaborate branching structures of neurons, then the simplistic principles ‘electrotonic length’. While not every synapse has the prototypical bulbous spine head poised atop a restrictive spine neck, this highly recognizable structure is common throughout the brain. While fabulous things like rapid mechanical twitches and shape changes have been attributed to spines by luminaries no less than Francis Crick himself, no one has really explained their curious form. Although not every spine has their own resident mitochondria, we might admit that ‘active’ synapses energetically asserting their influence on their local environment would probably retain a captive power source in the form of mitochondria.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">What I propose, is that the swollen endbulbs of postsynaptic spines found in the dendrites of Purkinje, pyramidal, and numerous other kinds of neurons serve as transient banks of incubators, up to 10,000 strong, for mitochondria. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Incubators for what?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">In this conception, the blatant informational bottlenecks inherent in the presumed Cajal-esque signal flow from dendrites to axons are transformed into physical bottlenecks with a new purpose: namely, the selection and transmission of desireable mitochondria to the axon, the larger nervous system, the body itself, and perhaps beyond.</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">I first suggested this idea of a dendritic proving ground where mitochondria must meet certain criteria for selection a few years ago(28). Perhaps more convincingly for the reader, evidence for this type process has just been found, along with several of the molecular mechanisms that underlie it. The authors found that a quality control system dependent on Parkin ensures the passage of healthy mitochondria to the axon in order to limit impact of sub-par mitochondrial stock(29).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">The real power of this simple idea is that when combined with the known penchant of neurons for sharing mitochondria, it also provides an explanation for the polarity of neurons themselves.</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Rather than passively arising as by-products of electrotonically-constrained neural architecture, I would offer that these structural mitochondrial bottlenecks </span><span style="font-family: "arial"; font-size: 14.6667px; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">actually drove</span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> the transformation of the initial unpolarized neuron-like cells found in the primitive neural nets of jellyfish and hydra into the highly polarized neurons and circuits we now find in the higher mammals. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Fortunately we do not have to take this idea on faith; The evolutionary history of this rectification process is on full display in the progression from the ganglionic nervous system architectures of jellyfish up through all the other intermediary invertebrate creatures to us. This taxonomy chronicles the inexorable refinement of primitive multipurpose symmetric synapses reciprocally bombarding each other with dense-core buckets (as seen on EM) filled with nonspecific peptide soup, into the highly asymmetric synaptic diodes with small clear vesicles and discriminating transmitter profiles that we now use. These amenities are also paralleled by subtle transformations of the cytoskeleton and primitive myelinating investments to increasingly chiral forms exclusively reserved for the axon as one goes up the phyla(30). </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Similarly, the inhibitory functions of the original dual purpose inhibitory-excitatory neurons were refined and off-loaded whole into small, specialized locally projecting interneurons. Traces of the primitive, more symmetric ganglia-style insect brains are all but gone in us, save perhaps for the unusual pseudounipolar dorsal root ganglion cells that still relay sensation up through our spines. In the twisted neuro-jargon of the terms ‘antidromic’ and ‘orthodromic’ the distinction in signal direction relative to the cell body seems to make little sense for this kind of ‘axon only’ cell. </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Are mitochondrial bottlenecks really a thing?</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">We might presume that the ultimate fate of mitochondria that manage to gain access to axons would depend on what kind of circuit they are in. Some circuits may act as selective filters and transmitters of mitochondria while others would be stylized more as bingers and purgers. Evidence for the later comes from the work of Mark Ellison who uncovered a quality control circuit in the visual system where mitochondria passing into the retinal ganglion cell axons are degraded at a place called the optic nerve head, and then packaged off to specialized glial cells. Here they are </span><span style="background-color: white; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">auto-phagocytically absorbed in a lysosomal fusion process akin to resorption and turnover of spent photoreceptor outer segments by retinal pigment epithelial cells. A strikingly similar mechanism is also responsible for elimination of paternal sperm </span><a href="http://medicalxpress.com/tags/mitochondria/" style="text-decoration: none;"><span style="background-color: white; color: #313d57; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">mitochondria</span></a><span style="background-color: white; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> at the moment the egg is fertilized. This axonal ‘transexudation’ as Ellisworth called it, is opposite and complementary to the above mentioned mitochondrial rescue circuit where astrocytes transmit mitochondria to ailing neurons after stroke.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Intriguingly, the axon is not the only place where selective mitochondrial bottlenecks are found. A series of so-called ‘maternal bottlenecks’ of this very sort can be found in the ovaries. The presumed function here is to ensure that only the purest, most desireable mitochondria get selected and transmitted by the nurse cells to charge the egg -- and therefore the next generation. In the germ cells of the hermaphroditic worm mentioned above this kind of mitochondrial scrimmage is taken to an extreme; the cells fuse into an open borders syncytium where they can duke it out unfettered by membranous barriers. There is now at least one company that offers a work-around to any woman for which the normal mitochondrial security measures have failed. One form of the treatment circumvents the now very dubious prospect of a ‘three-parent embryo’ by in vitro substitution of the misbegotten mitochondria of her eggs with alternative selections sourced from her own nurse cells. A second developmental bottleneck is found a bit later during the the early embryonic phase where the mitochondrial pool is serially diluted. Here, the replication of whole mitochondria, along with the very loosely synchronized replication the mtDNA nucleoids inside them, is completely arrested until after the 6-16 cell stage (depending on the species). </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The amalgamation of polarized neural components into larger bottlenecking networks may additionally provide a mechanism to explain even more esoteric phenomena only now beginning to enter the realm of the knowable. The transgenerational transmission of acquired characteristics, particularly of habits and memories, has been widely thought impossible. A few old, but fairly well-known experiments, linger at the back of this recently fashionable topic. The protocol involved training certain habits into Planaria and then grinding them up and feeding them to other Planaria. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">This sounds bizarre, but these creatures possess a peculiar facility for regeneration through a population of adult stem cells (known as neoblasts) that are dispersed through their body. Planaria have also proven their mettle at repurposing their tissues by making up for the lack of a standard issue lens by coaxing their own mitochondria into gorging on special light-refractive proteins until they are swollen and tightly packed together into an image forming device(31). While it was reported that the Planaria who were fed their ground up forebearers went on to develop similar habits despite having never been appropriately trained, these kinds of extra-genetic transfer are generally difficult to prove. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">However, more recent demonstrations of Lamarckian inheritance of ancestral fears in mice(32), or of similarly conditioned olfactory responses in flies(33), are very difficult to ignore. They are also difficult to explain by appealing to traditionally established epigentic mechanisms. For starters, the ‘many-to-one’ paternal sperm bottleneck is severely bandwidth-limited: generally it is not only impervious to mitochondrial transfer to the egg, but the sperm DNA also undergoes a genetic reboot’ where the histone chromatin is replaced with DNA-compressing protamines, and the many slowly accumulated epigenetic marks on the DNA are wiped clean. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">I don’t want to step into it too deep here other than to say that exceptions to rules like uniparental inheritance of mitochondria, or the blanking of the epigenetic slate in the maturation of gametes can often make the point of a larger understanding. For example, in bivalves like mussels there is an apparent violation of the axiomatic rule of uniparental inheritance because the sperm mitochondria manage to evade degradation or extrusion in the egg. </span><span style="background-color: white; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">This seeming contradiction to a well established evolutionary maxim is resolved by the fact that the male mitochondria are only transmitted from fathers to sons. Incredibly, the early embryo somehow distinguishes paternally inherited mitochondria and ships them exclusively to one of the blastomeres known as ‘4D’ -- which in males, goes on to differentiate into the germ cells which later make sperm(34).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Thinking and Breathing</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">When it comes to handling their own mitochondria, we might expect no less care than that seen in gametes or a blastula to be taken by the nervous system. While conducted at a speed considerably less than spikes, the apportioning of mitochondria is one, if not the, central preoccupation of nervous systems. Rather than electrical resistance of cytoplasm, neural structure might better be parameterized by a diffusion length of oxygen. Nervous systems then literally represent the inevitable terminus of the oxygenation of the biosphere, artisanal geophysical delicacies weathered through respiration of mitochondria.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The elementary logic typically applied to a sensory neuron receiving input bits of information from the world, integrating that information, and passing X number of bits down the line to the next neuron does not alway make good physiologic sense. For example, one can argue that a significant portion of the information in any spike train, particularly when idling away during unstimulated spontaneous activity, simply represents things a neuron is telling itself. As we know, when neurons want to speak to other neurons they generally don’t use spikes, they use vesicles, and the occasional gap junction. In this view, any external information that manages to become directionally superimposed upon a regularly spiking cell would only represent an incidental fraction of the bulk information flow throughout the neuron. Many spikes then, are just the din of the pump. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The primitive homeostatic function of a cell-wide or organelle-wide membrane potential originally served as gradient to power membrane transport, or to enable sensation of things in the local environment. Self-synchronizing spikes in the spatially extended structure of a large neuron may have arisen in part for the thousands of endosymbionts ambulating within to communicate their energetic activities to each other. Any realistic model of a nervous system would not just include a network geometry with volleys of spikes propagating from input to output -- it would also contain responsive mitochondria meandering about to power the generation of those spikes as sure as any model of a termite mound would contain models of termites.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">In Nature’s palette of extremes, the 10-meter long axons of the neurons that innervate the flukes of a blue whale have a serious logistics problem on their hands. Spikes may be able to influence the entire neuron in real time, but there is no obvious way the nucleus can adapt its output -- namely, the proteins and other products it normally makes to care for this cell -- in real time. The slow phase component of axonal transport consisting of large organelles could take decades to reach their target, while even the fast pool, moving at a rate of several mm/day would still take months. During the development phase, the axons tethered to the growing whale’s tail are being pulled aft at the astounding rate of 3cm per DAY. It would seem improbable that everything the growing neuron needs could be provided for by its own nucleus. If the synapses in the tail can obtain fresh mitochondria and other supplies from a local sources, their instantaneous energetic needs could be quickly met and adapted to those of the entire organism.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">At the other extreme of the animal world, are the infinitesimal fairy flies. These creatures are full-fledged invertebrate body plans packed into a footprint smaller than a paramecium. They achieve this compacted form by jettisoning huge contingents of genetic and energetic machinery during development. By offloading the nuclei and mitochondria of a large percentage of their neurons, reminiscent of what our own red blood cells do, they lighten their nervous systems down to the bare minimum. In this deprecated state they manage to run on fumes through a short inexorable while, but it is only through extreme metabolic adjustments. Although the developmental of all complex nervous systems (including fairy flies), requires the respiratory services of the ‘powerhouses of the cell’, paradoxically, it now appears that these services are not the primary essential function of mitochondria in all eukaryotes.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">To discover that mitochondrial BIOS we need to look afield to those rare single cells that have shredded their own mitochondria completely out of existence. The keys to understanding the origins of all metabolisms are the metal cofactors around which they later accreted. The molybdenum ‘Moco’ clusters, iron-sulfur clusters and hemes, iodine thyroxins, cobalt cobalamins, and many others, have all gone on to spawn entire industries favored to different extents by different niches of life. Invariably, mitochondria play a significant role in constructing each and every one of the these cofactors before handing them off to the cytoplasm for final assembly and insertion into enzyme cores. By toggling the labile mitochondrial and cytoplasmic localization motifs found at start sequences of each enzyme’s genetic instructions, cells can switch the synthesis sites between the two compartments with seeming ease. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The one cofactor which has proven fairly resistant to this kind of shuffling is our FeS clusters. Only a single protist family, the monocercomonoids, has been found that manages to cobble together the essential iron-sulfur gemstones without mitochondria. They have achieved this by appropriating cytoplasmic versions of mitochondrial synthesis enzymes through horizontal gene transfer from a combination of methanoarchael sulfur mobilization systems and bacterial nitrogen fixation systems(35).</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">The structural forms mitochondria take are a compromise between the need for respiration and the need to provide the countless other eclectic synthesis functions for each organ system in the body. Their skill as nearly universal synthesizers comes courtesy of their powerful oxidizing provisions and protections. For example, the unique tubular phase of the cristae found in liver mitochondria are specialized to pull off the exacting enzymatic flowchart required for steroidogenesis. On the other hand, the discoid cristae of sperm mitochondria are fused to form a large ringed syncytium optimized for ATP production. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: #fafafa; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">D’Arcy Wentworth Thompson’s quip that “the form of an object is a diagram of its forces,” may be particularly relevant to cristae. </span><span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">There aren’t many models available that attempt to depict the structure of cristae, and even less available that try to capture their function. One thing we do know is that that are not anything like the asymmetric baffle structures depicted in most popular images. There are modeling packages that can simulate parts of the metabolisms of cells or organelles, but they are generally nowhere near the complexity of the compartmental electric models that are available for simulating networks of neurons. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">At the height of the neuron simulation wars in the mid-to-late nineties, there were two basic modeling packages available -- Genesis and Neuron. Judging by its later selection to be the foundation of the big brain projects like Eurobrain, Neuron was the winner. However, the Genesis program had a couple cool things going for it. For one, it was Unix-based, and therefore inspired many young researchers to tackle the difficult installation of the newly available Linux operating system on their home computers. The other thing was that it had a plug-in module for adding new dendritic growth components that responded to more than just the old Hodgkin Huxley electrical dynamics. For example, there were built-in equations and solvers for diffusion of various key ion like calcium or other molecules. </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">These kinds of compartmental models have already been of practical use in improving what is probably the most successful brain implant to date -- the cochlear implant. By measuring the material properties of the cochlea, and the finding field potential distribution secondary to stimulation using complex boundary and finite element electromagnetic simulation software, the response of the auditory nerve to an implant can be predicted, at least in theory. The main difficulty with all things biological is that in engineering-speak, they tend to be ill-conditioned. That means that when you try to mesh their structure and replace it with code, long thin axons and thin wispy membranes of tissue are difficult to approximate. Before any multiphysics models of the nervous system at large can be developed to constrain the operation of implants, an accurate CAD model that won’t blow up at the edge will be needed.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Concluding remarks</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">To try and wrap this all up, I want to make the prediction that our current course of trying to stimulate and record neurons from the grey matter, won’t be the way forward to building practical implants for the masses. From a marketing point of view, companies have already found that there is no real market for advanced implants if the only people to use them are a small pool of paralyzed or locked-in patients. As long as we continue to simply jam 100-spot pincushion arrays onto the cortex, only to irreversibly scar everything in sight a short time later, we will not arrive at a solution for everyman any time soon.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">A better approach may be to develop smarter ways to access the brain, namely by putting the hardware into the ventricles and vascular system. Instrumenting tiny stents with recording electrodes -- building ‘stentrodes’ -- has already been shown to be one way to noninvasively record signals from deep inside the brain(36). Implants that noninvasively measure intracranial pressure inside the ventricles have long been sought for treating hydrocephalus. Electrode or optode arrays placed in these same interior spaces, and accurately positioned with external magnetic fields, might initially be quite similar in form and function to the implant leads now threaded through the fluid scala tympani chamber of the the cochlea.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">Unfortunately, no one has figured out how to get into the ventricles without plowing straight through precious real estate. However, there might be a way to minimize collateral damage if the ventricles can be assessed via the natural vents (ie., the foramen of Lushka and Magendie) that peek out of the fourth ventricle below the cerebellum. In order to pull this off, it will be necessary to demonstrate that the fragile ciliated ependymal cells that line the ventricles and control its flow will not be disrupted. Considering that these cells are the one single part of the original primitive brain cobbled together by cells lining the feeding pores of our spongelike ancestors that have remained largely unchanged to this day, we might not be too surprised if perturbing them has some consequences that can be directly felt.</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">On the other hand, if it works, coursing right above and below the ependymal cells lie vast tracts of myelinated axons as far as electrode can see. Notably, 300 million corpus callosum fibers roaring right overhead might can be hit from below and also bridged topside by hardware placed into the well of the medial longitudinal fissure. Stimulating and recording from the white matter locations would have several distinct advantages over grey matter depending on whether electrical, magnetic, optical, ultrasonic thermal or direct mechanical stimulation is used. Furthermore, the genetically enhanced counterparts to each of these techniques, eg. ‘optogenetic’, ‘magnetogenetic’, etc. provide further flexibility. These critical advantages are safety, reversibility, and access. ‘Safe’ because overstimulation of an axon or an axon collateral is much more survivable for the cell than overstimulation of the soma. ‘Reversible’ because vascular or intraventricular hardware is isolated from the neuron (it won’t scar it, and heat unavoidably generated by implants can be readily exhausted to the bulk CSF), and it can be removed in much the same way that it was put in. And finally, ‘access’, because in the brain location is everything(). </span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;">With each axon potentially accessible at multiple points along the ventricle one could in theory get many reads on any given cell. That would be advantageous in trying to determine the direction and connectivity of the projection you are targeting. It would also eliminate, or at least mitigate, one of the biggest headaches of any modern multiunit recording, the spike-sorting algorithm. Much of the lateral ventricles are lined by sensory projections coursing between the thalamus and cortex. For the large visual tracts in particular, there are around ten return projections back to the thalamus for each one going out to the cortex. No one has figured out what they really do. This is where you want to place those speech or image implants that you desire to be active at the level of the inner voice or the mind’s eye(). </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">1 J. Hewitt Do glial connectomes and activity maps make any sense? </span><a href="http://medicalxpress.com/news/2013-09-glial-connectomes.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2013-09-glial-connectomes.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">2 J. Hewitt Rise of the Cyborgs </span><a href="http://www.extremetech.com/extreme/144579-rise-of-the-cyborgs" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.extremetech.com/extreme/144579-rise-of-the-cyborgs</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">3 J. Hewitt The Thermodynamics of Thought: Soliton Spikes and Heimburg-Jackson pulses </span><a href="http://medicalxpress.com/news/2013-09-thermodynamics-thought-soliton-spikes-heimburg-jackson.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2013-09-thermodynamics-thought-soliton-spikes-heimburg-jackson.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">4 Luca Turin Smells, Spanners, and Switches Inference </span><a href="http://inference-review.com/article/smells-spanners-and-switches" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://inference-review.com/article/smells-spanners-and-switches</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">5 J. Hewitt </span><span style="background-color: white; font-family: "arial"; font-size: 12px; vertical-align: baseline; white-space: pre-wrap;">Using the 'deuterium switch' to understand how receptors work J. Hewitt</span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<a href="http://phys.org/news/2016-06-deuterium-receptors.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 12px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://phys.org/news/2016-06-deuterium-receptors.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">6 J. Hewitt </span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">How to Myelinate a nerve </span><a href="http://medicalxpress.com/news/2015-03-myelinate-nerve.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2015-03-myelinate-nerve.html</span></a></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Driving Myelination by Actin Disassembly http://phys.org/news/2015-07-myelination-actin-disassembly.html</span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">The Glial Menagerie: From Simple Beginnings to Staggering Complexity http://medicalxpress.com/news/2013-11-glial-menagerie-simple-staggering-complexity.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">7 J. Hewitt Mapping the Entire Brain with New and IMproved Brainbow II Technology </span><a href="http://medicalxpress.com/news/2013-11-entire-brain-brainbow-ii-technology.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2013-11-entire-brain-brainbow-ii-technology.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">8 J. Hewitt Physical Principles for Scalable Recording </span><a href="http://medicalxpress.com/news/2013-07-physical-principles-scalable-neural.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2013-07-physical-principles-scalable-neural.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">9 Mo Costandi Connectome? Not So Fast </span><a href="https://neurophilosophy.wordpress.com/2009/08/11/connectome_not_so_fast/" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://neurophilosophy.wordpress.com/2009/08/11/connectome_not_so_fast/</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">10 Transcellular degradation of axonal mitochondria PNAS </span><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;"><a href="http://www.pnas.org/content/111/26/9633.abstract" style="text-decoration: none;">http://www.pnas.org/content/111/26/9633.abstract</a></span><br />
<span style="font-size: x-small;"> J. Hewitt Fast spiking Neurons take mitochondria for a ride https://medicalxpress.com/news/2014-01-fast-spiking-axons-mitochondria.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">11 J. Hewitt</span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Horizontal transfer of Mitochondria in Sickness and in Health </span><a href="http://medicalxpress.com/news/2015-08-horizontal-mitochondria-sickness-health.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2015-08-horizontal-mitochondria-sickness-health.html</span></a></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Mitochondria control Oncogenesis Through Metabolic Reprogramming </span><a href="http://medicalxpress.com/news/2015-07-mitochondria-oncogenesis-metabolic-reprogramming.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2015-07-mitochondria-oncogenesis-metabolic-reprogramming.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">12 J. Hewitt Axons growing out of Dendrites? Neuroscientists Hate When That Happens </span><a href="http://medicalxpress.com/news/2014-09-axons-dendrites-neuroscientists.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2014-09-axons-dendrites-neuroscientists.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">13 Mo Costandi A New Way of Thinking About How the Brain Works https://www.theguardian.com/science/neurophilosophy/2013/aug/09/a-new-way-of-thinking-about-how-the-brain-works</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">14 J. Hewitt Pulse Propagation and Signal Conduction in the Hydraulic Brain </span><a href="http://medicalxpress.com/news/2013-09-pulse-propagation-transduction-hydraulic-brain.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2013-09-pulse-propagation-transduction-hydraulic-brain.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">15 </span><span style="background-color: white; color: #222222; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Connective tissue diseases: Mitochondria drive NETosis and inflammation in SLE http://www.nature.com/nrrheum/journal/v12/n4/full/nrrheum.2016.24.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">16 </span><a href="http://pubs.rsc.org/en/Content/ArticleLanding/2015/MB/C4MB00667D#!divAbstract" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://pubs.rsc.org/en/Content/ArticleLanding/2015/MB/C4MB00667D#!divAbstract</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">17 </span><a href="http://www.nature.com/nature/journal/v535/n7613/full/nature18928.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.nature.com/nature/journal/v535/n7613/full/nature18928.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">18 </span><span style="background-color: white; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Parkinson’s Disease-Related Proteins PINK1 and Parkin Repress Mitochondrial Antigen Presentation</span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/cell/pdfExtended/S0092-8674(16)30590-6</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">19 </span><span style="background-color: white; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Protons Trigger Mitochondrial Flashes </span><a href="http://www.cell.com/action/showAbstract?pii=S0006-3495%2816%2930459-3&doi=10.1016%2Fj.bpj.2016.05.052" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.cell.com/action/showAbstract?pii=S0006-3495%2816%2930459-3&doi=10.1016%2Fj.bpj.2016.05.052</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">20 J. Hewitt Fast contractions and depolarizations in mitochondria revealed with multiparametric imaging</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2014-05-fast-depolarizations-mitochondria-revealed-multiparametric.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">21 J. Hewitt When spikes collide: Shaking the foundation of neuroscience</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://medicalxpress.com/news/2014-09-spikes-collide-foundation-neuroscience.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2014-09-spikes-collide-foundation-neuroscience.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">22 J. Hewitt Origin of the Eukaryotic cell: Part I - How to train your endosymbiont</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://phys.org/news/2014-12-eukaryotic-cell-endosymbiont.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://phys.org/news/2014-12-eukaryotic-cell-endosymbiont.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">23 J. Hewitt Review of NickLane’s</span><span style="font-family: "arial"; font-size: 12px; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: white; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">The vital question: Why is life the way it is?</span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"> http://phys.org/news/2015-04-vital-life.html#ajTabs<br /></span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">24 Joe Kirschvink </span><a href="http://www.diamond.ysn.ru/IGC2012/IGC2012/PDF/AUTHOR/GC125501.PDF" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.diamond.ysn.ru/IGC2012/IGC2012/PDF/AUTHOR/GC125501.PDF</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">25 J. Hewitt How does the cerebellum work? </span><a href="http://medicalxpress.com/news/2014-07-cerebellum.html" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2014-07-cerebellum.html</span><span style="color: black; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span></a></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">26 J. Hewitt Controlling the internal structure of mitochondria http://phys.org/news/2015-05-internal-mitochondria.html?utm_source=nwletter&utm_medium=email&utm_content=splt-item&utm_campaign=daily-nwletter</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span></div>
<div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">27 Helical arrays of U-shaped ATP synthase dimers form tubular cristae in ciliate mitochondria</span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span><a href="http://www.pnas.org/content/113/30/8442.long" style="text-decoration: none;"><span style="color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.pnas.org/content/113/30/8442.long</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">28 J. Hewitt Fast spiking axons take mitochondria for a ride http://medicalxpress.com/news/2014-01-fast-spiking-axons-mitochondria.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">29 Compartmentalized Regulation of Parkin-Mediated Mitochondrial Quality Control in the Drosophila Nervous System In Vivo J. Neuroscience http://www.jneurosci.org/content/36/28/7375.short </span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">30 J. Hewitt The Origins of Polarized Nervous Systems </span><a href="http://phys.org/news/2015-03-polarized-nervous.html" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://phys.org/news/2015-03-polarized-nervous.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">31 J. Hewitt Fiber optic light pipes in the retina do much more than simple image transfer http://phys.org/news/2014-07-fiber-optic-pipes-retina-simple.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">32 J. Hewitt Scientists prove that fears and memories can be inherited via sperm</span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"> http://www.extremetech.com/extreme/171990-scientists-prove-that-fears-and-memories-can-be-inherited-via-sperm</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">33 J. Hewitt Fly dreams and the boundaries of evolutionary science</span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;"><br class="kix-line-break" /></span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">http://phys.org/news/2014-01-boundaries-evolutionary-science.html</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">34 J. Hewitt Mitochondrial DNA mutations: The good, the bad, and the ugly </span><a href="http://medicalxpress.com/news/2015-01-mitochondrial-dna-mutations-good-bad.html" style="text-decoration: none;"><span style="background-color: white; color: #1155cc; font-family: "arial"; font-size: 10.6667px; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://medicalxpress.com/news/2015-01-mitochondrial-dna-mutations-good-bad.html</span></a></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">35 A Eukaryote without a Mitochondrial Organelle http://www.cell.com/current-biology/fulltext/S0960-9822(16)30263-9</span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">36 </span><span style="background-color: white; color: #333333; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">Chronic impedance spectroscopy of an endoascular stent-electrode array </span><span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 10.6667px; vertical-align: baseline; white-space: pre-wrap;">http://iopscience.iop.org/article/10.1088/1741-2560/13/4/046020/meta;jsessionid=B5FC3E6562BC9F0A3F9AEEFB5492A312.c2.iopscience.cld.iop.org</span></div>
<br /><div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: white; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.44; margin-bottom: 6pt; margin-top: 0pt;">
<span style="background-color: white; color: #292f33; font-family: "arial"; font-size: 14px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.44; margin-bottom: 6pt; margin-top: 0pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<br /><div dir="ltr" style="line-height: 1.2218154545454545; margin-bottom: 6pt; margin-top: 6pt;">
<span style="background-color: white; color: #333333; font-family: "arial"; font-size: 14.6667px; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
</span>John Hewitthttp://www.blogger.com/profile/12361029646864521044noreply@blogger.com0