Jeff Lichtman (Harvard) Part 2: Neuromuscular Connectomics
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- เผยแพร่เมื่อ 31 พ.ค. 2024
- www.ibiology.org/neuroscience...
Talk Overview: The human brain is extremely complex with much greater structural and functional diversity than other organs and this complexity is determined both by one's experiences and one's genes. In Part 1 of his talk, Lichtman explains how mapping the connections in the brain (the connectome) may lead to a better understanding of brain function. Together with his colleagues, Lichtman has developed tools to label individual cells in the nervous system with different colors producing beautiful and revealing maps of the neuronal connections.
Using transgenic mice with differently colored, fluorescently labeled proteins in each neuron (Brainbow mice), Lichtman and his colleagues were able to follow the formation and destruction of neuromuscular junctions during mouse development. This work is the focus of Part 2.
In Part 3, Lichtman asks whether some day it might be possible to map all of the neural connections in the brain. He describes the technical advances that have allowed him and his colleagues to begin this endeavor as well as the enormous challenges to deciphering the brain connectome.
Speaker Bio: Jeff Lichtman's interest in how specific neuronal connections are made and maintained began while he was a MD-PhD student at Washington University in Saint Louis. Lichtman remained at Washington University for nearly 30 years. In 2004, he moved to Harvard University where he is Professor of Molecular and Cellular Biology and a member of the Center for Brain Science.
A major focus of Lichtman's current research is to decode the map of all the neural connections in the brain. To this end, Lichtman and his colleagues have developed exciting new tools and techniques such as "Brainbow" mice and automated ultra thin tissue slicing machines. - วิทยาศาสตร์และเทคโนโลยี
When i started to do movement work i would focus one one muscle and try to contract it. In the beginning it was nearly impossible. Some muscles i couldn‘t contract and others only with 20different muscles together. Over time i learned to isolate muscles and after that i could do certain movements involving different muscles in a refined way. This is also what makes tai-chi so beautiful to watch. You make strong clear connections over which you have control instead of being a neuromuscular-mess.
Interesting correlation for the energy flows of Chi, or Qi Gong, Wii Gong, or isometric movements and stretching to full limits... which I believe is simply part of the connectivity when the body is grounded to earth, makes regeneration, longevity, and flow of energy an explanation for the amazing energy that can pass through the neural pathways, making musculature not alone, but amplified as greater connectivity is made all the way up the spine, through the energy centers or chakras that allow the mature neurons and ganglia to then develop, link up gut, heart, and brain to finally in our mid-60's have the machine, the vessel performing and replicating nightly the DNA computers, increasing our potential, only if grounded... aware, operating the machine clean instead of a broken mess. Maintenance, respect for the vessel, honor and never underestimate the power of the Placebo effect for miraculous healing as well as performance levels that only those who believe and understand the energy humans can tap that is just now being understood, measured, and at ion levels, coming to a level of understanding that all will have to agree is miraculous. Intelligent design perhaps?
Was fuer eine erstaunende Unterricht, vielen Dank, ich habe das wirklich geliebt
I share below notes I wrote to strengthen my own understanding of this wonderful talk::
• Consider a bundle of axons from 6 motorneurons controlling a muscle comprising 400 fibres. With 400 toys, what would 6 kids do? In an embryo, each axon claims most of the 400 neuromuscular junctions by sending branches to them. There, they compete. A few weeks post-natal, each toy has only 1 owner, but each kid owns many toys.
• What determines which toys a kid gets? Lichtman and colleague Draft found 2 clues:
• Pick any kid, call him A. Let's call B the competitor that A faces most often, and C for the next less often, and so on. The first clue is this: If for A, the order he sees is B then C, D, E, F, then for B the SAME order aplies: A then C, D, E, F. For C, it's B then D, E, F, A. And so on. There is order in chaos!
• When a muscle is to move, muscle fibers are activated in a specific sequence. And the second clue which Lichtner has so far found some evidence for, is this: Take a fiber which A has won, then the next-in-line fiber is won by none other than B. And so on.
doanviettrung Thank you. Good comparison: Kids and neurons alike are of a very exploratory nature ;)
So very interesting, thank you for making these presentations available.
please do more of these they are amazing, and i'm really interested in studying connectomics
Congrats on joining Oxford!
@@Tbarlow99 haha thank you, wow this is a throwback
Incredible work! Thanks for sharing!
Thank you very much!
Is the weaker axon on the other side of the linear spectrum? When the main axon is damaged would this be why the healing process takes the time needed but is often never as strong as before? If the weaker axon is unable to be activated, could this be the cause of lingering uncontrollable muscle twitching or instead of movement being smooth the fast twitch muscle fibers being activated without the slow twitch first ( or ever ) being activated?
Would it be too pedestrian to say that this is a bit like those ice grooves on a skating rink? Created from repetition and anything going by can get pulled into it?
The pattern at 32:30 causes me to wonder if these connections are based on ion distribution during formation.
Thank you
Fascinating. Does this mean there is also a connection between connectivity and muscle fiber types? Easy everyday tasks (walking, body language etc.) don't require much of an exertion of mechanical force, thereby utilizing slow muscle fibers. 99% of one's time consists of this kind of activity and therefore might reflect this in the structure of motor neuron connectivity. On the other hand strenuous physical tasks requires more extensive firing of motor neurons eventually utilizing fast type II muscle fibers which could be less well connected by needing them less often? It would be interesting to see how the structure changes by increasing strenuous activity, like from a couch potato to strength athlete. Great talk, thank you.
you have highlighted the algarythem for natural selection.?
+colin nixon algorithm*
17:25 seems like a traumatic way to make these observation. doesn't necessarily invalidate the results, but couldn't that kind of injury also lead to the "pruning" phenomena?
I wonder if it has any relation to how all babies are clumsy.
Kakto Tak well it‘s one of the reasons. Babys have to learn to make their will corelate with their actual movement.