New Discovery turns Neuroscience Upsidedown
Sometimes finding out that something established isn’t true is more groundbreaking than finding something new. That is exactly what happened this week when it was found out that the covering that is on all nerves, isn’t really on all the axons in the brain.
Myelin, a fatty covering on nerves, protect the signals being sent and keeps the signals from “getting their wires crossed”. Much like the plastic coating on electrical cords, without it you wouldn’t get very far before you had a serious problem.
[Loony Hint: Think of axons like the telephone lines you see outside, attached to one end of the axon line is the neuron at the other end is another neuron but it is not attached, in other words one axon to neuron.]
However, a recent discovery shows that the brain does away with that. The covering on the axons are virtually non-existent in some places, “some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones” Arlotta, co-director of the HSCI neuroscience program, says.
Not only that, the patterns of that myelin coating, and the way it is positioned on the nerves in the brain, are like nothing ever seen before. They have ‘intermittent myelin’ with long axon tracts that lack myelin interspersed among myelin-rich segments.
“Contrary to the common assumptions that neurons use a universal profile of myelin distribution on their axons, the work indicate that different neurons choose to myelinate their axons differently.” said Arlotta.
“In classic neurobiology textbooks myelin is represented on axons as a sequence of myelinated segments separated by very short nodes that lack myelin. This distribution of myelin was tacitly assumed to be always the same, on every neuron, from the beginning to the end of the axon. This new work finds this not to be the case.”
So what does this mean exactly? It means that instead of a message in the brain going from point A to B to C it can go from A to C. It may even allow your brain to have a “party line” sort of communication so that multiple neurons can receive multiple signals.
Neurons are like the processors in a computer, they sort through information and figure out what to make of it. So splitting up the information, or allowing multiple processors to figure out how to handle it, can be incredibly useful. It allows very complex calculations to be broken up and solved much quicker than if you were to try to solve it line by line.
It’s incredible to think that we are still finding new things about the body, did you hear about the new body part found? It was a ligament in the Knee of all things. I can only imagine what we will find out next!
The simple explanation not challenging your neurons enough? You want the full study then — here!
Tomassy G.S., Berger D.R., Chen H.H., Kasthuri N., Hayworth K.J., Vercelli A., Seung H.S., Lichtman J.W. & Arlotta P. (2014). Distinct Profiles of Myelin Distribution Along Single Axons of Pyramidal Neurons in the Neocortex, Science, 344 (6181) 319-324. DOI: 10.1126/science.1249766