White matter and learning impairment.

Half of your brain has been neglected and it may be most significant half when it comes to understanding cognition and mental disorders. New research may even make it possible to improve your thinking –steroids for the brain – maybe not such a great analogy.

It seems that we are slowly becoming aware of the importance of the other half of our brains. Of course, popular culture has known for decades of the differences in the roles of each hemisphere and that same pop culture is slowly realizing the importance of even finer divisions of the gray matter including the mapping of regions of the PFC (prefrontal cortex) into lateral, VM (ventromedial), and orbitofrontal and even rostral regions involved in mixing our emotions with our logic, our memories real and imagined and our beliefs, true or not. We, as a society, are even learning how we might best do that mixing in order to improve our ability to reason as well as live and enjoy life –actually quite a complicated interaction. But that is not the other half of the brain that I’m referring to today.
Learning impairment, autism, schizophrenia, Alzheimer’s disease, age related cognitive impairments and even the well known lack of judgment experienced as a teenager may all have origins in the other half of the brain –namely the white matter. We have been aware of the importance of gray matter where the neurons are but our mental performance is actually quite dependent on the white matter where axons that connect different grey matter regions are and where non-neuronal brain cells (glia) are located. Several articles in Scientific American (including the recent March 2008 issue) have discussed the role of glia in cognition. They have also noted the fact that certain outside influences can be detrimental to the myelin sheaths created in the white matter insulating our axons which is essential to clear intelligent thinking. Deterioration of the myelin wrapped around the axons may be causal to many different types of impairments.

Noted in the SciAm article this month by R.Douglas Fields is something I do find rather exciting though. As we age, we wrap our brains in myelin and finally get the complete coating in our 20’s. We are better at learning new things while this is actually being done and we are less adept at learning once this wrapping is complete. There is however a protein, NoGo-A, which is responsible for determining when we are done cooking –or rather wrapping. When that protein is inhibited it may be possible to regain some of our learning capacity. Now that is what I consider exciting and definitely socially unacceptable: Prevent mental maturity, just so I can learn more.