What makes the human brain unique? Of the many explanations that can be offered, one that doesn't come readily to mind is -- myelin.
Conventional wisdom holds that myelin, the sheet of fat that coats a neuron's axon -- a long fiber that conducts the neuron's electrical impulses -- is akin to the wrapping around an electrical wire, protecting and fostering efficient signaling. But the research of UCLA neurology professor George Bartzokis, M.D., has already shown that myelin problems are implicated in diseases that afflict both young and old -- from schizophrenia to Alzheimer's.
Now, in a report published in the journal Biological Psychiatry and available online, Bartzokis argues that the miles of myelin coating in our brain are the key "evolutionary change that defines our uniqueness as a species" and, further, may also be the cause of "our unique vulnerability to highly prevalent neuropsychiatric disorders." The paper argues that viewing the brain as a myelin-dependent "Internet" may be key to developing new and novel treatments against disease and aid in assessing the efficacy of currently available treatments, including the use of nicotine (delivered by a patch, not smoking), which may enhance the growth and maintenance of myelin.
Myelin, argues Bartzokis, who directs the UCLA Memory Disorders and Alzheimer's Disease Clinic, is "a recent invention of evolution. Vertebrates have it; invertebrates don't. And humans have more than any other species."
Bartzokis studied the reported effects of cholinergic treatments, using drugs that are known to improve a neuron's synaptic signaling in people who suffer diseases like Alzheimer's. Furthermore, he notes, some clinical and epidemiological data suggest that such treatments may modify or even delay these diseases
Looking at such effects from a myelin-centric point of view, Bartzokis argues that cholinergic treatments may have nonsynaptic effects as well, perhaps by e
Contact: Mark Wheeler
University of California - Los Angeles