SAN FRANCISCO (Dispatches) -- Scientists report that anxiety behavior as well as post traumatic stress disorder increases myelin -- a substance that expedites communication between neurons -- in areas of the brain that are linked to emotions and memory.
Researchers at the University of California, Berkeley, and UC San Francisco (UCSF) have provided a possible explanation for why some people are resilient and others vulnerable to traumatic stress, and for the varied symptoms -- avoidance behavior, anxiety and fear, for example -- triggered by the memory of such stress.
If extreme trauma causes the increased myelination, the findings could lead to treatments -- drugs or behavioral interventions -- that prevent or reverse the myelin production and lessen the aftereffects of extreme trauma.
Researchers at the San Francisco Veterans Affairs Medical Center conducted brain MRI scans of 38 veterans -- half with PTSD, half without -- and found an increase in myelination in the gray matter of those with PTSD compared to that seen in the brains of those not suffering from PTSD.
Meanwhile, UC Berkeley scientists discovered a similar increase in myelination in the gray matter of adult rats subjected to an acute stressful event. While not all rats showed long-term effects from the stress -- just as not all traumatized veterans develop PTSD -- those that did had increased myelination in specific areas of the brain associated with particular symptoms of stress that was identical to what UCSF physicians found in veterans with PTSD.