Chronic Stress Reversibly Impairs Brain Function

Chronic stress affects the prefrontal cortex in rodents. It attenuates the arborization of dendrites (and, hence, neuronal connectivity), and produces changes in cognition and functional magnetic resonance images (fMRI). These changes are reversible after cessation of stress. We study rodents because, like us, they are mammals, but would we find similar results in humans?

A team from Rockefeller University and Cornell studied 20 healthy medical students for 1 month before and 1 month after they took important examinations and compared them with 20 matched “low-stress” controls. Stress exposure was measured on a validated scale. After 4 weeks of stress, attention (a cognitive function that resides in the prefrontal cortex) was impaired, as sh…