Acute Stress Primes Brain for Better Cognitive and Mental Performance

"You always think about stress as a really bad thing, but it's not," said Daniela Kaufer, associate professor of integrative biology at the University of California, Berkeley. "Some amounts of stress are good to push you just to the level of optimal alertness, behavioral and cognitive performance.

"New research by Kaufer and UC Berkeley post-doctoral fellow Elizabeth Kirby has uncovered exactly how acute stress -- short-lived, not chronic -- primes the brain for improved performance. In studies on rats, they found that significant, but brief stressful events caused stem cells in their brains to proliferate into new nerve cells that, when mature two weeks later, improved the rats' mental performance. "I think intermittent stressful events are probably what keeps the brain more alert, and you perform better when you are alert," she said.

Kirby subjected rats to what, to them, is acute but short-lived stress -- immobilization in their cages for a few hours. This led to stress hormone (corticosterone) levels as high as those from chronic stress, though for only a few hours. The stress doubled the proliferation of new brain cells in the hippocampus, specifically in the dorsal dentate gyrus.

They also found that nerve cell proliferation after acute stress was triggered by the release of a protein, fibroblast growth factor 2 (FGF2), by astrocytes -- brain cells formerly thought of as support cells, but that now appear to play a more critical role in regulating neurons.