Short-term stress lasting as little as a few hours can impair brain-cell communication in areas associated with learning and memory, University of California, Irvine researchers have found.

It has been known that severe stress lasting weeks or months can impair cell communication in the brain's learning and memory region, but this study provides the first evidence that short-term stress has the same effect. The study appears in the March 12 edition of the Journal of Neuroscience.

"Stress is a constant in our lives and cannot be avoided," said Dr. Tallie Z. Baram, the study leader. "Our findings can play an important role in the current development of drugs that might prevent these undesirable effects and offer insights into why some people are forgetful or have difficulty retaining information during stressful situations."

In their study, Baram and her colleagues identified a novel process by which stress caused these effects. They found that rather than involving the widely known stress hormone cortisol, which circulates throughout the body, acute stress activated selective molecules called corticotropin releasing hormones (CRH),which disrupted the process by which the brain collects and stores memories.

The researchers discovered that blocking the CRH molecules' interaction with their receptor molecules eliminated stress damage to areas involved with learning and memory.

Baram also noted that there are compounds under development that show the ability to block CRH receptors, and that this study can play a role in the creation of therapies based on these compounds to address stress-related learning and memory loss.

(Xinhua/Agencies March 12, 2008)