The researchers also determined that the stressful experience did not increase depression or anxiety-related behavior in the animals.
"It is known that stress has both positive and negative actions in the brain, but the underlying mechanism is elusive," said Yan. "Several key brain regions involved in cognition and emotions, including the prefrontal cortex, have been identified as the primary target of corticosteroid, the major stress hormone.
"Our current study identifies a novel mechanism that underlies the impact of acute stress on working memory, a cognitive process depending on glutamate receptor-mediated excitatory signals in prefrontal cortex circuits."
The investigators have expanded this research in several directions. In a paper currently under review, they have identified the key signaling molecules that link acute stress to the enhancement of glutamate receptors and working memory.
"In addition," noted Yan, "we have discovered that chronic stress suppresses the transmission of glutamate in the prefrontal cortex of male rodents, which is opposite to the facilitating effect of acute stress, and that estrogen receptors in female rodents make them more resilient to chronic stress than male rats.
"All these studies should bring new insights into the complex actions of stress in different circumstances that may be applicable to humans in the future," she said.
|Contact: Lois Baker|
University at Buffalo