New Rat US Study Shows How Chronic Stress Impairs Memory
Ever been in a situation where you come under severe stress and you find yourself unable to remember things?
If so, you may find comfort in a new US rat study which investigates how stress hormones influence the prefrontal cortex (PFC). The researchers discovered that when young male rats were exposed to repeated stress, they had significant memory impairment and a significant loss in glutamate receptors in the PFC which then resulted in a deficit of PFC-mediated cognitive processes.
Glutamate signaling plays a critical role in the functioning of the PFC, an area of the brain that controls high level “executive” functions such as working memory and decision-making and glutamate signaling plays a critical role in the functioning of the PFC. The researchers also discovered that by blocking the molecular mechanisms that led to decreased glutamate receptors, can also decrease stress-induced memory loss.
The rat study conducted by Zhen Yan, PhD, and her colleagues of the State University of New York at Buffalo. They have found that chronic stress in rats may lead to memory problems by interfering with glutamate signaling in the rats’ prefrontal cortex.
Earlier research had shown that stress hormones influenced the prefrontal cortex, an area of the brain associated with memories and decision-making. In human being, the prefrontal cortex is the area of the brain associated with risk-assessment and reward, decision-making and critical self-awareness—hence its role in controlling compulsive behavior. One of the best indicators of stress in humans is a hormone called cortisol which is released all over the body and brain in response to stress.
In their study, the study researchers concluded that the prefrontal cortex or PFC “is a more sensitive area in response to repeated stress, especially during the adolescent period when this region is still undergoing significant development.”
Chronic Stress Study Findings
The study authors suggest that repeated or chronic stress can cause a loss of glutamate receptors and abnormal PFC function and that their study findings may also help to explain how adolescent stress can lead to later adult mental illness.
The new rat study also lends supports to other previous rat studies which have found that chronic stress impairs both response inhibition and working memory.
Source: Published in. Neuron, 2012