Have you ever found yourself forgetting things (such as where you left your keys or where you parked your car) when you are under a great deal of stress? When facing a huge deadline at school or at work, you might find that it becomes more difficult to remember little details about your daily life. Previous research has linked chronic stress, or repeated stress that leads to continuous state of physiological arousal, to an array of problems including emotional distress and weakened immunity. A new study by researchers from the State University of New York at Buffalo demonstrates how chronic stress also impairs your memory.
The study, published in the journal Neuron, looks at the physiological effects of stress hormones on the brain. Earlier research had shown that stress hormones influenced the prefrontal cortex (PFC), an area of the brain associated with memories and decision-making. "However," explains lead author Dr. Zhen Yan, "little is known about the physiological consequences and molecular targets of long-term stress in PFC, especially during the adolescent period when the brain is more sensitive to stressors."
Researchers discovered that repeated exposure to stress led to a significant loss in glutamate receptors in juvenile rats. Glutamate plays an important role in the functioning of the prefrontal cortex. The researchers also discovered that by blocking the molecular mechanisms that led to decreased glutamate receptors, they were able to decrease stress-induced memory loss.
"Since PFC dysfunction has been implicated in various stress-related mental disorders, delineating molecular mechanisms by which stress affects the PFC should be critical for understanding the role of stress in influencing the disease process," Yan suggests.
Eunice Y. Yuen, Jing Wei, Wenhua Liu, Ping Zhong, Xiangning Li, Zhen Yan. Repeated Stress Causes Cognitive Impairment by Suppressing Glutamate Receptor Expression and Function in Prefrontal Cortex. Neuron, 2012 DOI: 10.1016/j.neuron.2011.12.033
Image by Carl Dwyer