A study involving lab rats could not only help explain how chronic stress impairs one’s cognitive functions, but the researchers who conducted the study believe their findings could also shed light on how adolescent stress can lead to mental illness in adulthood.

The newly published study outlines a method through which stress hormones affect the prefrontal cortex (PFC), a region in the brain responsible for high-level functions such as working memory and decision-making.

“Previous work has shown that chronic stress impairs PFC-mediated behaviors, like mental flexibility and attention,” said study author Zhen Yan. “However, 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.”

In conducting the experiment, the researchers investigated whether repeated stress had a negative influence on glutamate receptors in juvenile rats, as the signaling from this amino acid is key in PFC function.

The researchers found that, in response to repeated stress, there was a significant loss of glutamate receptors, and that resulted in a “deficit of PFC-mediated cognitive processes.”

The researchers also found the molecular mechanisms that linked stress with the decrease in glutamate receptors and proved that if these mechanisms were blocked, they could prevent the stress-induced decrease in both glutamate receptors and recognition memory.

This suggests that repeated/chronic stress could potentially cause the loss of glutamate receptors and the inability of the PFC to function normally, the researchers say.

“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 said.

The American Psychological Association’s national report on stress found chronic stress to be a growing problem.

Source: Cell Press, Psych Central

Heather Rudow is a staff writer for Counseling Today. Email her at hrudow@counseling.org.

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