New research at the Louisiana State University (LSU) Health Sciences Center points the way to a potential treatment against stress.
The team shows that stress can physically alter the structures of mouse brains, with long-lasting effects. They also identify a molecular pathway that could be used to prevent or reverse such changes.
“Stress alters brain function and produces lasting changes in human behavior and physiology. The experience of traumatic events can lead to neuropsychiatric disorders including anxiety, depression, and drug addiction,” explains Si-Qiong June Liu, MD, PhD, Professor of Cell Biology and Anatomy at LSU and lead author of the paper.
“Investigation of the neurobiology of stress can reveal how stress affects neuronal connections and hence brain function. This knowledge is necessary for developing strategies to prevent or treat these common stress-related neurological disorders.”
The team found that, for mice, experiencing even a single stressful event was enough to cause quick, long-lasting changes in the structure of astrocytes, brain cells that help feed neurons and maintain synaptic function. Such events cause the outer branches of these cells to shrink away from synapses (the contact spaces between neurons used to transmit impulses via chemical messengers).
Synapses perform the same role in our brains as transistors do in computers — they give us our processing power. And, without astrocytes, they can become clogged with waste ions.
During a stressful event, the team explains, the stress hormone norepinephrine suppresses a molecular pathway that normally produces a protein, GluA1. This protein is essential in allowing nerve cells and astrocytes to communicate with each other.
“Stress affects the structure and function of both neurons and astrocytes,” adds Dr. Liu. “Because astrocytes can directly modulate synaptic transmission and are critically involved in stress-related behavior, preventing or reversing the stress-induced change in astrocytes is a potential way to treat stress-related neurological disorders.”
They explain that the pathway they identified should, in theory, be targeted with medicine to prevent or even potentially reverse stress-induced changes.
For now, the findings only apply to mice. But many signaling pathways are conserved throughout evolution, the team notes. The molecular pathways that lead to astrocyte structural remodeling and suppression of GluA1 production may, therefore, also occur in humans who experience a stressful event — and they could hold the key to fighting stress.
The paper “. Emotional stress induces structural plasticity in Bergmann glial cells via an AC5-CPEB3-GluA1 pathway” has been published in The Journal of Neuroscience.