Research involving both animals and humans demonstrates that stress can significantly affect brain function.
Stress damages the body in significant ways.
Stress can cause memory loss, affect the mood and increase levels of anxiety, increase inflammation in the body and can impact heart health.
According to new research on mice, stress restructures the brain by stopping the production of crucial ion channel proteins. It alters brain function by modifying the structure and function of neurons (nerve cell) and astrocytes (a large star shaped cell with numerous functions such as providing nutrients to neurons).
The study, published in The Journal of Neuroscience, found that a single stressful event produced quick and long-lasting changes in astrocytes, the brain cells that clean up chemical messengers called “neurotransmitters” after they've communicated information between nerve cells.
The identified stressful episode caused branches of the astrocytes to shrink away from the synapses (junction between two nerve cells).
The team also found that stress is linked to communication interruptions between cells. They found that during a stressful event, the stress hormone norepinephrine suppresses a molecular pathway that normally produces a protein, GluA1. Without this protein nerve cells and astrocytes cannot communicate with each other.
"Stress alters brain function and produces lasting changes in human behaviour and physiology," explains Professor Si-Qiong June Liu, lead researcher and Professor of Cell Biology and Anatomy at Louisiana State University School of Medicine.
"The experience of traumatic events can lead to neuropsychiatric disorders including anxiety, depression and drug addiction. 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," Liu continued.
This research identified a molecular pathway that controls GluA1 synthesis and astrocyte remodelling during stress. This is important information for considering new pharmacological targets for possible prevention or reversal of stress-induced changes in the brain.
Stressful situations activate the sympathetic nervous system, which governs the body's fight or flight response. Increased adrenaline, blood pressure, and elevated heart rate kept humans alive thousands of years ago, when the ability to quickly recognise and overcome a threat meant the difference between life and death.
Life for humans in modern society requires less of the “fight or flight” function in the brain, but our sympathetic nervous system still activates when the brain perceives danger - be it physical or psychological.
Should we be looking for ways to push stress out of our lives altogether?
If stress is not persistent or classified as “chronic”, research suggests that it may just be a natural part of life that, in small doses, can lead to personal growth.
Kazuhiro Nakamura, a researcher from Nagoya University, Japan said: "Even in human societies, an adequate amount of mental stress would be helpful for better performance in social activities."
Reference: Christian Luis Bender, Xingxing Sun, Muhammad Farooq, Qian Yang, Caroline Davison, Matthieu Maroteaux, Yi-shuian Huang, Yoshihiro Ishikawa, Siqiong June Liu. ‘Emotional stress induces structural plasticity in Bergmann glial cells via an AC5-CPEB3-GluA1 pathway’, The Journal of Neuroscience, 2020; JN-RM-0013-19 DOI: 10.1523/JNEUROSCI.0013-19.2020