Animal and human studies show quite clearly that stress can affect brain function. Not only does it affect memory and many other brain functions, such as mood and anxiety, but it also promotes inflammation, which negatively affects heart health . Now, new research suggests that stress alters brain function by modifying the structure and function of neurons and astrocytes (those responsible for cleaning neurotransmitters after they have been released at the synapse).
Mouse experiment
In this study, the scientists showed that a single exposure to acute stress was sufficient to trigger a retraction of lateral / fine processes in rodent cerebellar astrocytes. Stress induces this change by stopping the production of GluA1, an essential subunit of glutamate receptors.
During a stressful event, the stress hormone norepinephrine suppresses a molecular pathway that normally culminates in GluA1 protein synthesis. Without functional GluA1 or glutamate receptors, neurons and astrocytes lose their ability to communicate with each other. In other words, the power of stress marks the synthesis of GluA1 proteins, thus remodeling our thinking organ, as it stops the production of crucial proteins from ion channels.
Thus, stress damages the brain and the body in a profound way because, at the cellular level, stress causes the branches of astrocytes to retract from the synapses they surround.
Deal with stress
Stressful situations activate the sympathetic nervous system, which governs the body’s fight or flight response. Rises in adrenaline, blood pressure, and elevated heart rate kept humans alive thousands of years ago, when the ability to quickly recognize and overcome a threat meant the difference between life and death. We are currently facing far fewer imminent risks to life, but our sympathetic nervous system still kicks in when we perceive danger.
Should we find a way to completely corner stress in our life? If stress isn’t persistent or chronic, research suggests it could just be a natural part of life that can lead to personal growth.
“Even in human societies, an adequate amount of mental stress would be helpful for better performance in social activities,” says Kazushiro Nakamura in another similar study – but with rats – recently published in the journal Science in which scientists believe they have found a circuit responsible for the physical feelings that accompany emotional stress. The circuit begins in a group of cells that send signals to the hypothalamus, the area of the brain that maintains basic body functions, such as body temperature, heartbeat, and our desire to eat or reproduce.
Referencia: Crhistian 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
