Every stressful event we experience could have a significant and lasting impact on our brain, damaging the structure and alteration of the function of key regions, new research reveals.
Chronic stress causes nefarious cognitive consequences, leading to a number of mental disorders such as post-traumatic stress. However, the dangers of isolated stress have remained unexplored for a long time.
Therefore, the team decided to look at the brains of mice after being subjected to a 40-minute stress episode, during which they were repeatedly given electric shocks to the legs. The study's authors explain how this triggered the release of a stress hormone called corticosterone, which in turn triggered a massive rise in levels of a neurotransmitter called glutamate in a part of the brain called the prefrontal cortex.
Because glutamate is an excitatory molecule, neurons in the prefrontal cortex were activated rapidly. By the time glutamate levels began to return to normal, about 24 hours later, many of these neurons had been completely damaged.
More precisely, the dendrites of these neurons - the connecting branches containing the glutamate receptors - were atrophied or dead. This is significant since the prefrontal cortex is involved in our higher cognition, and is essential for our ability to think rationally and make decisions.
The fact that this damage remains visible for up to two weeks after the experiment suggests that even brief bouts of stress can cause lasting destruction to our brain.
