How stress affects the brain

Stress shrinks the brain

Stress originates in the hypothalamic-pituitary-adrenal system. In a stressful situation, the adrenal cortex secretes cortisol, a catabolic hormone that keeps a person active so that he can cope with difficulties. But its long-term effects are bad for the brain.

The main blow is taken by the hippocampus. Stress effects on the hippocampus: a critical review, where there are many cortisol receptors. In a normal situation, they help to normalize hormone production. If the level of cortisol remains high for a long time, some of the receptors die. This can lead to memory impairment and learning disabilities. At the same time, the amygdala becomes more sensitive and this makes the person nervous and restless.

Another consequence is the decreased ability of the hormonal system to control stress levels. But that's not all.

Because of the increased cortisol content, the brain shrinks in size.

Exposure to the hormone disrupts synaptic connections between neurons and changes the size of the prefrontal cortex, which is responsible for concentration, decision-making, and social interaction.

Therefore, chronic stress doesn't just impair memory and concentration, it can lead to depression and dementia.

Stress affects genetics

Experiments show that chronic stress can affect the expression of certain genes. This conclusion was made by the scientists following the results of the experiment Reversal of Maternal Programming of Stress Responses in Adult Offspring through Methyl Supplementation: Altering Epigenetic Marking Later in Life on rats.

How the mother cares for her offspring determines how the children will subsequently respond to stress. A caring and attentive parent grows up a child resistant to stressful situations. He has more cortisol receptors in his brain, which regulate the response to negative effects. Babies of neglected mothers are more susceptible to stress due to fewer receptors.

Such changes are called epigenetic, since they do not affect the sequence of the DNA itself. But they are hereditary, and the stress response received by the offspring of one mother will spread over several generations.

Stress needs to be dealt with

To prevent irreversible changes in the brain, it is necessary to combat stress and reduce cortisol levels. The simplest methods are deep breathing and meditation. Exercise also helps, but it is important to know when to stop: excessive exercise can increase cortisol levels.