Question

How does chronic stress makes amygdala create new neuronal connections?

I only got that "that's the way it works, it gets more reactive to stress" but how?

If anyone knows the detail of how it creates more neuronal connections, it would be great.

Answer 1

Chronic stress has shrinking effect on prefrontal cortex, the area of the brain responsible for memory and learning. While stress can shrink the prefrontal cortex it can increase the size of amygdala which can make the brain more receptive to stress.

The first effect of the stress response is the immediate activation of hypothalamic pituitary adrenal(HPA) axis with release of specific hormones. Stress exposure increases the release of amygdala neurotransmitters including glutamate, GABA and serotonin.

Cortisol can trigger stem cells to malfunction. The stress hormone cortisol believed to create a dominate effect that hardwires pathways between the hippocampus and amygdala in a way that might create a vicious cycle by creating a brain that becomes predisposed into a constant state of fight or flight.

It promotes rest and digest response that cms the body down after the danger has passed. After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through autonomic nerves to the adrenal glands.

The clusters of amygdala activates when an individual express feelings of fear or agression. This occurs because the amygdala is the primary structure of the brain responsible for any response. The amygdala is directly associated with conditioned fear.

The amygdala is part if the limbic system of the brain which involved with emotions and other reactions to stimuli. The amygdala is a processing center that is hooked up to receive incoming messages from our senses and our internal organs. It is highly involved with different emotional responses.

Stres hormones influence the processes carried out in the hippocampus and amygdala which are also associated with emotional responses. Thus emotional memories are enhanced when stress is induced as they both associated with the same areas of the brain whereas neutral stimuli and stress are not.