But from that area, the message cascades into a structure called the amygdala in the limbic system, the emotional core of the brain, and that structure, called the amygdala, gauges the emotional significance of what you're looking at.

And then the message cascades into the amygdala, and then goes down the autonomic nervous system.

For example, it's been shown to stimulate neural growth in the amygdala, in the area where it controls emotions.

For example, it's been shown to stimulate neural growth in the amygdala, in the area where it controls emotions.

So if the amygdala is excited, and this is something important, the messages then cascade into the autonomic nervous system.

But maybe, in this chap, that wire that goes from the amygdala to the limbic system, the emotional core of the brain, is cut by the accident.

Data obtained from animal experiments show that harmful physiological changes result from the inability of the brain and body to respond to repeated stress with adaptive modifications in structure and function. Three brain areas the hippocampus, the prefrontal cortex, and the amygdala are particularly susceptible to pathological changes in size and function.

A hyperactive amygdala, along with abnormal activity in other regions of the brain, leads to disrupted patterns of sleep and physical activity, as well as irregular patterns of secretion of hormones and other chemical mediators that control many of the body's structures. For example, levels of the stress hormone cortisol increase in the evening, when they are normally low.

Similarly, there is evidence that the prefrontal cortex a key structure in emotional regulation as well as in decision making and working memory shrinks in major depression. On the other hand, rather than atrophying, the amygdala, the seat of emotional memories, becomes hyperactive both in post traumatic stress disorder and depressive illness, and there is evidence from animal studies of a hypertrophy of nerve cells after repeated stress.