What Stress Does to the Brain

To someone who is not a neuroscientist, what does this do? Yes the regions are rewired, but aren't they rewired all the time anyway?

So they stimulated norepinephrine release in rats in an fMRI machine and they found it increased "activity" in sensory processing and the amygdala. Presumably it would increase "activity" in "higher" regions of the brain, except those only exist to a limited extent in rats.

For most humans, the question about stress is, "what is the effect of chronic stress?" which this paper did not answer. I'm sure it was still a good study, largely because it's demonstrating concrete mechanisms for things we think are happening anyway, but I can't confirm that because it's behind a paywall, like most publicly-funded research.

Am busy doing the Win Hof method. From what I understand, norepinephrine and particularly epinephrine release are desired goals of the cold exposure part his method as they suppress release of pro inflammatory cytokines.

From the intro of this article:

Activity in the amygdala and networks that process sensory stimuli increased.

The amygdala is a part of the brain that will dictate reactions to crisis before you can consciously process it. It's called "amygdala hijack" and is responsible for people doing things like leaping into a river to save a drowning child before they fully register the child consciously, so they find themselves in a river going "Why the hell am I here?" and then realize there's a child drowning in front of them.

This is potentially dangerous. Vietnam vets and others with PTSD sometimes strongly overreact to stimuli that aren't actually a signal of a problem. For example, waking a Vietnam vet can get you assaulted before they realize you aren't a danger to them, sort of like that scene where Wolverine skewers Rogue because she wakes him from a nightmare, though usually not that dramatic. (I have heard of people winding up in the ER though.)

https://en.m.wikipedia.org/wiki/Amygdala_hijack

From an article written for lay people

Chronic Stress Increases the Risk of Mental Illness

Stress Changes the Brain's Structure.

Stress Kills Brain Cells.

Stress Shrinks the Brain.

Etc.

https://www.verywellmind.com/surprising-ways-that-stress-aff...

Any links?