The Physiological Mechanism for How Stress Affects the Brain


For those readers curious about the mechanisms by which emotional stress affects brain function, I found an interesting piece of research about the physical mechanisms for how chronic stress can induce brain changes that could lead to cognitive impairment.

Scientists at Salk Institute for Biological Studies subjected mice to mild chronic stress for two weeks. What they found was fascinating. First some background on the physiology of Alzheimer’s disease. As the article explains:

“Alzheimer’s disease is defined by the accumulation of amyloid plaques and neurofibrillary tangles. While plaques accumulate outside of brain cells, tangles litter the inside of neurons. They consist of a modified form of the tau protein, which–in its unmodified form–helps to stabilize the intracellular network of microtubules. In Alzheimer’s disease, as well as various other neurodegenerative conditions, phosphate groups are attached to tau. As a result, tau looses its grip on the microtubules, and starts to collapse into insoluble protein fibers, which ultimately cause cell death.”

So basically, when phosphate attaches the the tau molecules, it causes them to change from helpful molecules to damaging the neurons.

The mice research found that the brain-damaging effects of negative emotions are relayed through the two known corticotropin-releasing factor receptors, CRFR1 and CRFR2, which are part of the body’s central stress mediation system.

So what does this all mean? It suggests that we have to protect our brains from stress, particularly chronic stress. Occasional stress doesn’t cause problems, but daily chronic stress does. The mice only showed permanent brain changes after 2 weeks of daily stress.

So stress management through cognitive behavioral therapy (CBT) or other means is not just a nice comfort option, but may be essential if you want your brain to last. Emotional pain doesn’t just cause emotional damage, it also damages the brain.

Perhaps scientists will be able to develop drugs that change CRF1 and CRF2 levels, but in the meantime, better take up that yoga, meditation, relaxation exercise, or CBT stress management program!

Copyright 2007 The Psychology Lounge/TPL Productions

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