Chronic Stress Can Damage Your Brain

by Nina 

Opening Peas by Melina Meza

"Stress can damage the brain. The hormones it releases can change the way nerves fire, and send circuits into a dangerous feedback loop, leaving us vulnerable to anxiety, depression and post-traumatic stress disorder.” — Geoffrey Mohan, LA Times

One of my new areas of interest is brain health. Yes, not too surprisingly, I’d like to keep my brain—along with my body—healthy as I age (as I’m sure you all do, too). And one thing I’ve been noticing lately in my research is that chronic stress is as bad for the brain as it is for the body. In a way, that makes sense because really your brain is just another organ in your body, and we all know that chronic stress takes a toll on other organs, such as your heart and your digestive system. But I was fascinated to read recently in Stress matters to brain's white matter that neuroscientists at the University of California found evidence that one of our stress hormones, cortisol, actually causes the brain's stem cells to produce white matter that can change the way the brain's circuits are connected!

In a study published in Nature, Stress and glucocorticoids promote oligodendrogenesis in the adult hippocampus, researchers studied stem cells in the hippocampus. (The hippocampus is a very important part of that brain because it responsible for long-term memory and spatial navigation.)  Normally, the stems cells in the hippocampus produce new neurons or glia. But when the researchers examined the brains of mice that were chronically stressed out (yes, they’re stressing out those poor mice again), they discovered that the stress hormone corticosterone (the rodent equivalent of human cortisol) caused the stem cells produce an "abundance of oligodendrocytes." The LA Times quoted Daniela Kaufer, lead investigator of the study:

“Usually the brain doesn’t make much oligodendrocytes in adulthood from those neural stem cells. But under stress, all of a sudden, you discover they are making those cells.” 

Dr. Kaufer said that moderate stress, such as that caused by studying for an exam or competing in the Olympics, can build a more resilient brain with stronger circuitry, but that acute, prolonged stress can "wreak havoc."

So scientists are now actually finding specific evidence of how chronic stress can actually damage brain. We’d all like to avoid that, I’m sure. Of course, chronic stress can also cause high blood pressure, which leads to strokes, also damaging—sometimes very seriously—the brain. In fact, my father suffered in the later part of his life from stroke-related dementia, so I’ve seen it up close.

If you haven’t already incorporated some yoga stress management techniques into your daily life, take a look at one of my early posts The Relaxation Response and Yoga, which gives an overview of the many options that yoga provides. There are so many choices you’re sure to find something you enjoy and that you can practice on a regular basis.

P.S. After my post on Of Mice and Men, are you wondering how the scientists stressed out their test subjects? According to the LA Times, the researchers stressed out the mice by either immobilizing them in a straitjacket for three hours a day, seven days a week, or injecting them with corticosterone. Tiny straightjackets for mice? I’m not so sure what I think of that.

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