Is A Little Stress A Good Thing For The Brain?
If you’re basically a low-stress type, but your life is punctuated by short-lived stressors (a.k.a. acute stress), new research suggests that your brain may be the better for it. It seems that acute stress may actually be healthy, since it helps boost the production of new neurons. In particular, neurons may arise in the hippocampus – a part of the brain responsible for memory, and one that is highly sensitive to the effects of stress, both acute and chronic. Previous research has pointed at the benefits of “good stress,” but the new study outlines an actual mechanism for the chain of events that trigger the birth of baby neurons.
Chronic stress, of course, has been shown over and over to be a bad thing for body and brain. It actually seems to suppress the generation of new nerve cells and inhibit memory, not to mention increase one’s risk for being overweight; developing heart disease and possibly cancer; developing addictions; and experiencing depression, anxiety, and sleep problems.
But the UC Berkeley researchers wanted to look into the effects of acute stress on the brain and behavior of mice, since there’s existing evidence for its benefits. So they subjected the mice to acute stressors (foot shocks, a novel environment, or being immobilized for a period of time), and then looked at their levels of stress hormones and their memory, days to weeks later. Ultimately, they “sacrificed” the mice to see what was going on in their brains.
The mice who’d been subjected to stressors had higher levels of coriticosterone (a stress hormone not unlike humans’ cortisol) than non-stressed controls. But they also had better memories – not two days, but two weeks later. This lag may be because after a stressor it takes a little time for the brain to respond and to encourage the growth of new neurons. “In terms of survival, the nerve cell proliferation doesn’t help you immediately after the stress, because it takes time for the cells to become mature, functioning neurons,” lead author Daniela Kaufer said in a statement.
She adds that stress is not always the culprit we’re often led to believe it is. “You always think about stress as a really bad thing, but it’s not,” added Kaufer. “Some amounts of stress are good to push you just to the level of optimal alertness, behavioral and cognitive performance.” Interestingly, the increase in new nerve cells seems to be mediated by a growth factor called fibroblast growth factor 2 (FGF2), the dearth of which has been linked to depressive symptoms in animals and humans.
The authors point out that other activities and experiences that encourage the growth of new neurons are exercise and sexual activity.
“I think the ultimate message is an optimistic one,” she concluded. “Stress can be something that makes you better, but it is a question of how much, how long and how you interpret or perceive it.” There seems to be a sweet spot, since extreme acute stress can easily lead to post-traumatic stress syndrome (PTSD), and prolonged stress can become chronic.
Of course, it may not be so common to experience stress only periodically – it seems that these days, more people are chronically stressed than not, and the effect of acute stress on top of chronic stress is probably not so well understood. In the meantime, try to de-stress as best you can, and ‘progenate’ some new neurons with all the tools at your disposal – exercise, meditation, and maybe even a little sex.
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