Exercise, particularly running, while under stress may help protect memory, according to a new mouse study conducted by researchers at Brigham Young University (BYU).
The findings, published in the journal of Neurobiology of Learning and Memory, suggest that running mitigates the negative impact that chronic stress has on the hippocampus, the region of the brain associated with learning and memory.
“Exercise is a simple and cost-effective way to eliminate the negative impacts on memory of chronic stress,” said study lead author Dr. Jeff Edwards, associate professor of physiology and developmental biology at BYU.
Memory formation and recall occur best when the synapses or connections between neurons are strengthened over time. This process of synaptic strengthening is known as long-term potentiation (LTP). Chronic or prolonged stress weakens the synapses, which reduces LTP and ultimately affects memory.
The new study finds, however, that when we exercise when we’re stressed, these LTP levels do not decrease, but instead remain normal.
For the study, Edwards conducted experiments with mice. One group of mice used running wheels over a four week period (averaging slightly over three miles per day) while another set of mice was left sedentary.
Half of the mice in each group was then exposed to stress-inducing situations, such as walking on an elevated platform or swimming in cold water. One hour after the stressful experience, researchers carried out electrophysiology experiments on the animals’ brains to measure their LTP levels.
The researchers discovered that stressed mice who had been exercising on the wheel had significantly greater LTP than the stressed mice who were not running. They also found that stressed mice who exercised performed just as well as non-stressed mice in a maze-running experiment designed to test their memory. In fact, the exercising mice made significantly fewer memory errors in the maze than the sedentary mice.
The findings show that exercise may be a practical method to protect learning and memory mechanisms from the negative cognitive effects of chronic stress on the brain.
“The ideal situation for improving learning and memory would be to experience no stress and to exercise,” Edwards said. “Of course, we can’t always control stress in our lives, but we can control how much we exercise. It’s empowering to know that we can combat the negative impacts of stress on our brains just by getting out and running.”
Source: Brigham Young University