How Exercise Makes the Brain Resilient to Stress and Anxiety

Sharon Moore July 05, 2013

Is your anxiety making you ill? If yes, you may want to schedule a daily workout. New research reveals that physical activity reorganises the brain to make it more resilient to stress. It also boosts the areas that prevent anxiety from interfering with other brain functions.

The impact of exercise on the brain, particularly on the hippocampus – the region that regulates anxiety, has not been deeply explored. Prevailing concepts suggest that exercise reduces anxiety but at the same time promote the growth of new neurons in the ventral hippocampus. But because young neurons are more active than their matured counterparts, exercise should basically induce anxiety, not reduce it.

The new study, conducted by scientists at Princeton University, provides a resolution to this discrepancy. It suggests that even though exercise promotes neuronal growth in the hippocampus, it also strengthens the mechanisms that prevent anxiety-inducing excitable neurons from firing.

Reduced stress and anxiety

The researchers found that mice allowed to exercise regularly developed stronger resilience to stress and anxiety. When they are exposed to a stressor, such as cold water, their brains exhibited a spike in neurons that inhibit neuronal firing in the hippocampus. On the other hand, the mice not allowed to exercise showed an immediate response to the same stressor, due to a spike in their inhibitory neurons that regulate the excitable neurons.

The study, which appears in the Journal of Neuroscience, also determined the key brain cells and regions that are involved in anxiety regulation. Elizabeth Gould, a professor of psychology at Princeton and the study senior author, said their findings may help scientists better understand and treat human anxiety disorders.

Researchers have also shown that the brain can be extremely adaptive to an organism’s lifestyle and surroundings, and that the less physically fit creatures are more likely to develop or adapt an anxious behaviour.

"Understanding how the brain regulates anxious behaviour gives us potential clues about helping people with anxiety disorders.” said Gould. “It also tells us something about how the brain modifies itself to respond optimally to its own environment”

Source of this article:

Physical Exercise Prevents Stress-Induced Activation of Granule Neurons and Enhances Local Inhibitory Mechanisms in the Dentate Gyrus