Study looks at your brain on exercise

Vigorous exercise boosts two brain chemicals that help people ward off severe depression, according to a new imaging study by scientists at the University of California, Davis Health System.

It has long been noted that exercise can boost mental acuity and mood. But the underlying biochemical mechanism has remained a mystery.

Researchers say the discovery could lead to new therapeutic insights, improving our understanding of brain metabolism and the chemicals that regulate emotional health.

The research suggests a role for exercise in boosting the mood of those with major depressive disorder. The study is published in the latest issue of the Journal of Neuroscience.

The UC Davis scientists studied 38 volunteers, asking them to pedal on a stationary bicycle. The volunteers exercised strenuously for eight to 20 minutes.

A brain scan revealed increased levels of two critical neurotransmitters – glutamate and gamma-aminobutyric acid, or GABA – in the exercisers. The neurotransmitters were not elevated in a control group that did not exercise.

The most significant increases were found in the anterior cingulate cortex, which regulates some cognitive functions and emotion.

“Major depressive disorder is often characterized by depleted glutamate and GABA … ,” said lead author Richard Maddock, professor in the Department of Psychiatry and Behavioral Sciences, in a statement. “Our study shows that exercise activates the metabolic pathway that replenishes these neurotransmitters.

“Not every depressed person who exercises will improve, but many will,” Maddock said. ”It’s possible that we can help identify the patients who would most benefit from an exercise prescription.”

The research hints at a deleterious effect of a sedentary lifestyle, he added.