clipped from: www.reuters.com Studies have found that exercise can help ease depression symptoms, but the reasons for the benefit have not been clear. For the new study, scientists used a tool called a microarray to examine how exercise changed gene activity in the brains of mice.
The researchers found that mice that had a week's worth of workouts on a running wheel showed altered activity in a total of 33 genes, the majority of which had never been identified before.
In particular, exercise enhanced activity in the gene for a nerve growth factor known as VGF. Nerve growth factors are small proteins important in the development and maintenance of nerve cells.
Moreover, when the researchers infused a synthetic version of VGF into the brains of the mice, it produced a "robust antidepressant effect" in standardized tests of animals placed in stressful situations.