How Exercise Fights Depression Identified
Staying fit could protect people from depression, according to a new anxiety study.
Swedish studies show that physical activity stimulates changes in skeletal muscle that can help destroy toxins in the blood that harm the brain.
"In neurobiological terms, we actually still don't know what depression is. Our study represents another piece in the puzzle, since we provide an explanation for the protective biochemical changes induced by physical exercise that prevent the brain from being damaged during stress," researcher Mia Lindskog, from Department of Neuroscience at Karolinska Institutet, said in a news release.
In the study, researchers compared genetically modified mouse with high levels of PGC-1α1 to normal control mice. The rodents were exposed to stressful scenarios like loud noises, flashing lights and reversed circadian rhythm at irregular intervals. Researchers found that genetically modified mice developed no depressive symptoms. However, normal mice exposed to mild stress develop depressive behaviors.
"Our initial research hypothesis was that trained muscle would produce a substance with beneficial effects on the brain. We actually found the opposite: well-trained muscle produces an enzyme that purges the body of harmful substances. So in this context the muscle's function is reminiscent of that of the kidney or the liver," principal investigator Jorge Ruas, of the Department of Physiology and Pharmacology at Karolinska Institutet, said in a news release.
"It's possible that this work opens up a new pharmacological principle in the treatment of depression, where attempts could be made to influence skeletal muscle function instead of targeting the brain directly. Skeletal muscle appears to have a detoxification effect that, when activated, can protect the brain from insults and related mental illness," Ruas concluded.
The findings were published September 25 in the journal Cell.