The long-term health benefits of regular exercise for preventing heart disease, obesity and mood disorders are well established. However, until now, the underlying mechanisms linking exercise and depression remained elusive.

Depression affects around 121 million people worldwide. The social and economic consequences are profound. Although

MIF is highly expressed in immune cells and in the hippocampus, an area of the brain responsible for memory function. Image: 123rf.com

antidepressant drugs have been available for decades, their effectiveness varies in part because our understanding of the underlying neuronal mechanisms they affect is limited.

Studies have shown that certain genes in the brain are directly affected by exercise and may be responsible for antidepressant effects seen in people who take part in regular physical activity. To find out how exercise impacts these genes, a team led by Professor Pann-Gill Suh of Korea’s Ulsan National Institute of Science and Technology analysed previous studies and found that voluntary exercise and electroconvulsive seizures (one of the most effective treatments for depression symptoms) elevate levels of a protein – called macrophage migration inhibitory factor (MIF) – in the hippocampus, an area of the brain responsible for memory function.

Professor Suh and his colleagues wanted to find out the role of MIF in exercise-induced antidepressant therapy. To do so, they conducted behaviour tests using mutant mice that lack MIF. The results revealed that mice lacking this protein display depression-like behaviours and benefited less from exercise. In addition, the administration of recombinant MIF protein produced antidepressant-like behaviours in rats. Professor Suh suggests that MIF may mediate the antidepressant action of exercise, probably by increasing levels of serotonin (a chemical messenger involved in promoting feelings of well-being) and the formation of new brain cells.

 

 

For further information contact:

Professor Pann-Gill Suh
School of Life Sciences
Ulsan National Institute of Science and Technology (UNIST)
Republic of Korea
Email: pgsuh@unist.ac.kr