A new study led by the NYU Grossman School of Medicine has found that running increases the levels of a chemical involved in brain cell growth – the so-called “brain-derived neurotrophic factor” (BDNF) – that triggers the release of dopamine, a hormone which plays a crucial role in motivation, movement, and learning.
Scientists have long known that regular running raises dopamine activity in the brain, and could protect nerve cells from damage. Moreover, previous research has found correlations between exercise-driven boosts of BDNF and dopamine levels and significant improvements in learning and memory. However, the precise ways in which these factors interact has remained a mystery.
In the new study, researchers provided dozens of male mice with unlimited access to either a freely rotating wheel or a locked, immobile wheel.
After a month, they measured BDNF and dopamine levels in the mice’s brains, and found that running on a wheel for 30 days led to a 40 percent increase in dopamine release in the dorsal striatum – a part of the brain involved in movement – and a nearly 60 percent increase in BDNF levels, compared to their non-running counterparts.
The dopamine levels remained high even after a week of rest. However, when BDNF levels were artificially reduced, running did not result in additional dopamine release.
“Our findings suggest that BDNF plays a key role in the long-lasting changes that occur in the brain as a result of running,” said study lead author Guendalina Bastioli, a postdoctoral fellow in Neurobiology at NYU Langone Health. “Not only do these results help explain why exercise makes you move, think, and feel better, they also show that these benefits continue even if you do not work out every day.”
Since patients with Parkinson’s disease and other movement disorders are often treated with drugs mimicking the effect of dopamine on motor neurons, the results of this study could open paths for non-pharmaceutical treatment of such disease.
“Our results help us understand why exercise alleviates the symptoms of Parkinson’s disease, as well as those of neuropsychiatric disorders such as depression,” said study senior author Margaret Rice. “Now that we know why physical activity helps, we can explore it as a means of augmenting or even replacing the use of dopamine-enhancing drugs in these patients.”
Further research is needed to investigate whether these findings could be easily translated from rodents to humans, and to fully understand the role of BDNF and dopamine in movement disorders.
The study is published in the journal JNeurosci.