Boosting nerve growth protein helps explain why running supports brain health.
New research shows that exercise increases levels of a chemical that contributes to brain cell growth, which boosts the release of the “feel-good” hormone dopamine. Dopamine is a neurotransmitter known to play a key role in movement, motivation, and learning.
Experts have long known that regular running raises dopamine activity in the brain and may protect neurons from damage. Additionally, previous research has linked exercise-driven reinforcements in a dopamine-stimulating chemical called brain-derived neurotrophic factor (BDNF) and dopamine levels to improvements in learning and memory. However, the exact way in which these three factors interact has remained unclear until now.
The investigation, led by researchers at New York University’s Grossman School of Medicine, revealed that mice that ran at a wheel for 30 days had a 40% increase in dopamine release in the dorsal striatum, a part of the brain involved in movement, compared to levels in mice. not exercised. Additionally, the runners showed an approximately 60% increase in BDNF levels compared to their non-working counterparts. Notably, even after a week of rest, the increase in dopamine release remained elevated. Additionally, when BDNF levels were artificially reduced, running did not trigger the release of additional dopamine.
“Our findings suggest that BDNF plays a key role in the long-term changes that occur in the brain as a result of running,” says lead author of the study and neurobiologist Guendalina Bastioli, Ph.D. Adds Bastoli, a postdoctoral fellow in the Department of Neuroscience at NYU Langone Health.
While researchers have previously measured dopamine activity during running, the new investigation provides insight into the hormone’s long-term behavior and its effects on the brain after exercise has stopped, according to Estoli. The report was published online on May 16, 2022, at Neuroscience Journal.
In order to investigate, the researchers gave dozens of male mice unlimited access to a freely spinning wheel or a locked wheel that cannot move. One month later, the team measured dopamine release and BDNF levels in brain slices. They repeated this same process on a new group of rodents, some of which had been genetically modified to produce half as much BDNF as normal mice.
The study authors note that patients with Parkinson’s disease and other movement disorders are often treated with drugs that mimic dopamine’s effects on motor neurons. However, the mechanism underlying the role of dopamine in this protective benefit of exercise has not been thoroughly explored.
“Our findings help us understand why exercise relieves symptoms of Parkinson’s disease, as well as neuropsychiatric disorders such as depression,” said study senior author and neuroscientist Margaret Rice. “Now that we know why physical activity helps, we can explore it as a way to increase or even replace the use of dopamine-boosting drugs in these patients.”
Rice, a professor in the Departments of Neurosurgery, Neuroscience, and Physiology at NYU Langone, cautions that while initial results in rodents have been promising, future studies in humans will be required to fully understand the role of BDNF and dopamine in Parkinson’s disease.
She adds that the study team then plans to investigate the relationship between exercise and these chemicals in female mice, which work out more frequently than males. In addition, the researchers plan to conduct a direct examination of whether the active mice actually improved motor skills compared to those with limited physical activity.
Reference: “Voluntary exercise dangerously enhances dopamine release: evidence for the necessary and sufficient role of BDNF” by Gwendalina Bastioli, Jennifer C. Margaret Rice, May 16, 2022, Available here. J Neurosci.
DOI: 10.1523 / JNEUROSCI.2273-21.2022
In addition to Bastioli and Rice, other NYU study researchers involved in the study were Moses Chow, Ph.D. Jennifer Arnold, Ph.D.; Maria Mancini, Ph.D.; Adam Marr, Ph.D.; Begoña Gamallo-Lana, Ph.D.; and Khalil Saadipur Ph.D.
Funding for the study was provided by National Institute on Drug Abuse grant DA0510165. Further funding support has been provided by the Marilyn and Paolo Fresco Institute for Parkinson’s Disease and Movement Disorders.