Pictured: graduate student Matthew Sacheli with a research participant. Image credit: Don Erhardt/UBC Faculty of Medicine.

Exercise increases dopamine release and synaptic plasticity, changing the way the brain is wired in people with Parkinson’s disease (PD) and potentially slowing the degenerative effects of the disorder, according to a new study published recently in the journal Movement Disorders. The study, led by Dr. Jon Stoessl, professor and head of the Division of Neurology and Director of the Djavad Mowafaghian Centre for Brain Health, showed changes in motor pathways and activation of reward circuitry as a result of aerobic exercise.

The study, which looked at the mechanism by which exercise benefits the brain, is among the first to show how the brain changes as a result of exercise, providing a new path to understanding the mechanisms of neuroplasticity and the brain’s ability to rewire itself even after being altered by neurodegenerative conditions.

“Most research on exercise in PD has looked at the potential benefits of physical activity on brain health,” said Dr. Stoessl. “This is among the first studies to demonstrate how it actually works in humans.”

Dopamine is a neurotransmitter involved in bodily movement and coordination. It is also plays an important role in decision-making, affecting the brain’s responsiveness to risk and reward.

Parkinson’s disease symptoms are associated with the progressive loss of dopamine-producing nerve cells. Over time, these cells effectively become out of tune, and eventually they stop working altogether. Loss of dopamine contributes to a loss of movement ability and altered reward signaling, both symptoms of PD. Additional symptoms of PD include stiffness, tremor, and behavioural and cognitive symptoms.

Physical activity has been shown to stimulate the release of dopamine in the brain. In this study, Dr. Stoessl and colleagues demonstrated that aerobic exercise altered the responsivity of the ventral striatum, a part of the brain that is integral to decision-making and reward-seeking behavior. This increased responsivity was associated with increased dopamine release in the caudate nucleus, the part of the brain associated with motor processes and inhibitory control.

The team’s findings suggest that aerobic exercise may have therapeutic benefits for people with Parkinson’s disease, including improvements in motor function and mood when used in conjunction with drug treatment.

“With this new understanding of these mechanisms we can now improve the design of exercise programs to maximize the therapeutic benefits of aerobic activity for people with Parkinson’s disease,” said first author of the paper and PhD candidate Matt Sacheli.

“It’s still early,” said Dr. Stoessl, “and we have more to uncover, but our research suggests there is the possibility that long-term exercise may help the brain build the capacity to ‘rewire’ itself, leading to improvements in motor function and mood over time.”