Daily Aerobic Exercise Changes Brain’s Dopamine Pathways

New research makes clearer how aerobic exercise could affect the brain in ways that may support treatment — and potentially even prevention strategies — for addiction.

Also known as “cardio,” aerobic exercise is brisk exercise that increases heart rate, breathing, and circulation of oxygen through the blood, and is linked to a decrease in a variety of health problems, including diabetes, dementia, and arthritis. It also is linked to mental health benefits, such as reducing stress, anxiety, and depression.

“Several studies have shown that, in addition to these benefits, aerobic exercise has been effective in preventing the start, increase, and relapse of substance use in a number of categories, including alcohol, nicotine, stimulants, and opioids. Our work seeks to help identify the underlying neurobiological mechanisms driving these changes,”

senior author Panayotis (Peter) Thanos, senior research scientist at the Research Institute on Addictions at the University at Buffalo, said.

Normalizing Dopamine Signaling

The researchers found that daily aerobic exercise altered the mesolimbic dopamine pathway in the brains of animal models. Rats who exercised had 18% and 21% lower dopamine binding levels compared to sedentary rats in the olfactory tubercle and nucleus accumbens shell, respectively.

Dopamine is a key neurotransmitter associated with substance use disorders, playing an important role in reward, motivation, and learning.

“Current work is looking at whether exercise can normalize dopamine signaling that has been changed by chronic drug use, as this may provide key support of how exercise could serve as a treatment strategy for substance abuse. Further studies that focus on people with substance use disorders should help researchers develop new methods to integrate exercise into treatment regimens that may help prevent relapses,”

Thanos said.

The mesolimbic pathway is a dopaminergic pathway in the brain. The pathway connects the ventral tegmental area, which is located in the midbrain, to the nucleus accumbens and olfactory tubercle, which are located in the ventral striatum.

Release of dopamine from the mesolimbic pathway into the nucleus accumbens regulates motivation and desire for rewarding stimuli, and facilitates reinforcement and reward-related motor function learning; it may also play a role in the subjective perception of pleasure.

Dysregulation of the mesolimbic pathway and its output neurons in the nucleus accumbens plays a significant role in the development and maintenance of an addiction.

Lisa S. Robison; Sabrina Swenson; John Hamilton; Panayotis K. Thanos
Exercise Reduces Dopamine D1R and Increases D2R in Rats: Implications for Addiction
Medicine & Science in Sports & Exercise APR 2018 DOI: 10.1249/MSS.0000000000001627