A team of researchers at UGA and Emory University will receive $1.9 million over the next five years from the National Institutes of Health to study the neurobiological mechanisms that determine how regular aerobic exercise may prevent drug abuse relapse.
“Drug abuse is closely linked to stress, and one of the most challenging aspects of treating addiction is preventing the relapse caused by stress,” said Philip Holmes, UGA professor of psychology and a co-investigator on the project. “Despite many years of research, no universal treatment to prevent relapse exists.”
Previous research in Holmes’ lab has demonstrated that exercise exerts anti-stress effects. A chemical called galanin, which increases in the brain during exercise, appears to reduce cravings associated with stress.
“Stress turns on norepinephrine, which turns on dopamine, which induces craving,” said Holmes. “Galanin decreases norepinephrine, so someone with high levels of galanin should experience reduced cravings.”
For the project, Holmes will measure exercise-induced increases of the galanin gene activity in the rat brain.
“These experiments will establish the relationship between exercise and galanin gene expression and support the hypothesis that exercise-induced regulation of galanin protects against over-activation of the norepinephrine system, thereby preventing drug self-administration following stress,” he said.
“This research will provide new insight into how regular exercise may attenuate drug abuse in humans,” said David Weinshenker, associate professor of human genetics in Emory University’s School of Medicine and a co-principal investigator on the project. “More importantly, it may reveal a neural mechanism through which exercise may prevent the relapse into drug-seeking behavior.”
Dr. Gaylen Edwards, professor and head of the department of physiology and pharmacology in UGA’s College of Veterinary Medicine, and Mark Smith, associate professor of psychology at Davidson College in North Carolina, also will assist in the investigation.
The research also may lead to the development of drugs that enhance galanin for the treatment of addiction.
“Of course, the better alternative would be to naturally increase galanin levels through exercise,” said Holmes, “but either way may help recovering addicts in stressful environments.”