Athens, Ga. - A team of researchers at the University of Georgia and Emory University will receive $1.9 million over the next five years from the National Institutes of Health to study the neurobiological mechanisms for 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, professor of psychology in the Franklin College of Arts and Sciences 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," said Holmes, "which turns on dopamine, which induces craving. 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."
"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, UGA College of Veterinary Medicine, and Mark Smith, associate professor of psychology, Davidson College, Davidson, N.C., also will assist in the investigation.
The research may also lead to the development of drugs that enhance galanin for the treatment of addiction.
"Of course, the better alternative would be to naturally increase one's galanin levels through exercise," said Holmes, "but either way may help recovering addicts in stressful environments."