Washington, DC -- Stimulating a region of the brain known to be involved in reward decreases binge eating behavior in mice, according to a study published in the April 24 issue of The Journal of Neuroscience. The findings add to a growing body of evidence supporting the role of the brain's reward system in driving the consumption of palatable food. It could one day pave the way for more effective and lasting treatments for obesity.
The numbers of people worldwide living with obesity continues to climb. Recent studies suggest that the consumption of high calorie foods activates regions of the brain associated with reward. As a result, scientists are increasingly interested in understanding how changes taking place in the brain may be responsible for driving individuals to consume more calories than needed.
In the current study, Tracy Bale, PhD, and colleagues at the University of Pennsylvania set out to see if activating the nucleus accumbens -- a region of the brain involved in the promotion of motivational behaviors -- would alter binge-eating behavior in mice. The researchers used a technique called deep-brain stimulation (DBS) to directly deliver electrical impulses to the nucleus accumbens of mice that regularly binged on their food (ate 25 percent of their daily caloric intake within one hour). While mice that did not receive DBS showed little change in their eating habits, DBS significantly lessened the others' interest in binging on high fat food.
"Little is currently known about the neurobiological mechanisms of binge eating, and there are few effective treatments," explained Paul Kenny, PhD, who studies addiction at the Scripps Research Institute and was not involved in this particular study. "This study provides insights into the mechanisms that play a role in binge eating," he added.
Bale's group also tested the long-term effects of DBS on obese mice that were given unlimited access to high-fat food. After four days of continuous DBS, the obese mice consumed fewer calories and their body weight dropped.
"Overall, these studies indicate that activity in the reward centers of the brain may be a critical component driving individuals to overeat despite known negative health consequences," Bale said. "These results are very exciting as they provide our best evidence yet that we might be able to modify specific behaviors linked with body weight changes and obesity," she added.
Future clinical trials will need to explore the effectiveness of DBS in reducing obesity in people before researchers know whether or not DBS presents a viable treatment option for the millions worldwide living with obesity. However, as noted by lead study author Casey Halpern, MD, a neurosurgeon at the University of Pennsylvania, DBS targeting other areas of the brain is currently used to treat Parkinson's disease, and is being tested in clinical trials for the treatment of depression, obsessive-compulsive disorder, and addiction.
"Once replicated in human clinical trials, DBS could rapidly become a treatment for people with obesity due to the extensive groundwork already established in other disease areas," Halpern said.
The research was supported by the National Institute on Drug Abuse and the National Heart, Lung, and Blood Institute.
The Journal of Neuroscience is published by the Society for Neuroscience, an organization of nearly 42,000 basic scientists and clinicians who study the brain and nervous system. Bale can be reached at firstname.lastname@example.org. More information on obesity, addiction, and the brain can be found on BrainFacts.org.