Jan. 26, 2007
UI And USC Scientists Identify Brain Region That Maintains Addiction
Scientists at the University of Southern California (USC) and the University of Iowa have identified a part of the brain that plays an important role in addiction. The researchers found that patients who experienced damage to a silver dollar-sized brain region called the insula were significantly more likely to lose their addiction to smoking than patients with lesions to other parts of the brain.
"We found that if this specific area of the brain is damaged, addiction to smoking gets wiped out," said Antoine Bechara, Ph.D. (photo, left), associate professor of psychology and neuroscience at USC and UI adjunct associate professor of neurology. "This is important because now we have identified a target for disrupting addiction, which gives us hope for developing new strategies to break the cycle of addiction."
The findings may point the way to pharmacological treatments for addiction that target the insula and also suggest that functional imaging of the insula may be a good way to monitor the success of addiction treatments. The findings are published in the Jan. 26 issue of the journal Science and in Science Express online Jan. 25. Nasir Naqvi (photo, right), an M.D./Ph.D. student in the UI Medical Scientist Training Program, is first author of the study.
The study involved 69 patients with brain damage all of whom had smoked more than five cigarettes per day for more than two years prior to their injury. Patients with insula damage were much more likely to have quit smoking easily and without relapse than patients with damage in other brain areas. In fact, in most cases, damage to the insula caused patients to completely lose the urge to smoke.
Comparing only patients who quit smoking after brain injury, the study found that 12 of 13 patients with insula damage lost their addiction compared to four of 19 patients with non-insula damage.
Bechara believes the insula likely plays a role in maintaining addiction of any kind. He also speculates that the finding may have implications for obesity treatments.
"It is possible that disrupting insula function might disrupt learned habits like overeating," he said.
The insula helps translate bodily sensations into conscious feelings and recent functional neuroimaging studies also suggest that the insula is important for conscious urges and cravings. The results of Bechara and Naqvi's study suggest that conscious urges may play an important role in maintaining addiction.
In addition to Bechara and Naqvi, the research team included David Rudrauf, Ph.D., UI postdoctoral research scholar in neurology, and Hanna Damasio, M.D., the Dana Dornsife Professor of Neuroscience, director of the Dana and David Dornsife Cognitive Neuroscience Imaging Center and professor of psychology, neuroscience and neurology at the University of Southern California. Damasio also is a distinguished adjunct professor at the UI.
The study was funded by the National Institute on Drug Abuse and the National Institute of Neurological Disorders and Stroke.
STORY SOURCE: University of Iowa Health Science Relations, 5135 Westlawn, Iowa City, Iowa 52242-1178
CONTACT: Jennifer Brown, 319-335-9917 email@example.com