Michael Michaelides, Panayotis K. Thanos, Nora D. Volkow, and Gene-Jack Wang
Michael Michaelides, PhD, is a postdoctoral fellow in the Pharmacology and Systems Therapeutics Department at Mount Sinai School of Medicine (MSSM) in New York, New York, and research associate in the Medical Department at Brookhaven National Laboratory (BNL) in Upton, New York. Panayotis K. Thanos, PhD, is a scientist in the Medical Department at BNL. Nora D. Volkow, MD, is Director of the National Institute on Drug Abuse at the National Institutes of Health in Bethesda, Maryland. Gene-Jack Wang, MD, is a senior scientist in the BNL Medical Department and
Professor of Psychiatry at MSSM. Address correspondence and reprint requests to Dr. Gene-Jack Wang, Senior Scientist, Medical Department, Brookhaven National Laboratory, 30 Bell Avenue, Upton, NY 11973 or email gjwang@bnl.gov.
Abstract
The use of translational noninvasive neuroimaging has revealed that drug addiction and obesity share striking similarities in functional impairment in discrete brain regions and neurotransmitter circuits. Imaging experiments in both humans and rodents (using complementary experimental designs) show similar abnormalities in brain glucose metabolism in the prefrontal cortex (involved in inhibitory control) and hippocampus (memory) as well as impairments in dopamine signaling in the striatum (involved in food and drug reward, goal orientation, motivation, and habit formation). In both species, many of these observations have been obtained through concurrent and parallel monitoring of both brain activity and behavioral manifestations during drug administration, food sensory (visual, olfactory) stimulation, and craving. This review aims to show that noninvasive brain imaging strategies such as small animal positron emission tomography offer signifi cant potential and promise for modeling motivational disorders such as drug addiction and obesity in humans. Rodent addiction models will prove valuable for understanding brain responses to drug cues and will help guide treatment, especially in relapse situations triggered by exposure to conditioned drug cues.