Neuropeptide Y (NPY) is a naturally-occurring brain molecule that helps regulate emotional behavior, stress responses, and other functions. Much research evidence suggests that NPY also plays an important role in regulating alcohol consumption. Scientists led by NIAAA Clinical Director Markus Heilig, M.D., Ph.D., recently investigated the effect of NPY on stress-induced relapse to alcohol use. Relapse prevention is an important aspect of alcoholism treatment, and researchers who study this phenomenon often rely on animal models of relapse-like behavior. Such models usually involve training laboratory rats to obtain alcohol by pressing a lever. Later, the lever-pressing behavior is "extinguished," or unlearned, by removing the alcohol reward. Researchers then simulate alcohol relapse by exposing the animals to stress, which causes them to again seek alcohol by lever-pressing. Stress in rats is reliably induced by injections of yohimbine, a drug that causes anxiety and panic. Using this approach, Dr. Heilig and colleagues from the NIAAA Laboratory of Clinical and Translational Studies found that by injecting rats with NPY, they could suppress the relapse-like alcohol-seeking behavior brought on by yohimbine. The findings, they note, support further study of NPY as a potential treatment for alcoholism.