Washington D.C, April 25: Manipulating a particular system -- stress signal -- found in a specific brain region, could act as a therapy to taper binge drinking, according to a recent study. The study to appear in the May issue of Neuropharmacology pinpoints that deactivating a stress-signalling system found in a specific brain region can help to reduce harmful binge drinking. The Medical University of South Carolina (MUSC) team was led by Howard C. Becker, Ph.D., director of the Charleston Alcohol Research Center and professor in the Department of Psychiatry & Behavioral Sciences.

"Binge drinking is one of the most common patterns in which alcohol is consumed," explained Becker."It's risky behaviour, and one consequence of repeated binge drinking is increasing the risk for developing an alcohol use disorder," Becker added. In their study, Becker, and Haun, a graduate student in the Becker laboratory and first author on the article tested a potential strategy for reducing risky binge drinking."Through our investigation, we found a brain region and a system that we can manipulate to decrease binge drinking," said Haun.

The system that Becker's team investigated - the opioid receptor system - is well-recognized in the addiction field. Notorious narcotic drugs of abuse, such as morphine, heroin and oxycontin/oxycodone act on the opioid-receptor system, producing the pleasurable effects that make these drugs so addictive. However, there is an odd opioid receptor out, so to speak, that is not involved in signalling pleasure."The kappa opioid receptor system is the antithesis to other opioid receptors," explained Haun. Instead of feelings of pleasure, the kappa opioid receptor produces stress and discontent.

When people drink and experience positive effects, that is partially due to pleasurable opioid receptors being activated. However, after they have finished drinking and nausea, headache, and the stress of withdrawal start to set in, the kappa opioid receptor system has been activated. Becker's team found that turning off the kappa opioid receptors in the brain decreased binge drinking. This finding suggests that the kappa opioid receptor system is important not only in the negative state of withdrawal but also in driving binge drinking itself. "It's not entirely clear why, but what we do know is that kappa opioid receptors play an important role in the negative emotional state that drives drinking when it becomes compulsive in alcohol use disorders," said Haun.

To begin testing their hypothesis, Becker and Haun first identified the exact region in the brain that is involved in binge drinking driven by kappa opioid receptors. To determine how kappa opioid receptors in the extended amygdala affect binge drinking, Becker's team specifically inactivated kappa opioid receptors in this region in mice. The results supported Becker and Haun's hypothesis that the kappa opioid receptor system in the extended amygdala promotes binge drinking. Hence, blocking kappa opioid receptors in the extended amygdala, therefore, could act as a therapy to taper binge drinking.