Scientists Link Brain Protein to Binge-drinking Behavior

In findings published in the journal Proceedings of the National Academy of Sciences, scientists from The Scripps Research Institute (TSRI) discovered that a specific brain protein has a key role in controlling binge drinking in animal models. During the study, they found that deleting the gene for the associated protein in mice ramped up alcohol consumption and prevented the brain from signaling the rewarding properties of alcohol. The goal of the study was to identify the role of a member of the “G protein-gated inwardly rectifying potassium channel” family or, GIRK, in the behavioral and cellular responses to alcohol. GIRK channels are distributed throughout the nervous system, where they decrease the excitability of neurons, making them less likely to fire. Previous studies in isolated cells revealed that alcohol can directly activate GIRK channels; however, scientists did not know whether this action mattered for the behavioral effects of alcohol. In the current study, scientists decided to focus on GIRK3, which has previously been shown to modulate the effects of other drugs. To do so, they compared “knockout” mice missing GIRK3 with normal mice. The researchers found that GIRK3 knockout mice consumed much more alcohol than the control group. This effect was not observed when mice were given continuous access to alcohol, conditions under which mice do not get intoxicated. This result pointed to a role for GIRK3 specifically in binge drinking, leading scientists to consider two possibilities. “Mice lacking GIRK3 could be drinking more because they feel more pleasure from alcohol and are therefore more motivated to drink — or they could be drinking more because they feel less pleasure and therefore need to drink more to reach the same level of pleasure as normal mice,” said the lead author.  To read more about this study, click here.