Gene Changes Associated with Motivation to Drink Alcohol
Research Society on AlcoholismEpigenetics refers to external changes to DNA that turn genes “on” or “off.” These modifications do not change the sequence of the “letters” in DNA, but are physical changes that affect how cells "read" genes. Researchers hypothesized that alcohol’s effect on one kind of epigenetic change - called DNA methylation - on certain genes is associated with the motivation to drink alcohol in binge and heavy drinkers. Methylation is a change in the DNA that reduces gene expression. They measured changes in the methylation of two genes that have been implicated in the control of drinking behavior or the response to stress: the period 2 (PER2) and proopiomelanocortin (POMC) genes. Methylation changes were measured in blood samples drawn from groups of non-smokers who were moderate drinkers, binge drinkers, or heavy drinkers. These drinkers also participated in a laboratory study that measured behavioral alcohol motivation. During the three-day experiment, the participants experienced str