Adolescent but not adult ethanol binge drinking modulates ethanol behavioral effects in mice later in life

Alcohol use disorder is a serious illness marked by uncontrollable drinking and a negative withdrawal state when not using. Alcohol is one of the most commonly used drugs among adolescent populations. Given that adolescence is a unique developmental stage during which alcohol has long-term effects on future drug-taking behavior; it is essential to understand how early exposure to ethanol during adolescence may affect the abuse liability of the drug later in life. Our studies focused on characterizing how exposure to alcohol in adolescence alters later adult alcohol dependence behaviors, by using well-established mouse models of ethanol drinking. We hypothesized that early exposure to ethanol leads to increased ethanol intake in adults and other behavioral phenotypes that may lead to dependence.

We investigated the impact of ethanol drinking in early adolescent C57BL/6J mice using a modified Drinking in the Dark (DID) model.

Our results showed that exposure to ethanol during adolescence enhanced ethanol intake in adulthood in the DID, and the 2-bottle choice drinking paradigms. In contrast, adult exposure of alcohol did not enhance later alcohol intake. We also conducted tests for ethanol behavioral sensitivity such as loss of righting reflex and anxiety-related behaviors to further elucidate the relationship between adolescent ethanol exposure and enhanced ethanol intake in adult mice.

Overall, our results suggest that adolescence is a critical period of sensitivity and binge drinking that can lead to lasting changes in ethanol intake in adulthood. Further research will be required in order to more fully examine the neurochemical mechanisms underlying the lasting changes in adulthood.