Impact of Adolescent Social Isolation on Adult, Binge-Like Ethanol Consumption and Plasma Corticosterone in High-Alcohol-Preferring Mice

Abstract

Adolescent stress exposure increases the likelihood of alcohol misuse and alcohol use disorder (AUD) in adulthood; however, it is not clear how genetic and environmental factors interact to increase risk. This study examined how adolescent social isolation affects adult binge-like ethanol drinking and levels of the stress hormone corticosterone in male and female mice with a genetic predisposition toward high alcohol preference (HAP). Twenty-eight HAP mice were separated into group-housed (GH) and socially isolated (SI) conditions (n = 13, 13). Binge drinking was assessed using a drinking in the dark (DID) procedure. Blood samples were taken before DID and after the 4th (last) day of DID. Overall, adolescent social isolation increased adult binge drinking in a sex-and time-dependent manner. Analysis of Hour 1 intake across the 4 days indicated that SI males drank significantly more than GH males, and this was not the case in females. There was no significant effect of housing for Hour 2. On Day 4, after 2 hours of consumption, social isolation increased drinking regardless of sex. Plasma corticosterone (CORT) levels decreased following drinking, but there were no sex or housing group differences. There were correlations between CORT levels and drinking, but only for SI females. These findings demonstrate that adolescent social isolation promotes binge-like drinking in both male and female adult mice with a genetic predisposition for high alcohol preference; however, this relationship is time-dependent, and males may be more sensitive than females to social isolation stress. Additionally, corticosterone levels change with regard to binge-drinking and sex.