Effects of adolescent ethanol exposure on adult nondrug reward seeking behavior in male and female mice.

Abstract

Adolescent alcohol use is associated with an increased likelihood of developing an alcohol use disorder in adulthood, potentially due to the effects of alcohol exposure on reward-seeking behavior. However, it remains unclear whether adolescent drinking is sufficient to alter nondrug reward seeking in adulthood. As adolescence is a period of both brain and sexual maturation, which occur in a sex-dependent manner, males and females may be differentially sensitive to the consequences of adolescent alcohol exposure. The present study investigated whether adolescent ethanol exposure affected food reward taking and seeking in male and female adult mice. Male and female C57BL/6J mice underwent intermittent ethanol exposure (AIE) via vapor inhalation during early adolescence (28-42 days of age). At 10 weeks of age, the mice were trained in a conditioned place preference paradigm (CPP) for a food reward. We measured food consumption, CPP, and cFos expression in multiple brain regions following CPP testing. Data were analyzed using repeated measures analysis of variance with exposure (air vs. AIE), sex, and time as factors. AIE exposure increased food consumption during CPP training in adult male mice, but reduced pellet consumption in adult female mice. AIE exposure impaired CPP expression only in female mice. Despite these behavioral differences, exposure to the reward-paired chamber did not induce differential cFos expression following CPP testing in the prelimbic and infralimbic cortices or the nucleus accumbens core and shell. These findings indicate that adolescent ethanol exposure disrupted nondrug reward taking and seeking in adulthood in female mice and altered consumption in adult male mice.