The Effects of Ethanol Exposure during Adolescence on Ethanol-induced Conditioned Taste Avoidance in Adulthood
Although the adverse effects of alcohol have been the focus of many research studies over the last few decades, it is still not clear why certain individuals are more vulnerable to developing alcohol abuse problems than others. Current research suggests that initial alcohol exposure occurs during adolescence and an individual’s response during this critical developmental period may have a significant impact on future drinking behaviors. The goal of this project was to use an animal model to investigate the effects of adolescent alcohol exposure on responses to the aversive properties of alcohol in adulthood. A total of 34 female and 48 male rats were given alcohol (ethanol) or vehicle (saline) via intraperitoneal injections during 8 days of their approximately 15-day adolescent period. After they reached adulthood, rats were tested in a conditioned taste aversion paradigm where they were trained to associate ethanol’s aversive properties with the availability of a saccharin solution. We found evidence of ethanol-induced aversion in both males and females that were given saline during adolescence. However, ethanol exposure during adolescence significantly decreased ethanol-induced aversion in adult male rats while having no effect in adult female rats. Because alcohol’s aversive properties likely contribute to reducing alcohol consumption, individuals that have a reduced aversive response may be more likely to consume alcohol, and in turn, develop alcohol dependence. Thus, future studies should investigate the neurobiological basis of this reduced aversion response in males and also determine the role of sex hormones in the sex differences we observed.