Social interaction with an alcohol-intoxicated or cocaine-injected peer selectively alters social behaviors and drinking in adolescent male and female rats

Abstract

AbstractBackgroundDrinking alcohol is facilitated by social interactions with peers, especially during adolescence. The importance of peer social influences during adolescence on alcohol and substance use have recently received more attention. We have shown that social interaction with an alcohol-intoxicated peer influences adolescent alcohol drinking differently in male and female rats using the demonstrator-observer paradigm. The present set of experiments analyzed the social interaction session to determine behaviors that influence alcohol drinking in adolescent male and female rats.MethodsSpecifically, in experiment one we determined which behaviors were altered during social interaction with an alcohol-intoxicated demonstrator and assessed changes in ethanol intake in adolescent observers. Experiment two examined changes in voluntary saccharin consumption to determine if social interaction with an alcohol-intoxicated demonstrator altered consumption of a palatable solution. In experiment three, we administered a low (5 mg/kg) or high (20 mg/kg) dose of cocaine to the demonstrator and assessed changes in the adolescent observers to determine if social interaction with a ‘drugged’ peer altered social behaviors and voluntary ethanol intake.ResultsWe showed that social interaction with an alcohol-intoxicated demonstrator (1) decreased social play and increased social investigation and social contact in adolescent male and female observers, (2) did not alter non-social behaviors, (3) did not alter saccharin consumption and (4) increased voluntary ethanol intake in adolescent female but not male observers. When the peer was injected with cocaine (1) social play was dose-dependently decreased, (2) there were no changes in other social or non-social behaviors, and (3) voluntary ethanol intake in adolescent male and female observers was unaffected.ConclusionsThe present results are consistent and extend our previous work showing that social interaction with an alcohol-intoxicated peer selectively alters social behaviors and alcohol-drinking in adolescent rats. Females appear to be more sensitive to elevating effects of social interaction on voluntary ethanol consumption.