Effects of Social-Interaction on Reward Sensitivity in Adolescent Mice

This study examined alterations in the rewarding properties of opioids due to social interaction. The first experiment explored the role of peer interactions on drug reward. Adolescent male mice were administered morphine for 6 days while socially housed with cage-mates receiving different pharmacological treatments (i.e., exposure to different social interaction with peers). Then, drug reward was examined, using the conditioned place preference (CPP) paradigm. It was shown that exposure to drug-naïve peers had a protective effect on drug-administered mice, reducing the amount of morphine CPP, and that exposing drug-naive to drug-administered mice had a harmful effect. The second experiment explored the possible role the oxytocin (OT) system plays in mediating the effects of social interaction on drug reward. This was accomplished by examining the effect of an OT antagonist on the acquisition of CPP in mice that are housed in different social environments. It appears that suppressed or under-functioning OT system correlates with increases in morphine CPP, and thus, the potential for morphine abuse. Ultimately, these studies sought to better elucidate the role that social interaction plays in the development of drug abuse, dependence, and addiction