Operant Social Reward Decreases Incubation of Heroin Craving in Male and Female Rats

Abstract

BackgroundWe recently reported that operant social choice–induced voluntary abstinence prevents incubation of methamphetamine craving. Here, we determined whether social choice–induced voluntary abstinence would prevent incubation of heroin craving. We also introduce a fully automatic social reward self-administration model that eliminates the intense workload and rat–human interaction of the original semiautomatic model. MethodsIn experiment 1, we trained male and female rats for social self-administration (6 days) and then for heroin self-administration (12 days). Next, we assessed relapse to heroin seeking after 1 and 15 abstinence days. Between tests, the rats underwent either forced or social choice–induced abstinence. In experiment 2, we developed a fully automatic social self-administration procedure by introducing a screen between the self-administration chamber and the social-peer chamber; the screen allows physical contact but prevents rats from crossing chambers. Next, we compared incubation of craving in rats with a history of standard (no-screen) or automatic (screen) social self-administration and social choice–induced abstinence. ResultsThe time-dependent increase in heroin seeking after cessation of drug self-administration (incubation of craving) was lower after social choice–induced abstinence than after forced abstinence. There were no differences in social self-administration, social choice–induced abstinence, and incubation of craving in rats trained in the standard semiautomatic procedure versus the novel fully automatic procedure. ConclusionsOur study demonstrates the protective effect of rewarding social interaction on heroin self-administration and incubation of heroin craving and introduces a fully automatic social self-administration and choice procedure to investigate the role of volitional social interaction in drug addiction and other psychiatric disorders.