In this study, we investigated behavioral factors underlying conditioned place preference (CPP) induced by social interaction in adolescent rats. We found that the magnitude of socially-induced CPP depended on the social motivation of the animals and on the amount of training. After extinction, socially-induced CPP could be reinstated by a single reconditioning session. Treatment with methylphenidate, which disrupts social play behavior in adolescent rats, but not social exploratory behavior, prevented the development of socially-induced CPP. Interestingly, methylphenidate by itself induced CPP. These data demonstrate that: 1. social interaction is rewarding in adolescent rats; 2. appetitive and mnemonic factors influence the development of socially-induced CPP; 3. comparable to drug-induced CPP, socially-induced CPP can be extinguished and reinstated; 4. social play is likely to be the most rewarding aspect of social interaction in adolescent rats; 5. social context influences the subjective effects of methylphenidate.
