Treatment with low doses of nicotine but not alcohol affects social play reward in rats

Social play behaviour is a vigorous, highly rewarding activity inyoung animals. It is thought to facilitate social, cognitive andemotional development, but its underlying neural mechanisms areincompletely understood. Previously, we found that low doses ofalcohol and nicotine enhanced social play behaviour in youngrats. Using place and operant conditioning setups to assess thepleasurable and motivational aspects of social play, weinvestigated how treatment with nicotine and alcohol affectssocial play reward. Nicotine-treatment increased the incentivemotivational properties of social play as well as the expression ofsocial play itself. Moreover, while nicotine by itself evokedconditioned place preference (CPP), it reduced social play-inducedCPP. Alcohol-treatment did not affect the motivation for andexpression of social play, nor did it affect social play-induced CPP.Thefinding that nicotine but not alcohol modulates social playreward increases our understanding of the neural underpinningsof this developmentally important behaviour.