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

Abstract

Social play behaviour is a vigorous, highly rewarding activity in young animals. It is thought to facilitate social, cognitive and emotional development, but its underlying neural mechanisms are incompletely understood. Previously, we found that low doses of alcohol and nicotine enhanced social play behaviour in young rats. Using place and operant conditioning setups to assess the pleasurable and motivational aspects of social play, we investigated how treatment with nicotine and alcohol affects social play reward. Nicotine-treatment increased the incentive motivational properties of social play as well as the expression of social play itself. Moreover, while nicotine by itself evoked conditioned place preference (CPP), it reduced social play-induced CPP. Alcohol-treatment did not affect the motivation for and expression of social play, nor did it affect social play-induced CPP. The finding that nicotine but not alcohol modulates social play reward increases our understanding of the neural underpinnings of this developmentally important behaviour.