Effects of acute social stress on the conditioned place preference induced by MDMA in adolescent and adult mice
Behavioural Pharmacology – September 01, 2014
Source: OpenAlex
Summary
Social defeat stress significantly reduces the rewarding effects of MDMA in adult male mice. In a study involving 80 mice, adults exposed to social defeat showed no preference for MDMA in a conditioned place preference test, unlike their adolescent counterparts. Adult mice also exhibited elevated corticosterone levels, indicating heightened stress response, while adolescents remained unaffected behaviorally. Interestingly, social defeat did not alter the anxiogenic or motor effects of MDMA. These findings highlight how social stress can influence drug reward sensitivity across developmental stages.
Abstract
Exposure to social defeat stress increases the rewarding effects of psychostimulants in animal models, but its effect on 3,4-methylenedioxymethylamphetamine (MDMA) reward has received little attention. In the present study, we evaluated the influence of social defeat on the rewarding effects of MDMA in adolescent [postnatal day (PND) 29-40] and adult (PND 50-61) male mice using the conditioned place preference paradigm. Experimental mice were exposed to social defeat in an agonistic encounter before each session of conditioning with 1.25 or 10 mg/kg of MDMA. The effects of social defeat on corticosterone levels and the motor or the anxiogenic effects of MDMA were also evaluated. Mice exposed to social defeat during adulthood did not show conditioned place preference after conditioning with either dose of MDMA. Conversely, social defeat did not affect the anxiogenic and motor effects of MDMA. Adult mice exposed to social defeat showed higher levels of corticosterone than their controls and adolescent mice. Social stress did not induce behavioural effects in adolescent mice. Our results show that stress induced by social defeat decreases the sensitivity of adult mice to the rewarding effects of MDMA.