Enhancement of conditioned place preference response to cocaine in rats following subchronic administration of 3,4-methylenedioxymethamphetamine (MDMA)

In this study, we measured conditioned place preference (CPP) responses to cocaine following subchronic administration of the recreationally abused dr ug (+/-)-3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") in male Spragu e-Dawley rats. Animals were given either vehicle (1 ml/kg of distilled wate r, s.c.) or MDMA (20 mg/kg, s.c.) twice a day for 4 consecutive days. Two w eeks later, CPP responses to cocaine (5, 10, or 20 mg/kg, i.p.) were measur ed. The MDMA-treated animals showed a significantly greater CPP response to cocaine than the vehicle-treated animals. Since conditioned place preferen ce is believed to be a measure of appetitive behavior, these results sugges t that MDMA abuse could lead to an increased vulnerability to the rewarding actions of cocaine and, hence, to increased vulnerability to cocaine addic tion and dependence. (C) 2000 Wiley-Liss, Inc.