Behavioural responses induced by acute and chronic administration of MDMA (“ecstasy”) in mice

PATRICIA ROBLEDO, GRACIELA BALERIO AND RAFAEL MALDONADO

Paris, Francia

Congreso; 3rd Forum of European Neuroscience; 2002

Behavioural responses induced by acute and chronic administration of MDMA ("ecstasy") in mice. Laboratorio de Neurofarmacología, Universitat Pompeu Fabra. Barcelona, SPAIN. Patricia Robledo, Graciela Balerio and Rafael Maldonado. In this study, we investigated several behavioural responses induced by acute and chronic administration of MDMA in mice, including rewarding effects and the development of physical dependence. The rewarding properties of MDMA were studied using the conditioned place preference paradigm. Animals received different doses of MDMA (0.3, 1.0, 3.3, y 10 mg/kg; i.p.) 30 min before conditioning in the drug-paired environment and saline in the non drug-paired environment on alternate days. Control animals received saline in both environments. Results showed that mice treated with MDMA at the dose of 10 mg/kg displayed a significant conditioned place preference with respect to saline treated controls. In a second experiment, mice were treated with MDMA (10 mg/kg, i.p.) twice daily (9:00 and 18:00) for 5 days. On day six, mice received a single administration of MDMA (10 mg/kg, i.p.), and 4 hours later they received an acute injection of either the mixed beta 1 and beta 2 adrenergic antagonist, timolol (2 and  10 mg/kg, i.p.), the selective alfa 1 adrenergic antagonist, prazosin (0.25 and 1 mg/kg, i.p.), or vehicle. Immediately following the administration of the antagonists, several somatic and vegetative manifestations of withdrawal were evaluated for 45 min. Results showed that mice chronically treated with MDMA displayed some behavioural alterations following administration of the beta adrenergic antagonist. Prazosin did not produce any behavioural manifestations of withdrawal in  MDMA treated mice. These results reveal the rewarding properties of MDMA in mice, and provide evidence for the possible involvement of beta adrenergic receptors in mediating behavioural manifestations of chronic MDMA exposure.