Role of the cannabinoid system in the effects induced by nicotine on anxiety-like behaviour in mice

BALERIO G., ASO E., AND MALDONADO R.

Córdoba, Argentina

Congreso; XXXVIII Reunión Anual de Comunicaciones Científicas; 2006

Sociedad Argentina de Farmacología Experimental

ROLE OF THE CANNABINOID SYSTEM IN THE EFFECTS INDUCED BY NICOTINE ON ANXIETY-LIKE BEHAVIOUR IN MICE Balerio G2,3 Aso E1, and  Maldonado Rl 1Laboratorio de Neurofarmacología, Universitat Pompeu Fabra, Barcelona, España; 2ININFA (CONICET) y 3Cát. de Farmacología (FFYB, UBA).  Junín 956, 5º. Bs As-Argentina.. gbalerio@ffyb.uba.ar The present study was designed to examine the possible involvement of the cannabinoid system in the anxiolytic- and anxiogenic-like responses induced by NIC in mice. Animals were only exposed once to nicotine. The acute administration of low (0.05, sc) or high (0.8 mg/kg, sc) doses of NIC produced opposite effects in the elevated plus-maze, i.e., anxiolytic- and anxiogenic-like responses, respectively. The effects of the pretreatment with the CB1 cannabinoid receptor antagonist, rimonabant (0.25, 0.5 and 1 mg/kg, ip), and the cannabinoid agonist, D9-tetrahydrocannabinol (D9-THC) (0.1 mg/kg, ip), were evaluated on the anxiolytic- and anxiogenic-like responses induced by NIC. Rimonabant completely abolished NIC-induced anxiolytic-like effects and increased the anxiogenic-like responses of NIC, suggesting an involvement of CB1 receptors in these behavioural responses. On the other hand, D9-THC failed to modify NIC anxiolytic-like responses, but attenuated its anxiogenic-like effects. In addition the association of non-effective doses of D9-THC and NIC produced clear anxiolytic-like responses. These results demonstrate that the endogenous cannabinoid system is involved in the regulation of NIC anxiety-like behaviour in mice, and provide new findings to support the use of cannabinoid antagonists in the treatment of tobacco addiction.      Presentación en póster