CHRONIC ETHANOL CONSUMPTION REGULATES CANNABINOID CB 1 RECEPTOR GENE EXPRESSION IN SELECTED REGIONS OF RAT BRAIN

Aims: The aim of this study was to examine the effects of chronic ethanol consumption in cannabinoid CB1 receptor gene expression in Wistar rats. Methods: Rats were exposed to a bottle containing a solution of ethanol (10% v/v) and saccharin (0.25% w/v) for 52 days. At the end of this period, rats were killed by decapitation and cannabinoid CB1 receptor gene expression was measured by in situ hybridization histochemistry. Results: Our results indicated that chronic ethanol consumption reduced cannabinoid CB1 receptor gene expression in caudate-putamen (CPu) (24%), ventromedial nucleus of the hypothalamus (VMN) (43%), CA1 (27%) and CA2 (22%) fields of hippocampus and increased dentate gyrus (DG) (30%). Conclusions: These results reveal for the first time that prolonged exposure to ethanol produces marked alterations in cannabinoid CB1 receptor gene expression in selected regions of the rat brain, supporting an interaction between ethanol consumption and the endogenous cannabinoid receptor. Furthermore, these findings suggest that cannabinoid CB1 receptor may be considered as a new pharmacological target for treating ethanol dependence. Alcohol & Alcoholism Vol. 39, No. 2 © Medical Council on Alcohol 2004; all rights reserved *Author to whom correspondence should be addressed at: Servicio de Psiquiatría, Pabellón de Medicina Comunitaria, Hospital Universitario 12 de Octubre, Avda. de Córdoba s/n 28041 Madrid, Spain. Tel.: +34 91 390 8022; Fax: +34 91 390 8538; E-mail: jmanzanares6@terra.es

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