EFFECTS OF 5-HT3 RECEPTOR AGONISTS ON VOLUNTARY ETHANOL INTAKE IN RATS MAINTAINED ON A LIMITED ACCESS PROCEDURE

Recent evidence from a variety of laboratory studies suggeststhat the central effects of ethanol (EtOH) are mediated by serotonin5-HT₃ receptors. Notably, EtOH is able to potentiate 5-HT actionon 5-HT₃ ionophore, and 5-HT₃ antagonists are known to reducecertain effects of EtOH. In the present study, we evaluatedthe effects of two agonists of 5-HT₃ receptors, 2-methyl-5-HT(2-Me-5-HT) and m-chlorophenylbiguanide (m-CPBG) that were microinjectedi.c.v. and into the nucleus accumbens (NAC) on EtOH intake inWistar rats with high EtOH preference. 2-Me-5-HT given i.c.v.(1 and 10 µg per rat) and into the NAC (bilaterally 1and 10 µg per site) significantly reduced EtOH intakein the limited access paradigm (2 h session). On the other handm-CPBG was inactive after intra-NAC administration. It is concludedthat central 5-HT₃ receptors are involved in the regulationof EtOH consumption.