Comparison of effects of a range of 5 -HT receptor modulators on consumption and preference for a sweetened ethanol solution in rats

Abstract

This study assessed the effects of a range of serotonergic agents on preference for a slightly sweetened ethanol solution (10% ethanol, 3% glucose) in rats. A two-bottle, free-choice paradigm was used following induction of ethanol consumption. The model used provides a robust and reliable level of ethanol self-administration in normal laboratory rats. Ethanol consumption was significantly and selectively reduced by the 5- hydroxytryptamine-1A (5-HT_1A) full agonist 8-OH-DPAT (0.3-1.0 mg/kg) and the 5-HT ₃ antagonist granisetron (0.1-1.0 mg/kg). Non-specific reductions in fluid consumption were induced by the 5-HT_1B agonist RU 24969 (0.1- 1.0 mg /kg) and the 5-HT₂ antagonist ritanserin (1.0-6.0 mg/kg). These studies thus confirm the potential for decreasing ethanol consumption and ethanol preference of 5-HT _1A agonists and 5-HT₃ antagonists, but failed to find any selective effects for agents acting at 5-HT_1B or 5-HT₂ receptors.