VOLUNTARY INTAKE OF ALCOHOL IS ATTENUATED BY IPSAPIRONE IN MICE AND ROLE OF 5-HT1A-RECEPTOR

Emerging evidences have suggested that the brain serotonin (5-hydroxytryptamine, 5-HT) neurotransmitter system is involved in the compulsive alcohol-seeking behaviors in humans and animal models. The aim of this study is to examine the effect of ipsapirone, which is a specific 5-HT1A agonist with a pyrimidinylpiperazine structure, on alcohol consumption in mice (C57BL/6J) by a voluntary alcohol intake paradigm. When the consumed alcohol was expressed as g/kg B.W., the total 12-day amount was significantly lower in the ipsapirone-treated mice than in the saline-treated mice. However, 5-HT1A receptor binding sites labeled with [H-3]8-OH-DPAT in hippocampal membranes did not differ significantly in either the total number of binding sites (Bmax) or dissociation constant (Kd) between the two groups. The possible mechanism regarding the role of ipsapirone that attenuated the alcohol consumption, and its relationship to the subtyping 5-HT receptors are further discussed.