Expression and function of glycine receptors in striatal cholinergic interneurons from rat and mouse

Although glycine receptors are widely expressed in the forebrain their func tion is obscure, We studied their activation by two possible endogenous lig ands, glycine and taurine. and demonstrate a different expression pattern o f glycine receptors in neostriatal cholinergic interneurons from two rodent species. Single-cell-reverse transcription-polymerase chain reaction analy sis of glycine receptor-subunit expression was combined with whole-cell rec ordings from acutely isolated cholinergic interneurons. All cells expressed the alpha2-glycine receptor subunit. the majority (72%) in mice ut none in young and aged rats expressed the alpha3-subunit. The beta -subunit expres sion was associated with both a higher efficacy and a higher potency of the partial agonist taurine. Cells expressing the alpha3-subunit displayed a s lower desensitization of taurine responses than of glycine responses, in co ntrast to cells expressing the alpha2-, beta -subunits where desensitizatio n time constants were similar. Glycine responses were reduced by preapplica tion of taurine this effect was more pronounced in cells lacking the alpha3 -subunit. We demonstrate interspecies differences and heterogeneity in expression and function of glycine receptors within the same neuronal population in the n eostriatum. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights re served.