SEROTONIN INHIBITION OF THE NMDA RECEPTOR NITRIC-OXIDE CYCLIC-GMP PATHWAY IN RAT CEREBELLUM - INVOLVEMENT OF 5-HYDROXYTRYPTAMINE(2C) RECEPTORS

Previous studies have shown that 5-hydroxytryptamine (5-HT) can potent ly inhibit glutamatergic transmission in rat cerebellum through the ac tivation of multiple 5-HT receptors. The aim of this study was to subc lassify the 5-HT2 receptor mediating inhibition of the cyclic GMP resp onse elicited by N-methyl-D-aspartate in adult rat cerebellar slices. Seven receptor antagonists, endowed with relative selectivities for th e 5-HT2A, 5-HT2B, and 5-HT2C subtypes, differentially affected the inh ibition by (+/-)-1-(2,5-dimethoxy-4-iodophenyl) -2-aminopropane of the cyclic GMP response, suggesting that the receptor involved belongs to the 5-HT2C subtype.