5-HT receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on [198] and subsequently revised [180]) are, with exception of ionotropic 5-HT3 class, GPCRs where endogenous agonist is 5-hydroxytryptamine. The diversity metabotropic increased alternative splicing that produces isoforms 5-HT2A (non-functional), 5-HT2C 5-HT4, 5-HT6 (non-functional) 5-HT7 receptors. Unique amongst GPCRs, RNA...