The 5-HT1 receptors are a subfamily w 2 of 5-HT receptors that bind the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT1 subfamily consists of five G protein-coupled receptors (GPCRs) that are coupled to Gi/Go and mediate inhibitory neurotransmission, including 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F. There is no 5-HT1C receptor, as it was reclassified as the 5-HT2C receptor. For more information, please see the respective main articles of the individual subtypes: