5-HT₁ receptor

endogenous neurotransmitter serotonin (also known as 5-hydroxytryptamine, or 5-HT).^[1] The 5-HT₁ subfamily consists of five G protein-coupled receptors (GPCRs) that share 40% to 63% overall sequence homology, including 5-HT_1A, 5-HT_1B, 5-HT_1D, 5-HT_1E, and 5-HT_1F.^[2] Receptors of the 5-HT₁ type, specifically, the 5-HT_1A and 5-HT_1D receptor subtypes, are present on the cell bodies. Receptors of the 5-HT1 type, specifically, the 5-HT_1B and 5-HT_1D receptor subtypes, are also present on the nerve terminals. These receptors are broadly distributed throughout the brain and are recognized to play a significant part in regulating synaptic levels of 5-HT.^[3]

inhibitory neurotransmission by inhibiting the function of adenylate cyclase and modulating downstream ionic effects.^[4] This R-coupling to G_i/G_o proteins leads to a reduction in local concentrations of cAMP, proving that 5-HT₁ are primarily inhibitory.^[5] There is no 5-HT_1C receptor, as it was reclassified as the 5-HT_2C receptor.^[6]