Ligand-gated channels classification

The classification of 5-HT-receptors is still an ongoing field of research. 5-HTi, 5-HT2, 5-HT4, 5-HTe and S-HT subtypes belong to the superfamily of G-protein coupled receptors whereas the 5-HT3 subtype is a ligand-gated ion channel. The activation of 5-HTi-receptors induces excitatory or inhibitory effects in the periphery as well as in the central nervous system. There are presynaptic 5-HTi-autoreceptors. 5-HT2-receptors in the periphery are located postsynaptieally, their stimulation induce only excitatory effects. 

Basic Classification of Ligand-Gated Ion Channels, Their Inhibitors and Activators... 

Ligand-gated Chloride Channel Structure and Classification... 

Based on one current classification system, fourteen serotonin receptor subtypes have been described for the peripheral and central actions of 5-HT. A brief summary is provided in Table 18.1 but the reader is referred to the appropriate pharmacological literature for details. Only the 5-HT3 receptor is a ligand-gated ion channel the remaining subfamilies are G-protein coupled receptors. It is also worth noting that the situation is more complicated based on the presence of additional receptors which... 

---