Tachykinin receptors are a family of G protein-coupled receptors (GPCRs) comprised of three receptor subtypes: NK1, NK2, and NK3. While NK1 and NK3 receptors are found within the central nervous system, NK2 receptors are found within smooth gastrointestinal muscle and specific parts of the brain. Tachykinin receptor antagonists have therapeutic potential in the treatment of anxiety, depression, and schizophrenic disorders, although recent clinical studies have not proved successful. Aprepitant, an NK1 antagonist, has current application as an anti-nausea drug for chemotherapy treatment.
