Chapter VI Neurokinin receptors in the CNS

Publisher Summary This chapter reviews the discovery of the tachykinin peptides, their distribution in the central nervous system, (CNS) and their biological effects. The chapter focuses on the characterization and distribution of neurokinin receptors in the CNS. Recent developments involve the generation of antibodies against the receptors as well as in situ hybridization probes. The chapter also focuses on the information obtained from immunocytochemical studies and provides a short review of in situ hybridization studies and an update on radioactive ligand investigations. There is strong evidence that substance P (SP) preferentially innervates neurons expressing its receptor and that, at least in some systems, communication should be at a short distance from the release site. The available data suggests that, like SR neurokinin B (NKB) may act at a short distance from the site of release. Unfortunately, information on the NK-2r in the CNS is too limited to allow any conclusion on type of prevailing communication. The limited concentrations of NK-2 receptors in the CNS suggest, however, that NKA acts on NK-2 receptors mostly outside the CNS.