POSSIBLE THERAPEUTIC APPLICATION OF GABA(B) RECEPTOR AGONISTS AND ANTAGONISTS

After their discovery within the mammalian periphery in 1981, gamma-am inobutyric acid-B (GABA(B)) receptors have been characterized also in the central nervous system (CNS). The highest concentrations of GABA(B ) binding sites appear to be in the cerebellum, frontal cortex, and th alamic nuclei, where they are located on pre- and postsynaptic neurons . On activation, the primary effects appear to be membrane hyperpolari zation, suppression of transmitter release, and changes in the levels of cyclic nucleotides. GABA(B) receptors have been implicated in a var iety of neurological phenomena and, as a consequence, receptor agonist s and antagonists may well have therapeutic potential. This article is an introduction to GABA(B) receptor pharmacology and reviews the futu re of the receptor ligands. Particular attention is given to the role of spinal cord GABA(B), receptors in chronic pain.