Intracellular effectors and modulators of GABA-A and GABA-B receptors: a commentary.
The inhibitory neurotransmitter GABA activates two receptor subtypes that can be distinguished by their pharmacology. The GABA-A site is competitively antagonized by bicuculline and exclusively coupled to a chloride channel. The GABA-B receptor, for which baclofen is the only specific agonist, is resistant to bicuculline inhibition and, depending upon its localization, will activate K currents and/or inhibit Ca currents. Both electrophysiological and biochemical approaches have been applied to the study of each receptor. The membrane and intracellular components that to date have been implicated in GABA-B activation are discussed: G proteins, adenylate cyclase and intracellular calcium levels. This latter factor is also discussed with respect to GABA-A receptor action.
D002118:Calcium / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000502:physiology; D011963:Receptors, GABA-A / Q000187:drug effects*
C029152:G-substrate; D007473:Ion Channels; D009419:Nerve Tissue Proteins; D011963:Receptors, GABA-A; D002118:Calcium