The benzodiazepine--GABA--chloride ionophore receptor complex: common site of minor tranquilizer action.

The demonstration of specific recognition sites for benzodiazepines in the mammalian CNS has altered current thinking on the mechanisms of action of the benzodiazepines as well as the neurochemical events which are associated with anxiety. Recent studies suggest that the physiological regulation of the benzodiazepine receptor is far more complex than initially believed and includes a functional coupling to both a GABA receptor and an associated chloride ionophore. It now appears that a number of other psychopharmacologic agents, including minor tranquilizers other than the benzodiazepines as well as several convulsants and anticonvulsants, may exert their pharmacologic effects by affecting one or more regulatory sites on the benzodiazepine receptor complex. In addition to a number of drugs, at least one endogenous small molecular weight compound that has been isolated from the crude synaptosomal fraction of bovine cerebral cortex also appears to modulate this receptor complex.