Abstract
A short update about the data accumulated so far on the brain-specific binding sites of the benzodiazepines is the subject of this paper. Today, a large variety of biochemical and pharmacological data clearly indicates that these benzodiazepine receptors are the endogenous targets which mediate the pharmacological effects of the benzodiazepines. Furthermore, considerable evidence suggests that the benzodiazepine receptor serves as an amplifying system for GABAergic transmission by increasing the affinity of the GABA receptor. Since the physiological function of this receptor and its endogenous ligand are not yet known, one of the major topics of future research will be to finally identify the endogenous ligand(s) of the benzodiazepine receptor.