Benzodiazepine receptors: are there endogenous ligands in the brain?

Abstract

The search goes on. There is as yet no compelling evidence for the existence of an endogenous benzodiazepine receptor ligand in the brain. At present, nicotinamide appears to be the most promising candidate in view of its benzodiazepine-like neuropharmacological profile. Purine derivatives also have to be considered as putative endogenous ligands. In the future, the search will become more selective: the recently discovered benzodiazepine antagonists will help to specify whether a response of a putative endogenous ligand is mediated via the benzodiazepine receptor or not.