Differential modulation of etazolate or pentobarbital enhanced [3H]muscimol binding by benzodiazepine agonists and inverse agonists

Abstract Flunitrazepam, a benzodiazepine agonist increases, and DMCM, an inverse agonist decreases the stimulation by etazolate or pentobarbital of [ 3 H]muscimol binding to membranes of rat cerebral cortex. Ro 15–1788 has no marked effects but antagonizes the action of both flunitrazepam and DMCM. The investigation of several drugs acting on benzodiazepine receptors on etazolate enhancement of [ 3 H]muscimol binding suggests that their receptor interaction reflects a spectrum from agonists to inverse agonists.