Neuropharmacological specificity of the diazepam stimulus complex: effects of agonists and antagonists.

A food-reinforced two-lever operant method was used to train rats (n = 10) to discriminate diazepam (3.0 mg/kg i.p.) from saline. Thereafter drugs with supposed agonist and antagonist activity were submitted for test. Pentobarbital was the only agonist able to produce the diazepam discriminative stimulus complex (DSC), while pentylenetetrazol was the only antagonist able to abolish the diazepam DSC. It is concluded that the diazepam DSC is highly specific in this test and is suitable for the investigation of the neuropharmacological action of the benzodiazepines.