The intrinsic effects of the benzodiazepine receptor ligand beta-CMC (3-(methoxycarbonyl)-amino-beta-carboline) and its interaction with the anticonvulsant and sedative effects of diazepam were assessed. beta-CMC (100 mg/kg i.p.) significantly elevated seizure threshold to bicuculline. beta-CMC (10 mg/kg) failed to alter the anticonvulsant action of diazepam (5 mg/kg i.p.), but significantly attenuated diazepam's sedative effect. A higher dose of beta-CMC (40 mg/kg) did attenuate diazepam's anticonvulsant action. The data suggest that beta-CMC is a partial agonist at benzodiazepine receptors.