beta-CCE and chlordiazepoxide reduce exploratory head-dipping and rearing: no mutual antagonism.

Intravenous injection of ethyl beta-carboline-3-carboxylate (beta-CCE, 2 mg/kg) significantly reduced exploratory behaviour in a holeboard and 1 & 2 mg/kg markedly reduced the number of rears made. These effects were similar to those found with chlordiazepoxide (5 mg/kg). When they were given together the two drugs neither counteracted each other's effects, nor were their combined effects additive. We suggest that beta-CCE and the benzodiazepines might both act at one class of benzodiazepine receptor, as agonists to produce the same behavioural effects. The results are also discussed with reference to other intrinsic actions of these compounds.