Effects of diazepam, meprobamate, chlorpromazine and apomorphine on a quickly learned conditioned suppression in mice.

Mice exhibited a marked suppression of motor activity when placed into the same environment in which they had previously received electric foot shocks. Apomorphine-HCl (0.1 - 10 mg/kg) produced a dose-dependent reduction of the conditioned suppression of activity, but did not increase activity in non-shocked mice. Diazepam (0.2, 1, and 5 mg/kg), meprobamate (25 and 50 mg/kg), and chlorpromazine-HCl (2 and 5 mg/kg) did not reduce conditioned suppression. Thus, the conditioned suppression caused by a quick conditioning technique does not produce similar results to those using the conditioned emotional response involving suppression of operant lever-pressing behavior.