[Effects of psychotropic drugs by the cumulative-dosing procedure on lever-press and shuttle discrete avoidance responses in mice].

Effects of psychotropic drugs on lever-press and shuttle discrete avoidance responses were investigated by the cumulative-dosing procedure in mice. For cumulative determination, doses of drugs were given 3 times every 1 h within the same session. As a control, the intermittent-dosing procedure in which a single dose was given twice a week was also tested. Cumulative-dosing of chlorpromazine, haloperidol, tetrabenazine, diazepam, and pentobarbital all produced dose-dependent suppression in lever-press and shuttle avoidance responses. Each cumulative dose-effect curve for chlorpromazine and haloperidol in both avoidance responses, and for tetrabenazine and diazepam in lever-press avoidance response was almost identical with that obtained by the intermittent dosing. The cumulative effects of tetrabenazine in shuttle avoidance response and pentobarbital in both avoidance responses were weak. In contrast, diazepam suppressed shuttle avoidance response in the cumulative dosing, but not in the intermittent dosing. Cumulative dosing of methamphetamine and morphine increased response rates without marked changes in avoidance rates in the shuttle avoidance response. Cumulative dosing of methamphetamine was less effective than the intermittent dosing. In contrast, the cumulative dose-effect curve for morphine was almost identical with that obtained by the intermittent dosing. The present results indicate that the cumulative-dosing procedure may be applicable to the drug evaluation in lever-press and shuttle avoidance responses.