Effects of drugs on schedule-controlled running of mice in a circular runway.

Partially food deprived mice ran in a 1-m circular runway. Every 30 circuits, diluted evaporated milk was delivered. Under control conditions mice averaged 0.18 circuits/s for 1 h. The rate was reduced to 0.11 circuits/s 1 h after gavage of Tylose (cellulose derivative) vehicle. Amphetamine, chlordiazepoxide and pentobarbital increased the rate of responding over some dose range, but chlorpromazine, clozapine, imipramine and morphine caused only decreases in responding at effective dose levels. The results are generally similar to reports of effects of the drugs on responses of much briefer duration occurring at similar rates.