Abstract
A simple avoidance procedure in mice was investigated for the purpose of testing psychotropic drugs. A box with two compartments, darkened and lightened, was used. Mice were put into the darkened compartment where they would be punished unless they moved into the lightened compartment within 5 sec. Most of mice quickly acquired an active avoidance in this apparatus with training less than 50 successive trials. Major tranquilizers such as chlorpromazine, haloperidol, clozapine and oxypertine depressed the avoidance response at doses lower than those at which the escape response was impaired. Diazepam and doxepin had depressant effects at doses which impaired the escape response. Imipramine and nortriptyline did not affect the avoidance response at the doses tested. It is concluded that mice quickly acquire an active avoidance under the present procedure and that this conditioned behavior is selectively depressed by major tranquilizers.
