Effects of psychotropic drugs on behavior and EEG, following direct administration to dog's brain.

Abstract

Summary1. Two kinds of psychotropic drugs, chlorpromazine and imipramine, were examined in forty‐one dogs by means of the conditioned avoidance response and the electrocorticogram. These drugs were administered through three routes, namely intra‐peritoneal, intra‐arachnoid, and intra‐ventricular injection, with neither anaesthesia nor restraint.2. Following the intra‐arachnoid injection: Chlorpromazine produced the slow conditioned avoidance response in behavior, and asymmetrical ECoG, synchronized pattern. Imipramine demonstrated no attenuation of the conditioned avoidance response, and slight synchronization on the ECoG. The depressant action of chlorpromazine to the cerebral cortex was confirmed.3. Following the intra‐ventricular injection: Both drugs blocked tentatively the conditioned avoidance response and produced a continuous desynchronized pattern on the ECoG. The dissociation between the behavior and the ECoG was noticeable. The periventricular area might have a more important role on the conditioned avoidance response than the cerebral cortex.4. The difference of drug action between chlorpromazine and imipramine was manifested following the intra‐arachnoid injection.5. The significance of the function of the cerebral cortex and periventricular structures to the conditioned avoidance response and to the action of the drug was discussed.