Effet d'un traitement prolongé au chlordiazepoxide sur un conditionnement temporel chez le rat

Summary

Six rats were trained to press a lever for food in a Skinner-box, on a fixed-interval schedule of reinforcement (F I 2 min.). The effects of various doses of chlordiazepoxide (1 to 8 mg, i.p.) on their behavior was studied. Then, each animal underwent a series of 35 daily experimental sessions with 6 mg of the drug. Chlordiazepoxide induced an increase of conditioned activity and a disruption of the temporal discrimination characterizing the behavior in the F I schedule. The first of these effects persisted, in most subjects, throughout the treatment, while the second was attenuated. No clear-cut effect of tolerance is shown, in the experimental conditions used, at the behavioral level. Results are discussed with reference to the complexity of the concept of tolerance, especially when behavioral data are involved.