Influence of the suspension of continued treatment with flurazepam and amobarbital on two discrimination learning schedules.

The authors have studied the effect of the suspension of chronic treatment with flurazepam and amobarbital on the operant behavior of rats that for the first time were in the presence of two fixed-interval discrimination schedules. With the sound discrimination schedule, the responses emitted by the treated animals had characteristics similar to those of control animals. With the temporal discrimination schedule, though it is not possible to distinguish between learning rates, modifications in the intensity of the effect (increases in lever pressing) indicate that, considering the doses, the action of flurazepam is slight and that of amobarbital clear and statistically significant.

Modification of depressant and disinhibitory action of flurazepam during short term treatment in the rat

Employing a fixed-interval schedule of reinforcement (temporal discrimination), alternated punished (fixed-ratio) and unpunished (variable-ratio) schedules of reinforcement, a Conditioned Avoidance Response, and studying its interaction with Pentobarbital on general anaesthesia, it has been shown that flurazepam hydrochloride after a single treatment induces very intense depressant effects and slight disinhibitory effects. Short term treatment at longer than daily intervals reduces the depressant effect and unmasks the disinhibitory effect. The phenomenon is probably caused by selective tolerance concerning the depressant action. The results are discussed from the point of view of the signi…

Water-intake and conflict-behaviour after acute and chronic treatment with rolipram, a phosphodiesterase inhibitor; interaction with chlordiazepoxide

The effects of castration and of progestin-oestrogen combinations upon avoidance condtioning in female rats

Summary Using avoidance conditioning the authors show that female rats, three months after castration, emit a lower number of responses. Isolation has no effect whatever on rats, whether normal or castrated. Brief treatment with progestin-oestrogen combinations, interrupted 60 hours before the commencement of the session, brings the behaviour of castrated rats back to the norm. Identical effects occur with the use of a cortical stimulating drug (methylphenidate); while, the action of this drug soon ceases, the effect of hormonal treatment lasts for the duration of the experiments. The results are discussed with reference to the significance to be attributed to the experiments.