Abstract
The previous paper (1) has shown that effects of psychotropic agents on the exploratory behavior of rats placed into a symmetrical Y-shaped box are modified by degree of familiarity with the apparatus. In the experienced rats which had received the training trials in the box three or four times, chlorpromazine and diazepam produced a prolongation of the start latency with decrease in the ambulation and rearing scores. However, diazepam shortened the start latency and increased the ambulation scores in the inexperienced animals which had never been placed in the apparatus.
Although major and minor tranquilizers have been found to interfere with normally trained conditioned avoidance responses (2-5), information about the effects of these agents on poor performance of rats is still insuficient. Rech (6, 7) has reported that amphetamine and scopolamine improve conditioned avoidance behavior for rats which performed poorly, in spite of extensive training, in a shuttle-box procedure. The present experiments were designed to determine effects of several psychotropic agents on Sidmantype avoidance responding in the good- and poor-performed rats.