[Behavioral characteristics of F344/DuCrj (Fischer) strain rats: spontaneous motor activity and acquisition of conditioned avoidance responses (author's transl)].

In order to study the behavioral characteristics of F344/DuCrj (Fischer) strain rats, male rats of this strain were compared with those of the Wistar strain regarding both spontaneous motor activity and the processes of acquisition of conditioned avoidance responses under two types of avoidance situations, namely the Sidman (continuous) avoidance schedule and the discriminated (discrete) avoidance schedule with an escape contingency. It was found on the first point that the Fischer strain rats displayed higher activity than the Wistar strain rats under a 12 : 12 hr light-dark situation. On the second point, strain differences were observed in the processes of acquisition of the avoidance responses. Here, in the early stage of the training, the Fischer strain rats received many shocks than the Wistar strain rats under the Sidman avoidance situation, while the wistar strain rats showed a lower avoidance rate than the Fischer strain rats under the discriminated avoidance situation. However, in the final stages of the training, no marked difference was observed in the results between the two strains. The present results suggest that the Fischer strain rats may show behavioral characteristics those differ from the Wistar strain rats.