Interacting effects of handling and d-amphetamine on avoidance learning.

Rats were injected with either saline or 2 mg/kg of d-amphetamine 10 min prior to 50 trials of training with either the one-way, shuttle or shuttle-with-handling procedure. One-way training yielded more avoidances and shorter avoidance latencies than did either variant of shuttle training; it was not affected by the drug. The frequency of avoidances under shuttle training, on the other hand, was increased either by d-amphetamine or by handling the animal during the intertrial interval. When both the drug and handling were administered together, performance was similar to that during the usual shuttle training.