Interaction of tail-pressure stress and d-amphetamine in disruption of the rat's ability to ignore an irrevelant stimulus.

Rats received either 0 or 30 preexposures to a tone that was later used as a warning stimulus in a two-way active avoidance task. Consistent with previous data, tone preexposure resulted in retarded acquisition of the conditioned avoidance response (CAR) in saline control animals and in animals that received chronic administration of a low dose of d-amphetamine. Similarly, animals that received tail-pressure stress prior to stimulus preexposure also showed retarded acquisition of the CAR. However, animals that received a combination of tail pressure and d-amphetamine did not show retarded CAR acquisition following stimulus preexposure. These results suggest an interaction between environmental stressors and d-amphetamine in producing attentional deficits.