Effects of piracetam on indices of cognitive function in a delayed alternation task in young and aged rats.

The effects of piracetam (64, 128, and 256 mg/kg PO) on the performance of a delayed alternation in a Skinner Box were investigated. Test sessions consisted of 36 trials during which animals were first presented with a single lever (left or right) followed 5, 10, or 20 s later by two levers. A press on the lever opposite to that presented previously (nonmatching to sample) was rewarded. The number of correct responses and the reaction times to the one- and two-lever presentations were recorded. All animals received all treatments in a balanced order. Aged animals showed clear deficits on all three parameters. Piracetam was without effect on the performance of young animals but dose-dependently decreased the choice reaction times (two levers) in aged animals without affecting the other two parameters. These results suggest that piracetam does not affect short-term memory but may facilitate choice behavior in aged animals.