The effects of the administration of metoclopramide, cisapride and SR-17 on memory processes were evaluated in the mouse passive avoidance test. The administration of dicyclomine (0.1-3 mg kg-1 i.p.), immediately after termination of the training session, produced a dose-dependent amnesic effect. Metoclopramide (1-5 mg kg-1 i.p.), cisapride (0.5-2 mg kg-1 i.p.) and SR-17 (1-10 mg kg-1 i.p.), administered 20 min before the training session, prevented dicyclomine-induced amnesia. In the same experimental conditions piracetam (30 mg kg-1 i.p.), physostigmine (0.2 mg kg-1 i.p.) and CGP 35348 (100 mg kg-1 i.p.) prevented dicyclomine amnesia. At the highest effective doses, none of the drugs impaired motor coordination, as revealed by the rota-rod test, nor did they modify spontaneous motility, as revealed by the Animex test. These results suggest that metoclopramide, cisapride and SR-17 play an important role in the modulation of memory processes. On these bases, these compounds could be useful in the treatment of cognitive deficits.