DETAILED BEHAVIORAL-ANALYSIS OF WATER MAZE ACQUISITION UNDER SYSTEMICNMDA OR MUSCARINIC ANTAGONISM - NONSPATIAL PRETRAINING ELIMINATES SPATIAL-LEARNING DEFICITS

A detailed behavioral analysis of water-maze acquisition showed that t he N-methyl-D-aspartate (NMDA) antagonist NPC17742 and the muscarinic antagonist scopolamine caused sensorimotor disturbances in behaviors r equired for maze performance and that these correlated with acquisitio n impairments in both hidden and visible platform versions of the maze in male rats. Behavioral disturbances included thigmotaxic swimming, swimming over and deflecting off the platform, abnormal swim behavior, and hyperactivity. Rats familiar with the behavioral strategies invol ved in the task performed normally under NPC17742 or scopolamine. The results indicated that drug-induced sensorimotor disturbances contribu ted to poor acquisition scores in naive rats. NMDA or muscarinic activ ity may contribute to but do not appear to be essential for spatial le arning in the water maze.