Scopolamine alters rhesus monkey performance on a novel neuropsychologicaltest battery

Rhesus monkeys (6) were trained on a test battery including cognitive tests adapted from a human neuropsychological assessment battery (CANTAB; CeNeS Cambridge, UK) as well as a bimanual motor skill task. The complete battery included tests of memory (delayed non-match to sample, DNMS; self-ordered spatial search, SOSS), reaction time (RT), motivation (progressive ratio; P R) and fine motor coordination (bimanual). The animals were trained to asym ptotic performance in all tasks and then were administered two of the four CANTAB tasks on alternate weekdays (PR/SWM; DNMS/RT) with the bimanual task being administered on each weekday. The effect of acute administration of scopolamine (3-24 mu g/kg, i.m.) on performance was then determined. Althou gh performance on DNMS was impaired there was no interaction of drug treatm ent with retention interval, suggesting that scopolamine does not increase the rate of forgetting in this task. Scopolamine administration produced a decrement in SOSS performance that was dependent on task difficulty as well as dose. Scopolamine also impaired motor responses, resulting in increased time required to complete the bimanual motor task and increased movement t ime in the RT task. Performance in the PR task was decreased in a dose-depe ndent fashion by scopolamine. The results suggest that scopolamine interfer es with memory storage and motor responses but not memory retention/retriev al or vigilance. The findings demonstrate that the test battery is useful f or distinguishing the effects of neuropharmacological manipulation on vario us aspects of cognitive performance in monkeys. (C) 1999 Elsevier Science B .V. All rights reserved.