ACUTE EFFECTS OF D-AMPHETAMINE IN A MONKEY OPERANT BEHAVIORAL-TEST BATTERY

The acute effects of d-amphetamine were assessed using a battery of complex food-reinforced operant tasks that included responding in delayed matching-to-sample (DMTS, n=6), conditioned position responding (CPR, n=7), progressive ratio (PR, n=8), temporal response differentiation (TRD, n=4), and incremental repeated acquisition (IRA, n=9) tasks. Performance in these tasks is thought to depend upon specific brain functions such as short-term memory and attention (DMTS), color and position discrimination (CPR), motivation to work for food (PR), time perception (TRD), and learning (IRA). d-Amphetamine sulfate (0.01-1.0 mg/kg IV), given 15-min presession produced significant dose-dependent decreases in the number of reinforcers obtained in each task. Response accuracy was significantly decreased at doses of 0.3 and 1.0 mg/kg for TRD and at 1.0 mg/kg for CPR when compared to saline injections. Accuracy was not consistently affected in the DMTS or IRA tasks. Response rates decreased or response latencies increased significantly at doses of 0.3 and 1.0 mg/kg in the PR and DMTS tasks. A dose of 0.1 mg/kg for the IRA and TRD tasks, 0.3 mg/kg for DMTS and 1.0 mg/kg for the CPR tasks significantly decreased percent task completed. Thus, the relative sensitivities of these tasks for detecting d-amphetamine behavioral effects were IRA = TRD > PR = DMTS > CPR. These results indicate that in monkeys, performance of operant tasks designed to model learning ability and time perception is more sensitive to the disruptive effects of d-amphetamine than is performance in tasks designed to model motivation, short-term memory and attention, which is more sensitive than tasks that model color and position discrimination. © 1990.