Prior and ongoing experience as determinants of the effects of d-amphetamine and chlorpromazine on punished behavior
Bacotti, A.V.; McKearney, J.W.
Journal of Pharmacology and Experimental Therapeutics 211(1): 80-85
1979
ISSN/ISBN: 0022-3565 PMID: 114623 Document Number: 139692
Squirrel monkeys [Saimiri sciureus] responded under a 5 min fixed-interval schedule of food presentation. When responding was suppressed by presenting an electric shock after every 30th response (punishment), d-amphetamine sulfate (0.01-1.0 mg/kg) did not increase punished responding. d-Amphetamine markedly increased punished responding after the monkeys were given experience under a shock postponement schedule. The initial rate-decreasing effects of chlorpromazine were unaltered by interposed experience under shock postponement. Increases in punished responding produced by d-amphetamine diminished with repeated administrations for 2 of 3 monkeys. After a 2nd exposure to shock-postponement schedules, d-amphetamine again increased responding suppressed by shock in these monkeys but to a lesser extent. In the 3rd monkey, increases in responding with d-amphetamine diminished as the number of responses producing shock was decreased from 30 to 15 to 5 responses; d-amphetamine no longer increased responding when each response produced shock. When this monkey was again exposed to the 30-response shock requirement, d-amphetamine produced only marginal increases. The effects of d-amphetamine on punished responding depended on past experience under shock-postponement schedules, on recent experiences with the behavioral changes evoked by the drug and on current schedule parameters.