Abstract
A parametric examination of the interaction between drug-induced behavioral changes and the degree of predrug stimulus control was conducted with rats. A discrete-trial simultaneous discrimination was used, with the controlling stimuli varied over 6 values of distinctiveness. The effects of graded doses of scopolamine, d-amphetamine, and methylscopolamine on these performances were studied, with both scopolamine and d-amphetamine showing no increase in error rate under strong stimulus control, and dose-related increases in error rate under weak stimulus control. The similar interaction between drug effect and stimulus control for scopolamine and d-amphetamine indicates that the interaction reflects the degree of susceptibility of the behaviors to drug action, rather than two specific drug-behavior interactions.
Methylscopolamine produced a slight effect on error rate and no significant interaction with stimulus control. A decrease in the number of trials responded to was found with both scopolamine and methylscopolamine, but not with d-amphetamine.
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Research carried out while the author was a post-doctoral fellow at the Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts. Supported in part by NIMH Training Grant T01 MH 10625 to the Worcester Foundation, PHS grant MH 18421 to James W. McKearney, and PHS grant MH 24318 to the author.
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Ksir, C. Scopolamine and amphetamine effects on discrimination: Interaction with stimulus control. Psychopharmacologia 43, 37–41 (1975). https://doi.org/10.1007/BF00437612
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DOI: https://doi.org/10.1007/BF00437612