Scopolamine and amphetamine effects on discrimination: interaction with stimulus control.
A parametric examination of the interaction between drug-induced behavioral changes and the degree of predrug stimulus control was conducted with rats. A discretetrial 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.
D000818:Animals; D003216:Conditioning, Operant; D003913:Dextroamphetamine / Q000494:pharmacology*; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D012601:Scopolamine / Q000494:pharmacology*; D012602:Scopolamine Derivatives / Q000494:pharmacology
D012602:Scopolamine Derivatives; D012601:Scopolamine; D003913:Dextroamphetamine