Rastogi, S.K., and D.E. McMillan: Effects of some typical and atypical antidepressants on schedule-controlled responding in rats. Drug Dev. Res. 5:243-250, 1985.
The effects of tricylic antidepressant drugs with diverse chemical structures were studied in rats on responding maintained under a multiple fixed-ratio (30) fixed-interval (5 min) schedule of food presentation. Bupropion, mianserin, and nomifensine increased responding during the first half of the fixed-interval component and during the fixed-ratio component of the multiple schedule. Higher doses decreased rates under both the fixed-ratio component and during the second half of the fixed-interval component. Trazodone and trimipramine also increased rates of responding during the first half of the fixed-interval component. Higher doses of these drugs decreased rates under the fixed-ratio component more than the approximately equal rates during the second half of the fixed-interval component. Iprindole, protryptyline, fluvoxamine, fluoxetine, maprotiline, clomipramine, imipramine, lithium, and chlorpromazine did not increase rates of responding under the fixed-ratio component or under either half of the fixed-interval component. Among these drugs, only imipramine differentially affected the nearly equal rates of responding during the second half of the fixed-interval component and during the fixed-ratio component. The effects of antidepressants depended on both the control rate of responding and the schedule. Rate-increasing effects tended to be associated with antidepressants that interact with dopaminergic systems, but in general, the correlation between behavioral and biochemical effects was low.