The dose-response effects of chlorpromazine, imipramine, and thiazesim were investigated on unlearned behaviors (spontaneous motor activity, eating, drinking, mouse-killing, selfgrooming, and forced motor activity) and learned behavior using the rat pole-climbing unit. Three or four doses of each drug were used in the study of each parameter, and EDSO values were calculated from the generated log dose-response line. Ratios of the forced motor activity EDso divided by the ED,'s of the various behavioral tests were used to determine whether the blockades of the behavioral parameters occurred at debilitating or nondebilitating doses. The tranquilizer, chlorpromazine, required a debilitating dose to block four of the five unlearned behaviors. The antidepressant, imipramine, disrupted three of these at nondebilitating doses ; the antidepressant, thiazesim, blocked all unlearned behaviors at nondebilitating doses. All compounds required debilitating doses to block the learned behavior, a conditioned avoidance response. The results generally support the hypothesis that antidepressants selectively bIock unlearned behaviors which are not blocked by tranquilizers until debilitating doses are used.
Keyphrases 0 Tranquilizer, antidepressant effects-learned, unlearned behavior [7 Chlorpromazine, imipramine, thiazesimcomparative effects, learned, unlearned behavior 0 Behavioral response, learned, unlearned-antidepressants, tranquilizer effects