[The open-field, non-stressed behavior of rats under the acute and chronic effect of imipramine and tranylcypromine, depending on the individual reaction type (emotional and non-emotional)].

The acute and prolonged effects of imipramine and tranylcypromine were studied on 30 emotive and 30 non-emotive mature male Wistar rats to determine whether the drugs affect the behavior of these two reaction types differently. We found that both drugs change the typical behavior of the rats in the open field, each in a different way. Acute doses of imipramine inhibit symptoms of anxiety as well as the exploratory behavior so that the rats appear totally disinterested in their environment. This finding seems to confirm the assumed central nervous suppressing effects of this drug as mentioned in the literature. Single doses of tranylcypromine have effects similar to those mentioned for imipramine; however, long-term use results in a "vitalisation" of behavior: symptoms of anxiety remain inhibited and exploratory behavior becomes dominant. Both drugs produced a certain "flattening" of behavior. Due to the effects of drugs used, the original behavioral differences without stress disappear. Prolonged use of tranylcypromine makes emotive rats totally non-emotive.