[Effect of serotoninergic substances on escape behavior in acute stress situations]

The data are provided on the effect of some serotoninergic substances on the avoidance behavior under acute stress. 5-Hydroxytryptophan, zimelidine (low doses), pyrenepyron, ciproheptadine, trazodon (high doses), produced a noticeable positive action on the behavior pattern under study. Quipazin and zimelidine (high doses) provoked an increase in the number of affective manifestations and a rise of the latent avoidance time. Regardless of an appreciable fall in the number of affective manifestations, the powerful sedative effect of m-chlorphenylpiperazine led to an increase in the latent response periods. It was shown that substances that produced a direct or mediated activation effect on the serotoninergic system had an appreciable favourable influence on the avoidance behavior, which was a consequence of a decrease in the animals' emotional excitement. Combination of serotonin-blocking properties (action on S2-autoreceptors) and dopaminergic properties brought about optimal results, provided that pyrenepyron was applied.