[Participation of the serotoninergic system of the brain in regulation of emotional reactivity].

Vocalization and aggressiveness reactions were evoked in experiments on male Wistar rats by means of electric shock stimulation. The influence of serotonin- and dopaminergic drugs was studied in parallel on emotional reactivity and serotonin metabolism. It has been found that l-tryptophane depresses while l-Dopa intensifies emotional reactivity and aggressiveness, the latter lowering the level of endogenous serotonin and enhancing its catabolism. L-Dopa, dl-amphetamine, alpha-methyl-Dopa, parachlorophenylalanine and serotonino-blockators--deseryl and lysergide--eliminate the tranquilizing action of tryptophane on emotional reactivity, decreasing serotonin accumulation and intensifying the formation of 5-oxyindolacetic acid.