Effect of stimulation of brain serotonergic system on mouse-killing behavior in rats

Mouse-killing behavior was induced in male Wistar rats due to 6 weeks isolation. The selective stimulation of the dorsal raphe nucleus markedly reduced muricide behavior. On the other hand rats with electrodes situated outside of the dorsal raphe (within the substantia grisea centralis) showed no changes in muricide behavior when compared with control (non-stimulated) animals. Pharmacological stimulation of whole serotonergic brain neurons by quipazine, an agonist of serotonin receptors, and compound CGP 6085-A, a selective inhibitor of serotonin uptake, strongly decreased mouse-killing behavior. Our data indicates that serotonergic neurons inhibit predatory aggression in rats.