Effects of stimulation of the raphe nuclei on muricide behavior in rats

Mouse-killing behavior was induced in male Wistar rats by chronic isolation. Selective stimulation of the dorsal raphe nucleus markedly reduced this aggressive behavior. On the other hand, stimulation of the median raphe nucleus produced no changes in muricide behavior. Our results indicate that dorsal and median raphe nuclei function differentially in the regulation of muricide behavior with the dorsal raphe playing a critical role in this behavioral pattern.