Effects of bilateral olfactory bulbectomy on the aggressive behaviors and social organization of a colony of male CF-1 mice

The social behaviors of olfactory bulbectomized and control male CF-1 mice, housed in separate large enclosures, were observed for 25 days. Controls engaged in vigorous fighting and an alpha mouse established a territory, attacked and wounded subordinate mice which, in turn, engaged in a variety of non-aggressive social behaviors. In contrast, bulbectomized mice roamed freely throughout the enclosure, displayed little aggression, no territorial or other social behavior and had no body scarring. These mice seldom interacted. The groups did not differ in weight or in the amount of eating, drinking, sleeping, or general activity. Bilateral bulbectomy markedly reduces the aggressive and social interactions of colony-housed male mice.