THE DIFFERENTIAL RESPONSES TO THE ODOR OF UNFAMILIAR MALE CONSPECIFICS IN DOMINANT, SUBORDINATE, AND ISOLATED MICE

Male ddY mice were used to investigate the responses toward the odor o f unfamiliar male mice. They were reared either in isolation from 3 we eks of age or in pairs. At 10 weeks of age, they went through a 4-day test period, in which the responses of the mice toward the odor of unf amiliar dominant and subordinate mice were investigated by differentia ting the responses into the time to investigate the odor and the final decision of avoidance or preference. All the mice went through the en counter tests after this odor test in order to investigate the relatio nship between the responses toward the odor and the behavior toward th e odor donor. The pair-reared dominants and the subordinates responded to the odor of the dominant and subordinate mice differentially. This indicated that they could discriminate the dominance status of unfami liar mice by odor. Isolated mice did not respond to the odor of the do minant and subordinate mice differentially. Social experiences were co ncluded to be necessary to discriminate the dominance status of unfami liar mice through odor. The length of the investigation time and the f inal decision of avoidance or preference did not correlate in pair-rea red or isolated mice, and these 2 scales were concluded to be differen t. But the dominant mice that investigated the odor for longer periods tended to show aggression in the later encounter test.