CORTICOSTERONE AND INTERCHROMOSOMAL RACE DISCRIMINATION IN THE HOUSE MOUSE

We report results of a study on emotional arousal, as reflected by cor ticosterone variation, following dyadic encounters within and between chromosomal races of the house mouse (Mus musculus domesticus). Three contiguous chromosomal races from northeast Scotland were analyzed (2n = 32, 2n = 36, 2n = 40). Within-race encounters resulted in similar a verage corticosterone levels in mice from the three races. For all thr ee races, certain of the between-race encounters resulted in a signifi cant increase in corticosterone relative to those following within-rac e encounters. These results confirm our previous observations of a dif ferential behavioral treatment of house mice from the same vs from a d ifferent chromosomal race, and support our proposition for behavioral discrimination between chromosomal races of this species in northeast Scotland. (C) 1996 Academic Press, Inc.