Social Rank in Male Mice and Adrenocortical Response to Open Field Exposure ∗

Abstract

Summary

Plasma corticosterone levels were examined in socially dominant, subordinate, or unranked male mice taken directly from an undisturbed cage or following 10 min of a nonsocial neurogenic stress of exposure to an open field. There were no significant differences in plasma corticosterone levels among the social rank categories in undisturbed animals. Following open field exposure, subordinate males had the greatest levels of plasma corticosterone while dominant males had greater levels than unranked males. These data indicate that the process of social organization leads to an increase in responsiveness of male mice to a strange environment and under these circumstances the socially subordinate males are more responsive.