Deletion of ERα selectively in neurons abolishes sexual and aggressive behaviors in male mice

Abstract

Estrogen receptor (ER)α is a ligand-dependent transcription factor that is important for the display of social behaviors in male and female mice. ERα is expressed in both neurons and glia throughout the central nervous system (CNS). Previous work showed that sexual and aggressive behaviors are greatly reduced in male ERα KO mice. To investigate the contribution of neuronally-expressed ERα to these behaviors, we investigated social behaviors as well as home-cage running wheel activity in male mice that lack ERα selectively in neurons (ERα fl/fl) of the CNS but possess ERα in glia and peripheral tissues. Adult male mice were tested on a range of social behaviors, including aggressive behavior against olfactory bulbectomized male intruders and sexual behavior toward hormonally primed female mice. Among the ERα fl/fl mice, aggression was greatly reduced and sexual behavior was abolished compared to wild-type (WT) mice. In addition, increase in running wheel activity normally observed in gonadectomized WT mice after estrogen implantation was not seen in ERα fl/fl mice. These data suggest that sex and aggressive behaviors in males are governed by ERα expressed in neurons. Supported by Grant-in-Aid for Scientific Research 17052001 and 17330151 to SO. [J Physiol Sci. 2008;58 Suppl:S93]