Citation

Laredo SA, Landeros RV, Dooley JC, Steinman MQ, Orr V, Silva AL, Crean KK, Robles CF, Trainor BC. Horm. Behav. 2013; 64(3): 557-565.

Affiliation

Department of Psychology, University of California Davis, 1 Shields Ave, Davis, CA 95616, USA; Animal Behavior Graduate Group, University of California Davis, 1 Shields Ave, Davis, CA 95616, USA. Electronic address: salaredo@ucdavis.edu.

Copyright

(Copyright © 2013, Elsevier Publishing)

DOI

10.1016/j.yhbeh.2013.06.002

PMID

23763907

Abstract

In several vertebrate species, the effects of estrogens on male aggressive behavior can be modulated by environmental cues. In song sparrows and rodents, estrogens modulate aggression in the nonbreeding season or winter-like short days, respectively. The behavioral effects of estrogens are rapid, which generally is considered indicative of nongenomic processes. The current study further examined the hypothesis that estradiol acts nongenomically under short days by utilizing a protein synthesis inhibitor, cycloheximide (CX). Mice were housed in either short or long day photoperiods, and treated with an aromatase inhibitor. One hour before resident-intruder testing mice were injected with either CX or saline vehicle, and 30minutes laterwere treated orally with either cyclodextrin conjugated estradiol or vehicle. Under short days, mice treated with estradiol showed a rapid decrease in aggressive behavior, independent of CX administration. CX alone had no effect on aggression. These results show that protein synthesis is not required for the rapid effects of estradiol on aggression, strongly suggesting that these effects are mediated by nongenomicprocesses. We also showed that estradiol suppressed c-fosimmunoreactivity in the caudal bed nucleus of the striaterminalis under short days. No effects of estradiol on behavior or c-fos expression were observed in mice housed under long days. Previously we had also demonstrated that cage beddinginfluenced the directional effects of estrogens on aggression. Here, we show that the phenomenon of rapid action of estradiol on aggression under short days is a robust result that generalizes to different bedding conditions.

Language: en