Castration does not inhibit aggressive behavior in adult male prairie voles (Microtus ochrogaster)

The relationship between castration and reduced male aggression is well est ablished. However, anecdotal observations of male prairie voles (Microtus o chrogaster) suggest that castration does not reduce aggressive behavior. To investigate the role of testicular androgens on aggressive behavior, castr ated or gonadally intact male prairie voles were paired in a neutral arena with a gonadally intact vole. Castration did not reduce the frequency of in termale aggression. In Experiment 2, aggressive behavior was examined furth er using resident-intruder, grouped aggression, and aggression against a la ctating female models. Again, castration did not affect the frequency of ag gression in male prairie voles. Taken together, the results of this study s uggest that aggressive behavior may be independent of gonadal steroid hormo nes in adult male prairie voles. (C) 1999 Elsevier Science Inc.