title: Presence of intact and gonadectomized juveniles and the reduction of fighting between adult male rats.
abstract: Research is reported which investigated the aggressive interactions between adult male rats in the presence of 17-27 day old juvenile conspecifics. Following a brief exposure to an inaccessible juvenile male, juvenile female, estrous adult female, or empty compartment, the males of Experiment 1 were allowed to interact with another adult male. Results were that the presence of both genders of juveniles reduced fighting between the adult males, and pre-pubertal females were particularly effective as an aggression-inhibitor. The hormonal bases for those sex differences were examined in Experiment 2 using juveniles gonadectomized on Postnatal Day 10. Adult males were more aggressive following exposure to intact juvenile males than to castrated juvenile males; the latter males, intact juvenile females, and ovariectomized juvenile females provoked similar and low rates of fighting between adult males. These data suggest that the sexual dimorphism is a function of testicular hormones present during the juvenile stage which modify the stimulus characteristics of a pre-pubertal male rat.
mesh_terms: D000374:Aggression / Q000502:physiology*; D000375:Aging; D000378:Agonistic Behavior / Q000502:physiology; D000818:Animals; D002369:Castration; D004971:Estrus; D005260:Female; D006801:Humans; D008297:Male; D009115:Muridae; D011247:Pregnancy; D012919:Social Behavior; D013739:Testosterone / Q000502:physiology*
chemical_list: D013739:Testosterone