Study on the mechanisms underlying the effect of social experience on the development of social behavior in laboratory mice

当在成年期进行测试时，在雄性小鼠中断奶后单独圈养会增加攻击性行为和/或胆怯反应（对对手雄性的接近/接触退缩和冻结）。单独圈养的雄性动物暴露于其他单独圈养的雄性动物使用的笼子中，其攻击行为或胆怯反应未显示出任何变化，但暴露于分组雄性动物使用的笼子中减少了攻击行为。在雌性小鼠中，断奶后的单独住房在成年期测试时只增加了胆怯的反应。这些结果表明，这种增强的胆怯反应是单独圈养的小鼠的基本特征，并且分组雄性的排泄物中所含的物质参与了对攻击的控制。

Individually housing after weaning in male mice increases aggressive behavior and/or timid responses (withdrawal and freezing to the approach/contact of the opponent male) when tested in adulthood. Individually housed males exposed to the cage used by other individually housed males did not show any change in aggressive behavior or timid responses, but the exposure to the cage used by grouped males reduced aggressive behavior. In female mice, individual housing after weaning increased only timid responses when tested in adulthood. These results suggest that such an enhanced timid response is the fundamental trait of individually housed mice, and that substances contained in the excrement of grouped males are involved in the control of aggression.