Department of Psychology, University of California, Davis, CA 95616, USA.
Horm Behav. 2013 Mar;63(3):543-50. doi: 10.1016/j.yhbeh.2013.01.011. Epub 2013 Feb 4.
There is compelling evidence for important sex differences in behavioral and hormonal responses to psychosocial stress. Here we examined the effects of gonadal hormones on behavioral responses to social defeat stress in monogamous California mice (Peromyscus californicus). Three episodes of social defeat induced social withdrawal in intact females but not males. Gonadectomy blocked corticosterone responses to defeat in females and sensitized male corticosterone responses. However, gonadectomy had no effects on social interaction behavior, suggesting that social withdrawal is not dependent on gonadal hormones in the adult California mouse. In contrast, defeat reduced exploratory behavior in the open field test for intact but not castrated males. We also examined the effects of social defeat on social interaction behavior when California mice were raised on corncob bedding, which has estrogenic properties. In this dataset of over 300 mice, we observed that social defeat did not induce social withdrawal when females were raised on corncob bedding. This finding suggests that the use of corncob in rodent studies could mask important sex differences in the effects of stress on brain and behavior. Although gonadal hormones do not affect social withdrawal behavior in adults, our data suggest that hormones may act earlier in development to induce a more resilient social phenotype.
有确凿的证据表明，性行为和荷尔蒙对心理社会应激的反应存在重要的性别差异。在这里，我们研究了性腺激素对单配制加利福尼亚鼠（Peromyscus californicus）对社交挫败应激的行为反应的影响。三次社交挫败诱导未去势雌性出现社交回避，但雄性没有。去势阻断了雌性对挫败的皮质酮反应，并使雄性皮质酮反应敏感化。然而，去势对社交互动行为没有影响，这表明成年加利福尼亚鼠的社交回避行为不依赖于性腺激素。相反，挫败降低了完整雄性在开阔场测试中的探索行为，但对去势雄性没有影响。我们还研究了当加利福尼亚鼠在具有雌激素特性的玉米芯床上饲养时，社交挫败对社交互动行为的影响。在这个超过 300 只老鼠的数据集，我们观察到当雌性在玉米芯床上饲养时，社交挫败不会引起社交回避。这一发现表明，在啮齿动物研究中使用玉米芯可能会掩盖应激对大脑和行为影响的重要性别差异。尽管性腺激素不会影响成年动物的社交回避行为，但我们的数据表明，激素可能在发育早期发挥作用，诱导更具弹性的社交表型。
