雌雄同居对子午沙鼠情绪及下丘脑催产素表达的影响

雌雄同居是配偶关系形成的重要阶段，涉及到一系列生理和情绪的变化，对长期稳定的配偶关系形成具有重要意义。然而由于单配制动物模型较少，雌雄同居过程中的神经调控，尤其是两性差异仍不清楚。本研究以室内繁殖的子午沙鼠(Meriones meridianus)为研究对象，采用高架十字迷宫、强迫游泳和免疫组化法，探究雌雄同居对雌雄子午沙鼠的情绪变化及其相关脑区催产素表达的影响。结果表明：雌雄同居10 d后，在高架十字迷宫中，雌性沙鼠进入开放臂的频次显著减少(P <0.05)，焦虑指数显著升高(P <0.05)；在强迫游泳实验中，同居组雌性沙鼠停止游泳的频次和时间显著增加(P <0.05)；同居组雌性沙鼠在下丘脑室旁核和视上核中的催产素表达水平显著升高(P <0.05)。然而同居组雄性的行为和催产素水平均没有出现显著变化，这可能与雌雄配偶关系形成过程中的两性不同步有关。综上，雌雄同居仅使得雌性子午沙鼠表现出焦虑样行为，且下丘脑催产素系统可能参与了该过程。

Effects of cohabitation on emotion and hypothalamic oxytocin expression in middy gerbils

Cohabitation between male and female is an important stage of long lasting pair bonding, which involves a series of physical and emotional changes. However, due to the lack of monogamous animal models, the neurobiological regulation, especially the sex difference, in the process of pair bonding is still unclear. In this study, we investigated the effects of male and female cohabitation on emotion and the numbers of oxytocin-neuron in relative brain regions in middy gerbils (Meriones meridianus) using elevated plus maze, forced swimming and immunohistochemical methods. The results showed that, after 10 days of cohabitation, the frequency of entering the open arm of female gerbils in the cohabitation group (FF) was significantly decreased (P < 0.05), and the anxiety index was significantly increased (P < 0.05). In the forced swimming experiment, the frequency and time in immobility in FF were significantly increased (P < 0.05). The expression level of oxytocin in paraventricular nucleus and supraoptic nucleus of hypothalamus in FF was significantly increased (P < 0.05). However, there were no significant changes in behavior and oxytocin levels in cohabiting males, which may be related to sexual dyssynchrony in the formation of pair bonds. In conclusion, cohabitation only causes anxiety-like behavior in female middy gerbils, which may be related to hypothalamic oxytocin system.