Social interaction with unfamiliar individuals is necessary for species-preserving behaviors such as finding mates and establishing social groups. However, social conflict is a potential negative outcome to interaction with a stranger that can be distressing enough to cause an individual to later avoid interactions with other unfamiliar conspecifics. Unfortunately, stress research using a prominent model of social conflict, social defeat stress, has largely omitted female subjects. This has left a void in the literature regarding social strain on female stress biology and adequate comparison of the effect of sex in stress pathways. The prairie vole (Microtus ochrogaster) exhibits aggressive behavior in both sexes, making voles an attractive candidate to model social defeat in both sexes. This study sought to establish a model of social defeat stress in both male and female prairie voles, characterize behavioral changes in response to this stressor, and investigate the role of dopamine signaling in the response to social defeat stress. Defeated male and female prairie voles displayed social avoidance as well as an increase in the level of dopamine receptor D1 (DRD1) in the medial amygdala (MeA). Pharmacological manipulation of DRD1 signaling in the MeA revealed that increased DRD1 signaling is sufficient to induce a social avoidant state, and could be a necessary component in the defeat-induced social avoidance response. These findings provide the prairie vole as a model of social defeat in both sexes, and implicate the MeA in avoidance of unfamiliar conspecifics after a distressing social encounter.

中文翻译：

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雄性和雌性草原田鼠的内侧杏仁核 DRD1 调节失败引起的社交回避

与不熟悉的个体的社会互动对于物种保护行为（例如寻找配偶和建立社会群体）是必要的。然而，社会冲突是与陌生人互动的潜在负面结果，这可能会令人痛苦到足以导致个人以后避免与其他不熟悉的同种人互动。不幸的是，使用突出的社会冲突模型，社会失败压力的压力研究在很大程度上忽略了女性受试者。这在关于女性压力生物学的社会压力和性别对压力途径影响的充分比较的文献中留下了空白。草原田鼠（Microtus ochrogaster）在两性中都表现出攻击性行为，使田鼠成为模拟两性社会失败的有吸引力的候选者。本研究旨在建立雄性和雌性草原田鼠的社会失败压力模型，表征响应该压力源的行为变化，并研究多巴胺信号在应对社会失败压力中的作用。被击败的雄性和雌性草原田鼠表现出社交回避以及内侧杏仁核 (MeA) 中多巴胺受体 D1 (DRD1) 的水平增加。MeA 中 DRD1 信号的药理学操作表明，增加的 DRD1 信号足以诱导社交回避状态，并且可能是失败诱导的社交回避反应的必要组成部分。这些发现提供了草原田鼠作为两性社会失败的模型，并暗示 MeA 在痛苦的社会遭遇后避免不熟悉的同种动物。