Social isolation and the disruption of established social bonds contribute to several physical and psychological health issues. Animal models are a useful tool for investigating consequences of social stress, including social isolation. The current study examined morphological changes in the basolateral amygdala (BLA) and affect-related behavioral and endocrine changes due to prolonged social isolation, using the translational prairie vole model (Microtus ochrogaster). Adult male prairie voles were either socially paired (control) or isolated from a same-sex sibling for 4 weeks. Following this 4-week period, a subset of animals (n = 6 per condition) underwent a series of behavioral tasks to assess affective, social, and stress-coping behaviors. Plasma was collected following the last behavioral task for stressor-induced endocrine assays. Brains were collected from a separate subset of animals (n = 10 per condition) following the 4-week social housing period for dendritic structure analyses in the BLA. Social isolation was associated with depressive- and anxiety-like behaviors, as well as elevated oxytocin reactivity following a social stressor. Social isolation was also associated with altered amount of dendritic material in the BLA, with an increase in spine density. These results provide further evidence that social isolation may lead to the development of affective disorders. Dysfunction in the oxytocin system and BLA remodeling may mediate these behavioral changes. Further research will promote an understanding of the connections between oxytocin function and structural changes in the BLA in the context of social stress. This research can facilitate novel treatments for alleviating or preventing behavioral and physiological consequences of social stressors in humans.

社会孤立和已建立的社会纽带的破坏导致了一些身心健康问题。动物模型是研究社会压力后果（包括社会孤立）的有用工具。目前的研究使用平移草原田鼠模型 ( Microtus ochrogaster )检查了基底外侧杏仁核 (BLA) 的形态变化以及由于长期社会隔离而导致的与情感相关的行为和内分泌变化。成年雄性草原田鼠要么在社会上配对（对照），要么与同性兄弟姐妹隔离 4 周。在这 4 周之后，一部分动物（n = 每个条件 6 个）进行了一系列行为任务，以评估情感、社交和压力应对行为。在压力源诱导的内分泌测定的最后一个行为任务之后收集血浆。大脑是从一个单独的动物子集中收集的（n = 每个条件 10 个）在 BLA 中用于树突结构分析的 4 周社会住房期之后。社交孤立与抑郁和焦虑样行为以及社交压力源后催产素反应性升高有关。社会隔离还与 BLA 中树突状物质数量的改变以及脊柱密度的增加有关。这些结果进一步证明社会孤立可能导致情感障碍的发展。催产素系统功能障碍和 BLA 重塑可能介导这些行为变化。进一步的研究将促进对社会压力背景下催产素功能与 BLA 结构变化之间联系的理解。