Behaviors, emotions, and cardiovascular functions are influenced by stress. But these detrimental effects are not exclusive to an individual that directly experiences stress. Stress is also experienced vicariously through observation of another individual undergoing stress. The current study used the strong social bonds in socially monogamous prairie voles to determine effects of repeated vicarious stress on cardiac and behavioral outcomes. Male prairie voles were exposed to either a 5-minute open field chamber alone [separate (control)] or while concurrently witnessing their sibling undergo a tail-suspension stressor [concurrent (experimental)], repeated across 4 sessions. Cardiac responses in animals in the open field were evaluated for heart rate and heart rate variability prior to, during, and after each test session, and behaviors were evaluated for motion, exploration, stress reactivity, and anxiety-relevant behaviors during each test session. The concurrent condition (versus separate) displayed increased heart rate and reduced heart rate variability during repeated test sessions, and impaired recovery of these parameters following the test sessions. The pattern of disturbances suggests that both increased sympathetic and reduced parasympathetic influence contributed to the cardiac responses. Animals in the concurrent condition (versus separate) displayed disrupted rearing, grooming, and motion; reduced duration of center section exploration; and increased freezing responses across repeated test sessions. Collectively, cardiac and behavioral stress reactivity are increased as a function of vicarious stress in prairie voles, which are evident across repeated experiences of stress. These results inform our understanding of the experience of vicarious stress in social species, including humans.

行为、情绪和心血管功能都会受到压力的影响。但这些有害影响并非直接经历压力的个人所独有。通过观察另一个承受压力的人，也可以间接感受到压力。目前的研究利用社会一夫一妻制的草原田鼠的强大社会联系来确定重复替代压力对心脏和行为结果的影响。雄性草原田鼠被单独暴露于 5 分钟的露天室中[单独（对照）]，或者同时目睹其同胞经历尾部悬挂应激源[同时（实验）]，在 4 个疗程中重复。在每次测试之前、期间和之后评估旷场动物的心率和心率变异性心脏反应，并评估每次测试期间的运动、探索、应激反应和焦虑相关行为。并发条件（相对于单独条件）在重复测试过程中显示出心率增加和心率变异性降低，并且在测试过程后这些参数的恢复受损。干扰模式表明交感神经影响的增加和副交感神经影响的减少都有助于心脏反应。处于同时状态（相对于单独状态）的动物表现出饲养、梳理和运动的紊乱；减少中心段勘探的时间；并在重复的测试过程中增加了冻结反应。总的来说，草原田鼠的心脏和行为应激反应性随着替代应激的增加而增加，这在重复的应激经历中很明显。这些结果有助于我们了解包括人类在内的社会物种的替代压力经历。