The chronic variable stress (CVS) paradigm is frequently used to model the changes in hypothalamic pituitary adrenal (HPA) axis function characteristic of many stress-related diseases. However, male C57BL/6 mice are typically resistant to CVS’s effects, making it difficult to determine how chronic stress exposure may alter acute HPA function and regulation in these mice. As social support in rodents can profoundly influence physiological and behavioral processes, including the HPA axis, we sought to characterize the effects of CVS exposure on basal and acute stress-induced HPA axis function in pair- and single-housed adult male mice. Despite all subjects exhibiting decreased body weight gain after six weeks of CVS, the corticosterone response to a novel, acute restraint stressor was enhanced by CVS exclusively in single-housed males. CVS also significantly increased arginine vasopressin (AVP) mRNA in the hypothalamic paraventricular nucleus (PVN) in single-housed males only. Moreover, in single-, but not pair-housed mice, CVS attenuated decreases in circulating OT found following acute restraint. Only the effect of CVS to elevate PVN corticotropin releasing hormone (CRH) mRNA levels after an acute stressor was restricted to pair-housed mice. Collectively, our findings suggest that social isolation reveals effects of CVS on the HPA axis in male C57BL/6 mice.

慢性可变压力（CVS）范例通常用于模拟许多与压力有关的疾病的下丘脑垂体肾上腺（HPA）轴功能特征的变化。但是，雄性C57BL / 6小鼠通常对CVS的作用具有抗性，因此很难确定长期应激暴露如何改变这些小鼠的急性HPA功能和调节。由于啮齿动物的社会支持可以深刻影响包括HPA轴在内的生理和行为过程，因此我们试图表征CVS暴露对成对和单笼成年雄性小鼠基础和急性应激诱导的HPA轴功能的影响。尽管所有受试者在CVS六周后均表现出体重减轻，但仅在单身男性中，CVS增强了皮质酮对新型急性束缚应激源的反应。CVS还仅在单笼男性中下丘脑室旁核（PVN）中显着增加精氨酸加压素（AVP）mRNA。此外，在单只但不是成对饲养的小鼠中，CVS减弱了急性约束后发现的循环OT的降低。在急性应激源后，只有CVS能够提高PVN促肾上腺皮质激素释放激素（CRH）mRNA水平的作用仅限于成对饲养的小鼠。总体而言，我们的发现表明，社会隔离揭示了CVS对雄性C57BL / 6小鼠HPA轴的影响。仅CVS在急性应激源后升高PVN促肾上腺皮质激素释放激素（CRH）mRNA水平的作用仅限于成对饲养的小鼠。总体而言，我们的发现表明，社会隔离揭示了CVS对雄性C57BL / 6小鼠HPA轴的影响。仅CVS在急性应激源后升高PVN促肾上腺皮质激素释放激素（CRH）mRNA水平的作用仅限于成对饲养的小鼠。总的来说，我们的发现表明，社会隔离揭示了CVS对雄性C57BL / 6小鼠HPA轴的影响。