Hannibal Darcy L, Cassidy Lauren C, Vandeleest Jessica, Semple Stuart, Barnard Allison, Chun Katie, Winkler Sasha, McCowan Brenda
California National Primate Research Center, University of California Davis, Davis, California.
Department of Population Health and Reproduction, University of California Davis, Davis, California.
Am J Primatol. 2018 May;80(5):e22762. doi: 10.1002/ajp.22762. Epub 2018 Mar 14.
Laboratory rhesus macaques are often housed in pairs and may be temporarily or permanently separated for research, health, or management reasons. While both long-term social separations and introductions can stimulate a stress response that impacts inflammation and immune function, the effects of short-term overnight separations and whether qualities of the pair relationship mediate these effects are unknown. In this study, we investigated the effects of overnight separations on the urinary cortisol concentration of 20 differentially paired adult female rhesus macaques (Macaca mulatta) at the California National Primate Research Center. These females were initially kept in either continuous (no overnight separation) or intermittent (with overnight separation) pair-housing and then switched to the alternate pair-housing condition part way through the study. Each study subject was observed for 5 weeks, during which we collected measures of affiliative, aggressive, anxious, abnormal, and activity-state behaviors in both pair-housing conditions. Additionally, up to three urine samples were collected from each subject per week and assayed for urinary free cortisol and creatinine. Lastly, the behavioral observer scored each pair on four relationship quality attributes ("Anxious," "Tense," "Well-meshed," and "Friendly") using a seven-point scale. Data were analyzed using a generalized linear model with gamma distribution and an information theoretic approach to determine the best model set. An interaction between the intermittent pairing condition and tense pair adjective rating was in the top three models of the best model set. Dominance and rates of affiliation were also important for explaining urinary cortisol variation. Our results suggest that to prevent significant changes in HPA-axis activation in rhesus macaque females, which could have unintended effects on research outcomes, pairs with "Tense" relationships and overnight separations preventing tactile contact should be avoided.
实验室中的恒河猴通常成对饲养，可能会因研究、健康或管理原因而暂时或永久分开。虽然长期的社会隔离和重新组合都会引发应激反应，影响炎症和免疫功能，但短期过夜隔离的影响以及配对关系的质量是否会介导这些影响尚不清楚。在本研究中，我们调查了过夜隔离对加利福尼亚国家灵长类动物研究中心20对不同配对的成年雌性恒河猴（猕猴）尿皮质醇浓度的影响。这些雌性恒河猴最初被置于连续（无过夜隔离）或间歇（有过夜隔离）配对饲养环境中，然后在研究过程中中途切换到另一种配对饲养条件。每个研究对象被观察5周，在此期间，我们收集了两种配对饲养条件下的亲和、攻击、焦虑、异常和活动状态行为的测量数据。此外，每周从每个对象收集多达三份尿液样本，检测尿游离皮质醇和肌酐。最后，行为观察者使用七点量表对每对恒河猴的四种关系质量属性（“焦虑”、“紧张”、“融洽”和“友好”）进行评分。使用具有伽马分布的广义线性模型和信息论方法分析数据，以确定最佳模型集。间歇配对条件与紧张配对形容词评分之间的相互作用在最佳模型集的前三个模型中。优势地位和亲和率对于解释尿皮质醇变化也很重要。我们的研究结果表明，为了防止恒河猴雌性下丘脑-垂体-肾上腺（HPA）轴激活发生显著变化，这可能对研究结果产生意想不到的影响，应避免具有“紧张”关系且过夜隔离会阻止触觉接触的配对。
