Behavioral and endocrine evaluation of the stressfulness of single-pen housing compared to group-housing and social isolation conditions
Behavioral and endocrine evaluation of the stressfulness of single-pen housing compared to group-housing and social isolation conditions
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DOI：
10.1016/j.physbeh.2015.04.013
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发表时间：
2015-08-01
影响因子：
2.9
通讯作者：
Chaillou, Elodie
中科院分区：
文献类型：
--
作者：
Guesdon, Vanessa;Meurisse, Maryse;Chaillou, Elodie
神经内分泌反应的调节通常在室内连续圈养的动物中进行研究。在绵羊身上，这些住房条件被用来控制环境，促进生物采样，并限制社会压力。然而，这种类型的住房也会阻止探索性行为，并可能导致刻板印象，与福利不符，可能与压力状态有关。在此背景下，我们通过评估成年母羊的行为、荷尔蒙和神经元指标，研究了单圈饲养和其他常见的共同特征对情绪状态的影响。我们假设，在单圈饲养一周的动物(Pen)中，情绪状态会比自由活动的动物(Free)中的情绪状态更负面，但比社交孤立的受试者(Iso)中的情绪状态更负面。我们在去卵巢的母羊身上测试了我们的假设，以避免与性类固醇变异的相互作用。我们的行为、内分泌和神经元(下丘脑室旁核促肾上腺皮质激素释放激素神经元的Fos激活)测量证实，撤除熟悉的同种物质足以在isol绵羊中诱导强烈的应激反应，但没有迹象表明Pen ewes处于应激状态。然而，后者表现出比自由母羊更少的咀嚼活动，可能是由于获得稻草的机会有限。Iso和Free动物的血浆催乳素水平最高，这可能分别是应激和体力活动的结果。在自由母羊中，血浆中的多巴胺水平较低，这与其对催乳素的抑制控制一致。然而，isol动物同时具有高水平的催乳素和多巴胺，这表明社交压力下的母羊存在失衡的平衡。正如在其他物种中一样，我们认为多巴胺对催乳素的调节随着压力和/或社会背景的不同而不同。总体而言，这项研究表明，未来应该更多地考虑住房条件对不同神经内分泌系统的影响。(C)2015 Elsevier Inc.保留所有权利。
Regulation of neuroendocrine responses is often studied in animals housed indoors in individual contiguous pens. In sheep, these housing conditions are used to control the environment, facilitate biological sampling and limit social stress. However, this type of housing also prevents exploratory behaviors and could induce stereotypies, non-compliant with welfare and possibly associated with a state of stress. In this context, we investigated the impact of housing in a single-pen, with other familiar conspecifics, on emotional state by evaluating behavioral, hormonal and neuronal measures in adult ewes. We hypothesized that emotional state would be more negative in animals housed in a single-pen for one week (Pen) than in freely moving animals (Free) but less negative than in socially isolated subjects (Isol). We tested our hypothesis in ovariectomized ewes to avoid the interaction with sexual steroid variations. Our behavioral, endocrine and neuronal (Fos activation of the corticotropin-releasing hormone neurons in the paraventricular nucleus of the hypothalamus) Measures confirmed that withdrawing familiar conspecifics was sufficient to induce strong stress responses in Isol ewes, but there was no indication that Pen ewes were stressed. However, the latter showed less mastication activity than Free ewes, probably due to limited accessibility to straw. The highest plasma prolactin levels were observed in Isol and Free animals, which might result from stress and physical activity, respectively. In Free ewes, plasma dopamine was low, consistent with its inhibitory control of prolactin. However, Isol animals had both high levels of prolactin and dopamine, suggesting a dysregulated balance in socially stressed ewes. As in other species, we suggest that the regulation of prolactin by dopamine varies with stress and/or social context. Overall, this study shows that the impact of housing conditions on different neuroendocrine systems should be considered more in the future. (C) 2015 Elsevier Inc. All rights reserved.