Chronic stress reverses enhanced neophobia following an acute stressor in European starlings
Chronic stress reverses enhanced neophobia following an acute stressor in European starlings
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慢性应激可逆转欧洲八哥在急性应激源后增强的新恐惧症
DOI：
10.1002/jez.2431
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Romero, L. Michael
中科院分区：
文献类型：
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作者：
de Bruijn, Robert;Romero, L. Michael
新恐惧症是一种动物对新奇事物的回避。动物倾向于通过增加它们接近对象的潜伏期来对新对象做出反应，在反复暴露后，它们最终会通过减弱这种增加的接近潜伏期来适应。有趣的是，生理应激反应似乎与新恐惧症没有因果联系，尽管急性应激可以阻止动物习惯于新物体，可能是通过一种允许的效应。慢性压力会导致动物处于类似焦虑的状态，同时通常会扰乱对急性压力的反应能力。因此，我们假设慢性压力可能会增加新的恐惧症，并通过在野生捕获的欧洲八哥(Sturnus Ual Garis)中诱导慢性压力来测试这一假设。四种不同的人为应激源以随机顺序每天给予每个30 分钟，持续21天。然后，我们评估了暴露在慢性压力下是否改变了接近放置在隔夜禁食后呈现的食物盘上或附近的新物体的潜伏期。长期应激的鸟类和非应激的对照组对新事物表现出相似的初始恐惧反应，并在重复暴露时表现出相似的习惯化反应。然而，当鸟类在重复接触同一物体之前暴露于15 分钟的束缚中，对照组鸟类的习惯化被消除(即，它们继续以新的恐惧症反应)，而长期应激的鸟类继续表现出习惯化，这是通过衰减的接近潜伏期来衡量的。这些结果表明，急性应激反应(约束)对新的恐惧症有不同的影响，这取决于鸟是否同时暴露在慢性压力下。
Neophobia is an animal's avoidance of novelty. Animals tend to respond to novel objects by increasing their latency to approach the objects, and they eventually habituate after repeated exposure by attenuating this increased approach latency. Interestingly, the physiological stress response does not appear to have a causal link to neophobia, although acute stress can prevent animals from habituating to novel objects, possibly through a permissive effect. Chronic stress can induce an anxiety‐like state in animals, while often disrupting the ability to respond to acute stress. We thus hypothesized that chronic stress may increase neophobia and tested this by inducing chronic stress in wild‐caught European starlings (Sturnus vulgaris). Four distinct anthropogenic stressors were administered daily for 30 min each in a randomized order for 21 days. We then evaluated whether exposure to chronic stress altered the latency to approach a novel object placed on or near a food dish presented after overnight fasting. Chronically stressed birds and nonstressed controls exhibited similar initial neophobic responses to novel objects and showed similar habituation in response to repeated exposure. However, when birds were exposed to 15 min of restraint before repeated exposure to the same object, habituation was eliminated in control birds (i.e., they continued to respond with neophobia), whereas chronically stressed birds continued to show habituation as measured by attenuated approach latencies. These results demonstrate that an acute stress response (restraint) has a different impact on neophobia depending upon whether the bird is or is not concurrently exposed to chronic stress.