Animals in the wild must balance food intake with vigilance for predators in order to survive. The optic tectum plays an important role in the integration of external (predators) and internal (energy status) cues related to predator defense and prey capture. However, the role of neuromodulators involved in tectal sensorimotor processing is poorly studied. Recently we showed that tectal CRFR1 receptor activation decreases food intake in the South African clawed frog, Xenopus laevis, suggesting that CRF may modulate food intake/predator avoidance tradeoffs. Here we use a behavioral assay modeling food intake and predator avoidance to test the role of CRFR1 receptors and energy status in this tradeoff. We tested the predictions that 1) administering the CRFR1 antagonist NBI-27914 via the optic tecta will increase food intake and feeding-related behaviors in the presence of a predator, and 2) that prior food deprivation, which lowers tectal CRF content, will increase food intake and feeding-related behaviors in the presence of a predator. Pre-treatment with NBI-27914 did not prevent predator-induced reductions in food intake. Predator exposure altered feeding-related behaviors in a predictable manner. Pretreatment with NBI-27914 reduced the response of certain behaviors to a predator but also altered behaviors irrelevant of predator presence. Although 1-wk of food deprivation altered some non-feeding behaviors related to energy conservation strategy, food intake in the presence of a predator was not altered by prior food deprivation. Collectively, our data support a role for tectal CRFR1 in modulating discrete behavioral responses during predator avoidance/foraging tradeoffs.

中文翻译：

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Tectal CRFR1受体参与南非爪蛙Xenopus laevis的回避和进近行为。

为了生存，野外动物必须平衡食物摄入量并保持警惕。在与捕食者防御和猎物捕获有关的外部（捕食者）和内部（能量状态）线索的整合中，光学保护层起着重要作用。然而，神经调节剂在顶盖感觉运动过程中的作用研究很少。最近，我们显示了金属表面CRFR1受体的激活减少了南非爪蛙Xenopus laevis的食物摄入，这表明CRF可能会调节食物摄入/捕食者回避的权衡。在这里，我们使用行为分析来模拟食物摄入和避免捕食者，以测试CRFR1受体的作用和能量状态。我们测试了以下预测：1）在存在掠食者的情况下，通过视神经支配施用CRFR1拮抗剂NBI-27914将增加食物的摄入量和与进食相关的行为，以及2）先前的食物匮乏（其降低了总配体CRF含量）将增加捕食者在场时与食物摄入和喂养有关的行为。用NBI-27914进行的预处理并不能防止捕食者引起的食物摄入减少。捕食者的暴露以可预测的方式改变了与喂养有关的行为。用NBI-27914进行的预处理减少了某些行为对掠食者的反应，但也改变了与掠食者的存在无关的行为。尽管每周一度的食物匮乏改变了与节能策略有关的一些非进食行为，但在捕食者存在的情况下，食物摄取并没有因先前的食物匮乏而改变。