Graded hypoxia acts through a network of distributed peripheral oxygen chemoreceptors to produce changes in respiratory behaviour and plasticity
Graded hypoxia acts through a network of distributed peripheral oxygen chemoreceptors to produce changes in respiratory behaviour and plasticity
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DOI：
10.1111/ejn.12940
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发表时间：
2015-07-01
影响因子：
3.4
通讯作者：
Syed, Naweed I.
中科院分区：
文献类型：
--
作者：
Janes, Tara A.;Xu, Fenglian;Syed, Naweed I.
呼吸行为在很大程度上依赖于外周氧化学感受器的感觉反馈。在环境或全身缺氧期间，化学感受器的输入调节呼吸中枢模式发生器的活动，以产生基于反射的呼吸增加，并在更长的时间尺度上塑造呼吸可塑性。研究最多的氧化学感受器无疑是哺乳动物的颈动脉小体；然而，关于这个复杂的器官在影响呼吸以响应不同的氧气水平方面的作用仍然存在疑问。此外，许多分类群在肺、呼吸道和心血管系统都有不同的氧化学感受器，但多个化学感受器位置的功能优势尚不清楚。在这项研究中，证明了木兰中存在一个分布着的外周氧化学感受器网络，并显著地调节着空气呼吸。具体地说，淋巴呼吸频率和持续时间代表的参数是由缺氧严重程度及其时间过程之间的相互作用形成的。采用行为学和电生理学相结合的方法，探索了低氧引起的呼吸频率/持续时间变化背后的化学感觉通路。目前的发现表明，在中度缺氧时，呼吸频率独特地受到已知的中枢神经节氧化学感受器的调节，而新发现的气孔氧化学感受区在更严重的缺氧中具有类似的功能。综上所述，这些发现表明，多个氧化学感觉部位，每个都有自己的感觉和调节特性，协同作用，形成一个功能分布的网络，该网络动态地塑造呼吸，以响应系统或环境氧水平的变化。这些分布式网络可能代表了一种进化保守的呼吸适应性策略，并对理解基本的呼吸控制系统具有重要意义。
Respiratory behaviour relies critically upon sensory feedback from peripheral oxygen chemoreceptors. During environmental or systemic hypoxia, chemoreceptor input modulates respiratory central pattern generator activity to produce reflex-based increases in respiration and also shapes respiratory plasticity over longer timescales. The best-studied oxygen chemoreceptors are undoubtedly the mammalian carotid bodies; however, questions remain regarding this complex organ's role in shaping respiration in response to varying oxygen levels. Furthermore, many taxa possess distinct oxygen chemoreceptors located within the lungs, airways and cardiovasculature, but the functional advantage of multiple chemoreceptor sites is unclear. In this study, it is demonstrated that a distributed network of peripheral oxygen chemoreceptors exists in Lymnaea stagnalis and significantly modulates aerial respiration. Specifically, Lymnaea breath frequency and duration represent parameters that are shaped by interactions between hypoxic severity and its time-course. Using a combination of behaviour and electrophysiology approaches, the chemosensory pathways underlying hypoxia-induced changes in breath frequency/duration were explored. The current findings demonstrate that breath frequency is uniquely modulated by the known osphradial ganglion oxygen chemoreceptors during moderate hypoxia, while a newly discovered area of pneumostome oxygen chemoreception serves a similar function specifically during more severe hypoxia. Together, these findings suggest that multiple oxygen chemosensory sites, each with their own sensory and modulatory properties, act synergistically to form a functionally distributed network that dynamically shapes respiration in response to changing systemic or environmental oxygen levels. These distributed networks may represent an evolutionarily conserved strategy vis-a-vis respiratory adaptability and have significant implications for the understanding of fundamental respiratory control systems.