INTEGRATIVE REFLEX DYNAMICS IN RESPIRATORY CYCLE CONTROL

这一建议解决了这样的假设，即呼吸变异性 由于控制呼气末的机制存在“不稳定性” 具有顺应性胸壁的动物的体积(EEV)。这种“不稳定” 是非线性动力学意义上的一种复杂的不规则行为。 我们假设这是由于时变的非线性相互作用造成的。 具有整合中枢机制的肺机械感受器反馈 用于呼吸节律和模式的形成。我们已经描述了 呼吸相变对迷走神经传入活动的敏感性 会导致不同的呼吸模式。这一效果在以下过程中被突出 持续气道负压(CNAP)引起的肺放气，并可能 部分原因是对通缩敏感，适应缓慢的肺感受器 (DSARS)。本提案研究完整的上呼吸道，以 研究上述控制EEV的机制之间的相互作用 通过改变呼吸相变的动力学)与其他 调节上呼吸道呼气控制EEV的机制 活动。因为这两组机制都是由肺组织调节的 机械感受器反馈，我们假设它们的相互作用将 增加呼吸模式的可变性，可能会对 撞击气体交换。此外，我们还将评估化学驱动 影响这些机制。我们还将描述DSAR的特征，比较 它们有肺伸展和快速适应的受体和 确定了它们的一些主要投射。拟议的研究将 通过以下方式扩展目前关于呼吸模式反射控制的概念 检查迷走神经介导的反射的呼吸对呼吸的重复性 影响并阐明了一些预计会损害这种作用的机制 再现性。此外，与呼吸行为的类比 人类新生儿表明，预期的发现具有更广泛的适用性。

This proposal addresses the hypothesis that respiratory variability is due to an 'instability' in mechanisms for the control of end-expiratory volume (EEV) in animals with compliant chest walls. This 'instability' is a form of complex irregular behavior in the nonlinear dynamics sense. We hypothesize that it is due to interactions of time-varying nonlinear pulmonary mechanoreceptor feedback with integrative central mechanisms for respiratory rhythm and pattern formation. We have described how the sensitivity of respiratory phase transitions to vagal afferent activity causes a variable breathing pattern. This effect is accentuated during lung deflation by continuous negative airway pressure (CNAP) and may be due partly to deflation-sensitive, slowly-adapting pulmonary receptors (DSARS). The present proposal studies intact upper airways to investigate the interactions of the above mechanisms (which control EEV by altering dynamics of respiratory phase transitions) with other mechanisms which control EEV by modulating upper airway expiratory activity. Because both groups of mechanisms are modulated by pulmonary mechanoreceptor feedback, we hypothesize that their interactions will increase the variability of the breathing pattern and may adversely impact gas exchange. additionally we will assess how chemical drive affects these mechanisms. We will also characterize DSARs, comparing them with pulmonary stretch and rapidly-adapting receptors and identifying some of their central projections. The proposed studies will extend current concepts about reflex control of respiratory pattern by examining the breath to breath reproducibility of vagally-mediated reflex effects and elucidating some mechanisms which are expected to impair this reproducibility. Furthermore, analogies with respiratory behavior in human neonates suggest broader applicability of the expected findings.