INTEGRATIVE REFLEX DYNAMICS IN RESPIRATORY CYCLE CONTROL

呼吸循环控制中的综合反射动力学

• 批准号: 6296864
• 负责人: EUGENE N BRUCE
• 金额: $ 18.51万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6296864
• 关键词: afferent nerve; brain stem; chemoreceptors; electromyography; laboratory rat; mechanoreceptors; neural information processing; pulmonary respiration; pulmonary stretch receptors; respiratory airway volume; respiratory reflex; vagus nerve

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.

该提议解决了以下假设：呼吸可变性是 由于控制最终呼吸器的机制“不稳定” 具有符合胸壁的动物中的体积（EEV）。 这个“不稳定” 在非线性动力学意义上是复杂不规则行为的一种形式。 我们假设这是由于时间变化的非线性的相互作用 具有整合中心机制的肺机械感受器反馈 用于呼吸节奏和图案形成。 我们已经描述了如何 向迷走神经活动的呼吸相跃迁的敏感性 引起可变的呼吸模式。 这种效果在 连续负气道压力（CNAP）的肺部放气，可能是 部分原因是对通气敏感的，缓慢适应的肺受体 （DSARS）。 目前的提案研究完整的上呼吸道 研究上述机制的相互作用（哪些控制EEV 通过改变呼吸相变的动力学） 通过调节上呼吸道呼气来控制EEV的机制 活动。 因为两组机制均由肺部调节 机械感受器的反馈，我们假设它们的相互作用将 增加呼吸模式的变异性，可能会不利 影响气体交换。 此外，我们将评估化学驱动方式 影响这些机制。 我们还将描述DSAR，比较 它们具有肺部拉伸和快速适应受体，以及 确定他们的一些中心预测。 拟议的研究将 扩展了有关反射控制呼吸模式的当前概念 检查呼吸以重现模糊介导的反射 效果并阐明了一些预期会损害这一点的机制 可重复性。 此外，与呼吸行为的类比 人类新生儿表明预期发现的更广泛适用性。