CAROTID CHEMO--BARORECEPTORS ROLE IN APNEA & HYPERPNEA

我们开发了一种独特的非麻醉动物模型，在该模型中， 颈动脉窦区可以被隔离并独立于 体循环与血气、灌注压和化学 由调查人员控制。这将允许我们测试 特异性颈动脉化学和压力感受器刺激的通气性 单独或与系统(因此是中枢神经系统)的变化结合在一起 化学反应或血压。我们将解决三个具体问题； 1.颈动脉化学感受器刺激(生理水平的K+， 去甲肾上腺素、乳酸)和/或它们的相互作用有助于 运动性呼吸亢进？血气有通气作用吗？ 震荡？这些刺激是如何与低碳酸血症相互作用的？ 2.中枢神经系统缺氧本身对 呼吸和呼吸肌的大小、稳定性和时机 招聘？中枢神经系统缺氧对“滚落”有贡献吗？中枢神经系统缺氧吗 影响化学感受器传入的中枢整合？中枢神经系统是否 低氧影响上呼吸道肌肉的相对募集？在那里吗 睡眠状态的影响？中枢神经系统缺氧在周期性脑损伤中起作用吗 呼吸？ 3.颈动脉血压的一过性生理性变化 窦导致呼吸不稳定、中枢性呼吸暂停和/或 上呼吸道阻力？压力感受器和压力感受器之间是否存在相互作用 化学感受器反馈？ 我们的新动物模型使我们有能力研究 在完整的制剂中参与心肺控制的反射 在清醒状态、睡眠的所有阶段和锻炼过程中获得反馈。 这些反射与上呼吸道的控制直接相关。 通畅性、气体交换和血压，特别是在睡眠期间，以及 应该为睡眠障碍的病理生理学提供洞察力 呼吸。体力活动引起的呼吸暂停是最常见的 生理性呼吸亢进，但其机制仍不清楚 明白了。我们的研究，在一个具有完整反馈的生理模型中 收益，也应该回答几个关于 运动性呼吸暂停的控制。

We have developed an unique unanesthetized animal model in which the carotid sinus region can be isolated and perfused independently of the systemic circulation with blood gases, perfusion pressure, and chemistry controlled by the investigators. This will allow us to test the ventilatory effects of specific carotid chemo- and baroreceptor stimuli separately or in conjunction with changes in systemic (and therefore CNS) chemistry or blood pressure. We will address three specific questions; 1. Do carotid chemoreceptor stimuli (physiological levels of K+, norepinephrine, lactic acid) and/or their interactions contribute to exercise hyperpnea? Is there a ventilatory effect of blood gas oscillations? How do these stimuli interact with hypocapnia? 2. What is the effect of central nervous system hypoxia, by itself, on magnitude, stability, and timing of breathing and respiratory muscle recruitment? Does CNS hypoxia contribute to "roll off"? Does CNS hypoxia affect central integration of chemoreceptor afferent input? Does CNS hypoxia affect the relative recruitment of upper airway muscles? Is there an effect of sleep state? Does CNS hypoxia play a role in periodic breathing? 3. Can transient, physiological changes in blood pressure at the carotid sinus contribute to unstable breathing, central apnea, and/or changes in upper airway resistance? Is there interaction between baroreceptor and chemoreceptor feedback? Our new animal model gives us the ability to study fundamental aspects of reflexes involved in cardiorespiratory control in a preparation with intact feedback gains during wakefulness, all stages of sleep, and exercise. These reflexes have direct relevance to the control of upper airway patency, gas exchange, and blood pressure, especially during sleep, and should provide insights into the pathophysiology of sleep disordered breathing. Hyperpnea in response to physical activity is the most common physiological hyperpnea of all, yet its mechanisms are still not well understood. our studies, in a physiological model with intact feedback gains, should also answer several fundamental questions concerning the control of exercise hyperpnea.