MECHANISMS OF RESPIRATORY MUSCLE COORDINATION

越来越多的吸气肌肉的招募活动， 增加呼吸压力似乎是一种基本策略， 哺乳动物的呼吸行为 协调激活各种 呼吸肌，以实现特定的呼吸模式， 一种可能的使呼吸的能量或其他成本最小化的方法， 特别是在压力或疾病的情况下。 本提案的目的 是识别和表征中枢神经和外周反射 同时激发吸气的机制 肌肉. 频率范围为4-120的高频振荡（HFO） Hz的呼吸运动神经团放电活动将被确定 使用功率谱和相干谱分析技术。 HFO的 将被视为两个或更多个公共驱动输入的“标记” 运动神经元池，当它们在相应的神经中相关时 活动 膈神经、各种外部肋间神经、舌下神经和 将分析喉返神经活动。 的影响 各种刺激对个体神经活动中HFO存在的影响， 特别是，在吸气中的相关HFO的分布 神经将被评估。 刺激包括：高碳酸血症，缺氧， 来自腹侧延髓表面的神经输入（通过局部冷却改变 或药物应用），以及来自丘脑底运动区的驱动。 的 脊髓上行传入束损伤对HFO的影响将是 测定，以及HFO在膈神经活动中的关系 并研究单根膈纤维的放电模式。 在 此外，除最后一项研究外，所有上述研究均将在小猫中进行， 年龄范围为5-60天，以确定产后发育 呼吸运动神经HFO 根据这些数据，我们将确定 可能重要的机制的功能特征 在呼吸肌活动的协调，并确定其 在应对化学和其他压力方面相对重要。 我们 得出关于神经解剖学位点的推论， HFO的产生和传播。 最后，我们将评估 参与生产的中枢神经结构的成熟 HFO，并且可以是中枢呼吸节律发生器的组件。

The recruitment of more and more inspiratory muscles to activity as respiratory stress increases seems to be a fundamental strategy in mammalian respiratory behavior. Coordinated activation of the various respiratory muscles in order to achieve particular patterns of breathing is a likely means of minimizing the energetic or other costs of breathing, especially in stress or disease situations. The objective of this proposal is to identify and characterize central neural and peripheral reflex mechanisms which underly the simultaneous excitation of inspiratory muscles. High frequency oscillations (HFO's) in the frequency range 4-120 Hz in respiratory motor nerve mass discharge activities will be identified using power spectral and coherence spectral analysis techniques. HFO's will be considered as "markers" of common drive inputs to two or more motoneuron pools when they are correlated in the corresponding nerve activities. Phrenic, various external intercostal, hypoglossal, and recurrent laryngeal nerve activities will be analyzed. The effects of various stimuli on the presence of HFO's in individual nerve activity and, particularly, on the distribution of correlated HFO's among the inspiratory nerves will be assessed. Stimuli will include: hypercapnia, hypoxia, neural inputs from the ventral medullary surface (altered by local cooling or drug applications), and drives from subthalamic motor areas. The effects of lesioning of ascending spinal afferent tracts on HFO's will be determined, and the relationship between HFO's in phrenic nerve activity and the firing patterns of single phrenic fibers will be studied. In addition, all the above studies except the last will be done in kittens at ages ranging from 5-60 days in order to determine the postnatal development of respiratory motor nerve HFO's. From these data we will determine the functional characteristics of mechanisms which are likely to be important in the coordination of respiratory muscle activities and determine their relative importance in responding to chemical and other stresses. We would draw inferences regarding the neuroanatomical loci responsible for the generation and propogation of the HFO's. Finally, we would assess the maturation of central neural structures that are involved in the production HFO's and may be components of central respiratory rhythm generator(s).