POSTNATAL DEVELOPMENT OF RESPIRATORY ACTIVITES

呼吸神经元的发育和成熟， 两天内检查运动神经元放电特性， 两个月大的猪 将追求三个具体目标： 确定与年龄相关的吸气次数差异， 神经元的轴突终止于膈运动神经元池和 对肺传入输入的反应;（B）研究年龄相关的 神经元对缺氧反应的变化和鉴定神经元 介导膈运动神经元的缺氧反应; (c)比较膈神经、喉返神经的传出放电 和舌下神经运动神经元的调制差异， 中枢模式发生器，对肺传入神经的反应 输入和缺氧时的反应 实验将 在Saffan麻醉仔猪中进行;麻醉深度将 通过记录脑电图、心电图和动脉血压进行监测。 吸气神经元将被记录在细胞外， 肺传入输入将使用No 充盈试验。 在切断迷走神经的仔猪中， 根据功率谱的变化对缺氧进行分类。 对于所有神经元，将验证单个神经元记录 使用峰间期分布确定， 与膈运动神经元的兴奋性连接的存在将 使用尖峰触发平均来确定。 调制 由共同的中央模式发生器的神经放电将是 使用功率和相干光谱分析进行评估。 年龄- 相关结果将通过统计比较确定， 不同年龄的小猪 这项研究将提供新的 关于延髓吸气性发展的信息 神经元以及膈神经、喉返神经和舌下神经 运动神经元 这些信息在临床上很重要，因为 新生儿呼吸紊乱的研究，即，婴儿猝死综合症，呼吸暂停， 在对传入输入的反应中， 突触连接作为致病因素。

The development and maturation of respiratory neuron and motoneuron discharge properties will be examined in two day to two month old swine. Three specific aims will be pursued: (a) to determine age-related differences in numbers of inspiratory neurons with axons terminating in phrenic motoneuron pool and in responses to pulmonary afferent inputs; (b) to study age-related changes of neuronal responses to hypoxia and to identify neurons which could mediate hypoxic responses of phrenic motoneurons; (c) to compare efferent discharges of phrenic, recurrent laryngeal and hypoglossal motoneurons for differences in modulation by central pattern generators, responses to pulmonary afferent inputs, and responses during hypoxia. Experiments will be performed in Saffan anesthetized piglets; depth of anesthesia will be monitored by recording EEG, EKG and arterial blood pressure. Inspiratory neurons will be recorded extracellularly and responses to pulmonary afferent inputs will be determined using the No Inflation Test. In vagotomized piglets, neuronal responses to hypoxia will be classified according to changes in power spectra. For all neurons verification of single neuron recordings will be determined using interspike interval distributions, and the presence of excitatory connections with phrenic motoneurons will be determined using spike-triggered averaging. Modulation of nerve discharges by common central pattern generators will be evaluated using power and coherence spectral analyses. Age- dependent results will be determined by statistical comparisons of piglets at different ages. This research will provide new information regarding the development of medullary inspiratory neurons as well as phrenic, recurrent laryngeal and hypoglossal motoneurons. This information is clinically important since studies of neonatal breathing disturbances, i.e., SIDS, apnea, have implicated immaturities in responses to afferent inputs and in synaptic connections as etiological factors.