BRAIN STEM INTEGRATION OF CHEMORECEPTOR ACTIVITY

化学感受器活性的脑干整合

• 批准号: 3336165
• 负责人: Walter St. John
• 金额: $ 17.75万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-09-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3336165
• 关键词: brain stem; cats; chemoreceptors; diaphragm; electromyography; experimental brain lesion; hypoglossal nerve; hypoxia; innervation; motor neurons; neural facilitation; neural information processing; neural inhibition; neuroanatomy; neuropharmacology; peripheral nervous system; phrenic nerve; pulmonary stretch receptors; respiration regulatory center; respiratory muscles; respiratory reflex; trigeminal nerve; vagotomy; vagus nerve

The objective is to characterize the activities of cranial motor nerves which innervate upper airway muscles and spinal nerves innervating muscles of the chest wall and diaphragm. These characterizations are important since patency of the upper airway requires an appropriate balance between these cranial and spinal nerve activities. Studies will be concerned with pulmonary reflex mechanisms. The influence of both the phasic and tonic discharge of pulmonary stretch receptors will be examined. The tonic discharge is hypothesized to be a major determinant of respiratory-modulated cranial motoneuronal activity during expiration. Moreover, the level of excitability of brainstem respiratory neurons is influenced by the tonic discharge of pulmonary stretch receptors. This level of excitability determines motoneuronal responses to peripheral chemoreceptor stimulation in hypoxia. Concerning the cranial motoneurons, their activity is influenced by the "history" of phasic activity of pulmonary stretch receptors; this history will be characterized. Another aspect of pulmonary stretch receptor discharge, its facilitation of inspiratory activity, is a continuous determinant of phrenic motoneuronal activity. Phrenic activity can also be inhibited by the discharge of pulmonary stretch receptors. Conditions for the expression of a new facilitation or inhibition will be defined. This definition will allow for a critical evaluation of the roles of I-alpha and I-beta groups of medullary respiratory neurons. Their discharge patterns are hypothesized to underlie the inhibition and facilitation of phrenic activity by the discharge of pulmonary stretch receptors. Thus, I-alpha and I-beta neurons are hypothesized to represent a continuum.

目的是表征颅运动神经的活动 支配上呼吸道肌肉和脊髓神经支配肌肉 胸壁和膈肌。 这些特征很重要 因为上呼吸道的通畅需要在 这些脑神经和脊神经活动。 研究将涉及肺反射机制。 影响力 肺牵张感受器的阶段性和强直性放电将 被检查。 强直放电被认为是一个主要决定因素 呼气期间呼吸调节的颅运动神经元活动。 此外，脑干呼吸神经元的兴奋性水平为 受肺牵张感受器强直放电的影响。这 兴奋性水平决定运动神经元对外周的反应 缺氧时化学感受器的刺激。 关于颅运动神经元， 他们的活动受到阶段性活动“历史”的影响 肺牵张感受器；这段历史将会被刻画出来。 肺牵张感受器放电的另一个方面，它促进 吸气活动，是膈运动神经元的连续决定因素 活动。 膈活动也可以通过放电来抑制 肺牵张感受器。 新的表达条件 将定义促进或抑制。 这个定义将允许 对 I-α 和 I-β 组的作用进行严格评估 髓质呼吸神经元。 假设它们的放电模式 是膈活动抑制和促进的基础 肺牵张感受器放电。 因此，I-α 和 I-β 神经元 假设代表一个连续体。