DISCHARGE PATTERNS OF CAROTID BODY CHEMORECEPTORS

颈动脉小体化学感受器的放电模式 学习。之所以选择禽类动物模型是因为禽类颈动脉 身体化学感受器在结构上和 对哺乳动物颈动脉小体的作用，因为鸟类的肺 提供了单向的强大实验优势 用于控制动脉血气的呼吸机(UDV)。 提出了联合(UDV)、在线血气监测的实验方案 测量，单单位神经记录技术，以及 电脑化在线数据采集在生理测试中的应用 颈动脉小体化学感受器以困难或困难的方式反应 用哺乳动物模型是不可能的。 颈动脉小体化学感受器是多模式的，对 动脉血氧分压、二氧化碳分压和其他刺激物。这个项目将 确定单个受体对动脉pH和 血压。该项目还将分析时间上的 单个化学感受器的动作电位发生 暴露在不同静态水平的刺激下会引起不同的 感受器放电模式。模式差异可能是 一种携带差动刺激的神经编码机制 信息发送给中央呼吸控制器，并且可以 代表了信号转导机制的根本区别 O2和CO2。 与潮汐相关的动脉血二氧化碳分压的动态波动 假设呼吸会产生前馈控制信号 通过颈动脉小体进行运动时的呼吸控制。 该项目将使用UDV诱导的动脉坡道振荡 二氧化碳分压、氧分压测定颈动脉体心率敏感性 化学感受器(它会放大前馈信号 锻炼)。UDV诱发的动脉血氧分压和动脉血氧饱和度正弦振荡 二氧化碳将被用来测试受体的频率响应 (确定受体对呼吸系统变化的反应 速率)，它将测试振荡之间的相位差 PO2或PCO2受体反应(这会影响 化学感受器放电到达中央控制器)。 正常动态和静态颈动脉小体的多个方面 化学感受器的敏感性仍然不确定。重要的是要 研究这些正常的生理反应，这样我们就可以确定 颈动脉小体化学感受器在血管紧张素转换酶调控中的作用 肺通风在健康和疾病中的作用。

The discharge patterns of carotid body chemoreceptors will be studied. An avian animal model was chosen because avian carotid body chemoreceptors are nearly identical in structure and function to mammalian carotid bodies, and because the avian lung offers the powerful experimental advantage of unidirectional ventilation (UDV) for controlling arterial blood gases. Experiments are proposed that combine (UDV), on-line blood gas measurement, single unit neural recording techniques, and computerized on-line data acquisition to test the physiological responses of carotid body chemoreceptors in ways difficult or impossible with a mammalian model. Carotid body chemoreceptors are multimodal, responding to arterial PO2, PCO2, and other stimuli. This project will determine the response of single receptors to arterial pH and blood pressure. This project will also analyze the temporal occurrence of action potentials from single chemoreceptors exposed to different static levels of stimuli cause different receptor discharge patterns. Pattern differences could be a neural encoding mechanism for carrying differential stimulus information to the central respiratory controller, and may represent fundamental differences in transduction mechanisms for O2 and CO2. Dynamic oscillations of arterial PCO2 associated with tidal breathing are hypothesized to cause a feed-forward control signal via the carotid bodies for ventilatory control during exercise. This project will use UDV-induced ramp oscillations of arterial PCO2, and PO2 to test the rate sensitivity of carotid body chemoreceptors (which would amplify the feed-forward signal in exercise). UDV-induced sinusoidal oscillations of arterial PO2 and PCO2 will be used to test the frequency response of the receptors (determining the receptor response to changes in respiratory rate), and it will test for phase differences between oscillating PO2 or PCO2 receptor response (which affects the efficacy of chemoreceptor discharge arriving at the central controller). Many aspects of the normal dynamic and static carotid body chemoreceptor sensitivity remain uncertain. It is important to study these normal physiological responses so that we can define the roles of carotid body chemoreceptors in the control of pulmonary ventilation in health and disease.