Cellular Mechanisms for Breathing and Hypoxia Tolerance

呼吸和耐缺氧的细胞机制

• 批准号: 6938451
• 负责人: MICHAEL Scott HEDRICK
• 金额: $ 12.06万
• 依托单位: CALIFORNIA STATE UNIVERSITY HAYWARD
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6938451
• 关键词: Rana; brain mapping; calcium flux; chemoreceptors; developmental neurobiology; electrophysiology; fluorescent dye /probe; hypoxia; metamorphosis; neuroprotectants; neuroregulation; oxygen tension; pulmonary respiration; respiration regulatory center; tissue /cell culture

The goals of this study are to test hypotheses regarding the development of cellular and synaptic mechanisms underlying respiratory rhythm generation and the tolerance to anoxia in the amphibian brain. An in vitro brainstem preparation, brainstem slices and isolated neurons from North American bullfrogs (Rana catesbeiana) at various stages of development will be used in this study. The bullfrog brainstem preparation was chosen because it produces a quantifiable, spontaneous respiratory motor ouput in vitro at ajl stages of development. The metamorphic transition from an aquatic to a terrestrial habitat in amphibians is accompanied by major maturationai changes of the respiratory system, but very little is known about the neural mechanisms that underlie this ontogenetic maturation. The specific aims of this project are to: 1) Identify specific neuroanatomical locations of the amphibian respiratory network; 2) Examine the role of pacemaker mechanisms for respiratory rhythm generation; 3) Determine the role of oxygen-sensing mechanisms in the respiratory response to anoxia; 4) Determine the role of intracellular calcium as a neuroprotective signaling mechanism in anoxia. Isolated brainstem preparations, spontaneously active medullary slices and isolated neurons will be used to carry out the specific aims. A multifaceted approach that combines fluorescent dyes for neuroanatomical tracing, electrophysiological measurements from respiratory neurons, intracellular calcium measurements, bath application and microinjection of neurochemicals into discrete brain locations, will be used to test hypotheses related to the specific aims. The proposed research should provide greater insight into the role of development and evolutionarily conserved mechanisms in the neural regulation of ventilation and cellular mechanisms of neuroprotection in vertebrates. The results of this project may provide a greater understanding of developmental mechanisms that contribute to abnormal breathing states in developing mammals.

这项研究的目标是检验有关呼吸节律产生的细胞和突触机制发展的假设，以及对两栖动物大脑缺氧的耐受性。本研究将使用体外的脑干制剂，脑干切片和来自北美牛蛙（Rana Catesbeiana）的各个发育阶段的孤立神经元。之所以选择Bullfrog脑干的制备，是因为它在AJL发育阶段会在体外产生可量化的，自发的呼吸运动OUPUT。两栖动物中从水生栖息地到陆生栖息地的变质过渡伴随着呼吸系统的重大变化，但对这种个体发生成熟的神经机制知之甚少。该项目的具体目的是：1）确定两栖动物呼吸网络的特定神经解剖位置； 2）检查起搏器机制在呼吸节奏产生中的作用； 3）确定氧敏感机制在对缺氧的呼吸反应中的作用； 4）确定细胞内钙作为神经保护信号传导机制在缺氧中的作用。孤立的脑干制剂，自发活跃的髓样片和孤立的神经元将用于执行特定目的。一种多面方法，结合了用于神经解剖学的荧光染料，来自呼吸神经元的电生理测量， 细胞内钙的测量，浴和对神经化学物的应用和显微注射 离散的大脑位置将用于测试与特定目标相关的假设。拟议的研究应更深入地了解发育和进化保守机制在脊椎动物中神经保护的通气和细胞机制的神经调节中的作用。该项目的结果可能会对发展哺乳动物中异常呼吸状态的发育机制有更深入的了解。