Respiratory Network Organization and Cellular Mechanisms

这个项目的目的是测试关于脊椎动物振荡运动网络的假设，以及它们的组织和细胞机制，在体外使用海龟脑干进行节律发生。选择脊椎动物呼吸控制系统是因为该系统是生命所必需的，并且它在体外条件下产生自发的可量化的节律运动输出。该项目研究了成年龟的呼吸控制系统，因为爬行动物代表了两栖动物和哺乳动物之间重要的系统发育中间物，海龟具有独特的生理特征，有利于体外研究。有待验证的假设包括：(1)成年海龟呼吸节律发生器由独立的突触耦合振荡网络组成；(2)呼气神经元，如新的呼气前细胞，启动呼吸周期；(3)呼吸神经元的内源性起搏器特性是节律产生所必需的。为了解决这些假设，将采用多学科方法，即首次应用成熟的多通道记录技术来研究体外呼吸神经控制。这一建议的结果将有助于将呼吸节律发生的组织原理和潜在机制置于更广泛的系统发育和进化背景下，从而将注意力集中在对呼吸节律发生和其他脊椎动物节律运动网络至关重要的保守机制上。该项目将资助一名博士后和一名研究生。每年夏天，波多黎各大学将招收来自代表性不足的少数民族的本科生。

The goal of this project is to test hypotheses regarding vertebrate oscillatory motor networks with respect to their organization and cellular mechanisms underlying rhythmogenesis using turtle brainstems in vitro. The vertebrate respiratory control system was chosen because this system is necessary for life and it produces spontaneous quantifiable rhythmic motor output under in vitro conditions. This project examines the adult turtle respiratory control system because reptiles represent an important phylogenetic intermediate between amphibians and mammals, and turtles have unique physiological features that are advantageous for in vitro studies. Hypotheses to be tested include: (1) the adult turtle respiratory rhythm generator is composed of separate synaptically-coupled oscillatory networks, (2) expiratory neurons, such as novel pre-expiratory cells, initiate breathing cycles, (3) endogenous pacemaker properties in respiratory neurons are necessary for rhythm generation. To address these hypotheses, a multidisciplinary approach will be used whereby well-established multichannel recording techniques are applied for the first time to study respiratory neural control in vitro. The results of this proposal will help place the organizational principles and underlying mechanisms for respiratory rhythmogenesis within a broader phylogenetic and evolutionary context, thereby focusing attention on conserved mechanisms that are critical for respiratory rhythmogenesis and other rhythmic motor networks in vertebrates. The project will support a postdoctoral fellow and graduate student. Undergraduate students from underrepresented minorities will be recruited each summer from the University of Puerto Rico.