NEUROBIOLOGY OF RESPIRATION IN DEVELOPING AMPHABIAN

自发呼吸节律的发展和维持对所有脊椎动物的生存至关重要。负责呼吸节律发生的神经元的精确位置，以及呼吸性婴儿猝死综合征和睡眠呼吸暂停的传入和传出连接，这些疾病折磨着发育范围的两端，为了研究牛蛙（Rana catesbeiana）蝌蚪中枢呼吸模式所必需的神经基质的发育，建立了牛蛙蝌蚪离体脑干标本生成和化学感受。拟议的研究将进一步了解产生和维持自发的，有节奏的呼吸运动输出所需的神经成分。此外，在发展过程中的呼吸中枢模式发生器（CPG）的中枢和外周化学感受器输入的意义将被描述。具体而言，实验设计：1。确定在发育过程中中枢和外周呼吸化学感受器输入对中枢呼吸模式产生和运动输出的相对贡献。2.目的明确脊椎动物鳃和肺呼吸模式发生的神经元的确切位置。3.开始确定，在发育中的脊椎动物，细胞，离子，生物物理特性和网络连接的鳃和肺呼吸模式的产生。在半完整和体外灌流蝌蚪脑干制备物中，将采用全神经和细胞内记录与神经元相关的神经元。将使用半完整脑干/鳃弓制备物检查中枢和外周化学感受器刺激的影响;所有其他研究将使用体外脑干制备物。荧光染料的离子电渗法将用于产生呼吸运动神经元、中间神经元和候选中枢模式生成神经元的投射图。将进行记录为负责脊椎动物呼吸节律的各种神经递质激动剂和拮抗剂的浴应用，以表征其对鳃和肺运动模式的影响。将进行脑干的薄片制备，以阐明鳃和肺模式产生神经元的精确位置。将通过对所有发育阶段的蝌蚪进行上述实验来解决每项研究的发育方面。

The development and maintenance of a spontaneous respiratory rhythm is essential for the survival of all vertebrates. The precise location of neurons responsible for respiratory rhythmogenesis , as well as the afferent and efferent connections of the respiratory Sudden Infant Death Syndrome (SIDS) and sleep apnea, disorders which afflict both ends of the developmental spectrum, An in vitro brainstem preparation of the bullfrog tadpole Rana catesbeiana has been developed in order to investigate the development of the neural substrates essential to central respiratory pattern generation and chemoreception. The proposed research will further the understanding of the neural components necessary to produce and maintain spontaneous, rhythmic respiratory motor output. In addition, the significance of both central and peripheral chemoreceptor input to the respiratory central pattern generator (CPG) during development will be described. Specifically, experiments have been designed: 1. To determine during development the relative contribution both of central and peripheral respiratory chemoreceptor input on central respiratory pattern generation and motor output. 2. To define the precise location of neurons responsible for both gill and lung respiratory pattern generation in the developing vertebrate. 3. To begin to determine, in the developing vertebrate, the cellular, ionic, biophysical properties and network connections underlying gill and lung respiratory pattern generation. Both whole nerve and intracellular recordings from respiratory-related neurons will be employed in semi-intact and in vitro superfused tadpole brainstem preparations. A semi-intact brainstem/gill arch preparation will be used to examine the influence of both central and peripheral chemoreceptor stimulation; all other studies will use the in vitro brainstem preparation. lontophoresis of fluorescent dyes will be used to create maps of the projections of respiratory motor neurons, interneurons, and candidate central pattern generation neurons. Bath application of various neurotransmitter agonists and antagonists documented to be responsible for respiratory rhythmicity in vertebrates will be performed in order to characterize their effects on gill and lung motor patterns. Thin slice preparations of the brain stem will be performed to elucidate the precise location of gill and lung pattern generating neurons. The developmental aspect of each study will be addressed by performing the above experiments on tadpoles from all stages of development.