BRAINSTEM RESPIRATORY NEURON INTERACTIONS

长期目标是确定大脑之间的突触关系 干性呼吸神经元及其对细胞生成和发育的贡献 作为呼吸节律基础的放电模式的协调 驱动到运动神经元。计划中的实验解决了三个假设。 1.空间间冗余的、互补的突触相互作用 与呼吸运动有明显功能联系的分布神经元 而运动前神经元对运动障碍的发展和终止都有贡献 呼吸的每一个阶段。 2.几类共同活动之间的突触耦合强度 呼吸神经元随其他脑干的门控作用而变化 在呼吸的每个阶段的神经元。这些调节过程有助于 调整阶段持续时间。 3.位于脑干某一区域的神经元能够独立 心律失常的发生与多种细胞的协调机制有关。 彼此这样的地区。 实验将在麻醉或去大脑、瘫痪、 双侧迷走神经切断，有呼吸机的猫。三个独立控制 胞外钨电极阵列和多管吸管电极 (总数=12)将用于同时监测 延髓(包括背侧和腹侧呼吸组)和/或 脑桥(包括头端呼吸组或“肺气肿”区)。 氨基酸、多肽或递质拮抗剂的微离子导入 将用于增强或抑制选定细胞的活动。 具有脊髓或迷走神经投射的神经元将使用 逆行刺激方法。将检测到功能交互 并使用交叉相关和尖峰触发平均进行评估 方法，一种“重力聚类法”，药理手法 假设的驱动神经元和调制神经元，以及网络模拟。这个 这些实验的结果将提供对中枢神经的深入了解 呼吸节律背后的机制和非凡的能力 容忍不同来源的侮辱的制度。

The long term objective is to define the synaptic relationships among brain stem respiratory neurons and their contribution to the generation and coordination of discharge patterns which underlie the rhythmic respiratory drive to motor neurons. Planned experiments address three hypotheses. 1. Redundant, ccomplementary synaptic interactions among spatially distributed neurons with demonstrable functional links to respiratory motor and premotor neurons contribute to both the development and termination of each phase of breathing. 2. The strength of synaptic coupling among some classes of co-active respiratory neurons varies with the gating actions of other brain stem neurons during each phase of breathing. These modulatory processes help to regulate phase durations. 3. Neurons located in one region of the brain stem capable of independent rhythmogenesis are linked by multiple coordinating mechanisms to cells in each other such region. Experiments will be performed with anesthetized or decerebrate, paralyzed, bilaterally vagotomized, ventilated cats. Three independently controlled arrays of extracellular tungsten and multi-barrel pipette electrodes (total=12) will be used to monitor simultaneously respiratory neurons in the medulla (including the dorsal and ventral respiratry groups) and/or pons (including the rostral respiratory group or "pneumotaxic area"). Microiontophoresis of amino acids, peptides, or transmitter antagonists will be used to enhance or suppress the activities of selected cells. Neurons with spinal or vagal projections will be identified using antidromic stimulation methods. Functional interactions will be detected and evaluated using cross-correlational and spike triggered averaging methods, a "gravitational clustering" method, pharmacological manipulations of putative driver and modulatory neurons, and network simulations. The results of these experiments will provide insights into the central neural mechanisms underlying the breathing rhythm and the remarkable ability of the system to tolerate insults of various origins.