BRAINSTEM RESPIRATORY NEURON INTERACTIONS

长期目标是确定大脑中的突触关系 干呼吸神经元及其对产生和 节律性呼吸的基础放电模式的协调 驱动运动神经元。 计划中的实验涉及三个假设。 1.空间上冗余互补的突触相互作用 与呼吸运动有明显功能联系的分布式神经元 和前运动神经元有助于发展和终止 呼吸的每一个阶段 2.某些类型的共活性物质之间的突触耦合强度 呼吸神经元的门控行为与其他脑干不同 神经元在呼吸的每个阶段。 这些调节过程有助于 调节相位持续时间。 3.位于脑干某个区域的神经元能够独立 节律发生通过多种协调机制与细胞联系在一起， 彼此都是这样的区域。 实验将在麻醉或去大脑，瘫痪， 双侧迷走神经切断通气的猫 三个独立控制 细胞外钨电极和多管吸管电极阵列 （共=12）将用于同时监测呼吸神经元， 髓质（包括背侧和腹侧髓质组）和/或 脑桥（包括吻侧呼吸组或“呼吸区”）。 氨基酸、肽或递质拮抗剂的微离子电渗疗法 将用于增强或抑制所选细胞的活性。 具有脊髓或迷走神经投射的神经元将使用 逆向刺激法 将检测功能性相互作用 并使用交叉相关和尖峰触发平均进行评估 方法，“重力聚类”方法，药理学操作 和调制神经元，以及网络模拟。 的 这些实验的结果将提供深入了解中枢神经系统 呼吸节律的潜在机制和 容忍各种来源的侮辱。

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.