BRAINSTEM RESPIRATORY NEURON INTERACTIONS

本研究的目的是界定职能组织， 脑干神经网络的内部操作， 压力感受器和化学感受器调节呼吸。 颈 化学感受器和压力感受器将被选择性地刺激以干扰 麻醉或去大脑动物的呼吸相关神经活动 人工呼吸的猫 尖峰序列分析方法（例如， 重力，关节刺激周时间直方图），光学测量 散射光信号，和尖峰触发的细胞内平均 记录，将用于评估动态功能连接之间 心肺相关神经元。 网络模型的可扩展性 将用计算机模拟测试这些方法得出的结果。 计划中的实验将解决六个假设。 1.颈动脉诱发呼吸驱动的长时程易化 化学感受器刺激可以被颈动脉以分级方式“消除”， 压力感受器刺激 LTF的去除重置了 一个分布式的神经元集合体，调节这些反射的增益， 和呼吸驱动。 2.孤束核神经元之间的相互作用， 对颈动脉压力感受器或化学感受器的反应有助于动态 获得对这些受体输入的控制。 3.尾侧孤束核的神经元携带来自颈动脉化学感受器的信息 以及心肺中缝神经元的压力感受器。 4.中缝神经元组装影响孤束核神经元的反应性 颈动脉压力感受器和化学感受器通过动态调制 NTS神经元之间的脉冲同步。 5.中缝神经元影响呼吸和血管反射，通过共同的 腹外侧尾侧和吻侧的“多功能”中间神经元 髓质 6.中缝核神经元在运动前区的同步聚集 球脊髓神经元 长期促进呼吸驱动是由于， 至少部分是由于中缝神经元放电率的持续变化 这些神经元的神经系统。 许多呼吸和心血管控制障碍的结果， 中枢神经系统异常 改善治疗和 这些问题的管理取决于更好地了解 调节这些功能的神经网络。

The goal of this research is to define the functional organization and internal operations of the brainstem neural network through which carotid baroreceptors and chemoreceptors regulate breathing. Carotid chemoreceptors and baroreceptors will be selectively stimulated to perturb respiratory related neural activity in anesthetized or decerebrate artificially ventilated cats. Spike train analysis methods (e.g., gravity, joint peristimulus time histograms), optical measurements of scattered light signals, and spike triggered averaging of intracellular recordings, will be used to assess dynamic functional connectivity among cardiorespiratory related neurons. The plausibility of network models derived from these approaches will be tested with computer simulations. Planned experiments will address six hypotheses. 1. Long-term facilitation (LTF) of respiratory drive induced by carotid chemoreceptor stimulation can be "erased" in a graded manner by carotid baroreceptor stimulation. Removal of LTF resets the equilibrium state of a distributed neuronal assembly that regulates the gain of these reflexes and respiratory drive. 2. Interactions among neurons of the nucleus tractus solitarius (NTS) that respond to carotid baroreceptors or chemoreceptors contribute to dynamic gain control of inputs from these receptors. 3. Neurons in the caudal NTS carry information from carotid chemoreceptors and baroreceptors to cardiorespiratory raphe neurons. 4. Raphe neuronal assemblies influence the responsiveness of NTS neurons to carotid baroreceptors and chemoreceptors through the dynamic modulation of impulse synchrony among NTS neurons. 5. Raphe neurons influence breathing and vasomotor reflexes through common "multifunctional" interneurons in the caudal and rostral ventrolateral medulla. 6. Synchronous assemblies of raphe neurons converge on premotor bulbospinal neurons. Long-term facilitation of respiratory drive is due, at least in part, to maintained changes in firing rate of raphe neurons that innervate these neurons. Numerous disorders of breathing and cardiovascular control result from abnormalities in the central nervous system. Improved treatments and management of these problems are dependent on a better understanding of the neural networks that regulate these functions.