Functional dissection of medullary respiratory microcircuits

描述(由申请人提供)：描述复杂行为背后的神经元是基本兴趣所在。我们将利用一种新的方法来极快速地改变遗传靶向神经元的兴奋性，以影响啮齿动物强大而重要的正在进行的调节行为，即呼吸。呼吸是一种非凡的行为，它通过调节气体交换来支持新陈代谢和调节pH。一个可靠而有力的节奏对于哺乳动物的呼吸是必不可少的。睡眠呼吸暂停、早产儿呼吸暂停、先天性中枢低通气综合征、过度换气综合征、Rett综合征，甚至可能是婴儿猝死综合征的人类无法保持正常的呼吸节律，会导致严重的不良健康后果，甚至死亡。各种神经退行性疾病，如帕金森氏病、多系统萎缩和肌萎缩侧索硬化症，都与睡眠呼吸障碍有关，我们推测是由于控制呼吸的大脑区域神经元丢失所致。如果要在正常和病理条件下理解呼吸，就必须揭示呼吸节律发生的机制。我们专注于两个对正常呼吸模式的产生至关重要的大脑部位，前Bvtzinger复合体和后梯形核/面旁呼吸群。利用病毒传递系统，我们将在这些关键区域的不同表型神经元中表达遗传编码的视蛋白。在麻醉、清醒或睡眠的大鼠身上，通过植入这些部位的光纤发出的光脉冲，这些神经元的兴奋性迅速发生变化，应该会对呼吸产生明显甚至深刻的干扰。对这种扰动的分析将为理解呼吸节律和模式产生的机制提供一个特别的窗口。

DESCRIPTION (provided by applicant): Delineating neurons that underlie complex behaviors is of fundamental interest. We will exploit a novel method for extremely rapid changes in excitability of genetically targeted neurons to affect a robust and vital ongoing regulatory behavior in rodents, i.e., breathing. Breathing is a remarkable behavior that mediates gas exchange to support metabolism and regulate pH. A reliable and robust rhythm is essential for breathing in mammals. Failure to maintain a normal breathing rhythm in humans suffering from sleep apnea, apnea of prematurity, congenital central hypoventilation syndrome, hyperventilation syndrome, Rett syndrome, and perhaps sudden infant death syndrome, leads to serious adverse health consequences, even death. Various neurodegenerative diseases, such as Parkinson's disease, multiple systems atrophy and amyotrophic lateral sclerosis, are associated with sleep disordered breathing that we hypothesize results from the loss of neurons in brain areas controlling respiration. If breathing is to be understood in normal and in pathological conditions, the mechanisms for respiratory rhythmogenesis must be revealed. We focus on two brain sites essential for generation of the normal breathing pattern, the preBvtzinger Complex and the retrotrapezoid nucleus/parafacial respiratory group. Using a viral delivery system, we will express genetically encoded opsins in various phenotypes of neurons in these key regions. Rapid changes in excitability of these neurons by administration of light pulses delivered via an optical fiber implanted in these sites in anesthetized, awake or sleeping rats should produce noticeable, even profound perturbations in breathing. Analysis of such perturbations will provide an extraordinary window into understanding mechanisms of respiratory rhythm and pattern generation.