Mechanisms of respiratory long-term facilitation

描述（由申请人提供）：可塑性是神经系统的重要特征，包括控制呼吸的神经系统。尽管它具有潜在的生物学和临床意义，但我们对引起任何形式的呼吸可塑性的机制的理解是不完整的。在这个修订后的申请竞争性更新，调查将继续有关细胞机制引起膈长期促进，呼吸可塑性的一个重要模型急性暴露于间歇性缺氧诱导。在大鼠模型中，将使用多种实验方法研究长期易化的机制，包括麻醉大鼠的神经记录、未麻醉大鼠的通气测量、RNA干扰的应用、调节在呼吸可塑性中起作用的潜在重要基因的新方法、固定组织中的蛋白质分析和荧光方法以确定重要分子的表达变化，例如活性氧物质。使用这些方法，五个假设将在本申请中进行测试，以进行竞争性更新。首先，在目标1中，将探索蛋白质NADPH氧化酶和蛋白磷酸酶2A作为长期易化的关键调节因子的假设。接下来，将测试不同的细胞机制引起膈神经活动的长期促进的可能性，其中膈神经长期促进只是其中之一。在目标2中，将研究这些机制中的两个，指定为膈运动易化的“Q”和“S”通路。在最后三个目标中，将测试以下假设：Q和S通路通常相互抑制（目标3），但动物有能力在Q和S通路之间转换膈运动促进（目标4），或者它们可以同时使用两种通路（目标5）。在实现呼吸神经活动的促进方面的这种灵活性可以赋予个体在一生中响应生理挑战（诸如疾病的发作）的灵活性。对引起膈运动促进的细胞机制的详细了解将指导严重的呼吸控制障碍的新治疗策略的开发，包括脊髓损伤或运动神经元疾病（ALS）患者的阻塞性睡眠呼吸暂停和呼吸功能不全。因此，我们的研究的一个重要的潜在目标是确定调节PMF的分子作为潜在的治疗靶点。 公共卫生相关性：一些呼吸控制障碍，如婴儿猝死综合征（SIDS）或呼吸功能不全的颈椎损伤或神经退行性疾病，如ALS患者是灾难性的。其他疾病，如阻塞性睡眠呼吸暂停，对公众健康有着深远的影响。我们的目标是开发新的治疗策略，呼吸可塑性的基础上，详细了解呼吸控制系统的一个重要方面，已成为赞赏，只有在最近几年的呼吸控制障碍。

DESCRIPTION (provided by applicant): Plasticity is an important feature of neural systems, including the neural system controlling breathing. Despite its potential biological and clinical significance, our understanding of mechanisms giving rise to any form of respiratory plasticity is incomplete. In this revised application for competitive renewal, investigations will be continued concerning cellular mechanisms giving rise to phrenic long-term facilitation, an important model of respiratory plasticity induced by acute exposure to intermittent hypoxia. In a rat model mechanisms of long- term facilitation will be investigated using multiple experimental approaches, including nerve recordings in anesthetized rats, measurements of ventilation in unanesthetized rats, application of RNA interference, a novel method of regulating potentially important genes that play a role in respiratory plasticity, protein analysis and fluorescent methods in fixed tissues to determine expression changes in important molecules, such as reactive oxygen species. Using these approaches, five hypotheses will be tested in this application for competitive renewal. First, in Aim 1, the hypothesis that the proteins NADPH oxidase and protein phosphatase 2A function as key regulators of long term facilitation will be explored. Next, the possibility that distinct cellular mechanisms give rise to long-lasting facilitation of phrenic nerve activity, of which phrenic long term facilitation is only one, will be tested. In Aim 2, two of these mechanisms will be investigated, designated the "Q" and "S" pathways to phrenic motor facilitation. In the final three aims, the hypotheses will be tested that the Q and S pathways normally suppress one another (Aim 3), but that animals have the capacity to shift between the Q and S pathways phrenic motor facilitation (Aim 4), or that they can engage both pathways at the same time (Aim 5). Such flexibility in achieving facilitation of respiratory nerve activity may impart flexibility as an individual responds to physiological challenges throughout life, such as the onset of disease. A detailed understanding of cellular mechanisms giving rise to phrenic motor facilitation will guide the development of novel therapeutic strategies for severe ventilatory control disorders, including obstructive sleep apnea and respiratory insufficiency in patients with spinal injury or motor neuron disease (ALS). Thus, an important underlying goal of our research is to identify molecules regulating PMF as potential therapeutic targets. PUBLIC HEALTH RELEVANCE: Some ventilatory control disorders such as sudden infant death syndrome (SIDS) or respiratory insufficiency in patients with cervical spinal injury or neurodegenerative diseases like ALS are catastrophic. Others, such as obstructive sleep apnea, have profound consequences for public health. Our goal is to develop novel therapeutic strategies for ventilatory control disorders based on a detailed understanding of respiratory plasticity, a critical aspect of the ventilatory control system that has become appreciated only in recent years.