C1, Rostroventrolateral Medulla and the Central Integration of Cardiovascular Reg

C1，延髓头腹外侧和心血管调节的中央整合

• 批准号: 7645308
• 负责人: John Patrick Card
• 金额: $ 38.29万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7645308
• 关键词: Address; Animals; Attention; Axon; Brain Stem; Brain region; Cardiovascular Diseases; Cardiovascular Physiology; Cardiovascular system; Catecholamines; Cause of Death; Cell Nucleus; Cells; Complement component C1s; Data; Development; Diffuse; Disease; Electron Microscopy; Enterobacteria phage P1 Cre recombinase; Failure; Homeostasis; Hypertension; Immunotoxins; Investigation; Label; Lead; Lentivirus Vector; Lesion; Link; Maintenance; Maps; Mediating; Methods; Midbrain structure; Neuraxis; Neurons; Pattern; Phenotype; Play; Population; Population Heterogeneity; Presynaptic Terminals; Prosencephalon; Recurrence; Regulation; Reporter Genes; Reporting; Research; Risk Factors; Role; Source; Subfamily lentivirinae; Suid Herpesvirus 1; Synapses; System; Technology; Testing; Thoracic spinal cord structure; United States; Viral; Virus Replication; base; diencephalon; improved; insight; neurogenic hypertension; neuromechanism; new technology; novel; pressure; public health relevance; relating to nervous system; research study; retrograde transport; statistics; transgene expression

DESCRIPTION (provided by applicant): Cardiovascular disease is the leading cause of death in the United States and hypertension is a major risk factor for the development of cardiovascular disease. Alarmingly, statistics indicate that more than a quarter of the US population had hypertension in 2004. Contemporary research has demonstrated that the caudal brain stem exerts a profound influence over cardiovascular function. In particular, neurons of the rostroventrolateral medulla (RVLM) are known to be an important node in a central network that contributes to this regulation and malfunction of the network in experimental animals can produce hypertension. This network involves multiple cell groups in the brain stem, midbrain, diencephalon and forebrain. We recently developed a novel technology that allowed us to map the projections of C1 catecholamine neurons in RVLM. The data from that investigation confirmed the projection of C1 neurons to the sympathetic column in thoracic spinal cord but also revealed dense projections to a number of supraspinal cell groups with demonstrated influences upon cardiovascular function. In this application we hypothesize that collateralization of the C1 population to cardiovascular regulatory cell groups provides the neural substrate to coordinate activity within this distributed network. Experiments in three Specific Aims are advanced to test this hypothesis. Aim 1 will use our novel technology (lentivirus mediated anterograde tracing of C1 projections) and electron microscopy to test the hypothesis that recurrent collaterals of C1 neurons synapse upon projection specific and phenotypically distinct populations of RVLM neurons. Lentivirus mediated reporter gene (EGFP) expression will be used to label C1 axon terminals and ultrastructural analysis will characterize the synaptology of these afferents with subpopulations of neurons that differ in phenotype, projection patterns and topography within RVLM. Aim 2 will test the hypothesis that reticulospinal C1 neurons provide a substrate for coordination of network activity through projections that collateralize diffusely to supraspinal targets. Although surprisingly few studies have addressed this issue it is widely accepted that reticulospinal C1 neurons do not contribute substantially to supraspinal projections. Nevertheless, our data and that derived from a small number of studies examining C1 efferents challenge this conclusion. Experiments in this aim will employ dual retrograde labeling combined with immunocytochemical characterization of neuronal phenotype to address this question in a comprehensive fashion. Aim 3 will utilize conditional replication of pseudorabies virus and transneuronal labeling to test the hypothesis that reticulospinal C1 neurons receive synaptic input from all sources of RVLM afferents. Importantly, we hypothesize that neuronal circuits synaptically linked to reticulospinal C1 neurons will constitute a subset of the neurons that project to RVLM. These experiments will exploit a novel technology for conditional replication of PRV. Lentivirus vectors will be injected into RVLM to achieve targeted expression of cre recombinase (CRE) in C1 neurons or in neurons throughout RVLM. A strain of pseudorabies virus (PRV- 2001) whose replication is conditional upon the presence of CRE will be injected into the projection targets of reticulospinal RVLM neurons in thoracic spinal cord. Retrograde transport of PRV-2001 to RVLM will lead to restricted replication of the virus in CRE-containing neurons and retrograde transneuronal labeling of synaptically linked neurons. Collectively these data promise to provide important functional insights into the way in which C1 and the RVLM contribute to cardiovascular homeostasis as well as providing a wiring diagram that should improve understanding of the neural basis of neurogenic hypertension. PUBLIC HEALTH RELEVANCE: A distributed network of neurons in the central nervous system is known to exert a regulatory influence over cardiovascular function and malfunction of the network can produce hypertension, a major risk factor for the development of cardiovascular disease. However, the way in which neuronal activity is coordinated within the central cardiovascular network is not known. This proposal tests the hypothesis that collateralized projections of C1 catecholamine neurons in the rostroventrolateral medulla provides the neural substrate for this integration.

描述（由申请人提供）：心血管疾病是美国死亡的主要原因，高血压是心血管疾病发展的主要危险因素。令人震惊的是，统计数据表明，超过四分之一的美国人口在2004年患有高血压。当代研究表明，尾脑干对心血管功能产生了深远的影响。尤其是，众所周知，罗斯特罗外外侧髓质（RVLM）的神经元是中央网络中的重要节点，在实验动物中有助于该网络的这种调节和故障可以产生高血压。该网络涉及脑干，中脑，脑脑和前脑中的多个细胞组。我们最近开发了一种新颖的技术，使我们能够绘制RVLM中C1 Catecholamine神经元的预测。该研究的数据证实了C1神经元对胸椎脊髓的交感神经柱的投影，但也揭示了许多对许多对心血管功能影响的上卧层细胞组密集的投影。在此应用中，我们假设C1人群与心血管调节细胞组的抵押品提供了神经底物，以协调该分布式网络中的活动。提出了三个特定目标的实验以检验该假设。 AIM 1将使用我们的新技术（慢病毒介导的C1投影的循环跟踪）和电子显微镜测试以下假设：C1神经元在投影特异性和表型不同的RVLM神经元种群中复发的侧支。慢病毒介导的报告基因（EGFP）的表达将用于标记C1轴突末端，超微结构分析将表征这些传入的神经元亚群的突触，这些神经元在RVLM中的表型，投影模式和地形不同。 AIM 2将检验以下假设，即网状脊髓C1神经元通过预测扩散到上脊髓靶标的预测提供了网络活动协调的底物。尽管令人惊讶的是，很少有研究解决了这个问题，但人们普遍认为，网状脊髓C1神经元对上植物的预测没有很大贡献。然而，我们的数据和少量研究C1侵蚀的研究挑战了这一结论。此目标中的实验将采用双重逆行标签，结合神经元表型的免疫细胞化学特征，以全面的方式解决这个问题。 AIM 3将利用拟曲线病毒和跨神经元标记的条件复制来检验网状脊髓C1神经元从所有RVLM传入来源获得突触输入的假设。重要的是，我们假设与网状脊髓C1神经元相关的神经元电路将构成投射到RVLM的神经元的子集。这些实验将利用一种新技术来进行PRV的有条件复制。慢病毒载体将被注入RVLM中，以实现C1神经元或整个RVLM神经元中CRE重组酶（CRE）的靶向表达。复制的伪标记病毒（PRV-2001）的菌株将以CRE的存在为条件，将其注入胸脊髓中网状脊髓RVLM神经元的投影靶标。 PRV-2001向RVLM的逆行转运将导致含Cre的神经元中病毒的复制限制，并将突触连接神经元的逆行跨神经元标记在逆行中。这些数据共同承诺，将为C1和RVLM促进心血管稳态的方式提供重要的功能见解，并提供一个接线图，以提高对神经源性高血压神经基础的理解。公共卫生相关性：已知中枢神经系统中神经元的分布式网络对心血管功能和网络故障产生调节性影响会产生高血压，这是心血管疾病发展的主要风险因素。但是，尚不清楚在中央心血管网络中进行神经元活动协调的方式。该提案检验了以下假设：rosstroventrololololalightal髓质中C1儿茶酚胺神经元的抵押投影为这种整合提供了神经底物。