Amacrine Cell Signaling

无长突细胞信号传导

• 批准号: 7577415
• 负责人: EVANNA L GLEASON
• 金额: $ 29.4万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7577415
• 关键词: Address; Affect; Albers-Schonberg disease; Amacrine Cells; Birds; Brain; Brain Part; Cell physiology; Cells; Cellular Membrane; Chickens; Chloride Ion; Chlorides; Cytosol; Defect; Disease; Event; Excitatory Synapse; Family; Fluorescent Dyes; Gene Silencing; Genes; Glycine; Goals; Histocompatibility Testing; Image; Inhibitory Synapse; Interneurons; Ions; Kidney; Learning; Link; Mediating; Membrane; Methods; Movement; Neurons; Neurotransmitters; Nitric Oxide; Nitric Oxide Synthase Type I; Pathologic; Property; Proteins; Protons; Regulation; Research; Retina; Retinal; Role; Shapes; Signal Transduction; Signaling Molecule; Slice; Small Interfering RNA; Synapses; Testing; Visual; Whole-Cell Recordings; Work; base; bone; cell growth regulation; computerized data processing; digital imaging; experience; extracellular; gamma-Aminobutyric Acid; ganglion cell; immunocytochemistry; member; novel; visual process; visual processing

DESCRIPTION (provided by applicant): Amacrine cells are interneurons in the vertebrate retina that help to shape the visual signals that ganglion cells send to other visual centers in the brain. The ultimate goal of the research proposed here is to understand how the signaling molecule nitric oxide functions in the retina to shape amacrine cell signaling and to contribute to normal visual processing in the retina. This proposal specifically addresses the role of nitric oxide in controlling chloride levels in amacrine cells. This is highly relevant to neuronal function because the level of chloride in a cell determines the effect of traditionally inhibitory neurotransmitters such as GABA and glycine on cells at synapses. If chloride is kept low in a neuron, then GABA and glycine will mediate inhibitory signals but if chloride levels are increased, excitatory signals can be generated by these neurotransmitters. The research proposed here is based on our previous work demonstrating that nitric oxide causes release of chloride from internal stores and has the power to temporarily switch inhibitory synapses into excitatory synapses. Although this effect of nitric oxide has been clearly demonstrated, very little is understood about the underlying mechanisms and how this action affects retinal function. To learn more about this, the following three specific aims are proposed: Specific Aim 1: To elucidate the mechanisms underlying the nitric oxide-dependent redistribution of chloride in amacrine cells, Specific Aim 2: To discover the transporter(s) involved in regulating the distribution of internal chloride, Specific Aim 3: To determine the effects of endogenously generated NO. Elucidation of the mechanisms underlying the action of nitric oxide on amacrine cell chloride (Aims 1 and 2) will be achieved using cultures containing identified GABAergic amacrine cells derived from the chick retina. Recordings of amacrine cells in retinal slices will be used to explore the impact of nitric oxide on amacrine cell function. These studies will involve a combination of electrophysiological recordings, digital imaging using ion- sensitive fluorescent dyes and siRNA gene knockdown methods. What is learned here about the role of nitric oxide in regulating internal chloride fluxes may be a valuable component of understanding pathologic conditions related to defects in cellular cytosolic chloride management such as Dent's disease, and osteopetrosis. Understanding how NO regulates amacrine cell function will contribute to our understanding of retinal signal processing. PUBLIC HEALTH RELEVANCE: The proposed research will expand our understanding of the regulation of cellular chloride levels and the actions of the signaling molecule nitric oxide. These factors are relevant to the normal and disease states of cells in multiple tissue types including kidney, bone and brain. In particular we will discover how nitric oxide regulates cellular chloride levels and how this regulation contributes to plasticity in the retina and other parts of the brain.

描述（由申请人提供）：无分钟细胞是脊椎动物视网膜中的中间神经元，有助于塑造神经节细胞发送给大脑其他视觉中心的视觉信号。这里提出的研究的最终目标是了解视网膜中信号分子一氧化氮的功能如何塑造无链氨基细胞信号传导并为视网膜中的正常视觉处理做出贡献。该建议专门解决了一氧化氮在控制氯化物水平中的作用。这与神经元功能高度相关，因为细胞中的氯化物水平决定了传统抑制性神经递质（例如GABA和甘氨酸）对突触下细胞的影响。如果氯化物在神经元中保持较低，则GABA和甘氨酸将介导抑制信号，但是如果氯化物水平升高，这些神经递质可以产生兴奋信号。此处提出的研究基于我们以前的工作，表明一氧化氮导致内部商店释放氯化物，并具有将抑制性突触暂时切换为兴奋性突触的能力。尽管已经清楚地证明了一氧化氮的这种作用，但几乎没有理解的基本机制以及该作用如何影响视网膜功能。为了了解有关此的更多信息，提出了以下三个特定目的：具体目的1：阐明一氧化氮依赖性重新分布的氯化氧化物依赖性重新分布的机制，具体目的2：发现涉及的转运蛋白（S）调节内部氯化物的分布，具体目标3：确定植入植物的效应。使用含有鉴定出鉴定的Gabaergic amacrine细胞的培养物来阐明一氧化氮对无氧细胞氯化物氯化物氯化物氯化物氯化物氯化物氯化物氯化物的作用的机制（目标1和2）。在视网膜切片中的无链氨氨酸细胞的记录将用于探索一氧化一氧化氮对无长血细胞功能的影响。这些研究将涉及电生理记录，使用离子敏感荧光染料和siRNA基因敲低方法的数字成像。关于一氧化氮在调节内部氯化物通量中的作用的知识可能是理解与细胞胞质氯化物治疗（如Dent的疾病和骨质疏松症）缺陷有关的病理状况的重要组成部分。了解无调节的无链氨基细胞功能将有助于我们对视网膜信号处理的理解。公共卫生相关性：拟议的研究将扩大我们对细胞氯化物水平调节的理解以及信号分子一氧化氮的作用。这些因素与多种组织类型的细胞的正常和疾病状态有关，包括肾脏，骨骼和大脑。特别是我们将发现一氧化氮如何调节细胞氯化物水平，以及该调节如何促进视网膜和大脑其他部位的可塑性。