Molecular Mechanisms Regulating Inhibitory Circuitry in the Spinal Cord

调节脊髓抑制电路的分子机制

基本信息

批准号：
10624944
负责人：
Julia Anna Kaltschmidt
金额：
$ 36.16万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10624944
关键词：
Adhesions Adhesives Afferent Neurons Animal Behavior Binding Biological Assay CNTNAP1 gene Cell Adhesion Cell Adhesion Molecules Central Nervous System Cholera Toxin Protomer B Coupled Dedications Development Disease Distal Dyes Electrophysiology (science)Extensor Flexor Functional disorder Generations Goals Health In Vitro Individual Injections Injury Interneurons Knowledge Label Limb structure Measures Mediating Medical Methodology Microanatomy Mission Molecular Motor Motor Neurons Mus Muscle Muscle function Neurodegenerative Disorders Neurologic Neurons Neurotrophin 3 Phenotype Physiological Process Proprioceptor Proteins Public Health Reporter Research Role Schizophrenia Science Sensory Signal Transduction Specificity Spinal Spinal Cord Spinal cord injury Synapses Tamoxifen Testing Tracer United States National Institutes of Health Vertebral column Work contactin density differential expression effective therapy experimental study fluorophore improved in vivo inhibitory neuron innovation knowledge base mouse genetics nervous system disorder neural neural circuit neuronal circuitry neuropsychiatry neurotransmitter release presynaptic protein complex receptor sensory input synaptic inhibition synaptogenesis targeted treatment time use

Adhesions Adhesives Afferent Neurons Animal Behavior Binding Biological Assay CNTNAP1 gene Cell Adhesion Cell Adhesion Molecules Central Nervous System Cholera Toxin Protomer B Coupled Dedications Development Disease Distal Dyes Electrophysiology (science)Extensor Flexor Functional disorder Generations Goals Health In Vitro Individual Injections Injury Interneurons Knowledge Label Limb structure Measures Mediating Medical Methodology Microanatomy Mission Molecular Motor Motor Neurons Mus Muscle Muscle function Neurodegenerative Disorders Neurologic Neurons Neurotrophin 3 Phenotype Physiological Process Proprioceptor Proteins Public Health Reporter Research Role Schizophrenia Science Sensory Signal Transduction Specificity Spinal Spinal Cord Spinal cord injury Synapses Tamoxifen Testing Tracer United States National Institutes of Health Vertebral column Work contactin density differential expression effective therapy experimental study fluorophore improved in vivo inhibitory neuron innovation knowledge base mouse genetics nervous system disorder neural neural circuit neuronal circuitry neuropsychiatry neurotransmitter release presynaptic protein complex receptor sensory input synaptic inhibition synaptogenesis targeted treatment time use

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项目摘要

Establishing specific neuronal circuits is fundamental for the generation of coordinated muscle function. However, the signals underlying the specificity of connection between interneurons and their targets in the mammalian central nervous system (CNS) remain largely unknown to date. Our long-term research goal is to understand the rules of interneuron circuit wiring and the molecular mechanisms that control it. The objective of the proposed research is to describe how a combination of adhesive and neurotrophic signals determine GABAergic interneuron circuit connectivity. A class of GABAergic interneurons, termed GABApre, forms synaptic contacts with the terminals of proprioceptive sensory afferents, and thus directly controls proprioceptive sensory input through an inhibitory strategy known as presynaptic inhibition. We will test the hypothesis that the connectivity of a class of spinal GABAergic neurons varies between functionally-distinct sensory neurons and that this connectivity is mediated via (ii) differential expression of muscle-derived neurotrophin (NT)-3 and (ii) a matrix of IgSF adhesion proteins. The rationale underlying this proposal is that through understanding the mechanisms underlying GABAergic interneuron circuit formation, we will enhance our understanding of — and ultimately control over — inhibitory neuronal circuit development and function in vivo. We will test our hypothesis with the following three aims: #1) Determine the functional specificity of GABAergic interneuron circuitry; #2) Investigate the influence of muscle-derived NT-3 on GABApre synapse formation; and #3) Assess the role of Contactin-5 in GABApre-sensory synapse formation. In the first aim, we combine timed tamoxifen injections, mouse genetics and CTb labeling to analyze whether the specific connectivity of individual GABApre interneurons may be functionally relevant. In the second aim, we examine the expression of Gabrg1 in functionally distinct proprioceptive sensory neurons and assess consequences of changing NT-3 levels on both Gabrg1 expression and GABApre terminal number. In the third aim, we perturb cell adhesion signaling using mouse genetics and perform phenotypic analysis using molecular, micro-anatomic and functional assays, including an electrophysiological measure of presynaptic inhibition. We also use an in vitro binding assay to screen for new adhesion molecule candidates relevant for GABApre synaptic specificity in vivo. The research proposed in this application is innovative because it combines a molecularly-defined interneuronal circuit with a unique constellation of methodologies to integrate functional specificity with target-derived signals. The research will provide an understanding of functional diverse GABApre circuitry and also advance our understanding of how basic circuit paradigms may be adapted for diverse motor functions. The proposed work is significant because it will contribute to fundamental knowledge of the formation of circuit-level mechanisms and neural strategies used in the CNS; this in turn will advance our efforts to develop effective therapies to rebuild circuitry and muscle function after spinal cord injury or other neurological diseases.

建立特定的神经元电路对于生成协调的肌肉功能至关重要。但是，在中间神经元与其目标之间连接特异性的信号中的信号迄今为止，哺乳动物中枢神经系统（CNS）在很大程度上还不为人所知。我们的长期研究目标是了解中间电路接线的规则以及控制其的分子机制。目的拟议的研究是描述如何确定粘合剂和神经营养信号的组合 GABA能中心电路连接。一类GABA能中间神经元称为Gabapre，形成突触与本体感受的感官传统的终端接触，因此直接控制了本体感受的感觉通过一种被称为突触前抑制的抑制策略的输入。我们将检验以下假设一类脊柱GABA能神经元的连通性在功能上赋予的感觉神经元和通过（ii）肌肉衍生的神经营养蛋白（NT）-3和（ii）a的差异表达介导这种连通性 IGSF粘合剂蛋白的基质。该提议的基本原理是，通过了解 GABA能中间电路形成的机制，我们将增强我们对的理解 - 最终控制 - 抑制性神经元回路的发育和体内功能。我们将检验我们的假设以以下三个目标：＃1）确定GABA能中间神经元电路的功能特异性；＃2）研究肌肉衍生的NT-3对Gabapre突触形成的影响；和＃3）评估 Gabapre-Sensory突触形成中的Contactin-5。在第一个目标中，我们结合了定时的他莫昔芬注射，小鼠遗传学和CTB标记，以分析单个Gabapre的特定连通性是否中间神经元可能与功能相关。在第二个目标中，我们检查了gabrg1在在功能上独特的本体感知性感觉神经元和在两者中改变NT-3水平的评估后果 GABRG1表达和GABAPRE终端号。在第三个目标中，我们使用小鼠遗传学并使用分子，微动物和功能测定法进行表型分析，包括对突触前抑制的电生理测量。我们还使用体外结合测定法筛选与体内Gabapre突触特异性相关的新粘附分子候选物。研究在此应用中提出的是创新的将功能特异性与目标衍生信号集成的方法的独特星座。研究将提供对功能性潜水员加巴打电路的理解，也可以提高我们对基本电路范式如何适应潜水员运动功能。拟议的工作很重要因为它将有助于对电路级机制形成和中性的形成的基本知识中枢神经系统中使用的策略；反过来，这将促进我们开发有效疗法以重建电路的努力脊髓损伤或其他神经系统疾病后的肌肉功能。