Connexins in Neuronal and Glial Gap Junctions in the Central Nervous System

中枢神经系统神经元和胶质间隙连接中的连接蛋白

• 批准号: 7849506
• 负责人: JOHN E RASH
• 金额: $ 38.94万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7849506
• 关键词: Area; Arousal; Autistic Disorder; Binding; Brain; Brain region; Caliber; Cells; Cerebral cortex; Chemicals; Cognition; Cognitive; Communication; Complex; Confocal Microscopy; Connexins; Connexon; Conscious; Coupled; Coupling; Data; Data Correlations; Detection; Diffusion; Discrimination; Disease; Electrical Synapse; Electron Microscopy; Epilepsy; Event; Freeze Fracturing; Frequencies; Functional disorder; Gap Junctions; General Anesthesia; Glutamate Receptor; Health; Hippocampus (Brain); Human; Immunofluorescence Microscopy; In Situ Hybridization; Individual; Intercellular Junctions; Interneurons; Ion Channel; Ion Exchange; Ions; Label; Lasers; Learning; Link; Long-Term Potentiation; Maps; Measurement; Measures; Memory; Messenger RNA; Metabolic; Methods; Microscopic; Microtomy; Molecular; Mus; N-Methylaspartate; Nature; Neuraxis; Neurons; Neurotransmitter Receptor; Neurotransmitters; Parkinson Disease; Pharmaceutical Preparations; Phenotype; Prevalence; Proteins; Regulation; Relative (related person); Reporting; Retina; Rodent; Role; Scanning; Schizophrenia; Second Messenger Systems; Site; Sleep; Spinal Cord; Structure; Synapses; Thinking; Time; Tracer; awake; base; cell type; connexin 36; design; gene discovery; gray matter; human disease; immunocytochemistry; motor control; public health relevance; second messenger; virtual

DESCRIPTION (provided by applicant): Gap junctions are microscopic intercellular junctions that provide for direct intercellular ionic, electrical, and metabolic coupling between nerve cells in the brain, retina, and spinal cord. Previously, gap junctions between neurons were thought to consist of hundreds or thousands of connecting channels ("connexons"), but they were also thought to be rare, to occur only between a few types of neurons, and to occur only in limited, non- cognitive areas of the central nervous system. The discovery of "miniature" gap junctions (<100 connexons) and preliminary evidence for their abundance throughout the brain suggests that "mini" gap junctions, particularly those at "mixed" (chemical plus electrical) synapses, may provide the structural basis for the detection of tiny sub-threshold electrical "spikelets" or "partial spikes" in principal neurons that are distributed throughout the brain. Gap junctions / partial spikes are thought to be essential for regulating and optimizing the high-frequency neuronal oscillatory synchronizations that are thought to underlie consciousness, arousal from sleep, cognition, associative binding for learning and memory, and fine motor control, and which become pathologically altered in epilepsy, schizophrenia, Parkinson's disease, and autism spectral disorders. We will combine laser scanning confocal immunofluorescence microscopy with newly-developed freeze-fracture replica immunogold labeling (FRIL) electron microscopy to detect, quantify, determine the protein composition of, and measure the sizes of gap junctions throughout the complex circuitry of the mouse brain, to make detailed measurements of "mini" gap junctions in cerebral cortex and hippocampus of both mouse and human brain, and to identify the neuronal subtypes linked by "mini" gap junctions. We will emphasize analysis of those regions that are primarily responsible for thinking and consciousness (cerebral cortex) and for learning and memory (hippocampus) and that represent the primary sites of origin of epileptic discharges. These complementary approaches will allow direct correlation of data from large-scale (whole mouse brain) to ultrastructural and molecular levels. The data to be obtained will be essential for understanding how consciousness is created, what distinguishes sleeping vs. awake states, how consciousness is altered during general anesthesia, and how memories are created, and will also be essential for identifying subcellular sites that may become targets for designing new drugs to treat disorders of electrical synaptic communication in the brain. PUBLIC HEALTH RELEVANCE A newly-discovered class of "miniature" gap junctions, found to be abundant between many classes of neurons, may provide the structural basis for propagation of small electrical "spikelets" between neurons, and thereby, to regulate the oscillatory synchronizations of cerebral cortex and hippocampus that are associated with human consciousness and for associative binding for learning and memory. We will detect, map, quantify, and determine the connexin protein composition of "mini" gap junctions throughout mouse brain, both at electrical and at "mixed" (chemical plus electrical) synapses, and compare the distributions of gap junctions and their constituent connexins proteins in mouse vs. normal human cerebral cortex and hippocampus. These data will serve as a prelude to measuring changes in these structures in human disease such as epilepsy, schizophrenia, Parkinson's disease, and autism spectral disorders.

描述（由申请人提供）：间隙连接是微观细胞间连接，其在脑、视网膜和脊髓中的神经细胞之间提供直接的细胞间离子、电和代谢耦合。此前，神经元之间的间隙连接被认为由数百或数千个连接通道（“连接子”）组成，但它们也被认为是罕见的，仅发生在少数类型的神经元之间，并且仅发生在有限的、非认知区域中枢神经系统。“微型”缝隙连接（<100个连接子）的发现及其在整个大脑中丰富的初步证据表明，“微型”缝隙连接，特别是那些在“混合”（化学加电）突触中的缝隙连接，可能为检测分布在整个大脑中的主要神经元中的微小亚阈值电“尖峰”或“部分尖峰”提供结构基础。缝隙连接/部分尖峰被认为是调节和优化高频神经元振荡同步化的必要条件，所述高频神经元振荡同步化被认为是意识、从睡眠唤醒、认知、学习和记忆的关联结合以及精细运动控制的基础，并且在癫痫、精神分裂症、帕金森病和自闭症谱系障碍中发生病理改变。我们将联合收割机激光扫描共聚焦免疫荧光显微镜与新开发的冷冻断裂复制免疫金标记（FRIL）电子显微镜相结合，检测、定量、确定蛋白质组成并测量整个复杂电路中间隙连接的大小小鼠大脑，对小鼠和人类大脑大脑皮质和海马中的“迷你”间隙连接进行详细测量，并鉴定由“微型”缝隙连接的神经元亚型。我们将强调对主要负责思维和意识（大脑皮质）以及学习和记忆（海马体）以及代表癫痫放电主要起源部位的区域的分析。这些互补的方法将允许从大规模（整个小鼠大脑）的超微结构和分子水平的数据直接相关。获得的数据对于理解意识是如何产生的，睡眠与清醒状态的区别，意识在全身麻醉期间如何改变以及记忆如何产生至关重要，并且对于确定亚细胞位点也至关重要，这些亚细胞位点可能成为设计新药的目标，以治疗大脑中的电突触通讯障碍。公共卫生相关性新发现的一类“微型”缝隙连接，发现在许多类别的神经元之间是丰富的，可以提供神经元之间的小电“小穗”的传播的结构基础，从而调节与人类意识相关的大脑皮层和海马的振荡同步，并用于学习和记忆的关联结合。我们将检测，地图，量化，并确定整个小鼠大脑的“迷你”间隙连接的连接蛋白的蛋白组成，在电和“混合”（化学加电）突触，并比较小鼠与正常人大脑皮层和海马间隙连接及其组成的连接蛋白的分布。这些数据将作为测量人类疾病（如癫痫、精神分裂症、帕金森病和自闭症谱系障碍）中这些结构变化的前奏。