Molecular Mechanisms of Electrical Synapse Formation in Vivo

体内电突触形成的分子机制

• 批准号: 10079028
• 负责人: Adam C Miller
• 金额: $ 40.14万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10079028
• 关键词: Adherens Junction; Adhesions; Adult; Animals; Behavior; Behavioral; Binding; Biochemical; Biochemistry; Biological; Biological Models; Brain; Cells; Cellular biology; Chemical Synapse; Chemicals; Communication; Complex; Connexins; Cytoskeleton; Data; Dendrites; Development; Electrical Synapse; Epilepsy; Epithelial; Family; Foundations; Future; Gap Junctions; Gene Proteins; Genes; Genetic; Genetic Screening; Goals; Golgi Apparatus; Homologous Gene; Human; In Vitro; Individual; Interneurons; Investigation; Ions; Link; Mauthner' s neuron; Modeling; Molecular; Molecular Machines; Motor; Motor output; Neuraxis; Neurodevelopmental Disorder; Neurons; Oregon; Output; Pathway interactions; Pattern; Perception; Play; Postdoctoral Fellow; Process; Property; Proteins; Publishing; Role; Schizophrenia; Sensory; Site; Stereotyping; Structure; Synapses; System; Testing; Tight Junctions; Universities; Vesicle; Work; Zebrafish; autism spectrum disorder; developmental disease; gap junction channel; genetic regulatory protein; in vivo; in vivo Model; insight; member; membrane-associated guanylate kinase; neural circuit; neuronal circuitry; novel; postsynaptic; protein transport; response; reverse genetics; scaffold; small molecule; synaptic function; synaptogenesis; targeted treatment; therapeutic development; trafficking; vertebrate embryos

All of brain function, from sensory perception to behavior, is derived from the pattern and properties of the synaptic connections among billions (in humans) of individual neurons. The long-term goal of this project is to understand molecular pathways that regulate synapse formation in vivo using a vertebrate model with a focus on the underappreciated electrical synapse. Electrical synapses are sites of direct communication between neurons that allow the passage of ions and small molecules. They contribute extensively to neural circuit formation and function, both during development as well in adulthood where they contribute to sensory perception, interneuron processing, and motor output. However, the molecular mechanisms controlling the formation of electrical synapse are poorly understood. This proposal utilizes the zebrafish Mauthner circuit to investigate the genetics, cell biology, and biochemistry of electrical synapse formation and function. Mauthner neurons are individually identifiable and their pre- and postsynaptic partners, synapses, and function are exquisitely visualized in a living, vertebrate embryo. Classic forward and novel reverse genetic screens have identified the Connexins that form the inter-neuronal channels of the Mauthner electrical synapses, found that there are dedicated pre- and postsynaptic Connexins, and identified Neurobeachin, a post-Golgi trafficking protein, and Tight Junction Protein 1b (Tjp1b), a membrane-associated guanylate kinase (MAGUK) family scaffold, as being required for electrical synapse formation. These findings suggest that electrical synapses are comprised of a molecular complexity that is not generally appreciated; they further suggests that intricate biochemical mechanisms are required to control the formation, function, and plasticity of these critical sites of neuronal communication. Aim1 of this proposal examines the cell biological mechanisms of electrical synapse formation, examining the hypothesis that electrical synapses require the postsynaptic localization and function of Tjp1b to stabilize Connexins at the synapse. Aim2 examines the biochemical mechanisms of synaptogenesis, examining the hypothesis that a direct interaction between Tjp1b and the Connexins is required for localization to the synapse. Aim3 looks to expand the molecular repertoire of proteins required for electrical synapse formation, and provides a new view of electrical synapses as complex multi-molecular machines. Given that electrical synapses are essential to early developmental wiring of the brain, they may be intricately linked to developmental disorders of wiring. Indeed, both Neurobeachin and the MAGUKs are associated with autism and other neurodevelopmental disorders. The proposed studies will provide novel insight into the mechanisms of electrical synapse formation and provide a foundation for the identification of targets for therapy of complex neurodevelopmental disorders.

从感觉感知到行为的所有大脑功能都来自于该模式和特性 单个神经元（人类）数十亿（人类）之间的突触联系。该项目的长期目标是 了解使用脊椎动物模型在体内调节突触形成的分子途径 在未充分的电气突触上。电气突触是在 允许通过离子和小分子的神经元。它们为神经电路做出了广泛的贡献 在发展期间以及成年期间的形成和功能，它们有助于感官 感知，内神经元处理和电动机输出。但是，控制的分子机制 电气突触的形成知之甚少。该提案利用斑马鱼毛特纳电路 研究电突触形成和功能的遗传学，细胞生物学和生物化学。毛特纳 神经元是单独识别的，其前和突触后伴侣，突触和功能是 在活生生的脊椎动物胚胎中精美可视化。经典前进和新颖的反向遗传筛选具有 鉴定出形成Mauthner电气突触的神经元通道的连接素，发现 有专门的前和突触后连接蛋白，并确定了神经病，这是高尔基贩运后的贩运 蛋白质和紧密连接蛋白1B（TJP1B），一种与膜相关的鸟苷酸酯激酶（MAGUK）家族 脚手架，是电气突触形成所必需的。这些发现表明电突触是 由通常不理解的分子复杂性组成；他们进一步提出了复杂的 需要生化机制来控制这些关键位点的形成，功能和可塑性 神经元交流。该提案的AIM1检查电细胞生物学机制 形成，检查电气突触需要突触后定位和功能的假设 TJP1b的稳定在突触处的连接素。 AIM2检查的生化机制 突触发生，研究了TJP1B与连接素之间直接相互作用的假设是 定位到突触所必需的。 AIM3旨在扩大所需蛋白质的分子曲目 电触突的形成，并提供了电气突触的新视图，如复杂的多分子 机器。鉴于电突触对于大脑的早期发育接线至关重要，它们可能是 与接线的发育障碍相关。确实，Neurobeachin和Maguks都是 与自闭症和其他神经发育障碍有关。拟议的研究将提供新颖 深入了解电突触形成机制，并为识别 复杂神经发育障碍治疗的靶标。