Molecular mechanisms of electrical synapse formation in vivo

体内电突触形成的分子机制

• 批准号: 9500819
• 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/9500819
• 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.

所有的大脑功能，从感觉知觉到行为，都源自大脑的模式和特性。 数十亿（人类）单个神经元之间的突触连接。该项目的长期目标是 使用有重点的脊椎动物模型了解体内调节突触形成的分子途径 关于未被充分认识的电突触。电突触是神经元之间直接交流的场所 允许离子和小分子通过的神经元。它们对神经回路有广泛贡献 形成和功能，无论是在发育过程中还是在成年期，它们都有助于感觉 感知、中间神经元处理和运动输出。然而，控制的分子机制 人们对电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 神经元是单独可识别的，它们的突触前和突触后伙伴、突触和功能是 在活的脊椎动物胚胎中清晰可见。经典的正向和新颖的反向遗传筛选 确定了形成毛斯纳电突触神经元间通道的连接蛋白，发现 有专门的突触前和突触后连接蛋白，并确定了 Neurobeachin，一种高尔基体后转运蛋白 蛋白和紧密连接蛋白 1b (Tjp1b)，一种膜相关鸟苷酸激酶 (MAGUK) 家族 支架，作为电突触形成所需的。这些发现表明电突触 由通常不被理解的分子复杂性组成；他们进一步表明，错综复杂的 需要生化机制来控制这些关键位点的形成、功能和可塑性 神经元通讯。该提案的目标1检查电突触的细胞生物学机制 形成，检验电突触需要突触后定位和功能的假设 Tjp1b 稳定突触处的连接蛋白。 Aim2 检查生化机制 突触发生，检验 Tjp1b 和连接蛋白之间直接相互作用的假设 定位到突触所需的。 Aim3 旨在扩展所需蛋白质的分子库 电突触的形成，并提供了电突触作为复杂的多分子的新观点 机器。鉴于电突触对于大脑的早期发育连接至关重要，它们可能是 与线路发育障碍密切相关。事实上，Neurobeachin 和 MAGUK 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的 深入了解电突触形成的机制，为识别电突触提供基础 复杂神经发育障碍治疗的目标。