Spinal Cord Development: Interplay Between Electrical Activity and Sonic Hedgehog

脊髓发育：电活动与 Sonic Hedgehog 之间的相互作用

• 批准号: 8185636
• 负责人: Laura Noemi Borodinsky
• 金额: $ 33.11万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8185636
• 关键词: Address; Affect; Biological; Biological Assay; Biosensor; Brain; Calcium; Calcium Spikes; Cell Proliferation; Cells; Childhood; Cilia; Complex; Cues; Development; Developmental Biology; Developmental Process; Dominant-Negative Mutation; Dorsal; Embryo; Epilepsy; Equilibrium; Erinaceidae; Event; Exhibits; Generations; Goals; Image; Investigation; Knowledge; Label; Lead; Life; Link; Luciferases; Mediating; Molecular; Natural regeneration; Nerve Regeneration; Nervous system structure; Neural tube; Neuronal Differentiation; Neurons; Neurosciences; Neurotransmitters; Outcome; Pathway interactions; Patients; Pattern; Phenotype; Positioning Attribute; Process; Production; Proteins; Recovery; Research; Research Project Grants; Role; Second Messenger Systems; Signal Transduction; Signal Transduction Pathway; Sonic hedgehog protein; Spinal; Spinal Cord; Spinal cord injury; Staging; Surface; Synapses; System; Testing; Thinking; Tissues; Transcriptional Regulation; Western Blotting; Wound Healing; Xenopus; axon guidance; axonal pathfinding; base; cancer stem cell; cell injury; cell type; human SMO protein; in vivo; injured; innovation; migration; morphogens; nerve stem cell; nervous system development; nervous system disorder; novel; receptor; relating to nervous system; repaired; second messenger; smoothened signaling pathway; synaptogenesis

DESCRIPTION (provided by applicant): Nervous system development encompasses generation of neural cells, followed by their positioning and differentiation to culminate with establishment of specific connections that enable the execution of innumerable functions. Although both the developing and mature nervous system exhibit tremendous plasticity, comparatively, the former has a greater capacity for remodeling. When the neural tissue is injured or its function is imbalanced, as for patients suffering from spinal cord injury or epilepsy, recreating the remarkable plasticity of the developing nervous system towards repairing and regenerating damaged cells and connections is the ultimate goal. Understanding developmental processes becomes crucial to devising therapies targeting nervous system regeneration and repair. Two major developmental cues are key for nervous system development, the morphogentic protein, Sonic hedgehog (Shh), and early electrical activity. Although many aspects of their action are known, there has been no previous consideration of the interaction between them. This research project wil study the molecular mechanisms underlying the interplay between Shh and electrical activity and how their interaction affects nervous system development and maturation. This study will test the hypothesis that the Shh gradient across the dorsoventral axis of the nervous system contributes to establish a gradient of calcium-dependent electrical activity across the dorsoventral developing spinal cord that in turn regulates neuronal differentiation. Pharmacological and molecular manipulations of Shh gradient and signaling wil be implemented in developing Xenopus embryos. Calcium dynamics will be imaged in neurons on the dorsal and ventral surfaces of the neural tube of control and experimentally perturbed embryos. Reciprocally, manipulations of calcium spike activity will be carried out and the consequences to Shh signaling in the developing spinal cord will be assessed. To investigate the functional consequences of the interplay between Shh signaling and calcium spike activity, a crucial biological outcome will be studied: dorsoventral differentiation of developing spinal neurons. The involvement of calcium spike activity-dependent pathways in this process will be studied in vivo following pharmacological and molecular perturbations of Shh signaling and electrical activity. This project may lead to new ways of thinking of how the nervous system develops and how different pathways interact to promote its formation and maturation. When generation and differentiation of neural cells is needed to reestablish lost connections, the ability to direct the affected system toward the production of appropriate number and type of cells is paramount. This investigation of mechanisms underlying neuronal differentiation may set the basis for devising treatments for neurological disorders such as pediatric epilepsy and spinal cord injury, in which both the reestablishment of balanced excitability and the reposition of damaged cells are key events for promoting recovery. PUBLIC HEALTH RELEVANCE: This project investigates the complex developmental process of neuronal specification and differentiation during nervous system development. We will elucidate the interaction between two major developmental cues, electrical activity and the morphogenetic protein Sonic hedgehog. When the neural tissue is injured or its function is imbalanced, as for patients suffering from spinal cord injury or epilepsy, recreating the remarkable plasticity of the developing nervous system towards repairing and regenerating damaged cells and connections is the ultimate goal. The knowledge of how different patterns of activity are established during development and how they relate to other regulatory factors will help devising therapies aimed at inducing restorative plasticity in a pathological context of loss or impaired synaptic connectivity. This study wil contribute to the understanding of how to direct the affected system toward the production of appropriate number and type of cells when generation and differentiation of neural cells are needed. Moreover, results from this project may identify novel non-canonical mechanisms of action of Sonic hedgehog that may be of relevance to many fields of research, including developmental biology, neuroscience, cancer, stem cells and tissue repair.

描述（由申请人提供）：神经系统发育包括神经细胞的产生，随后是它们的定位和分化，最终建立能够执行无数功能的特定连接。虽然发育中的神经系统和成熟的神经系统都具有很大的可塑性，但相对而言，发育中的神经系统具有更大的重塑能力。当神经组织受损或其功能失衡时，如患有脊髓损伤或癫痫的患者，重建发育中的神经系统的显著可塑性，以修复和再生受损的细胞和连接是最终目标。了解发育过程对于设计针对神经系统再生和修复的疗法至关重要。两个主要的发育线索是神经系统发育的关键，形态发生蛋白，音速刺猬（Shh）和早期电活动。虽然他们的行动的许多方面是已知的，但以前没有考虑过他们之间的相互作用。 本研究计划将研究Shh和电活动之间相互作用的分子机制，以及它们的相互作用如何影响神经系统的发育和成熟。这项研究将测试的假设，Shh梯度的背腹轴的神经系统有助于建立一个梯度的钙依赖性电活动的背腹发展脊髓，反过来又调节神经元的分化。 Shh梯度和信号传导的药理学和分子操作将在非洲爪蟾胚胎发育中实施。钙动力学将在对照和实验扰动胚胎的神经管的背侧和腹侧表面上的神经元中成像。反过来，将进行钙峰活性的操作，并评估发育中的脊髓中Shh信号传导的后果。为了研究Shh信号和钙峰活性之间相互作用的功能后果，将研究一个重要的生物学结果：发育中的脊髓神经元的背腹侧分化。在这个过程中的钙峰活性依赖性途径的参与将在体内研究以下的药理学和分子扰动的Shh信号和电活性。 这个项目可能会导致对神经系统如何发育以及不同途径如何相互作用以促进其形成和成熟的新思维方式。当需要神经细胞的生成和分化来重建失去的连接时，引导受影响的系统产生适当数量和类型的细胞的能力是至关重要的。神经元分化机制的研究可能为设计神经系统疾病（如小儿癫痫和脊髓损伤）的治疗方法奠定基础，其中平衡兴奋性的重建和受损细胞的重新定位是促进恢复的关键事件。 公共卫生关系：本研究旨在探讨神经系统发育过程中神经元特化和分化的复杂发育过程。我们将阐明两个主要的发展线索，电活动和形态发生蛋白质音速刺猬之间的相互作用。当神经组织受损或其功能失衡时，如患有脊髓损伤或癫痫的患者，重建发育中的神经系统的显著可塑性，以修复和再生受损的细胞和连接是最终目标。在发育过程中如何建立不同的活动模式以及它们如何与其他调节因素相关的知识将有助于设计旨在在突触连接丧失或受损的病理背景下诱导恢复性可塑性的疗法。本研究将有助于理解当需要神经细胞的产生和分化时，如何引导受影响的系统产生适当数量和类型的细胞。此外，该项目的结果可能会发现Sonic hedgehog的新型非经典作用机制，这些机制可能与许多研究领域相关，包括发育生物学、神经科学、癌症、干细胞和组织修复。