The Roles of Pioneer Neurons and Adhesion Molecules in Neuronal Migration

先锋神经元和粘附分子在神经元迁移中的作用

• 批准号: 1555972
• 负责人: Victoria Prince
• 金额: $ 62万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1555972&HistoricalAwards=false
• 关键词: Roles; Pioneer; Neurons; Adhesion; Molecules

Nerves, the major communication pathways of our brain and spinal cord, are made of many individual communication fibers called axons. Each axon carries information from one single nerve cell (neuron). As an embryo develops, these fibers have to connect up correctly in order to make working neural circuits. Before these connections can form, the neurons have to move from the place they are born to the location where they will perform their role. Previously, the Principal Investigators have studied this process in the facial nerve, which controls facial expressions, and found that a single "pioneer" neuron guides the movement of the remaining neurons to their final destinations. Where do pioneer neurons come from, how do they know where to go, and how do other neurons know how to follow them? This project will address these questions in developing zebrafish embryos (animals with facial nerves similar to humans). Zebrafish embryos are transparent, and the experiments use specially-engineered zebrafish whose facial neurons are fluorescently labeled to make their cell migration visible. Experiments will also examine the roles of particular molecules found on the cell surface that are important for cell migration (cell adhesion molecules). A new kind of 3-dimensional imaging (light sheet microscopy) will be used to measure cell movements, and new software will be developed to visualize and analyze cell movement data. Once developed and tested at the University of Chicago and the Marine Biological Laboratory, these software tools will be made freely available. The project will additionally provide training opportunities for high school, undergraduate and graduate students; introduce elementary and middle school students to research; and engage the public via interactive displays at the Museum of Science and Industry (MSI).Subsets of neurons migrate tangentially within the neuroepithelial plane, often over significant distances. To better understand mechanisms underlying tangential migration that are important for neural circuit formation, this project focuses on facial branchiomotor neurons (FBMNs), which undergo a tangential migration that is conserved in vertebrates ranging from fishes to mammals. The study will utilize zebrafish embryos as they are accessible, transparent, and a powerful genetic model. Migrating FBMNs will be imaged in transparent zebrafish embryos with genetically marked cells, and tracked using light sheet microscopy. The Principal Investigator recently described the pioneer neuron as the first FBMN to migrate on each side of the hindbrain, and demonstrated the critical role of this neuron. Aim 1 will study the newly recognized pioneer neuron by establishing its cellular origins and tracking its subsequent trajectory through development. FBMN tangential migration also relies on interactions with two different pre-laid axon tracts and both interactions depend on adhesion molecule N-Cadherin. Aim 2 will investigate the role of N-Cadherin in mediating interactions between FBMNs and axon tracts, and whether it functions autonomously within neurons during migration. Additional adhesion molecules important for FBMN migration will be identified using RNAseq. An integral part of this project will be the development of new, broadly-applicable computational tools to analyze imaging data.

神经是我们大脑和脊髓的主要通信途径，由许多称为轴突的单独通信纤维组成。每个轴突携带来自单个神经细胞（神经元）的信息。随着胚胎的发育，这些纤维必须正确连接，以形成工作的神经回路。在这些连接形成之前，神经元必须从它们出生的地方移动到它们将发挥作用的地方。在此之前，主要研究人员已经研究了控制面部表情的面神经中的这一过程，并发现单个“先锋”神经元引导其余神经元运动到最终目的地。先驱神经元从哪里来，它们如何知道去哪里，其他神经元如何知道如何跟随它们？该项目将在开发斑马鱼胚胎（具有与人类相似的面部神经的动物）时解决这些问题。斑马鱼胚胎是透明的，实验使用了经过特殊工程改造的斑马鱼，其面部神经元被荧光标记，使其细胞迁移可见。实验还将检查细胞表面上发现的对细胞迁移很重要的特定分子（细胞粘附分子）的作用。一种新的三维成像（光片显微镜）将用于测量细胞运动，新的软件将被开发来可视化和分析细胞运动数据。这些软件工具一旦在芝加哥大学和海洋生物实验室开发和测试后，将免费提供。该项目还将为高中生、本科生和研究生提供培训机会;介绍小学生和中学生进行研究;并通过科学与工业博物馆（MSI）的互动展示吸引公众。神经元子集在神经内切向迁移上皮平面，通常距离很远。为了更好地了解切向迁移的机制是重要的神经回路的形成，该项目的重点是面鳃神经元（FBMNs），它经历了切向迁移，是保守的脊椎动物，从鱼类到哺乳动物。这项研究将利用斑马鱼胚胎，因为它们是可访问的，透明的，并且是一个强大的遗传模型。迁移的FBMN将在具有遗传标记细胞的透明斑马鱼胚胎中成像，并使用光片显微镜进行跟踪。首席研究员最近将先驱神经元描述为第一个在后脑两侧迁移的FBMN，并证明了该神经元的关键作用。目标1将通过建立其细胞起源并跟踪其随后的发育轨迹来研究新认识的先驱神经元。FBMN切向迁移还依赖于与两个不同的预先铺设的轴突束的相互作用，并且这两种相互作用都依赖于粘附分子N-钙粘蛋白。目的2将探讨N-钙粘蛋白在介导FBMNs和轴突束之间的相互作用中的作用，以及它是否在迁移过程中自主地在神经元内发挥作用。将使用RNAseq鉴定对FBMN迁移重要的其他粘附分子。该项目的一个组成部分将是开发新的，广泛适用的计算工具来分析成像数据。