Role of Fat3 at the intersection of neuronal morphology and synapse localization

Fat3 在神经元形态和突触定位交叉点中的作用

• 批准号: 9210739
• 负责人: Steven J Henle
• 金额: $ 2.45万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2016-05-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9210739
• 关键词: Role; Fat3; intersection; neuronal; morphology

DESCRIPTION (provided by applicant): Repairing the nervous system after injury, neurodegenerative disease, or dysfunctional development represents a significant challenge to biomedical research. Understanding how newly born neurons are guided by signals in their environment to form the correct neuronal morphology and synaptic connections is key to developing therapies to repair these disease states. Our current understanding of how neurons develop their specific shape and set of synapses is primarily the result of cell culture studies, where developing neurons are not exposed to the normal set of extracellular cues. This proposal combines mouse genetics, time-lapse imaging, and phenotypic analysis to understand how neuronal polarization and synaptogenesis are orchestrated in the context of the developing tissue. The atypical cadherin Fat3 offers a unique molecular entry point to investigate the relationship between synapse formation and neuronal morphology. Fat3 is expressed in the amacrine and retinal ganglion cells of the retina. Genetic deletion of fat3 in mice results in ectopic synapses and disrupted morphology in amacrine cells. The events that underlie this phenotype are unknown. This proposal will test the central hypothesis that Fat3 mediates cell-cell interactions that position and shape axons and dendrites, which in turn restricts synaptic location. To this end I will investigate the role of Fat3 in linking extracellular cues to neuronal polarity and synaptogenesis, and then ask if Fat3 plays a similar role in the development of other neurons. Specific Aim 1 is focused on investigating cellular events that lead to the correct development of amacrine cells, and then determining what events are Fat3-dependent. Establishment of a novel time-lapse retinal slice imaging method will facilitate the analysis of single amacrine cells developing in their natural context in mammals. Additionally, this aim seeks to understand the relationship between neuronal polarization and synaptogenesis. Specific Aim 2 is directed at understanding the role of Fat3-mediated cell-cell interactions with other neurons that controls the development of retinal ganglion cell axonal and dendritic morphology. Deletion of fat3 from specific populations of retinal ganglion and amacrine cells, followed by phenotypic analysis of the morphology of the resulting retinal ganglion cell axon and dendrites will provide a clear understanding of how cell-cell contacts mediate development. Collectively, the work described here will provide novel insight into amacrine and retinal ganglion cell development. Specifically, the results will answer key questions about the relationship between neuronal morphology and synapse formation in the context of the extracellular environment, as well as the role of cellular interactions in forming neuronal circuit.

描述（由申请人提供）：损伤、神经退行性疾病或发育障碍后的神经系统修复是生物医学研究的一个重大挑战。了解新生神经元如何被其环境中的信号引导以形成正确的神经元形态和突触连接是开发修复这些疾病状态的疗法的关键。我们目前对神经元如何发育其特定形状和突触集的理解主要是细胞培养研究的结果，其中发育中的神经元没有暴露于正常的细胞外信号。该提案结合了小鼠遗传学，延时成像和表型分析，以了解神经元极化和突触发生如何在发育组织的背景下进行协调。非典型钙粘蛋白Fat 3为研究突触形成和神经元形态之间的关系提供了一个独特的分子切入点。Fat 3在视网膜的无长突细胞和视网膜神经节细胞中表达。小鼠fat 3基因缺失导致异位突触和无长突细胞形态学破坏。这种表型的基础事件是未知的。这项提议将检验核心假设，即Fat 3介导细胞-细胞相互作用，定位和塑造轴突和树突，从而限制突触的位置。为此，我将研究Fat 3在连接细胞外信号和神经元信号中的作用。 极性和突触发生，然后询问Fat 3是否在其他神经元的发育中发挥类似的作用。具体目标1的重点是研究导致无长突细胞正确发育的细胞事件，然后确定哪些事件是Fat 3依赖的。建立一种新的时间推移视网膜切片成像方法将有助于分析单个无长突细胞在其自然环境中发育的哺乳动物。此外，这一目标旨在了解神经元极化和突触发生之间的关系。具体目标2是针对理解Fat 3介导的细胞与其他神经元的相互作用的作用，控制视网膜神经节细胞轴突和树突形态的发展。从视网膜神经节细胞和无长突细胞的特定群体中删除fat 3，然后对所得到的视网膜神经节细胞轴突和树突的形态进行表型分析，将提供对细胞-细胞接触如何介导发育的清晰理解。总的来说，这里描述的工作将提供新的见解无长突和视网膜神经节细胞的发展。具体而言，这些结果将回答有关神经元形态和突触形成在细胞外环境的背景下，以及在形成神经元回路的细胞相互作用的作用之间的关系的关键问题。