Role of Neurexin in Synapse Formation and Maintenance

Neurexin 在突触形成和维持中的作用

• 批准号: 8843546
• 负责人: Lulu Yiju Chen
• 金额: $ 6万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8843546
• 关键词: Alleles; Autistic Disorder; Biological; Biological Neural Networks; Brain; Breeding; Cell Adhesion Molecules; Cells; Cognition Disorders; DLG4 gene; Dendrites; Development; Disease; Etiology; Fiber; Financial compensation; Frequencies; Genes; Genetic; Genetic Polymorphism; Health; Hippocampus (Brain); Imagery; Immunofluorescence Immunologic; In Vitro; Individual; Inferior; Injection of therapeutic agent; Knock-out; Knockout Mice; Lead; Link; Maintenance; Measures; Mus; Mutant Strains Mice; Neurocognitive; Neurons; Olives - dietary; Phase; Phenotype; Play; Preparation; Presynaptic Terminals; Probability; Production; Purkinje Cells; Research; Research Proposals; Role; Schizophrenia; Staging; Suggestion; Synapses; Synaptic Potentials; Synaptic Receptors; Synaptic Transmission; System; Testing; Training; Vertebral column; Work; autism spectrum disorder; base; career; cognitive process; homologous recombination; immunoreactivity; in vivo; insight; interdisciplinary approach; mouse model; neuronal cell body; novel; patch clamp; postnatal; presynaptic; recombinase; research study; synaptic failure; synaptic function; synaptogenesis

DESCRIPTION (provided by applicant): Synapse formation and elimination are fundamental to the assembly of neural networks during development and give rise to nearly every cognitive process. Neurexins are presynaptic cell-adhesion molecules whose polymorphisms have been implicated in autism and schizophrenia. Reduced systems have strongly implicated neurexin as a potent synaptogenesis molecule, but no phenotype in synaptogenesis was observed in α-neurexin KO studies; this result suggests that there may be compensation for α-neurexins. This research proposal aims to 1) develop and analyze novel conditional knockout mice in which both the α- and ß-forms of all 3 neurexin genes can be deleted by Cre recombinase, and 2) use this novel mouse model to investigate fundamental requirements for neurexins in synapse formation and function. Specifically, synapse formation will first be determined in vitro in culturd neurons by morphological and electrophysiological approaches, and subsequently in vivo at the olivo-cerebellar synapse, which provides a unique and elegant preparation to examine synapse formation, development, and maintenance. The proposed studies will test the following hypotheses: whether the complete knockout of neurexins (Nrxn1/2/3 α/ß) will 1) decrease the frequency, but not amplitude, of spontaneous miniature synaptic potentials, and lead to the loss of active synapses; 2) decrease synapse numbers as measured from morphological analysis in culture systems; and 3) lead to the failure of synapse elimination or maturation in the developing climbing fiber-Purkinje cell synapse. These experiments provide the first direct test of the hypothesis that neuron-specific adhesion molecule, neurexin, plays the crucial role in synapse development and synaptic functions. The conditional mouse model is so-far the most complete and approachable system for neurexin, mainly due to neurexin's critical biological importance, where knocking out only the α-form of neurexin is postnatally lethal, thus limits research approaches. It is projected that the results will expand extensively to our understanding of neurexin actions in brain and will provide valuable insights to this fundamental hypothesis. Furthermore, the proposed work hopefully would produce insights into the etiology of neurocognitive diseases/disorders based on neurexins' polymorphism that is strongly implicated in autism spectrum disorders, schizophrenia, and other cognitive diseases. Finally, the proposed project will provide outstanding training opportunities to develop my professional qualifications in pursuing an independent academic career that requires a multidisciplinary approach.

描述（由适用提供）：突触形成和进化是开发过程中神经网络组装的基础，几乎引起了每个认知过程。神经毒素是突触前细胞粘附分子，其在自闭症和精神分裂症中已隐含多态性。减少的系统强烈暗示神经氧蛋白是潜在的突触发生分子，但是在α-纽苏蛋白KO研究中未观察到突触发生中的表型。该结果表明可能有α-系素的补偿。该研究建议的目的是1）开发和分析新型有条件敲除小鼠，其中所有3种神经氧蛋白基因的α-和β形式均可通过CRE重组酶删除，并且2）使用这种新型小鼠模型来研究突触形成和功能中Neuroxin的基本需求。具体而言，首先将通过形态学和电生理方法在文化神经元中在体外确定突触形成，然后在Olivo-Cerebellar Synapse的体内在体内确定，这为检查突触的形成，发育和维持提供了独特而优雅的准备。拟议的研究将检验以下假设：神经氧素的完整敲除（NRXN1/2/3α/ß）是否会降低赞助商 - 循环微型突触电位的频率，但不是放大器，并导致活性突触丧失； 2）减少从培养系统中形态分析测量的突触数量； 3）导致突触消除或成熟的失败。这些实验提供了关于神经特异性粘合分子神经氧蛋白在突触发育和突触功能中起关键作用的假设的首次直接检验。有条件的小鼠模型是神经氧蛋白的最完整，最平易近人的系统，这主要是由于神经氧蛋白的关键生物学重要性，在这种情况下，仅敲除了神经氧蛋白的α-形式后致命，因此限制了研究方法。预计结果将广泛扩展到我们对大脑神经氧蛋白作用的理解，并将为这一基本假设提供宝贵的见解。此外，拟议的工作希望将基于神经认知疾病/疾病的病因产生洞察力，基于神经氧蛋白的多态性，这与自闭症谱系障碍，精神分裂症和其他认知疾病强烈牵涉。最后，拟议的项目将提供出色的培训机会，以发展我的专业资格，以追求需要多学科方法的独立学术职业。