Analysis of activity-dependent interactions between microglia and synapses

小胶质细胞和突触之间活动依赖性相互作用的分析

• 批准号: 8618105
• 负责人: Dorothy Patricia Schafer
• 金额: $ 9万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8618105
• 关键词: Address; Affect; Autistic Disorder; Automobile Driving; Award; Boston; Brain; Candidate Disease Gene; Cells; Characteristics; Data; Development; Developmental Process; Disease; Elements; Event; Functional disorder; Funding; Future; Gene Delivery; Gene Expression; Genes; Genetic; Goals; Image; Immediate-Early Genes; Immune; Immunohistochemistry; In Vitro; Indium; Interleukin 12 Receptor Beta; Interleukin-12; Knockout Mice; Label; Laboratories; Learning; Life; Link; Maintenance; Measures; Mediating; Mental disorders; Mentors; Microglia; Modeling; Molecular; Mus; Nervous system structure; Neurodevelopmental Disorder; Neuroglia; Neurons; Pathology; Pathway interactions; Pediatric Hospitals; Phagocytes; Phagocytosis; Phase; Physiology; Play; Presynaptic Terminals; Process; Property; Proteins; Proteomics; Research Personnel; Resolution; Role; Schizophrenia; Sensory; Shapes; Signal Transduction; Structure; Study models; Synapses; System; Techniques; Testing; Time; Training; Translating; Viral; Virus; Visual; Visual system structure; Work; area striata; career; career development; cell type; density; design; experience; immune function; in vivo; in vivo imaging; interest; interleukin-12 receptor; medical schools; neural circuit; postnatal; postsynaptic; public health relevance; receptor; relating to nervous system; research study; response; synaptogenesis; time use; two-photon

7. Project Summary/Abstract To achieve the exquisite precision characteristic of synaptic circuits in the mature nervous system, immature synapses form a crude wiring diagram that must remodel during postnatal development. While it is clear that neural activity drives developmental synaptic remodeling, the underlying mechanisms are not fully understood. This K99/R00 proposal will support my career development as I investigate underlying cellular and molecular mechanisms driving activity-dependent synaptic remodeling in the developing brain. I have firmly established that microglia, the resident CNS immune cells, phagocytose synaptic elements in the postnatal brain in response to changes in neural activity. These data raise the intriguing possibility that microglia are a cellular mechanism driving activity-dependent synaptic remodeling. However, it is unknown whether microglia actively phagocytose intact synapses or passively phagocytose synaptic remnants. In addition, the molecular mechanisms underlying activity-dependent microglia-synapse interactions are unknown. These questions will be addressed during the mentored phase of the award at Boston Children's Hospital and Harvard Medical School under the guidance of Dr. Beth Stevens and Dr. Michael Greenberg. Aim 1 is designed to test the hypothesis that microglia are actively phagocytosing intact synapses in response to changes in neural activity. In doing so, I will learn viral-mediated gene delivery to fluorescently label specific neural circuits and 2-photon in vivo live imaging to analyze microglia-synapse interactions in real time. Aim 2 is designed to investigate molecular mechanisms underlying these interactions. After genetic and proteomic screens, I have identified a candidate, interleukin 12 (IL-12). I will test the hypothesis that IL-12 regulates activity-dependent microglia-synapse interactions by in vivo imaging in IL-12 and IL-12 receptor KO mice. Specific Aim 3 (to be completed in my own laboratory) will determine the functional significance of activity- dependent microglia-synapse interactions by testing the hypothesis that these interactions regulate the functional development of synaptic circuits. I will genetically ablate microglia during a specific window of postnatal development and assess synapse structure and physiology. To manipulate microglia function more specifically, I will also test the role of the IL-12 pathway. Furthermore, as an alternative and/or future direction, my genetic and proteomic screens have identified several other putative molecular pathways that I will test. Given that aberrant synaptic circuits and microglial dysfunction have now been linked with several neurodevelopmental and psychiatric disorders, this proposal will have broad implications. My long term career goal as an independent investigator is to translate my findings to understand how microglia and other glial cell types may contribute to synaptic circuit abnormalities associated with disorders such as autism and schizophrenia. This award will help me to complete my training and provide an opportunity to learn techniques and obtain data for a successful R01 application to fund my future work.

7.项目总结/摘要 为了达到成熟神经系统中突触回路的精确特性， 未成熟的突触形成了一个粗糙的线路图，必须在出生后的发育过程中重新塑造。虽然 显然，神经活动驱动发育突触重塑，但其潜在机制尚不完全 明白这个K99/R00提案将支持我的职业发展，因为我调查了基础蜂窝和 在发育中的大脑中驱动活动依赖性突触重塑的分子机制。 我已经确定，小胶质细胞，常驻中枢神经系统的免疫细胞，吞噬突触元件， 出生后的大脑对神经活动变化的反应。这些数据提出了一个有趣的可能性， 小胶质细胞是驱动活性依赖性突触重塑的细胞机制。但不清楚 无论小胶质细胞主动吞噬完整的突触还是被动吞噬突触残余物。在 此外，活动依赖性小胶质细胞-突触相互作用的分子机制是 未知这些问题将在波士顿儿童基金会的指导阶段得到解决。 医院和哈佛医学院的指导下，博士贝丝史蒂文斯和博士迈克尔格林伯格。目的 1旨在检验小胶质细胞积极吞噬完整突触的假设， 神经活动的变化。在这样做的过程中，我将学习病毒介导的基因传递， 神经回路和2-光子活体成像，以真实的时间分析小胶质细胞-突触相互作用。目标二是 旨在研究这些相互作用的分子机制。在基因和蛋白质组学 通过筛选，我已经确定了一个候选者，白细胞介素12（IL-12）。我将检验IL-12调节 在IL-12和IL-12受体KO小鼠中通过体内成像观察活性依赖性小胶质细胞-突触相互作用。 具体目标3（将在我自己的实验室完成）将确定活动的功能意义- 依赖的小胶质细胞-突触相互作用，通过测试假设，这些相互作用调节 突触回路的功能发育。我会在一个特定的时间段内去除小胶质细胞 出生后发育和评估突触结构和生理学。为了操纵小胶质细胞的功能 具体来说，我也将测试IL-12通路的作用。此外，作为替代和/或未来方向， 我的基因和蛋白质组筛选已经确定了其他几个假定的分子途径，我将进行测试。 鉴于异常的突触回路和小胶质细胞功能障碍现在已经与几个 神经发育和精神疾病，这项建议将有广泛的影响。我的长期职业生涯 作为一名独立研究者，我的目标是将我的发现转化为理解小胶质细胞和其他胶质细胞 类型可能会导致与自闭症等疾病相关的突触回路异常， 精神分裂症这个奖项将帮助我完成我的培训，并提供一个机会，学习技术 并获得成功的R01应用程序的数据，以资助我未来的工作。