Characterizing age-related decline of neural circuits by single-cell profiling

项目总结/摘要 神经系统的功能依赖于适当的神经回路组装和长期的维持。 电路的完整性。采用整合的单细胞基因组方法，在这里，我建议研究细胞 以及神经回路发育组装和年龄诱导衰退的分子机制， 果蝇嗅觉系统 在果蝇嗅觉回路中，50类嗅觉受体神经元（ORN;每类 表达一种独特的嗅觉受体）与50类嗅觉投射神经元精确连接， 为研究神经元布线特异性提供了一个强有力的模型。单细胞谱分析方法（RNA-seq和 ATAC-seq）正在成为研究许多生物学问题的强大方法，包括 神经发育[22-27]。最近，我开发了第一个针对果蝇的单细胞RNA-seq方案， 神经元（Li等人，2017 Cell）[25].在这里，我想应用单细胞分析方法来1）分类ORN 类，2）识别布线特异性基因，3）探索协调嗅觉受体的机制 表达和ORN布线特异性（目的1和2;主要在K99训练阶段）。 嗅觉灵敏度的丧失是衰老和神经退行性疾病的最初迹象之一，例如 老年痴呆在果蝇中，嗅觉灵敏度也随着年龄的增长而显著下降。在此，我提议 机制研究，以确定细胞和分子机制与年龄相关的嗅觉下降的果蝇。 我们的实验室最近发现，神经胶质细胞对于调节苍蝇嗅觉回路的组装至关重要[8]。 许多研究表明，胶质细胞-神经元相互作用对许多脑功能都很重要。 神经元系统[9-11]。总之，我假设神经胶质细胞仍然是维持神经元功能所必需的。 嗅觉回路功能在整个生命中，年龄相关的神经胶质功能障碍有助于 老苍蝇的嗅觉衰退我想把联合收割机单细胞分析技术和遗传学方法结合起来 这一假设（目标3;主要是在R 00独立阶段）。 我的导师团队由世界著名的神经科学家罗立群博士（导师）和 霍华德·张（共同导师）和斯蒂芬·奎克（合作者），单细胞基因组学领域的两位领先科学家 和表观基因组学，以及托尼博士Wyss-Coray（顾问），对衰老和神经退行性疾病的专家， 和马克·弗里曼博士（顾问），果蝇胶质细胞专家。在他们的指导下，我相信我会获得 在我成为独立私家侦探的过程中接受了大量培训

Project Summary/Abstract The function of the nerves system relies on appropriate neural circuit assembly and long-term maintenance of the circuit integrity. Employing integrated single-cell genomic approaches, here I propose to investigate cellular and molecular mechanisms of developmental assembly and age-induced decline of neural circuits using the Drosophila olfactory system. In the Drosophila olfactory circuit, 50 classes of olfactory receptor neurons (ORNs; each class expresses a unique olfactory receptor) connect precisely with 50 classes of olfactory projection neurons, providing a powerful model to study the neuronal wiring specificity. Single-cell profiling methods (RNA-seq and ATAC-seq) are emerging as powerful approaches to study numerous biological questions, including neurodevelopment [22-27]. Recently, I have developed the first single-cell RNA-seq protocol for Drosophila neurons (Li et al., 2017 Cell) [25]. Here, I would like to apply single-cell profiling approaches to 1) classify ORN classes, 2) identify wiring specificity genes, and 3) explore mechanisms that coordinate olfactory receptor expression and ORN wiring specificity (Aims 1&2; mainly on K99 training phase). Loss of olfactory sensitivity is among the first signs of aging and neurodegenerative diseases, such as Alzheimer's. In Drosophila, the olfactory sensitivity also significantly declines with age. Here, I propose a mechanistic study to identify cellular and molecular mechanisms for age-related olfactory decline in Drosophila. Our lab has recently found that glia cells are critical for regulating the assembly of the fly olfactory circuit [8]. Numerous studies have shown that the glia-neuron interactions are important for the brain function in many neuronal systems [9-11]. Together, I hypothesize that glial cells continue to be required for maintaining the olfactory circuit function throughout the life, and that age-associated glial dysfunction contributes to the olfactory decline in old flies. I would like to combine single-cell profiling techniques with genetic methods to test this hypothesis (Aim 3; mainly on R00 independent phase). My mentoring team consists of Dr. Liqun Luo (mentor), a world-renowned neuroscientist, and Drs. Howard Chang (co-mentor) and Stephen Quake (collaborator), two leading scientists in single-cell genomics and epigenomics, as well as Dr. Tony Wyss-Coray (consultant), an expert on aging and neurodegeneration, and Dr. Marc Freeman (consultant), an expert on Drosophila glia. With their guidance, I believe that I will gain extensive training in my transition to be an independent PI.