Identifying mechanisms ofsynapse maturation at neuronal subtype resolution

项目摘要/摘要 人脑的功能依赖于形成和维持多个 100个神经元亚型。这些回路是由突触介导的，突触的特性因 关于神经元亚型。突触功能障碍在大多数(如果不是全部)人类大脑疾病中起着关键作用。因此， 了解突触多样性及其发育起源对于我们理解大脑如何 以及它在精神障碍中是如何出错的。在大脑发育过程中，突触经历了深刻的 变化，变得成熟和功能齐全。谷氨酸能突触的成熟涉及到 突触后密度(PSD)，由1,000种蛋白质组成的高度复杂的蛋白质复合体。然而， PSD在发育过程中的成分变化没有得到很好的描述。我的初步数据显示 大脑皮层发育过程中&gt；1,000个PSD蛋白的时间动态，提供了对 突触成熟的机制。此外，对发育中的PSD蛋白质组和单个PSD蛋白质组进行了整合分析。 细胞RNA-seq数据表明，不同的神经元亚型经历了不同的突触成熟过程。 然而，我们对神经元亚型特异性突触的成分多样性或不同的 它们会经历成熟的过程。此外，突触的成熟度、多样性和特异性 由转录控制，但潜在的基因调控程序仍然难以捉摸。此信息是 尤其与精神障碍有关，如自闭症谱系障碍，在这种疾病中，基因突变集中在 转录调控和突触传递。因此，这个项目的具体目标首先试图揭示 用一种新的方法研究发育中的大脑皮层神经元亚型特异性突触的成分多样性 化学发生法(目标1，K99相)。第二个目标是破译与疾病相关的基因调控 通过应用单细胞基因组学和机器学习方法产生这种多样性的机制(AIM 2，K99相)。最后，使用我的建议书K99阶段的培训、工具和初步数据，我将 启动一项独立研究项目，重点研究神经元活动对突触的影响 神经元亚型分解时的成熟和可塑性(R00期)。这些研究的结果将提供 对突触多样性、其调节机制及其在自闭症中的调节失调的洞察。我的长期目标是 研究突触多样性对神经回路和行为的功能重要性，并有针对性地开发 减轻精神障碍患者突触功能障碍的治疗。在此期间获得的其他培训 发展神经生物学奖(与阿诺德·克里格斯坦博士合作)，突触生物学奖(与罗伯特·爱德华兹博士合作)， 化学遗传学(与Alice Ting博士合作)和高级机器学习(与李晶晶博士合作)，与我的 以前在啮齿动物模型、蛋白质组学和单细胞基因组学方面的经验将为我提供坚实的 为独立研究事业奠定基础，实现我的目标。

Project Summary/Abstract The human brain function relies on the formation and maintenance of precise neural circuits among more than 100 subtypes of neurons. These circuits are mediated by synapses, the characteristics of which vary depending on neuronal subtype. Synaptic dysfunction plays a critical role in most, if not all, human brain disorders. Thus, understanding synaptic diversity and its developmental origin are crucial for us to understand how the brain functions and how it goes awry in mental disorders. During brain development, synapses undergo profound changes to become mature and fully functional. Maturation of glutamatergic synapses involves changes in the postsynaptic density (PSD), a highly sophisticated protein complex composed of >1,000 proteins. However, the compositional changes of the PSD in development were not well characterized. My preliminary data revealed the temporal dynamics of >1,000 PSD proteins during cerebral cortex development, providing initial insight into mechanisms of synapse maturation. Moreover, integrative analysis of the developing PSD proteome and single- cell RNA-seq data suggested that different neuronal subtypes undergo divergent synapse maturation processes. However, we know little about the compositional diversity of neuronal subtype-specific synapses or the different maturation processes they go through. In addition, synapse maturation, diversity, and specificity can be controlled by transcription, but the underlying gene regulatory programs remain elusive. This information is particularly relevant to mental disorders like autism spectrum disorder, in which genetic mutations converge on transcription regulation and synaptic transmission. Thus, the specific aims of this project first seek to uncover the compositional diversity of neuronal subtype-specific synapses in the developing cerebral cortex using a novel chemogenetic method (Aim 1, K99 phase). The second aim is to decode the disease-relevant gene regulatory mechanisms that generate this diversity by applying single-cell genomics and machine learning approaches (Aim 2, K99 phase). Finally, using the training, tools, and preliminary data from the K99 phase of my proposal, I will launch an independent research project that focuses on investigating the effects of neuronal activity on synapse maturation and plasticity at neuronal subtype resolution (R00 phase). Results from these studies will provide insights into synapse diversity, its regulatory mechanisms, and its dysregulation in autism. My long-term goal is to study the functional importance of synapse diversity on neural circuits and behaviors and develop targeted therapies to alleviate synaptic dysfunction in mental disorders in patients. Additional training obtained during this award in developmental neurobiology (with Dr. Arnold Kriegstein), synaptic biology (with Dr. Robert Edwards), chemogenetics (with Dr. Alice Ting), and advanced machine learning (with Dr. Jingjing Li), combined with my previous experience in rodent models, proteomics, and single-cell genomics will provide me with a solid foundation for an independent research career to achieve my goal.