Identifying mechanisms ofsynapse maturation at neuronal subtype resolution

项目总结/摘要 人类大脑的功能依赖于在超过1000个神经元中形成和维持精确的神经回路。 神经元的100种亚型这些回路是由突触介导的，突触的特性根据 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，在本发明中， 了解突触的多样性及其发育起源对于我们理解大脑如何 以及它在精神疾病中的作用。在大脑发育过程中， 变化变得成熟和功能齐全。神经元突触的成熟涉及神经元内 突触后致密物（PSD）是由超过1，000种蛋白质组成的高度复杂的蛋白质复合物。但 没有很好地表征发展中PSD的组成变化。我的初步数据显示 大脑皮层发育过程中> 1，000 PSD蛋白的时间动态，提供了对 突触成熟的机制。此外，综合分析发展PSD蛋白质组和单一的， 细胞RNA-seq数据表明，不同的神经元亚型经历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组成多样性或不同的突触类型知之甚少。 他们经历的成熟过程。此外，突触的成熟、多样性和特异性也可能是 基因调控是由转录控制的，但潜在的基因调控程序仍然难以捉摸。该信息 特别是与自闭症谱系障碍等精神障碍有关，其中基因突变集中在 转录调节和突触传递。因此，本项目的具体目标首先是揭示 在发育中的大脑皮层神经元亚型特异性突触的组成多样性，使用一种新的 化学发生法（Aim 1，K99相）。第二个目标是解码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，利用我的建议书K99阶段的培训、工具和初步数据，我将 启动一个独立的研究项目，重点研究神经元活动对突触的影响。 在神经元亚型分辨（R 00期）的成熟和可塑性。这些研究的结果将提供 深入了解突触多样性，其调节机制，以及自闭症的失调。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， 缓解精神障碍患者的突触功能障碍的疗法。在此期间获得的额外培训 发育神经生物学（与Arnold Kriegstein博士合作），突触生物学（与Robert Edwards博士合作）， 化学遗传学（与Alice Ting博士）和先进的机器学习（与Jingjing Li博士），结合我的 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 独立研究生涯的基础，以实现我的目标。

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.