Molecular Development and Diversity of Callosal Projection Neurons

胼胝体投射神经元的分子发育和多样性

• 批准号: 10558466
• 负责人: JEFFREY D MACKLIS
• 金额: $ 39万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10558466
• 关键词: Area; Axon; Behavior; Behavior Disorders; Behavioral; Brain; Cells; Cerebral cortex; Cerebral hemisphere; Cognition; Cognitive; Complex; Corpus Callosum; Development; Developmental Biology; Diagnosis; Disease; Electroporation; Evolution; Exhibits; Functional disorder; Future; Gene Expression; Gene Expression Regulation; Generations; Genes; Genetic Transcription; Goals; Growth Cones; Human; Individual; Intellectual functioning disability; Investigation; Knowledge; Label; Link; Location; Maps; Mental disorders; Molecular; Motor; Mus; Nature; Neocortex; Neurons; Parents; Persons; Phenotype; Plasmids; Play; Population; Population Analysis; Positioning Attribute; Prevention; Process; Proteins; Proteome; Proteomics; Publishing; RNA; Regulation; Research; Role; Schizophrenia; Sensory; Somatosensory Cortex; Specific qualifier value; Structure; System; Technology; Therapeutic; Time; Transcriptional Regulation; Visualization; Work; autism spectrum disorder; axon growth; behavior test; behavioral phenotyping; candidate validation; combinatorial; developmental disease; gain of function; genetic analysis; genetic manipulation; hippocampal pyramidal neuron; human disease; in utero; innovation; insight; interest; mosaic; mosaic analysis; neocortical; neuron development; neuronal cell body; neuronal circuitry; neuronal growth; novel; novel strategies; postmitotic; prevent; progenitor; programs; recombinase; somatosensory; tool; transcriptomics

The long-term goals of the proposed research are both to elucidate central molecular controls over development and diversity of neocortical callosal projection neuron (CPN) connectivity, and to identify potential causes and therapeutic approaches to disease involving CPN circuitry. CPN are the broad population of inter-hemispheric pyramidal neurons whose axons connect the two cerebral hemispheres via the corpus callosum. CPN play key roles in high-level associative, integrative, cognitive, behavioral, sensory, and motor functions, based on precise, area-specific CPN subtype connectivity and diversity. Disruptions in CPN development are correlated with deficits in multiple disorders, including agenesis of the corpus callosum, autism spectrum disorders, and schizophrenia. Currently, how the remarkable diversity of CPN subtypes and connectivity is specified, and how transcriptional programs implement specific connectivity via local, cell-autonomous effectors, is unknown. Our lab recently identified a combinatorially-expressed set of genes that both define CPN as a broad population, and identify novel subpopulations of CPN during development (Neuron, 2005, 2016a,b; J Neurosci, 2009; Cer Cor, 2016a,b). We also developed innovative approaches to investigate subtype-specific, subcellular growth cone (GC) molecular machinery. Building on this work, we propose deep and rigorous functional investigation of Cited2 control over precise CPN connectivity & circuit wiring, including RNAs & proteins detected uniquely in GCs. Cited2 is an exemplar transcriptional co-regulator that we hypothesize functions importantly in development of precise areally- and functionally-specific CPN circuitry in somatosensory cortex, and its dysfunction elucidates disorders of CPN connectivity and diversity. We have already identified that Cited2 regulates and refines two stages of precise CPN development and diversity, functioning 1) broadly in basal progenitors to regulate generation of superficial layer CPN, and 2) postmitotically in an area-restricted manner to refine distinct, precise identity and development of somatosensory (S1) CPN. To connect Cited2 transcriptional regulation to local implementation of S1 CPN connectivity in developing GCs, we propose to: Aim 1) investigate CPN-autonomy of Cited2 regulatory function in S1 CPN postmitotic development and connectivity, via novel mosaic, recombinase-based genetic manipulation technology (“BEAM”) for dual population analysis; Aim 2) investigate GC & soma RNA & proteomes of WT vs Cited2 cKO S1 CPN during axon development via new and innovative approaches, to gain direct mechanistic understanding of CPN circuit development at critical developmental stages; Aim 3) investigate the specific function of GC-localized downstream effectors that are dysregulated in Cited2-null CPN; and Aim 4) investigate the integrated function of precise CPN circuit development in cognitive & ASD-relevant behavior. Together, the proposed studies will provide substantial insight from gene to circuit to behavior into molecular control over development, diversity, and precision of connectivity of CPN subtypes with distinct function and integration of cortical information, processes centrally disrupted in human disorders. Controls over CPN connectivity are now essentially unknown, and transcriptional dysregulation has not been previously connected to downstream local effectors of circuit development. This research will contribute to understanding cortical organization, function, and potentially toward prevention, diagnosis, and therapy of human disorders.

拟议研究的长期目标是阐明对发育和发育的中央分子控制 新皮质胼胝体投射神经元 (CPN) 连接的多样性，并确定潜在原因和治疗方法 涉及 CPN 电路的疾病的治疗方法。 CPN 是半球间锥体神经元的广泛群体 其轴突通过胼胝体连接两个大脑半球。基于精确的、特定区域的 CPN 亚型连接性和多样性，CPN 在高级联想、整合、认知、行为、感觉和运动功能中发挥着关键作用。 CPN 发育中断与多种疾病的缺陷相关，包括胼胝体发育不全、自闭症谱系障碍和精神分裂症。目前，如何指定 CPN 亚型和连接的显着多样性，以及转录程序如何通过局部细胞自主效应器实现特定连接，尚不清楚。我们的实验室最近发现了一组组合表达的基因，它们既将 CPN 定义为一个广泛的群体，又在发育过程中确定了 CPN 的新亚群（Neuron，2005，2016a，b；J Neurosci，2009；Cer Cor，2016a，b）。我们还开发了创新方法来研究亚型特异性、亚细胞生长锥 (GC) 分子机制。在此工作的基础上，我们建议对 Cited2 对精确 CPN 连接和电路布线的控制进行深入而严格的功能研究，包括在 GC 中独特检测到的 RNA 和蛋白质。 Cited2 是一个典型的转录共调节因子，我们假设它在体感皮层中精确的区域和功能特异性 CPN 回路的发育中发挥重要作用，并且它的功能障碍阐明了 CPN 连接性和多样性的紊乱。 我们已经确定 Cited2 规范和完善了精确 CPN 发展和多样性的两个阶段， 1) 广泛地在基底祖细胞中发挥作用，调节浅层 CPN 的生成，2) 以区域限制的方式在有丝分裂后完善体感 (S1) CPN 的独特、精确的身份和发育。为了将 Cited2 转录调控与发育中 GC 中 S1 CPN 连接的局部实现联系起来，我们建议： 目标 1) 通过新型嵌合、基于重组酶的基因操作技术 (“BEAM”) 进行双群体分析，研究 Cited2 调控功能在 S1 CPN 有丝分裂后发育和连接中的 CPN 自主性；目标 2) 通过新的创新方法研究 WT 与 Cited2 cKO S1 CPN 在轴突发育过程中的 GC、体细胞 RNA 和蛋白质组，以获得对关键发育阶段 CPN 电路发育的直接机制理解；目标 3) 研究 Cited2-null CPN 中失调的 GC 定位下游效应器的特定功能；目标 4) 研究精确 CPN 回路发展在认知和 ASD 相关行为中的综合功能。总之，拟议的研究将为从基因到电路到行为的分子控制提供深入的见解，了解 CPN 亚型的发育、多样性和连接精度，具有独特的功能和皮质信息的整合，在人类疾病中集中破坏的过程。对 CPN 连接的控制现在基本上是未知的，并且转录失调之前尚未与电路发育的下游局部效应器相关联。这项研究将有助于了解皮质组织、功能，并有可能有助于预防、诊断和治疗人类疾病。