The role of acetylcholine signaling in the axonal wiring of cortical interneurons

乙酰胆碱信号在皮质中间神经元轴突布线中的作用

• 批准号: 10372840
• 负责人: HIROKI TANIGUCHI
• 金额: $ 23.63万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10372840
• 关键词: Acetylcholine; Action Potentials; Address; Adult; Attention deficit hyperactivity disorder; Axon; Brain; Brain Diseases; Brain Pathology; CRISPR/Cas technology; Calcium Channel; Cells; Cholinergic Receptors; Data; Defect; Development; Disease; Electroporation; Epilepsy; Equilibrium; Event; Exhibits; Filopodia; Gene Dosage; Gene Transfer; Generations; Genes; Germ Lines; Goals; Individual; Interneurons; Knockout Mice; Link; Mediating; Mental Depression; Modeling; Molecular; Morphogenesis; Morphology; Mus; Mutation; Neurons; Neurotransmitters; Nicotine; Phenotype; Production; Role; Schizophrenia; Series; Shapes; Signal Pathway; Signal Transduction; Signaling Molecule; System; T-Type Calcium Channels; Testing; Transplantation; Varicosity; Vertebral column; Viral Genes; basal forebrain; base; cholinergic; cholinergic neuron; cognitive function; experimental study; gain of function; gain of function mutation; genome editing; hippocampal pyramidal neuron; in vivo; loss of function; loss of function mutation; malformation; mouse genetics; mutant; novel; postnatal; prevent; relating to nervous system; stereotypy; transmission process

Project Summary/Abstract The cholinergic system, using acetylcholine (ACh) as a neurotransmitter, shapes plasticity and cognitive functions in the adult cortex by tuning cortical activity, and has been implicated in brain disorders such as epilepsy, attention-deficit hyperactivity disorder, depression, and schizophrenia. However, the role of ACh signaling in development of cortical circuits in normal and diseased conditions remains poorly understood. In particular, little is known about whether and how ACh signaling regulates the wiring of inhibitory interneurons (INs), cellular components critical for cortical computations. Cortical INs generally develop highly branched axons to establish local, dense circuit modules. Despite representing a crucial event during the wiring of IN circuits, the cellular and molecular mechanisms underlying IN axonal arborization remain elusive. The objective of our proposal is to establish the role of ACh signaling in shaping IN axonal arbors in vivo. We will also provide evidence that disease-relevant mutations in genes that are essential for ACh signaling could impact IN axonal branching, and that the axonal phenotype could be ameliorated by manipulating downstream components in ACh signaling. To achieve this goal, we will perform a series of experiments using the chandelier cell (ChC), which exclusively innervates axon initial segments of pyramidal neurons (PNs) and thus powerfully controls spike generation in PNs. Because of its stereotypy of the axonal organization, the ChC serves as an ideal model to study IN axonal morphogenesis. Our preliminary data has shown that (1) Axonal filopodia arising from varicosities serve as precursors of branches in vivo, (2) Filopodia initiation as well as the basal Ca2+ levels in ChC axonal varicosities are regulated by signaling from nicotinic AChRs (nAChRs) to T-type voltage dependent calcium channels (T- VDCCs), independently of action potentials/network activity, (3) CRISPR/Cas9-mediated T-VDCC loss-of- function (LOF) in single ChCs significantly reduces their axonal branching points, and (4) Systemic nicotine administration to developing postnatal mice increases ChC axonal arbors. Based on these results, we propose to test the hypothesis that the nAChR-T-VDCC signaling pathway shapes ChC axonal arborization, and disease- relevant mutations in ACh signaling molecules cause wiring defects in ChCs. In Aim 1, we will elucidate the role of the nAChR-T-VDCC signaling pathway in ChC axonal arborization in vivo. In Aim 2, we will determine the effect of the epilepsy-related gain-of-function (GOF) mutation in nAChRs on ChC axonal arborization, and elucidate whether manipulating T-VDCCs can be a way to revert the nAChR GOF phenotype. Our study will provide first evidence for the developmental role of ACh signaling in the wiring of INs in the normal and diseased cortices as well as a novel hint for developing strategies to prevent and ameliorate brain disorders associated with ACh signaling.

项目摘要/摘要 胆碱能系统，使用乙酰胆碱（ACH）作为神经递质，塑造可塑性 通过调整皮质活性在成年皮层中的功能，并与脑疾病（如癫痫）有关 注意力缺陷多动障碍，抑郁和精神分裂症。但是，ACH信号在 在正常和患病状况下的皮质回路发展仍然很少了解。特别是，很少 知道ACH信号是否以及如何调节抑制性中间神经元（INS），细胞的接线 对皮质计算至关重要的组件。皮质INS通常会形成高分支的轴突以建立 局部密集的电路模块。尽管在电路接线期间代表了至关重要的事件，但蜂窝和 轴突树木化的分子机制仍然难以捉摸。 我们提议的目的是确定ACH信号在轴突乔木中塑造中的作用 体内。我们还将提供证据表明，基因中与疾病有关的突变对ACH至关重要 信号传导可能会影响轴突分支，并且轴突表型可以通过 在ACH信号传导中操纵下游组件。为了实现这一目标，我们将执行一系列 使用枝形纤维电池（CHC）的实验，该实验仅支配了金字塔的轴突初始段 神经元（PN），因此可以强大地控制PN中的尖峰产生。 由于其对轴突组织的定型观念，CHC是研究轴突的理想模型 形态发生。我们的初步数据表明，（1）由静脉曲张引起的轴突丝虫病作为 体内分支的前体，（2）丝状启动以及CHC轴突静脉曲张的基底Ca2+水平 受信号从烟碱ACHR（NACHR）到T型电压依赖性钙通道的信号传导（T-） VDCC），独立于行动电位/网络活动，（3）CRISPR/CAS9介导的T-VDCC损失 - 单个CHC中的功能（LOF）显着降低了其轴突分支点，（4）全身尼古丁 用于发展产后小鼠的施用会增加CHC轴突轴。基于这些结果，我们建议 为了测试NACHR-T-VDCC信号通路塑造CHC轴突化和疾病 - ACH信号分子中的相关突变导致CHC中的接线缺陷。在AIM 1中，我们将阐明角色 CHC轴突一子体内的NACHR-T-VDCC信号通路。在AIM 2中，我们将确定 NACHR中与癫痫相关的功能获得（GOF）突变对CHC轴突化的影响，并且 阐明操纵T-VDCC是否可以是恢复NACHR GOF表型的一种方式。 我们的研究将为ACH信号在INS接线中的发育作用提供第一证据 正常和患病的皮质以及开发预防和改善大脑策略的新提示 与ACH信号相关的疾病。