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

基本信息

批准号：
10578784
负责人：
HIROKI TANIGUCHI
金额：
$ 19.69万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-01 至 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10578784
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 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 neural novel postnatal prevent stereotypy transmission process

项目摘要

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.

项目概要/摘要胆碱能系统使用乙酰胆碱 (ACh) 作为神经递质，塑造可塑性和认知能力通过调节皮质活动在成人皮质中发挥作用，并与癫痫等脑部疾病有关注意力缺陷多动障碍、抑郁症和精神分裂症。然而，ACh 信号传导在正常和患病条件下皮质回路的发育仍知之甚少。特别是，很少已知 ACh 信号传导是否以及如何调节抑制性中间神经元 (IN)、细胞对于皮质计算至关重要的组件。皮质 IN 通常会发育出高度分支的轴突来建立局部、密集的电路模块。尽管在 IN 电路布线过程中代表了一个关键事件，但蜂窝和 IN 轴突树枝化的分子机制仍然难以捉摸。我们提案的目标是确定 ACh 信号传导在塑造 IN 轴突乔木中的作用体内。我们还将提供证据证明 ACh 所必需的基因中与疾病相关的突变信号传导可能影响 IN 轴突分支，并且轴突表型可以通过以下方式改善操纵 ACh 信号传导中的下游组件。为了实现这一目标，我们将进行一系列的工作使用枝形吊灯细胞（ChC）进行的实验，该细胞专门支配锥体轴突的初始部分神经元（PN），从而有力地控制 PN 中尖峰的产生。由于其轴突组织的刻板印象，ChC 成为研究 IN 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状伪足充当体内分支的前体，(2) 丝状伪足起始以及 ChC 轴突静脉曲张中的基础 Ca2+ 水平受烟碱乙酰胆碱受体 (nAChR) 至 T 型电压依赖性钙通道 (T- VDCC），独立于动作电位/网络活动，（3）CRISPR/Cas9介导的T-VDCC丢失- 单个 ChC 中的功能（LOF）显着减少其轴突分支点，以及（4）全身尼古丁对发育中的出生后小鼠进行给药会增加 ChC 轴突乔木。根据这些结果，我们建议检验 nAChR-T-VDCC 信号通路塑造 ChC 轴突树枝化和疾病的假设 ACh 信号分子的相关突变会导致 ChC 中的线路缺陷。在目标 1 中，我们将阐明角色体内 ChC 轴突分枝中 nAChR-T-VDCC 信号通路的研究。在目标 2 中，我们将确定 nAChRs 中癫痫相关的功能获得（GOF）突变对 ChC 轴突树枝化的影响，以及阐明操纵 T-VDCC 是否可以成为恢复 nAChR GOF 表型的一种方法。我们的研究将为ACh信号传导在INs布线中的发育作用提供第一个证据。正常和患病的皮质以及制定预防和改善大脑策略的新提示与 ACh 信号传导相关的疾病。