Scalable electron tomography for connectomics

用于连接组学的可扩展电子断层扫描

• 批准号: 10410742
• 负责人: Mark H Ellisman
• 金额: $ 291.62万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-07-14
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10410742
• 关键词: Address; Affect; Anatomy; Brain; Cells; Cerebellar Cortex; Cerebellar Nuclei; Cerebellum; Chemical Synapse; Chemicals; Collection; Computer Models; Computer software; Coupling; Data Set; Development; Electrical Synapse; Electron Beam; Electron Microscopy; Electrons; Elements; Engineering; Foundations; Gap Junctions; Goals; Image; Label; Machine Learning; Mechanics; Methods; Microscopic; Microtomy; Modeling; Modernization; Molecular Genetics; Morphology; Mus; Nervous system structure; Neurodegenerative Disorders; Neurons; Neurosciences; Optics; Physiology; Purkinje Cells; Reporter; Research; Resolution; Resources; Reverse engineering; Role; Scanning; Scanning Electron Microscopy; Series; Social Behavior; Specificity; Speed; Structure; Synapses; System; Techniques; Testing; Thick; Thinness; Transmission Electron Microscopy; Work; advanced system; base; cell type; cognitive function; comparative; connectome; connexin 36; effective therapy; electron optics; electron tomography; method development; motor control; nanoscale; network models; neural circuit; neural network; neuronal circuitry; next generation; novel; reconstruction; sample collection; tomography; tool; treatment strategy; voltage

Project Summary / Abstract A fundamental goal in neuroscience is understanding how neural network function arises from circuit structure. However, the immense complexity of most brain networks has been a significant barrier to progress. We do not have a comprehensive wiring diagram for any mammalian local circuit, much less a whole brain. We do not yet have a comprehensive list of cell types and how they are defined for even the simplest mammalian neuronal circuit. Moreover, synapse resolution connectomics has focused almost entirely on chemical synapses and ignored electrical synapses formed by gap junctions, which are thought to be crucial for network synchrony and oscillations. Recent advances in automated sample collection and imaging for transmission electron microscopy (TEM) and molecular genetic tools have allowed us to begin detailed mapping of neural network anatomy. Development of intermediate voltage TEMs has demonstrated the ability to volumetrically image through thick (~1 μm) sections with high resolution tomography. Here, we propose combining automated sample collection and imaging using GridTape, with electron microscopic tomography (EMT) and conical beam procession “VortexBeam” imaging. This new combination of approaches will increase both the resolution and throughput of connectomics, while decreasing the number of sections that need to be collected and acquired. The cerebellum is an ideal system to validate our novel platform as part of a systematic effort to reverse engineer a functional neural circuit that is involved in motor control and social behavior. Its basic structure is well ordered, relatively simple and sufficiently described to have inspired computational models that capture aspects of cerebellar function. However, even the most advanced models are limited by an incomplete characterization of the cell types and connectivity within the cerebellum. Here, we propose to validate our next-generation EMT platforms and characterize long-range, local, and gap junctional connectivity in the cerebellum. We will combine tools recently developed in our labs to a circuit that offers the advantages of relative simplicity and a strong starting foundation. These studies will allow us to understand principles of cerebellar circuit organization and may help us determine the role of specific circuit elements in neurodegenerative disorders.

项目概要/摘要 神经科学的一个基本目标是了解神经网络功能如何从电路结构中产生。 然而，大多数大脑网络的巨大复杂性一直是进步的重大障碍。我们不 拥有任何哺乳动物局部电路的综合接线图，更不用说整个大脑了。我们还没有 拥有完整的细胞类型列表以及如何定义最简单的哺乳动物神经元 电路。此外，突触解析连接组学几乎完全集中于化学突触和 忽略了间隙连接形成的电突触，间隙连接被认为对于网络同步至关重要 振荡。透射电子显微镜自动样品采集和成像的最新进展 （TEM）和分子遗传学工具使我们能够开始详细绘制神经网络解剖图。 中压 TEM 的开发已经证明了通过厚层进行体积成像的能力 (~1 μm) 高分辨率断层扫描切片。在这里，我们建议结合自动化样本收集 并使用 GridTape 进行成像，并采用电子显微断层扫描 (EMT) 和锥形束处理 “VortexBeam”成像。这种新的方法组合将提高分辨率和吞吐量 连接组学，同时减少需要收集和获取的切片数量。小脑 是一个理想的系统，用于验证我们的新颖平台，作为对功能进行逆向工程的系统工作的一部分 参与运动控制和社会行为的神经回路。其基本结构较为有序， 简单且描述充分，激发了捕捉小脑各个方面的计算模型 功能。然而，即使是最先进的模型也受到细胞表征不完整的限制 小脑内的类型和连接性。在这里，我们建议验证我们的下一代 EMT 平台 并表征小脑中的远程、局部和间隙连接连接。我们将结合工具 我们的实验室最近开发了一种电路，具有相对简单和启动能力强的优点 基础。这些研究将使我们了解小脑回路组织的原理，并可能有助于 我们确定特定电路元件在神经退行性疾病中的作用。