Optogenetic Tools for in vivo Analysis of Cortical Circuit Plasticity

用于皮层回路可塑性体内分析的光遗传学工具

• 批准号: 7914333
• 负责人: PETER SAGGAU
• 金额: $ 58.88万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7914333
• 关键词: 3-Dimensional; Adult; Behavior; Biological Neural Networks; Brain; Cells; Cerebral cortex; Data; Development; Dimensions; Electroporation; Functional Imaging; Glutamates; Goals; Image; In Vitro; Individual; Injury; Ion Channel; Knowledge; Label; Lasers; Learning; Maps; Measures; Methods; Microscope; Microscopy; Molecular; Monitor; Mus; Neuronal Plasticity; Neurons; Optics; Pattern; Plastics; Population; Process; Property; Proteins; Rabies virus; Radial; Ramp; Research; Research Infrastructure; Research Personnel; Resolution; Sampling; Scanning; Sensory; Shadowing (Histology); Shapes; Site; Slice; Source; Speed; Substance of Abuse; Surface; Synapses; System; Technology; Time; Tracer; Translating; Viral; Visual Cortex; experience; imaging modality; in vivo; interest; light microscopy; method development; multi-photon; neural circuit; novel; photolysis; plasmid DNA; presynaptic; relating to nervous system; response; skills; tool; two-photon

Neuroplasticity is central to fundamental processes in the brain, including learning, and long-lasting changes in neural circuits that result from employing substances of abuse. In contrast to significant advances at the cellular/molecular level, our understanding of the functional organization and reorganization of brain circuits remains limited. Increasing in vivo evidence suggests that single cells remain plastic into and during adulthood. However, our knowledge of the functional properties of single cells is primarily descriptive. This limits our understanding of the underlying mechanisms involved in assembling and modifying neuronal tuning functions during plasticity. In order to understand how the properties of cells change during plasticity, it is imperative to record from a population of interconnected neurons in vivo. More than half of all synaptic contacts in the cortex arise from neurons within a -200 j.lm radius from the target cell. Importantly, connections between cells in the cerebral cortex are predominantly along cortical depth. Therefore, we need to monitor simultaneously the activity of all adjacent neurons in a cortical volume, and thus record in three dimensions. To date, no experimental tool exists that would allows us to do this. This project seeks to establish novel in vivo methods that will allow us to analyze neural circuits in three dimensions. For this purpose, we will advance two technologies to record from and manipulate circuits in the mammalian cortex: (1) Ultra-fast three-dimensional two-photon imaging, and (2) Optical manipulation of neural activity with single-cell and single-spike resolution using optogenetic tools. The proposed developments have become possible because of recent technical advances in ultra-fast multi-photon microscopy and light-activated ion channels. In short: Inertia-free nearinfrared laser scanning technology allows for in vivo fast structural and functional imaging as well as for high resolution optical stimulation. The proposed project will combine these key technologies to generate the infrastructure and the experimental skills to study the function and plasticity of cortical microcircuits and thus will help researchers to understand mechanisms of neuroplasticity in the intact brain.

神经可塑性是大脑基本过程的核心，包括学习，以及滥用物质导致的神经回路的长期变化。与细胞/分子水平上的重大进展相比，我们对脑回路的功能组织和重组的理解仍然有限。越来越多的体内证据表明，单细胞在成年期和成年期仍具有可塑性。然而，我们对单细胞功能特性的了解主要是描述性的。这限制了我们对可塑性过程中神经元调节功能的组装和修改的潜在机制的理解。为了了解细胞的特性在可塑性过程中是如何变化的，有必要从体内相互连接的神经元群体中进行记录。皮层中超过一半的突触接触来自于距离目标细胞半径在- 200j.lm以内的神经元。重要的是，大脑皮层中细胞之间的连接主要沿皮层深度分布。因此，我们需要同时监测皮质体积内所有相邻神经元的活动，从而进行三维记录。到目前为止，还没有实验工具能让我们做到这一点。该项目旨在建立新的体内方法，使我们能够从三维角度分析神经回路。为此，我们将推进两种技术来记录和操纵哺乳动物皮层的电路：(1)超快速三维双光子成像；(2)利用光遗传学工具对单细胞和单峰分辨率的神经活动进行光学操纵。由于最近在超快多光子显微镜和光激活离子通道方面的技术进步，所提出的发展成为可能。简而言之：无惯性近红外激光扫描技术允许体内快速结构和功能成像以及高分辨率光学刺激。本项目将结合这些关键技术，为研究皮层微回路的功能和可塑性提供基础设施和实验技能，从而帮助研究人员了解完整大脑中神经可塑性的机制。