Developing A Quantitative, Multiscale Imaging Approach to Identify Peripheral Mechanisms of Noxious and Innocuous Force Encoding in Mouse Models

开发定量、多尺度成像方法来识别小鼠模型中有害和无害力编码的外围机制

• 批准号: 10467144
• 负责人: Gregory John Gerling
• 金额: $ 24.48万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-15 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10467144
• 关键词: 3-Dimensional; Address; Afferent Neurons; Area; Biological; Brain; Calcium; Cells; Collaborations; Complement; Complex; Computer Models; Computer Vision Systems; Coupling; Cues; Electrophysiology (science); Engineering; Environment; Filament; Finite Element Analysis; Four-dimensional; Freund' s Adjuvant; Future; Goals; Hair; Human; Hypersensitivity; Image; Inflammation; Inflammatory; Injections; Injury; Intervention Studies; Knowledge; Lateral; Lead; Location; Mammals; Manipulative Therapies; Massage; Measurement; Measures; Mechanical Stress; Mechanics; Methods; Modeling; Molecular; Monitor; Motion; Movement; Mus; Nervous system structure; Neurons; Neurosciences; Nociceptors; Output; Pain; Pattern; Peripheral; Persistent pain; Physiological; Population; Property; Radial; Research; Research Personnel; Seeds; Sensory; Shapes; Site; Skin; Solid; Spinal Ganglia; Stimulus; Stress; Stretching; Surface; System; Tactile; Techniques; Technology; Time; Tissues; Touch sensation; Transgenic Mice; Translating; allodynia; base; digital imaging; experience; genetic manipulation; imaging approach; imaging modality; imaging platform; in vivo; in vivo calcium imaging; in vivo imaging; inflammatory pain; innovation; interest; mechanical stimulus; millisecond; mouse model; non-invasive imaging; novel; novel strategies; pain relief; pressure; receptor; recruit; relating to nervous system; response; social; spatiotemporal; temporal measurement; tissue injury; tool; vibration; viscoelasticity

Populations of touch-sensitive afferents in the skin transduce mechanical stimuli into neural responses that inform the brain about our natural environment. There is a need to mechanistically understand how superficial and deep tissues, as well as mechanosensitive and nociceptive neurons, are engaged during touch. We currently have little quantitative understanding of how innocuous stimuli elicit pain after tissue injury, how touch-based manipulations relieve pain, or their exact impact, in terms of change in tissue stiffness or extensibility. The overarching goal of this exploratory project is to develop a new, multiscale in vivo imaging platform for monitoring the spatiotemporal dynamics of skin deformation and mechanosensory neuron activity. If successful, the project will break technical barriers and enable mechanistic studies of persistent pain and its relief by manual therapies in mouse models amenable to genetic manipulations. Recent studies that combine transgenic mouse models with calcium imaging or electrophysiology have identified genetically distinct populations of sensory neurons that respond preferentially to innocuous (e.g., brush, vibration) or noxious mechanical stimuli (e.g., hair pull). Currently, however, single point measurements of stimulus force or displacement are typical. To understand sensory encoding, we must instead ask – how does the skin move during touch, and how does these skin deformations lead to activation of sensory neurons? Such mechanical quantities ultimately recruit a population of sensory afferents to encode different qualities of touch. To address this technological gap, these studies will develop 3D computer vision and digital image correlation to directly quantify the distribution of stresses and strains over the entire surface of the skin, simultaneously with stimulus movement, and while recording from populations of sensory neurons in vivo. Aim 1 focuses on a non-invasive, imaging approach in mice to evaluate localized skin surface deformation, strain fields, and lateral stretch and motion, at high spatial (5 µm) and temporal resolution (1,000 frames/s), and computational modeling to estimate mechanical stress in four dimensions (x/y/z/time). Aim 2 will demonstrate the utility of these newly validated methods in contexts relevant for mechanistic studies of 1) mechanical pain and 2) manual therapies. To do so, the methods for estimating skin mechanics will be used during in vivo calcium imaging of DRG neurons and well-validated mouse models in two biological contexts, a well-established model of inflammatory pain in glabrous paw skin, as well as hair-bearing skin areas. The latter is an essential step in creating relevant mouse models for mechanistic studies of touch-based manual therapies such as massage. This project is innovative because it will reveal how dynamic changes in the stress and strain in skin drive the recruitment of distinct neural complements. Understanding their coupling is relevant to addressing key questions in the context of heightened mechanical pain, such as in inflammation, as well as creating a proof-of- concept, physiologically compatible approach for use in studying interventions used in manual therapy. 1

皮肤中的触觉传入神经群将机械刺激转化为神经反应， 需要让大脑了解我们的自然环境有多么肤浅。 目前，深层组织以及机械敏感和伤害感受神经元在触摸过程中参与。 对无害刺激如何在组织损伤后引起疼痛、基于触摸的疼痛如何进行定量了解很少 手法可以减轻疼痛，或者通过改变组织硬度或延展性来减轻疼痛的确切影响。 该探索性项目的总体目标是开发一种新的多尺度体内成像平台 监测皮肤变形和机械感觉神经元活动的时空动态如果成功， 该项目将打破技术障碍，实现持续性疼痛的机制研究及其手动缓解 适合基因操作的小鼠模型的疗法。 最近的研究将转基因小鼠模型与钙成像或电生理学相结合 确定了遗传上不同的感觉神经元群体，它们优先对无害的物质（例如刷子、 然而，目前，单点测量。 刺激力或位移是典型的。要理解感觉编码，我们必须问——如何做到这一点。 触摸时皮肤会移动，这些皮肤变形如何导致感觉神经元的激活？ 机械量最终会招募一组感觉传入来编码不同的触觉质量。 为了解决这一技术差距，这些研究将开发 3D 计算机视觉和数字图像 相关性可直接量化整个皮肤表面的应力和应变的分布， 与刺激运动同时进行，并同时记录体内感觉神经元群体的目标。 1 重点关注小鼠的非侵入性成像方法，以评估局部皮肤表面变形、应变 场、横向拉伸和运动，在高空间 (5 µm) 和时间分辨率 (1,000 帧/秒) 下，以及 目标 2 将演示估计四个维度（x/y/z/时间）机械应力的计算模型。 这些新验证的方法在与 1) 机械性疼痛的机制研究相关的背景下的实用性 2) 手动治疗时，将在体内钙期间使用估计皮肤力学的方法。 DRG 神经元成像和两种生物背景下经过充分验证的小鼠模型，这是一个完善的模型 缓解无毛爪子皮肤以及有毛皮肤区域的炎症疼痛，后者是治疗的重要步骤。 创建相关的小鼠模型，用于按摩等基于触摸的手动疗法的机制研究。 该项目具有创新性，因为它将揭示皮肤应力和应变的动态变化如何驱动 不同神经互补的招募与解决关键问题有关。 肉质机械疼痛（例如炎症）中的问题，以及创建证明- 概念，生理上兼容的方法，用于研究手法治疗中使用的干预措施。 1