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: 10610468
• 负责人: Gregory John Gerling
• 金额: $ 18.87万
• 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/10610468
• 关键词: 3-Dimensional; Address; Afferent Neurons; Area; Biological; Brain; Calcium; Cells; Collaborations; Complement; Complex; Computer Models; Computer Vision Systems; Coupling; Cues; Dimensions; Elasticity; Electrophysiology (science); Engineering; Environment; Filament; Finite Element Analysis; 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; Neurons; Neurosciences; Nociceptors; Output; Pain; Pattern; Peripheral; Persistent pain; Physiological; Population; Property; Radial; Research; Research Personnel; Sensory; Shapes; Site; Skin; Solid; Spinal Ganglia; Stimulus; Stress; Stretching; Surface; System; Tactile; Techniques; Technology; Time; Tissues; Touch sensation; Transgenic Mice; Translating; allodynia; 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; meter; millisecond; mouse model; neural; novel; novel strategies; pain relief; pressure; receptor; recruit; 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

皮肤传播机械刺激中的触摸敏感传入量的群体到神经反应中 告知大脑我们的自然环境。有必要从机械上理解如何表面 在接触过程中，深层组织以及机械敏感和伤害性神经元都参与了。我们目前 对无害的刺激如何引起组织损伤后疼痛，几乎没有定量的了解 在组织僵硬或可扩展性的变化方面，操纵可以缓解疼痛或确切的影响。这 这个探索性项目的总体目标是开发一个新的，多尺度的体内成像平台 监测皮肤变形和机理感知性神经元活性的时空动力学。如果成功， 该项目将打破技术障碍，并能够对持续性疼痛进行机械研究及其逐步缓解 小鼠模型中的疗法可容纳遗传操作。 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的研究具有 确定的一般不同的感觉神经元种群对无害的反应（例如，刷子， 振动）或有害的机械刺激（例如，拉毛）。但是，目前， 刺激力或位移是典型的。要了解感官编码，我们必须问 - 皮肤在接触过程中移动，这些皮肤变形如何导致感觉神经元激活？ 机械量最终招募了一系列感觉传入，以编码不同的触摸品质。 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 直接量化皮肤整个表面上应力和菌株的分布的相关性， 与刺激运动相似，同时从体内的感觉神经元的群体记录时。目的 1专注于小鼠的非侵入性成像方法，以评估局部皮肤表面变形，应变 高空间（5 µm）和临时分辨率（1,000帧/s），场以及横向拉伸和运动，以及 计算建模以在四个维度（x/y/z/time）中估算机械应力。 AIM 2将证明 这些新验证的方法在与机械研究相关的上下文中的实用性1）机械疼痛 2）手动疗法。为此，将在体内钙中使用估计皮肤力学的方法 在两个生物学环境中的DRG神经元和精心验证的小鼠模型的成像，这是一个建立的模型 无毛的爪子皮肤以及戴发皮肤区域的炎症性疼痛。后者是重要的一步 创建相关的小鼠模型，用于基于触摸的手动疗法（例如按摩）的机械研究。 该项目具有创新性，因为它将揭示皮肤驱动压力和应变的动态变化 招募独特的神经完成。了解它们的耦合与解决密钥有关 在增加机械疼痛（例如炎症中）的问题上的问题，并创造证明 概念，物理上兼容的方法，用于研究手动治疗中使用的干预措施。 1