Optical imaging of neural activity based on the Lorentz effect

基于洛伦兹效应的神经活动光学成像

• 批准号: 9977534
• 负责人: TANER AKKIN
• 金额: $ 39.92万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9977534
• 关键词: Action Potentials; Astacoidea; Axon; Basic Science; Birefringence; Communities; Detection; Development; Electrophysiology (science); Electroretinography; Family suidae; Feedback; Fiber; Goals; Image; Imaging technology; Implant; Interferometry; Invertebrates; Investigation; Label; Laboratories; Lateral; Light; Magnetic Resonance Imaging; Magnetism; Measurement; Measures; Mechanics; Methods; Microelectrodes; Modeling; Monitor; Movement; Mus; Nerve; Optical Coherence Tomography; Optics; Outcome; Peripheral Nerves; Phase; Pheretima sieboldi; Physiologic pulse; Physiological; Preparation; Research; Resolution; Retina; Scientific Advances and Accomplishments; Side; Signal Induction; Signal Transduction; Source; Structure; Structure of phrenic nerve; System; Techniques; Technology; Testing; Time; Torsion; Translating; Ultrasonography; Unmyelinated Nerve Fibers; Visible Radiation; Visual Cortex; Work; base; clinical practice; contrast enhanced; detector; experimental study; extracellular; in vivo; magnetic field; millisecond; nanometer; nanoscale; optical imaging; relating to nervous system; response; retinal nerve fiber layer; spatiotemporal; temporal measurement; tool

PROJECT SUMMARY / ABSTRACT The development of label-free imaging technologies that directly assess neural activity remains a pressing need. Among a variety of techniques that aim to detect transient signals associated with action potential (AP) propagation, optical techniques have the potential for revealing and locating APs with high spatio- temporal resolution. For instance, differential-phase interferometry and then phase-sensitive measurements of spectral-domain optical coherence tomography (OCT) have allowed us to detect AP- related nanometer-scale transient structural changes from unmyelinated invertebrate axons. To obtain useful tests of nerve function, however, investigations on contrast enhancement methods for both myelinated and unmyelinated nerve fibers are needed. The long term goal of this project is to provide non- contact depth-resolved optical measurements of nerve function that are useful in basic scientific research. The overall objective of this project is to use multi-contrast OCT and contrast enhancement methods for depth-resolved label-free imaging of neural activity in myelinated and unmyelinated nerve models. The hypothesis behind the work is that a properly directed external static magnetic field generates Lorentz force in functioning nerve (due to ionic movements / action currents), which consequently induces a mechanical wave accompanying AP propagation and facilitates the optical imaging of neural activity. Phase-sensitive OCT is well poised to locate such transient signals with sub-nanometer sensitivity. We will also monitor the intensity (reflectivity) and birefringence (retardance) signals as additional indications of neural activity. To achieve the objective of this application, we will pursue optical imaging of neural activity based on Lorentz effect in ex-vivo preparations (Specific Aim 1) and in-vivo visual cortex (Specific Aim 2). With successful completion of the proposed work, we will achieve the following outcomes. The feasibility of using Lorentz effect to aid label-free optical imaging of APs will be revealed. This will also inform people in related imaging fields to determine whether the Lorentz effect imaging is within the capabilities of current technology. If our work is shown to be useful, it will support functional neural investigations in laboratory setting. The results may also suggest more challenging in-vivo applications that require incorporation of active tracking systems for the needed stability.

项目摘要 /摘要 直接评估神经活动的无标签成像技术的开发仍然是一种压力 需要。在各种旨在检测与动作电位相关的瞬态信号的技术中 （AP）传播，光学技术具有揭示和定位高时空的AP的潜力 时间分辨率。例如，差分相干涉法，然后相敏感 光谱域光学相干断层扫描（OCT）的测量使我们能够检测到AP- 相关的纳米尺度瞬态结构发生了来自无叶状无脊椎动物轴突的变化。获得 但是，对神经功能的有用测试，对两者的对比增强方法进行了研究 需要髓鞘和不髓鞘的神经纤维。该项目的长期目标是提供非 - 在基础科学研究中有用的神经功能的接触深度分解的光学测量。 该项目的总体目的是使用多对比度OCT和对比度增强方法 深度分辨的无标记成像神经活动中的神经活性成像。这 工作背后的假设是正确定向的外部静态磁场会产生洛伦兹力 在功能性神经（由于离子运动 /动作电流）中，它诱导了机械 伴随AP传播的波浪并促进神经活动的光学成像。相位敏感 OCT已很好地定位具有亚纳米敏感性的这种瞬态信号。我们还将监视 强度（反射率）和双折射（延迟）信号作为神经活动的其他指示。到 实现此应用的目的，我们将基于Lorentz进行神经活动的光学成像 在体外制剂（特定目标1）和体内视觉皮层（特定目标2）中的影响。成功 完成拟议工作的完成，我们将取得以下结果。使用洛伦兹的可行性 将揭示有助于AP的无标签光学成像的效果。这也将告知与相关的人 成像字段以确定Lorentz效应成像是否在当前功能之内 技术。如果我们的工作被证明是有用的，它将支持实验室的功能神经调查 环境。结果还可能表明需要合并的更具挑战性的体内应用 所需稳定性的主动跟踪系统。