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.

项目概要/摘要 开发直接评估神经活动的无标记成像技术仍然是一个紧迫的任务 需要。旨在检测与动作电位相关的瞬态信号的各种技术 （AP）传播，光学技术具有揭示和定位高空间 AP 的潜力 时间分辨率。例如，微分相位干涉测量，然后是相敏测量 谱域光学相干断层扫描 (OCT) 测量使我们能够检测 AP- 无髓鞘无脊椎动物轴突的相关纳米级瞬时结构变化。获得 神经功能的有用测试，然而，对两者的对比增强方法的研究 需要有髓和无髓神经纤维。该项目的长期目标是提供非 对神经功能进行接触式深度分辨光学测量，可用于基础科学研究。 该项目的总体目标是使用多重对比 OCT 和对比增强方法 有髓神经和无髓神经模型中神经活动的深度分辨无标记成像。这 这项工作背后的假设是，正确定向的外部静磁场会产生洛伦兹力 在功能神经中（由于离子运动/动作电流），从而引起机械 波伴随 AP 传播并促进神经活动的光学成像。相敏 OCT 能够以亚纳米灵敏度定位此类瞬态信号。我们还将监测 强度（反射率）和双折射（延迟）信号作为神经活动的附加指示。到 为了实现这个应用的目标，我们将追求基于洛伦兹的神经活动光学成像 对离体制剂（具体目标 1）和体内视觉皮层（具体目标 2）的影响。与成功的 完成拟议的工作后，我们将取得以下成果。使用洛伦兹的可行性 将揭示辅助 AP 无标记光学成像的效果。这也将告知相关人士 成像场以确定洛伦兹效应成像是否在当前的能力范围内 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性神经研究 环境。结果还可能表明更具挑战性的体内应用，需要结合 主动跟踪系统可实现所需的稳定性。