Advanced Optical Image Probe for Neurophysiology

用于神经生理学的先进光学图像探头

• 批准号: 7089957
• 负责人: DAVID M RECTOR
• 金额: $ 28.14万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7089957
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; biophysics; brain electrical activity; brain imaging /visualization /scanning; brain metabolism; charge coupled device camera; computational neuroscience; computer system design /evaluation; confocal scanning microscopy; fluorescence spectrometry; laboratory rat; light scattering; monitoring device; nephelometry; neural information processing; neurophysiology; optical polarization; optics

DESCRIPTION (provided by applicant): At the center of most diagnostic tests for human mental function is an imaging technique that visualizes activity patterns across the brain. In the near future, we can imagine the development of an examination table which non-invasively bathes the patient with electromagnetic waves, scanning for both structure and function, and creating three dimensional (3D) images or movies. Many such imaging techniques are available, including PET, MRI, MEG, EEG and optical techniques which offer a unique complement and significant advantages. Most optical methods visualize comparatively slow processes such as the changes in blood flow, volume and oxygenation that accompany metabolic activation of neural tissue. Changes in light absorbance associated with metabolic and hemodynamic processes are robust and relatively easy to obtain non-invasively, but spatial and temporal resolution is limited by the anatomy and physiological regulation of cerebral perfusion. We have observed very fast optical changes in rat somatosensory cortex that are directly related to the evoked electrical response and to a fast (200-600 Hz) oscillation that accompanies the evoked response. Such in-vivo signals are small compared to noise, often requiring 1000 to 4000 averages, and preclude dynamic studies of neural activation. Our principal aim is to investigate the biophysical mechanisms of fast optical signals and to improve the signal-to-noise ratio in mammalian neural tissue. To accomplish this aim we will pursue 3 specific aims. First, we will test the hypothesis that confocal birefringence illumination will enhance the faster optical signals over the slower hemodynamic components traditionally seen with bright-field illumination. Our second aim will test the hypothesis that the early components of the fast optical signals will localize specifically to the cortical column. Within our third aim, we will test the hypothesis that birefringence signals originate from a change in refractive index due to cellular swelling and will follow voltage sensitive dye and membrane potentials. Over the past 3 years we have significantly improved the utility of optical measurements for recording fast neurophysiological events. Accomplishment of these new goals is crucial to moving optical techniques into more practical applications that image electrical correlates of neural activity with better signal-to-noise.

描述（由申请人提供）：大多数人类心理功能诊断测试的核心是一种成像技术，可以可视化整个大脑的活动模式。在不久的将来，我们可以想象开发出一种检查台，该检查台可以用电磁波非侵入性地照射患者，扫描结构和功能，并创建三维 (3D) 图像或电影。许多这样的成像技术都是可用的，包括 PET、MRI、MEG、EEG 和光学技术，它们提供了独特的补充和显着的优势。大多数光学方法可视化相对缓慢的过程，例如伴随神经组织代谢激活的血流、容量和氧合作用的变化。与代谢和血流动力学过程相关的光吸光度变化是稳健的并且相对容易非侵入性地获得，但空间和时间分辨率受到脑灌注的解剖学和生理调节的限制。我们观察到大鼠体感皮层中非常快速的光学变化，这些变化与诱发的电反应和伴随诱发反应的快速（200-600 Hz）振荡直接相关。与噪声相比，此类体内信号很小，通常需要 1000 到 4000 次平均值，并且妨碍了神经激活的动态研究。我们的主要目的是研究快速光信号的生物物理机制并提高哺乳动物神经组织的信噪比。为了实现这一目标，我们将追求 3 个具体目标。首先，我们将测试这样的假设：共焦双折射照明将增强较快的光学信号，而不是传统上通过明场照明看到的较慢的血流动力学成分。我们的第二个目标将测试快速光信号的早期成分将专门定位于皮质柱的假设。在我们的第三个目标中，我们将测试以下假设：双折射信号源于细胞肿胀引起的折射率变化，并将遵循电压敏感染料和膜电位。在过去的三年里，我们显着提高了光学测量在记录快速神经生理学事件方面的实用性。这些新目标的实现对于将光学技术推向更实际的应用至关重要，这些应用可以通过更好的信噪比对神经活动的电相关性进行成像。