Optical Tomography of Intrinsic Signals in Rat Cortex

大鼠皮层固有信号的光学断层扫描

• 批准号: 8285930
• 负责人: Bruce J. Tromberg
• 金额: $ 22.14万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8285930
• 关键词: Adult; Algorithms; Alzheimer' s Disease; Architecture; Ballistics; Beds; Blood Vessels; Blood flow; Brain; Brain Pathology; Brain imaging; Cattle; Cerebrum; Communities; Complex; Confocal Microscopy; Coupling; Development; Devices; Diffuse; Dimensions; Disease; Fat emulsion; Frequencies; Functional Imaging; Functional Magnetic Resonance Imaging; Funding; Goals; Hemoglobin; Heterogeneity; Image; Image Analysis; Imaging Techniques; Individual; Laboratories; Lateral; Length; Light; Lighting; Measurement; Measures; Metabolic; Methods; Microscopy; Modeling; Monitor; Monte Carlo Method; Neurons; Neurosciences; Optical Methods; Optical Tomography; Optics; Pattern; Play; Property; Protocols documentation; Rattus; Relative (related person); Research; Research Personnel; Resolution; Rodent Model; Role; Signal Transduction; Simulate; Somatosensory Cortex; Source; Spectrum Analysis; Stimulus; Stroke; Surface; Techniques; Testing; Three-Dimensional Imaging; Tissues; Vibrissae; Visible Radiation; Work; base; deoxyhemoglobin; design; digital; gain of function; hemodynamics; image reconstruction; imaging modality; in vivo; insight; instrument; instrumentation; light intensity; light scattering; meetings; millimeter; optical imaging; reconstruction; response; spectroscopic imaging; stem; success; tomography; tool; two-dimensional

DESCRIPTION (provided by applicant): Hemodynamic activity plays an important role in brain function and disease. The connection between neuronal and vascular activity in the brain is poorly understood. This in part stems from the lack of quantitative methods to localize hemodynamic changes in three-dimensions with sufficient temporal and spatial resolution to monitor the progression of the hemodynamic response to a stimulus. Intrinsic Signal Optical Imaging (ISOI) is a camera-based method for imaging cortical activity. ISOI allows researchers to image the hemodynamic changes that accompany neuronal activity by measuring changes in intensity of light remitted from an illuminated brain. Because it is capable of imaging large cortical regions with high spatial and temporal resolution, ISOI has become an important tool for studying the functional architecture and plasticity of the cortex. However, ISOI has two major limitations that have hampered our ability to decipher the complex relationship between hemodynamics and neuronal activity. First, it is often difficult to determine whether measured signals are due to changes in hemoglobin concentration or alterations in hemoglobin oxygenation state. Second, ISOI only provides two-dimensional images, and thus cannot localize hemodynamic activity in depth. We have recently acquired preliminary results using multi-spectral ISOI that demonstrate tomographic localization of hemodynamic activity in rat cortex during whisker stimulation. This is possible because near- infrared light penetrates much more deeply into the brain than visible light. By using many wavelengths of light spanning both the visible and near-infrared (NIR), and applying tomographic imaging methods, we have succeeded in forming three-dimensional tomographic images of hemodynamic activity in the rat somatosensory cortex. In addition, we have also been able to quantify dynamic changes in hemoglobin concentration and oxygenation state by employing spatial frequency domain imaging (SFDI) techniques in conjunction with multi-spectral image analysis. The purpose of this R21 proposal is to validate and refine this exciting new finding. Over the course of the two year funding period, we will incorporate snapshot hyperspectral imaging into our established optical brain imaging methods - ISOI and SFDI. We will optimize our tomographic image reconstruction methods to work in the rat cortex using dynamic tissue simulating phantoms, and validate our approach using our established protocol for whisker stimulation in the adult rat. PUBLIC HEALTH RELEVANCE: Deciphering the connection between hemodynamic and neuronal activity is crucial for advancing our understanding of normal brain function, gaining insight into brain pathologies, and developing more effective neuro-therapies. However, current brain functional imaging methods are limited in their ability to localize and quantify hemodynamic activity in the brain. The goal of this work is to develop and validate a new technique based on principles of hyperspectral spatial frequency domain imaging to meet this need for high- resolution three-dimensional functional tomography of cerebral hemodynamics.

描述(申请人提供)：血流动力学活动在脑功能和疾病中起着重要作用。人们对大脑中神经元和血管活动之间的联系知之甚少。这在一定程度上是由于缺乏定量方法来在三维中定位血流动力学变化，并具有足够的时间和空间分辨率来监控对刺激的血流动力学反应的进展。本征信号光学成像(ISOI)是一种基于相机的皮质活动成像方法。ISOI允许研究人员通过测量从被照亮的大脑发出的光的强度的变化来成像伴随神经元活动的血液动力学变化。由于它能够以高时空分辨率成像大范围的皮质区域，ISOI已成为研究大脑皮质功能结构和可塑性的重要工具。然而，ISOI有两个主要限制，这两个限制阻碍了我们破译血流动力学和神经元活动之间复杂关系的能力。首先，通常很难确定测量的信号是由于血红蛋白浓度的变化还是由于血红蛋白氧合状态的变化。其次，ISOI仅提供二维图像，因此不能深入定位血流动力学活动。我们最近利用多光谱ISOI获得了初步结果，证明了胡须刺激期间大鼠大脑皮质血流动力学活动的断层扫描定位。这是可能的，因为近红外光比可见光更能深入大脑。通过使用跨越可见光和近红外(NIR)的多个波长的光，并应用断层成像方法，我们成功地形成了大鼠体感皮质血流动力学活动的三维断层图像。此外，我们还能够利用空间频域成像(SFDI)技术结合多光谱图像分析来量化血红蛋白浓度和氧合状态的动态变化。这项R21提案的目的是验证和完善这一令人兴奋的新发现。在两年的资助期内，我们将把快照高光谱成像纳入我们现有的光学脑成像方法--ISOI和SFDI。我们将优化我们的断层图像重建方法，使用动态组织模拟模型在大鼠皮质中工作，并使用我们建立的成年大鼠胡须刺激方案来验证我们的方法。 公共卫生相关性：破译血流动力学和神经元活动之间的联系对于促进我们对正常大脑功能的理解、对大脑病理的洞察以及开发更有效的神经疗法至关重要。然而，目前的脑功能成像方法在定位和量化脑内血流动力学活动的能力方面存在局限性。这项工作的目的是开发和验证一种基于高光谱空间频域成像原理的新技术，以满足高分辨率脑血流动力学三维功能断层成像的需求。