Neurovascular Coupling in Aging--Optical Methods

衰老过程中的神经血管耦合——光学方法

• 批准号: 6654449
• 负责人: Monica Fabiani
• 金额: $ 54.68万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6654449
• 关键词: age difference; bioimaging /biomedical imaging; brain circulation; brain electrical activity; brain imaging /visualization /scanning; clinical research; cognition; electroencephalography; evoked potentials; functional magnetic resonance imaging; hemodynamics; human old age (65+); human subject; infrared spectrometry; neuroanatomy; neuromuscular system; neurophysiology; noninvasive diagnosis; physical fitness; young adult human (21-34)

DESCRIPTION (provided by applicant): Common non-invasive methods for studying the human brain function, such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI), are based on imaging some of the consequences of neuronal activity (i.e., increased blood flow to active areas of the brain) rather than reflecting this activity directly. However, the relationship between neuronal activity and blood flow - neurovascular coupling - is not well understood. The assumption that this relationship is linear and similar across subjects, brain areas, and experimental conditions may not always be valid, especially when individuals of varying age and cardiopulmonary fitness levels are compared. One significant limitation of most studies testing the linearity assumption is that only the hemodynamic signal is manipulated and measured, without an independent measure of neuronal activity. In this proposal we intend to use a novel approach to the investigation of neurovascular coupling, based on recording non-invasive optical brain imaging data in young adults, and in older adults selected for being high or low in cardiopulmonary fitness. Optical methods provide simultaneously recorded but independent measures of hemodynamic (near-infra-red spectroscopy, or NIRS) and neuronal (the event-related optical signal, or EROS) activity. Event-related brain potentials (ERPs) and the BOLD fMRI response will also be recorded in the same subjects and conditions to provide an external validation to this approach. Our specific goals are to determine whether and under which conditions the overall relationship between neuronal and hemodynamic signals is linear; what are the parameters of this function, and whether they vary with age, fitness, area of the brain, and sensory, motor and cognitive load. This approach is intended to provide an empirical, systematic, and parametric methodology for describing the neurovascular coupling in different brain regions and subject populations. We believe that this approach will provide data that will help explicate the relationship between neuronal and vascular events and provide a bridge between neuronal and hemodynamic imaging methods.

描述(由申请人提供)： 常用的研究人脑功能的非侵入性方法，如正电子发射断层扫描(PET)和功能磁共振成像(FMRI)，都是基于对神经元活动(即，流向大脑活跃区域的血液增加)的一些后果进行成像，而不是直接反映这种活动。然而，神经元活动和血流--神经血管耦合--之间的关系还不是很清楚。假设这种关系是线性的，并且在受试者、大脑区域和实验条件之间相似，这种假设可能并不总是有效的，特别是当比较不同年龄和心肺健康水平的人时。大多数测试线性假设的研究的一个显著局限性是，只有血流动力学信号被操纵和测量，而没有对神经元活动的独立测量。在这项建议中，我们打算使用一种新的方法来研究神经血管耦合，基于记录年轻人和老年人的非侵入性光学脑成像数据，这些数据被选为心肺健康水平高或低的人。光学方法提供同时记录但独立的血流动力学(近红外光谱，或NIRS)和神经元(事件相关光学信号，或EROS)活动的测量。事件相关脑电位(ERPs)和大胆的fMRI反应也将被记录在相同的受试者和条件下，以提供对这一方法的外部验证。我们的具体目标是确定神经元和血流动力学信号之间的总体关系是否以及在什么条件下是线性的；这种功能的参数是什么，以及它们是否随着年龄、健康、大脑区域以及感觉、运动和认知负荷的变化而变化。这一方法旨在提供一种经验的、系统的和参数的方法来描述不同脑区和受试者群体中的神经血管耦合。我们相信，这种方法将提供有助于阐明神经元和血管事件之间的关系的数据，并在神经元和血流动力学成像方法之间架起一座桥梁。