Neurophysiologic basis and specificity of fMRI

描述（由申请人提供）：使用血氧水平依赖（BOLD）功能磁共振成像（fMRI）对脑功能进行无创评估已经在认知神经科学研究者中获得了热情和广泛的接受。这种询问神经活动的间接方法是基于谢林顿的工作：对血流动力学变化与神经元活动耦合的理解。然而，BOLD效应在多大程度上真实反映和准确定位潜在的神经元活动仍不清楚。该项目的总体目标是利用无创功能磁共振成像（fMRI）优化大脑活动的定位和表征，并评估优化的fMRI测量与神经元电活动的关系。最终，这些优化措施将在人类手术切除前实施。具体目标是：1。利用BOLD和基于CBF的功能磁共振成像（fMRI）研究初级体感皮层（3b区）单个手指离散体位表征的差异，以确定BOLD和CBF测量的相对特异性。2. 使用这种体感觉模式和CBF与BOLD获取方法研究S1皮质层的不同激活。3. 通过对猴子S1大脑区域的多电极调查，确定BOLD- fmri的神经相关性，显示BOLD和CBF在响应中激活。

DESCRIPTION (provided by applicant): Noninvasive assessment of brain function using blood-oxygen-level-dependent (BOLD) fMRI has gained enthusiastic and widespread acceptance among cognitive neuroscience investigators. This indirect approach to interrogating neural activity is based on work originating with Sherrington: the understanding that hemodynamic changes are coupled to neuronal activity. However, the extent to which the BOLD effect truly reflects and accurately localizes underlying neuronal activity remains unclear. The overall aim of this project is to optimize localization and characterization of brain activity, using noninvasive functional magnetic imaging (fMRI) and to assess the relationship of the optimized fMRI measurement to neuronal electrical activity. Ultimately these optimized measures will be implemented in humans for planning prior to surgical resection. The specific aims are: 1. Investigate differences in the discrete somatotopic representation of individual digits of the hand in primary somatosensory cortex (Area 3b) using BOLD and CBF-based fMRI to determine the relative specificity of the BOLD and CBF measurements. 2. Investigate differential activation of cortical layers in S1 using this somatosensory paradigm and CBF versus BOLD acquisition methods. 3. Identify Neural Correlates of BOLD-fMRI using multi-electrode survey of brain regions within monkey S1 exhibiting BOLD and CBF activation in response.