Neurophysiologic basis and specificity of fMRI

描述(由申请人提供)：使用血氧水平依赖(BOLD)功能磁共振成像对脑功能进行无创性评估已经在认知神经科学研究人员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Sherrington的工作：理解血液动力学变化与神经元活动是耦合的。然而，这种大胆的效应在多大程度上真实地反映并准确定位了潜在的神经元活动仍不清楚。该项目的总体目标是使用非侵入性功能磁共振成像(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，这些优化的措施将在手术切除前在人体上实施规划。其具体目的是：1.使用BOLD和CBF功能磁共振成像技术，研究初级躯体感觉皮层(3b区)手部单个手指的离散体位表征的差异，以确定BOLD和CBF测量的相对特异度。2.使用此体感范式和CBF与BOLD采集方法，研究S1区皮质各层的差异激活。3.通过多电极检测猴子S1脑内BOLD和CBF激活的脑区，确定BOLD-fMRI的神经关联。

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.