Neurophysiologic basis and specificity of fMRI

描述（由申请人提供）：使用血氧水平依赖性（BOLD）功能磁共振成像（fMRI）对脑功能进行非侵入性评估已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Sherrington的工作：血液动力学变化与神经元活动相关联的理解。然而，BOLD效应真正反映和准确定位潜在神经元活动的程度仍不清楚。该项目的总体目标是优化定位和表征的大脑活动，使用非侵入性功能磁成像（fMRI），并评估优化的fMRI测量神经元电活动的关系。最终，这些优化的措施将在人类中实施，用于手术切除前的计划。具体目标是：1.调查的差异，在离散的躯体位置表示的个别手指的手在初级躯体感觉皮层（区3b）使用BOLD和CBF为基础的功能磁共振成像，以确定的BOLD和CBF测量的相对特异性。2.使用这种体感范例和CBF与BOLD采集方法研究S1皮质层的差异激活。3.使用猴S1内表现出BOLD和CBF响应激活的脑区的多电极调查来识别BOLD-fMRI的神经相关性。

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.