Molecular displacement in brain extracellular space

描述(由申请者提供)：临床核磁共振研究表明 分子扩散到脑组织内的异常区域。结果, 弥散加权MRI对脑部病理异常敏感 卒中。这项提议的目的是阐明分子的决定因素 脑细胞外空间的扩散及其影响因素 对于比较不同来源的扩散测量结果非常重要 实验技术。产生扩散的两种主要方法 脑组织的测量是离子导入和磁共振(MR)。 光谱学。尽管这两种方法都已被多个 研究小组在正常大脑和正常大脑中产生定量测量 许多病理性的大脑状态，两个研究机构之间的比较 因实验中差异的未知影响而变得复杂 方法论。这项建议勾勒出了一项战略，以校准这两者 方法：研究方法。基本的实验包括测量同一物质的扩散 分子与这两种技术。在进行初步比较后，MR 扩散测量将被改变，以便它们对运动敏感 在接近所用电极之间的距离的平均距离上 用于离子导入测量。最后，观察到的变化 扩散率将在缺血条件下评估，以评估程度 这两种扩散测量对相同的解剖变化做出了响应 脑缺血的发作。

DESCRIPTION (Provided by Applicant): Clinical MRI studies correlate decreases in molecular diffusion to abnormal regions within brain tissue. As a result, diffusion weighed MRI is exquisitely sensitive to brain pathologies such as stroke. The aim of this proposal is to elucidate determinants of molecular diffusion in the extracellular space of brain and to clarify the factors important for comparing diffusion measurements derived from different experimental techniques. The two primary methods that generate diffusion measurements in brain tissue are iontophoresis and magnetic resonance (MR) spectroscopy. Although both methods have been extensively used by multiple research groups to generate quantitative measurements in normal brain and in many pathological brain states, comparisons between the two bodies of research are complicated by the unknown effects of differences in the experimental methodologies. This proposal outlines a strategy for calibrating the two methods. The fundamental experimental involves measuring diffusion of the same molecule with both techniques. After initial comparisons are made, the MR diffusion measurements will be altered so that they are sensitive to motions over a mean distance that approaches the distance between the electrodes used for the iontophoresis measurements. Finally, the change in the observed diffusion rates will be assessed under ischemic conditions to assess the degree to which both diffusion measurements respond to the same anatomical changes at the onset of ischemia.