Molecular displacement in brain extracellular space

描述（由申请人提供）：临床MRI研究与降低相关 分子扩散到脑组织的异常区域。因此，在本发明中， 弥散加权MRI对脑部病变非常敏感， 中风这个建议的目的是阐明分子的决定因素 扩散在脑细胞外空间，并阐明因素 重要的是比较扩散测量来自不同的 实验技术产生扩散的两种主要方法 脑组织中的测量是离子电渗和磁共振（MR） 谱虽然这两种方法都被广泛使用， 研究小组在正常大脑和大脑中进行定量测量， 许多病理性的大脑状态，两个研究机构之间的比较， 由于实验中的差异的未知影响而变得复杂， 方法论。该提案概述了校准这两个方面的战略 方法.基本的实验涉及测量相同的扩散 分子与这两种技术。在进行初步比较后， 将改变扩散测量，使得它们对运动敏感 在接近所用电极之间距离的平均距离上 用于离子电渗测量。最后，观察到的变化 将在缺血条件下评估扩散速率以评估 两个扩散测量响应于相同的解剖学变化， 缺血的开始。

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.