Diffusion tensor imaging detects and differentiates axon and myelin degeneration in mouse optic nerve after retinal ischemia
Diffusion tensor imaging detects and differentiates axon and myelin degeneration in mouse optic nerve after retinal ischemia
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DOI：
10.1016/j.neuroimage.2003.07.005
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发表时间：
2003-11-01
期刊：
影响因子：
5.7
通讯作者：
Neufeld, AH
中科院分区：
文献类型：
--
作者：
Song, SK;Sun, SW;Neufeld, AH
轴突和髓鞘变性对白色物质障碍患者的长期残疾有显著影响。然而，由白色病变引起的神经功能障碍的临床表现不足以确定神经功能缺损的起源。一种能够检测和区分轴突和髓鞘变性的非侵入性生物标记物将是对目前可用工具的重要补充。来自扩散张量成像（DTI）的定向扩散系数先前已被该小组提出作为检测和区分轴突和髓鞘变性的潜在生物标志物。为了进一步检验轴向（λ（平行于））和径向（λ（垂直于））扩散率分别反映轴突和髓鞘病理的假设，在视网膜缺血的小鼠模型中使用DTI连续检查视神经。缺血后3天，观察到推定的DTI轴突标记物λ（平行于）显著减少，而推定的髓鞘标记物λ（垂直于）没有同时检测到变化。这一结果与缺血后3天无可检测脱髓鞘的显著轴突变性的组织学发现一致。缺血后5天观察到的λ（垂直于）的升高与此时髓鞘变性的组织学发现一致。这些结果支持的假设，λ（平行）和A，持有承诺作为轴突和髓鞘损伤的特异性标志物，分别，而且，轴突和髓鞘变性的共存不混淆这种效用。(C)2003年爱思唯尔公司All rights reserved.
Both axon and myelin degeneration have significant impact on the long-term disability of patients with white matter disorder. However, the clinical manifestations of the neurological dysfunction caused by white matter disorders are not sufficient to determine the origin of neurological deficits. A noninvasive biological marker capable of detecting and differentiating axon and myelin degeneration would be a significant addition to currently available tools. Directional diffusivities derived from diffusion tensor imaging (DTI) have been previously proposed by this group as potential biological markers to detect and differentiate axon and myelin degeneration. To further test the hypothesis that axial (lambda(parallel to)) and radial (lambda(perpendicular to)) diffusivities reflect axon and myelin pathologies, respectively, the optic nerve was examined serially using DTI in a mouse model of retinal ischemia. A significant decrease of lambda(parallel to), the putative DTI axonal marker, was observed 3 days after ischemia without concurrently detectable changes in lambda(perpendicular to), the putative myelin marker. This result is consistent with histological findings of significant axonal degeneration with no detectable demyelination at 3 days after ischemia. The elevation of lambda(perpendicular to) observed 5 days after ischemia is consistent with histological findings of myelin degeneration at this time. These results support the hypothesis that lambda(parallel to) and A, hold promise as specific markers of axonal and myelin injury, respectively, and, further, that the coexistence of axonal and myelin degeneration does not confound this utility. (C) 2003 Elsevier Inc. All rights reserved.