Cell death/proliferation and alterations in glial morphology contribute to changes in diffusivity in the rat hippocampus after hypoxia-ischemia
Cell death/proliferation and alterations in glial morphology contribute to changes in diffusivity in the rat hippocampus after hypoxia-ischemia
复制标题
DOI：
10.1038/jcbfm.2010.168
复制
发表时间：
2011-03-01
影响因子：
6.3
通讯作者：
Sykova, Eva
中科院分区：
文献类型：
--
作者：
Anderova, Miroslava;Vorisek, Ivan;Sykova, Eva
为了了解缺氧/缺血（H/I）后海马弥散性早期和晚期变化的结构改变，采用弥散加权磁共振成像（DW-MRI）研究了8周龄大鼠缺氧/缺血（H/I）后海马表观弥散系数（ADC(W)）的变化。在海马CA1区，在6个月的再灌注期间进行ADC(W)分析，并与实时离子电泳法获得的细胞数量/细胞类型组成、胶质形态和细胞外空间（ECS）扩散参数的变化进行比较。在再灌注早期（1 ~ 3天），神经元细胞死亡、胶质细胞增殖和胶质瘤形成伴ADC(W)降低和扭曲度增加。有趣的是，仅在H/I后第一天，ECS体积分数就下降了。再灌注后期（H/I后1个月开始），CA1区主要由小胶质细胞、星形胶质细胞和ng2胶质细胞组成，形态明显改变，ADC(W)、ECS体积分数和弯曲度增加。三维共聚焦形态分析显示星形胶质细胞增大，ng2 -胶质细胞萎缩，细胞体/突起对细胞总体积的贡献明显增加/减少。综上所述，CA1区ADC(W)的增加是由细胞组成和胶质形态的改变引起的，这表明在H/I后再灌注后期，细胞外信号传递可能发生了相当大的变化。脑血流与代谢杂志（2011）31,894-907；doi: 10.1038 / jcbfm.2010.168;2010年9月29日在线发布
To understand the structural alterations that underlie early and late changes in hippocampal diffusivity after hypoxia/ischemia (H/I), the changes in apparent diffusion coefficient of water (ADC(W)) were studied in 8-week-old rats after H/I using diffusion-weighted magnetic resonance imaging (DW-MRI). In the hippocampal CA1 region, ADC(W) analyses were performed during 6 months of reperfusion and compared with alterations in cell number/cell-type composition, glial morphology, and extracellular space (ECS) diffusion parameters obtained by the real-time iontophoretic method. In the early phases of reperfusion (1 to 3 days) neuronal cell death, glial proliferation, and developing gliosis were accompanied by an ADC(W) decrease and tortuosity increase. Interestingly, ECS volume fraction was decreased only first day after H/I. In the late phases of reperfusion (starting 1 month after H/I), when the CA1 region consisted mainly of microglia, astrocytes, and NG2-glia with markedly altered morphology, ADC(W), ECS volume fraction and tortuosity were increased. Three-dimensional confocal morphometry revealed enlarged astrocytes and shrunken NG2-glia, and in both the contribution of cell soma/processes to total cell volume was markedly increased/decreased. In summary, the ADC(W) increase in the CA1 region underlain by altered cellular composition and glial morphology suggests that considerable changes in extracellular signal transmission might occur in the late phases of reperfusion after H/I. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 894-907; doi:10.1038/jcbfm.2010.168; published online 29 September 2010