Li Lang, Wang Xiao-Yi, Gao Fa-Bao, Wang Lei, Xia Rui, Li Zhi-Xiao, Xing Wu, Tang Bei-Sha, Zeng Yi, Zhou Gao-Feng, Zhou Hai-Yan, Liao Wei-Hua
Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, China; Center for Molecular Imaging, Central South University, Changsha, Hunan, China.
Neurosci Lett. 2016 Jan 1;610:92-7. doi: 10.1016/j.neulet.2015.10.058. Epub 2015 Oct 28.
The aim of this study was to better understand the effect of amyloid-β plaques on magnetic resonance T2 relaxation time. We investigated these changes associated with age in an APP/PS1 mouse model of AD at 7 Tesla, combined with histology. Ten double-transgenic AD and ten wild type (WT) female mice (aged 12-20 months) were used in a cross-sectional study. Mean T2 values and standard deviations were calculated for each Regions of interest (ROIs) on T2 map. Immunohistochemistry for amyloid plaques and fluorescence staining with thioflavine S were performed of brain sections after imaging. The results showed that mean T2 values of the hippocampus, cortex, corpus callosum, and thalamus of older mice were significantly lower than of the younger. Compared to WT mice, the T2 values of the hippocampus, corpus callosum, and thalamus in younger AD mice were significantly greater, while the T2 values of the hippocampus and cortex in older AD mice were significantly less. Aβ-40 immunohistochemistry and thioflavine S stainging were positive in the matched region both for younger and older AD mice, while neither Aβ-40 nor thioflavine S were observed in WT mice. These findings suggest that regional T2 values of AD mice may decrease with age, and changes in T2 values in AD mice may be influenced by many factors besides amyloid-β plaque accumulation. Furthermore, they support that the standard deviation of the mean T2 value should be considered as well as the mean.
本研究的目的是更好地了解β淀粉样蛋白斑块对磁共振T2弛豫时间的影响。我们在7特斯拉磁场下，结合组织学方法，研究了APP/PS1阿尔茨海默病小鼠模型中与年龄相关的这些变化。在一项横断面研究中，使用了10只双转基因阿尔茨海默病雌性小鼠和10只野生型（WT）雌性小鼠（年龄12 - 20个月）。在T2图上为每个感兴趣区域（ROI）计算平均T2值和标准差。成像后，对脑切片进行淀粉样蛋白斑块的免疫组织化学和硫黄素S荧光染色。结果显示，老年小鼠海马体、皮质、胼胝体和丘脑的平均T2值显著低于年轻小鼠。与WT小鼠相比，年轻阿尔茨海默病小鼠海马体、胼胝体和丘脑的T2值显著更高，而老年阿尔茨海默病小鼠海马体和皮质的T2值显著更低。年轻和老年阿尔茨海默病小鼠匹配区域的Aβ - 40免疫组织化学和硫黄素S染色均为阳性，而WT小鼠中未观察到Aβ - 40和硫黄素S。这些发现表明，阿尔茨海默病小鼠的区域T2值可能随年龄降低，且阿尔茨海默病小鼠T2值的变化可能受除β淀粉样蛋白斑块积累之外的许多因素影响。此外，这些发现支持除了平均值外，还应考虑平均T2值的标准差。
