Label-Free Nanoimaging of Neuromelanin in the Brain by Soft X-ray Spectromicroscopy
Label-Free Nanoimaging of Neuromelanin in the Brain by Soft X-ray Spectromicroscopy
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通过软 X 射线光谱显微镜对大脑中的神经黑色素进行无标记纳米成像
DOI：
10.1002/ange.202000239
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发表时间：
2020
影响因子：
--
通讯作者：
Brooks J
中科院分区：
文献类型：
--
作者：
Brooks J
帕金森氏病的一个标志是神经黑色素沉着神经元的死亡，但神经黑色素的作用尚不清楚。 神经黑色素的原位表征仍然依赖于可检测的色素沉着，而不是直接定量的神经黑色素。我们表明，使用同步辐射扫描透射X射线显微镜（STXM）可以实现人脑组织中神经黑色素和相关金属离子的直接，无标记纳米级可视化，通过在287.4 eV处的神经黑色素X射线吸收光谱中的特征特征，该特征也存在于无铁和含铁的合成神经黑色素中。 通过将STXM神经黑色素成像与银染色的神经黑色素相关联，在连续脑切片中证实了这一点。分析表明，苯并噻嗪基团中的1 s-σ*（C-S）跃迁解释了这一特征。这种方法说明了STXM作为一种适用于有机和无机材料的无标记光谱技术的更广泛潜力。
A hallmark of Parkinson's disease is the death of neuromelanin‐pigmented neurons, but the role of neuromelanin is unclear. The in situ characterization of neuromelanin remains dependent on detectable pigmentation, rather than direct quantification of neuromelanin. We show that direct, label‐free nanoscale visualization of neuromelanin and associated metal ions in human brain tissue can be achieved using synchrotron scanning transmission x‐ray microscopy (STXM), through a characteristic feature in the neuromelanin x‐ray absorption spectrum at 287.4 eV that is also present in iron‐free and iron‐laden synthetic neuromelanin. This is confirmed in consecutive brain sections by correlating STXM neuromelanin imaging with silver nitrate‐stained neuromelanin. Analysis suggests that the 1s–σ* (C−S) transition in benzothiazine groups accounts for this feature. This method illustrates the wider potential of STXM as a label‐free spectromicroscopy technique applicable to both organic and inorganic materials.