Three-dimensional mouse brain cytoarchitecture revealed by laboratory-based x-ray phase-contrast tomography.
Three-dimensional mouse brain cytoarchitecture revealed by laboratory-based x-ray phase-contrast tomography.
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DOI：
10.1038/srep42847
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发表时间：
2017-02-27
影响因子：
4.6
通讯作者：
Salditt T
中科院分区：
文献类型：
--
作者：
Töpperwien M;Krenkel M;Vincenz D;Stöber F;Oelschlegel AM;Goldschmidt J;Salditt T
哺乳动物脑细胞结构的研究通常是通过连续切片和切片染色来进行的。这一过程是劳动密集型的，只有在对齐各个2D切片后才能确定3D结构，从而产生具有非各向同性分辨率的重建体积。基于传播的X射线相衬成像由于其高穿透深度和潜在分辨率，为完整生物样品的高分辨率3D成像提供了独特的潜力。我们在这里表明，即使是在优化的液体-金属喷射微焦点源下的紧凑实验室CT，结合适当的相位恢复算法和新的组织制备，也可以在毫米大小的小鼠脑样本中提供细胞和亚细胞分辨率。我们从整个小鼠大脑中去除了水分和脂肪，并测量了空气中剩余的干燥组织基质，降低了吸光度，但增加了相位对比度。我们提供了小鼠大脑细胞结构的单细胞分辨率图像，并表明轴突可以在有髓纤维束中发现。与光学3D技术相比，我们的方法既不需要细胞染色，也不需要清除组织，随着样本和大脑大小的增加，这些程序越来越难以应用。因此，该方法为哺乳动物脑结构的高分辨率、高通量研究开辟了一条新的途径。
Studies of brain cytoarchitecture in mammals are routinely performed by serial sectioning of the specimen and staining of the sections. The procedure is labor-intensive and the 3D architecture can only be determined after aligning individual 2D sections, leading to a reconstructed volume with non-isotropic resolution. Propagation-based x-ray phase-contrast tomography offers a unique potential for high-resolution 3D imaging of intact biological specimen due to the high penetration depth and potential resolution. We here show that even compact laboratory CT at an optimized liquid-metal jet microfocus source combined with suitable phase-retrieval algorithms and a novel tissue preparation can provide cellular and subcellular resolution in millimeter sized samples of mouse brain. We removed water and lipids from entire mouse brains and measured the remaining dry tissue matrix in air, lowering absorption but increasing phase contrast. We present single-cell resolution images of mouse brain cytoarchitecture and show that axons can be revealed in myelinated fiber bundles. In contrast to optical 3D techniques our approach does neither require staining of cells nor tissue clearing, procedures that are increasingly difficult to apply with increasing sample and brain sizes. The approach thus opens a novel route for high-resolution high-throughput studies of brain architecture in mammals.