Modern clearing techniques for the three-dimensional (3D) visualisation of neural tissue microstructure have been very effective when used on rodent brain but very few studies have utilised them on human brain material, mainly due to the inherent difficulties in processing post-mortem tissue. Here we develop a tissue clearing solution, OPTIClear, optimised for fresh and archival human brain tissue, including formalin-fixed paraffin-embedded material. In light of practical challenges with immunostaining in tissue clearing, we adapt the use of cresyl violet for visualisation of neurons in cleared tissue, with the potential for 3D quantification in regions of interest. Furthermore, we use lipophilic tracers for tracing of neuronal processes in post-mortem tissue, enabling the study of the morphology of human dendritic spines in 3D. The development of these different strategies for human tissue clearing has wide applicability and, we hope, will provide a baseline for further technique development.

中文翻译：

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用于新鲜和存档人脑组织三维成像的下一代组织学方法。

用于神经组织微观结构三维 (3D) 可视化的现代透明技术在啮齿类动物大脑中使用时非常有效，但很少有研究将其用于人脑材料，这主要是由于处理死后组织的固有困难。在这里，我们开发了一种组织透明解决方案 OPTIClear，针对新鲜和存档的人脑组织进行了优化，包括福尔马林固定的石蜡包埋材料。鉴于组织透明化中免疫染色的实际挑战，我们采用甲酚紫来可视化透明组织中的神经元，并具有对感兴趣区域进行 3D 量化的潜力。此外，我们使用亲脂性示踪剂来追踪死后组织中的神经元过程，从而能够以 3D 方式研究人类树突棘的形态。这些不同的人体组织清除策略的开发具有广泛的适用性，我们希望能为进一步的技术开发提供基线。