Scalable cytoarchitectonic characterization of large intact human neocortex samples

We describe MASH (Multiscale Architectonic Staining of Human cortex): a simple, fast and low-cost cytoarchitectonic labeling and optical clearing approach for human cortex samples, which can be applied to large formalin fixed adult brain samples. A suite of small-molecule fluorescent nuclear and cytoplasmic dyes in combination with new refractive index matching solutions allows deep volume imaging. This enables highly scalable human neocortical cytoarchitecture characterization with a large 3D scope.