NeuroCure Cluster of Excellence 1 article published in JoVE Neuroscience Visualization of Cortical Modules in Flattened Mammalian Cortices Simon M. Lauer*1, Undine Schneeweiß1, Michael Brecht1,2,3, Saikat Ray*1 1Bernstein Center for Computational Neuroscience, Humboldt University of Berlin, 2NeuroCure Cluster of Excellence, 3German Center for Neurodegenerative Diseases This article describes a detailed methodology to obtain flattened tangential sections from mammalian cortices and visualize cortical modules using histochemical and immunohistochemical methods.