Cryosectioning and Cresyl Violet Staining for Brain Histology

Protocols for brain histology were detailed previously (Song et al., 2018 (link); Liu et al., 2021 (link)). The control or extended kindled mice were euthanized for brain histology after the 60 days handling manipulation or the initial or late EEG-video monitoring (Figure 1F). Coronal brain sections (50 μm thick) were obtained via a Leica research cryostat (model CM3050) and stained with cresyl violet. Images were obtained using a slide scanner (Aperio digital pathology slide scanner AT2, Leica; at 20 × magnification) and analyzed using ImageScope (Leica) and Image J software (National Institute of Health, USA). Putative tip locations of the implanted electrodes were recognizable from three control mice and 10 extended kindled mice (Supplementary Figure 1).