Immunohistochemistry for DCX was performed, according to the previous method (Park and Kim, 2017 (link)). The sections were incubated in PBS for 10 min, washed three times in PBS, and then incubated in 1% hydrogen peroxide for 20 min. The sections were incubated 2 hr with goat anti-DCX antibody (1:1,000; Oncogene Research Product, Cambridge, UK). The sections were then incubated with the biotinylated goat secondary antibody (1:500; Vector Laboratories, Burlingame, CA, USA) for another 1 hr, washed, and incubated in ABC complex (Vector Elite ABC kit; 1:100; Vector Laboratories). Labeling was visualized using 0.03% diaminobenzidine, and the sections were mounted onto gelatin-coated slides. The slides were air-dried overnight at room temperature, and the coverslips were mounted using Permount (Thermo Fisher Scientific Inc., Waltham, MA, USA).