Immunohistochemistry for NeuN, caspase-3, and DCX were performed, as the previously described method (Kim et al., 2017 ; Lee et al., 2016 (link)). Six sections on average were selected in each brain region spanning from Bregma −2.50 mm to −4.50 mm. The sections were incubated overnight with mouse anti-NeuN antibody (1:500; EMD Millipore Corp., Billerica, MA, USA), rabbit anti-caspase-3 antibody (1:500; Santa Cruz Biotechnology, Santa Cruz, CA, USA), and mouse anti-DCX antibody (1:500; Santa Cruz Biotechnology), and then they were incubated for another 2 hr with the biotinylated secondary antibody (1:200; Vector Laboratories). The bound secondary antibody was then amplified using a Vector Elite ABC kit (Vector Laboratories). The antibody-biotin-avidin-peroxidase complex was visualized using 0.02% DAB. The sections were finally mounted onto gelatin-coated slides. The slides were air-dried overnight at room temperature, and the coverslips were mounted using Permount (Fisher Scientific).