Western blot was performed51 (link) to measure the protein expression levels of DNMTs in the PFC. Primary antibodies were rabbit DNMT1 (1:1000, #5032; Cell Signaling Technology), DNMT3a (1:1000, #2160; Cell Signaling Technology), DNMT3b (1:2000, NB300-516; Novusbio, Littleton, CO), brain-derived neurotrophic factor (1:500, sc-546; Santa Cruz Biotechnology), and mouse β-actin (1:10,000, A1978; Sigma-Aldrich). The membranes were then incubated with secondary horseradish peroxidase-conjugated goat anti-rabbit antibody (1:2000; Pierce, Rockford, IL) and anti-mouse antibody (1:30,000 for β-actin, Pierce). Signals were visualized using a chemiluminescence kit (Super Signal West Pico; Pierce) and intensity was measured by densitometry.