Western blotting was conducted according to previously published methodology [8 (link),16 (link)]. The hippocampal tissues were homogenized on ice and lysed in a lysis buffer. Protein (30 μg) was separated on sodium dodecyl sulfate-polyacrylamide gels and transferred onto a nitrocellulose membrane. Mouse beta-actin antibody (1:1,000; Santa Cruz Biotechnology, Santa Cruz, CA, USA), mouse GAP43 antibody (1:1,000; Santa Cruz Biotechnology), rabbit BDNF antibody (1:500; Santa Cruz Biotechnology), rabbit TrkB antibody (1:1,000; Santa Cruz Biotechnology), rabbit PSD95 antibody (1:1,000; Santa Cruz Biotechnology), rabbit Egr-1 antibody (1:1,000; Santa Cruz Biotechnology), and goat pCREB antibody (1:1,000; Santa Cruz Biotechnology) were used as the primary antibodies. Horseradish peroxidase-conjugated anti-rabbit antibody for BDNF, TrkB, PSD95, and Egr-1 (1:3,000; Vector Laboratories, Burlingame, CA, USA), horseradish peroxidase-conjugated anti-mouse antibody for beta-actin and GAP43 (1:2,000; Vector Laboratories), and horseradish peroxidase-conjugated anti-goat antibody for p-CREB (1:5,000; Santa Cruz Biotechnology) were used as the secondary antibodies. Band detection was conducted using an enhanced chemiluminescence detection kit (Santa Cruz Biotechnology).