Western blot analysis was conducted to characterize the expression of BDNF and TrkB, according to previously described methods [12 (link),14 (link)]. Mouse β-actin antibody (1:1,000; Santa Cruz Biotechnology), rabbit BDNF antibody (1:500; Santa Cruz Biotechnology), and rabbit TrkB antibody (1:1,000; Santa Cruz Biotechnology) were used as primary antibodies. The secondary antibodies were horseradish peroxidase conjugated antirabbit antibody for BDNF and TrkB (1:3,000; Vector Laboratories) and horseradish peroxidase-conjugated anti-mouse antibody for β-actin (1:2,000; Vector Laboratories). An enhanced chemiluminescence detection kit (Santa Cruz Biotechnology) was used for band detection.