Immunohistochemistry for brain-derived neurotrophic factor (BDNF) in the dentate gyrus of (A) vehicle-, (B) C300-, (C) D-gal-, and (D) D-gal+C300-treated groups. Scale bar=50 μm. (E) Levels of BDNF in vehicle-, C300-, D-gal-, and D-gal+C300-treated groups (n=5 per group; *P<.05, indicating a significant difference between vehicle/D-gal and C300/D-gal+C300; #P<.05, a significant difference between vehicle/C300 and D-gal/D-gal+C300). Error bar indicates SEM. Color images available online at www.liebertpub.com/jmf