Fig. 2. Neuronal damage and astrocyte activation in the hippocampal CA1 region. (A) Sections derived from the NS, AD, or AD+HBO group on postoperative day 21 were stained with hematoxylin and eosin for histological examination (upper panels). Some of the samples were stained with anti-GFAP antibody. The immunopositive cells are indicated by arrows. Magnification, 400×. (B) The percentage of activated astrocytes was calculated. (C) The TNF-α and IL-1β levels in the hippocampus were examined by ELISA. n=4. ^*p<0.05 compared with NS, ^†p<0.05 compared with AD. NS, normal saline; AD, Alzheimer’s disease; HBO, hyperbaric oxygen; TNF-α, tumor necrosis factor-α; IL, interleukin; ELISA, enzyme-linked immunosorbent assay.