Effect of isoflurane anesthesia on early and late protein expression of NMDA receptor subunits NR2B in the hippocampus of mouse brain. A. 24 hours post anesthesia, I1 and I2 group increased NR2B protein expression significantly (P < 0.05), I3 and I4 group decreased compared with control group (P < 0.05). B. 2 weeks post anesthesia, I1 and I2 group increased NR2B protein expression continuously, I4 dereased continously compared with control group. There was no difference between group I3 and control group [Data are presented as means, error bars represent SD, One-way ANOVA and LSD analysis were performed, *p < 0.05, **p < 0.01].