Figure 1.

Laparotomy induced impairment of contextual fear memory and alterations of hippocampal PGE2 concentration and EP1‐4 mRNA Levels. (A‐C) In the open field test, sham and laparotomy mice had similar path length, velocity, and percent of time spent in the center of the field. Representative exploration traces are presented. (n = 10) (D‐E) There were no significant differences in pretone and tone freezing time in the auditory‐cued fear conditioning test between 2 groups. When exposed to context, mice undergoing laparotomy demonstrated a significant reduction in freezing time compared with sham mice. (n = 10) (F) Laparotomy induced a marked upregulation of PGE2 expression at 6 h, 1 day, and 7 day postsurgery, measured by ELISA. (n = 3) (G‐J) Quantitative real‐time PCR results showed that laparotomy‐induced prolonged elevation of EP3 mRNA levels at 6 h, 1 day, and 7 days, but not EP1 and EP4. EP2 mRNA levels only increased at 6 h after surgery but not at 1 day and 7 days.(n = 3) Data presented as mean ± SEM. **P < 0.01