Figure 3.

Effect of PGE₂ EP1, EP2, and EP3 receptor deletion on passive avoidance memory test after rCHI. On day 1, mice were trained in passive avoidance apparatus and 24 hours later an identical test trial was performed in which the shock was omitted. (A) Both EP1^−/− and EP3^−/− aged mice had significantly greater latency time on day 1 than their respective young counterparts. (B) On day 2, no significant differences in latency time were observed between aged and young mice across the genotypes. (C) On day 2, significantly higher latency time was observed in EP1^−/−, EP2^−/−, and EP3^−/− aged mice compared with day 1. (D) For WT, EP2^−/−, and EP3^−/− young mice, the latency time was significantly higher on day 2 compared with day 1. Comparisons included aged male and young male wild type (n = 8, n = 7), EP1^−/− (n = 10, n = 8), EP2^−/− (n = 8, n = 9), and EP3^−/− (n = 8, n = 11), *P < .05, **P < .01, ***P < .001