Effects of pretraining and post-training injections of rolipram on learning in calpain-1 KO and WT mice. A, Effects of pretraining or post-training injection of rolipram (1 mg/kg, i.p.) on novel object recognition learning in WT and calpain-1 KO mice. *p < 0.05, compared with saline in calpain-1 KO mice (two-way ANOVA followed by Bonferroni test). #p < 0.05, compared with saline after in WT mice (two-way ANOVA followed by Bonferroni test). n = 6–8 animals for each experimental group. B, Effects of pretraining injection of rolipram on context fear conditioning 24 h after one footshock pairing in WT and calpain-1 KO mice. Data are means ± SEM of 6–8 animals. **p < 0.01, compared with calpain-1 KO saline before group (two-way ANOVA followed by Bonferroni test). *p < 0.05, compared with calpain-1 KO saline before group (two-way ANOVA followed by Bonferroni test). C, Effects of pretraining injection of rolipram on tone fear conditioning 24 h after one footshock pairing in WT and calpain-1 KO mice. D, Context and tone fear conditioning are not affected in calpain-1 KO mice 24 h after training with 3 footshock pairings. Data are means ± SEM of 4 animals in each group.