Figure 3: Hippocampal FMN2 is essential for extinction learning and cognitive flexibility.D. Experimental Design. Microcannulae were implanted into the hippocampus of wild type mice. All mice were subsequently subjected to contextual fear conditioning training. Fmn2 siRNA or scrambled control RNA was injected into the dentate gyrus 24h later and then every 12h for 3 days. On subsequent days mice were subjected to extinction trial (E) 1, E2, E3 and E4 (Fig 3B). The injection protocol was continued until E3. E. Fear Extinction is significantly impaired (P < 0.001, F = 15.55; * P < 0.05, ***P < 0.001 for post hoc analysis) in 3-month old mice that received intra-hippocampal injections of Fmn2 siRNA when compared to the scrambled control group (n=9/group). When siRNA injection was terminated, all mice exhibited normal extinction behavior. Error bars indicate SEM. 