Figure 4. Effects of knockout of claudin-5 on learning and memory and hippocampal LTP. (A, B) The claudin-5+/− mice exhibited decreased claudin-5 protein level in hippocampal region (n = 4 per group; two-tailed Student’s t-test). (C–F) The ability to search the platform (C), swim distance in the target quadrant (D), spend time in the target quadrant (E), and cross the target quadrant number of times (F) in MWM between WT and claudin-5+/− mice (n = 9–10 per group; Repeated measures two-way ANOVA in C; two-tailed Student’s t-test in D–F). (G) The freezing time in contextual fear conditioning test between WT and claudin-5+/− mice (n = 9–10 per group; two-tailed Student’s t-test). (H) The discrimination rate in NOR test between WT and claudin-5+/− mice (n = 9–10 per group; two-tailed Student’s t-test). (I, J) Hippocampal CA1 LTP induction between WT and claudin-5+/− mice (n = 6 per group; two-tailed Student’s t-test). Data show mean ± s.e.m. *P < 0.05, **P < 0.01, ***P < 0.001.