Fig. 4

Assessment and comparison of cognitive functions using the water maze test between Dnmt1+/+ and Dnmt1+/− mice at 12 months of age. Five mice in each genotype group were tested. Statistical analyses of the escape latency differences between these two groups were performed using the Systat program by ANOVA. By the end of the 5-day trial period, Dnmt1+/− mice displayed a significantly delayed escape latency time than the age- and gender-matched Dnmt1+/+ mice (i.e., on the last day of training *p = 0.026). a Improvement of escape latency with the number of trial days. b Bar graph illustrating the time that each mouse group spent in one of the four quadrants during the probe trial. Note that the Dnmt1+/+ mice spent significantly more time on the correct quadrant than the rest (p = 0.003), whereas the Dnmt1+/− mice explored the four quadrants randomly