Fig. 7

Confirmation of impaired cognitive functions in Dnmt1+/− mice vs. Dnmt1+/+ mice by using eight-arm radial water maze at 18 months of age. The same groups of mice as in Fig. 3 were used for this test, and statistical analyses were performed as described in Fig 2. a Improvement of escape latency over the five trial days. Dnmt1+/− mice have a much worse cognitive performance at the beginning of the test as well as at the end of the test (#p < 0.001; *p < 0.003), although their learning ability and short-term memory were not impaired. b Graphs illustrating the typical path for the mice to escape to the correct arm (containing the escape platform) on days 1 and 5 of the experiment. The Dnmt1+/+ mice escaped faster from the maze than Dnmt1+/− mice. c Comparison of the time spent in each arm between the Dnmt1+/+ mice and Dnmt1+/− mice in the probe trial at the end of the test (i.e., day 5). Note that Dnmt1+/− mice spent significantly (p < 0.03) less time in the correct arm than the Dnmt1+/+ mice did