Figure 2.

The TgTDP-25 mice develop cognitive deficits. Behavioral testing was conducted in 2- and 6-month-old NonTg, TgTDP-25(B) and TgTDP-25(F) mice (n = 14/genotype/time point). A–D: The open-field activity test was conducted to measure spontaneous activity and anxiety. No statistically significant differences were found among the three groups (at any of the ages analyzed) in the distance covered during the exploration time (A) or the speed of exploration (B), indicating that gross motor function was intact in both lines of TgTDP-25 mice. Also, no differences among the groups were found when measuring the time spent in the periphery and center of the arena (C and D, respectively), indicating that the TgTDP-25 mice had no detectable anxiety defects. E: To measure motor coordination, we used the accelerating rotarod and found no statistically significant changes among the three groups analyzed. F: T-maze data show that at 2 months of age, working memory was similar among the three groups of mice. In contrast, 6-month-old TgTDP-25(B) mice performed significantly worse compared to NonTg and TgTDP-25(F) mice. G: Novel object recognition tests, a behavioral task highly dependent on the cortex, show that at 2 months of age all three groups of mice performed similarly to each other. At 6 months of age, however, both lines of TDP-25 transgenic mice were significantly impaired compared to NonTg mice as they spent less time exploring the new object compared to the NonTg mice. *P < 0.01, **P < 0.001. Data are presented as means ± SEM, and each time point was independently analyzed by one-way analysis of variance.