Figure 5.

Tg-SwDI mice developed phenotypic deficits in the open field test and showed cognitive spatial impairment in the Morris water maze. In order to analyze some general aspects of the behavior of Tg-SwDI compared to wild type (WT) mice, an open field test was conducted, where mice were allowed to explore a square shaped arena freely for 30 min. The analysis of the test revealed that Tg-SwDI mice explored less the center of the arena (a) (two-way ANOVA genotypes p < 0.0001, Fisher LSD post hoc analysis WT vs. Tg-SwDI center and border p < 0.0001). Furthermore, they showed a reduced covered distance (b) and a reduced velocity (c) (both two-tailed t-test p = 0.0001). By analyzing the habituation effect of WT and Tg-SwDI mice to the arena, it was obvious that transgenic mice explored the center of the arena less than WT mice, indicating a reduced habituation effect to the arena (d) (two-way RM ANOVA, genotype p = 0.002, Fisher LSD post hoc analysis, WT vs. Tg-SwDI slot one p = 0.047, slot two n.s. (p = 0.052), slot three p = 0.034, slot four p < 0.014 and slot five p < 0.001). In the Morris water maze, a significant difference was detectable in the performance during the training of WT and Tg-SwDI mice starting at day 2, indicating spatial memory deficits (e) (two-way RM ANOVA, genotype p = 0.001, Fisher LSD post hoc analysis, WT vs. Tg-SwDI day one n.s. (p = 0.91), day two p = 0.018, day three p = 0.091, day four p < 0.001 and day five p = 0.004)). During the probe trial, WT mice spent more time in the platform zone than Tg-SwDI mice, indicating impairments with memory retrieval (f). Data are shown as mean ± SEM, * p < 0.05, ** p < 0.01 and *** p < 0.001 (WT N = 13 and Tg-SwDI N = 12).