On the first three days, all animals exhibited similar learning performances in the radial maze test, while they seemed to gradually improve their ability to learn the location of the baited arm during the learning phase from the 4th to the 8th day (Figure 2(Fig. 2)). A two-way repeated measure ANOVA was performed with “training days” as the within-subjects factor and “experimental groups” as the between-subjects factor. A significant difference was found for “training days” [(p < 0.001); F(7,378)=85.92)], “experimental groups” [(p < 0.001); F(8,54)=8.11)], and the “training days” by experimental groups” interaction [(p < 0.01); F(56,378)= 1.75)]. This suggests that the performance of the animals changed during the acquisition and that this change in performance was different between the groups (p < 0.001). The rats in the SD group showed less progress in the selection of the correct choices compared to the control animals from the 1st  to 8th  day.