Fig. 8

The passive-avoidance test. Latencies to enter the dark compartment on the 3rd day were shown for 2.5- (a) and 4.5-month-old (b) mice group. If mice did not enter the dark compartment within 300 s, retention latency time was recorded as 300 s. The data are presented as the mean ± SEM. One-way ANOVA was used for statistical analysis (****p < 0.001). A 2.5-month-old WT (n = 4), Hexa−/− (n = 6), Neu3−/− (n = 15), and Hexa−/−Neu3−/− (n = 6) mice; and 4.5-month-old WT (n = 10), Hexa−/− (n = 6), Neu3−/− (n = 10), and Hexa−/−Neu3−/− (n = 6)