Hippocampal memory performance is impaired in 3 months old APP/PS1 mice. a Hippocampal memory performance at 3 months of age was tested in a contextual fear memory task. In the acquisition phase animals received a mild foot shock, and memory retrieval was tested 24 later by re-exposing animals to the shock-associated context. b APP/PS1 transgenic (TG) mice and wildtype (WT) littermates exhibited similar locomotor and exploratory activity during training trials before shock delivery. c Memory retrieval, as assessed by freezing behavior upon re-exposure of mice to the shock-associated context, was significantly reduced in APP/PS1 mice compared with wildtype mice; n = 10 (Student’s t test; mean ± SEM; ns, not significant; *p < 0.05). d Spatial memory was tested in a Morris water maze. During the 5-day training no differences were observed in escape latencies between APP/PS1 and wildtype mice. e Representative swim traces during the probe test show that APP/PS1 and wildtype mice both remembered the original location of the escape platform. f Quantification of quadrant occupancy shows that memory acquisition occurred equally in both genotypes, and that there was no significant difference in time spent in the top-left target quadrant. TL, top-left; TR, top-right; BL, bottom-left; BR, bottom-right; n = 10–13 (Student’s t test; mean ± SEM; ns, not significant; **p < 0.01).