Fig. 4.

Deficits in spatial learning and memory were increased in PDAPP/LRP⁺ mice and correlated with soluble Aβ levels measured in the hippocampus. (A) Performance of PDAPP/LRP⁺ mice during standard place trials in terms of path length was inferior to that of PDAPP/LRP^– mice in both young and old groups. (B) The average number of trials to reach the acquisition criterion (three consecutive trials with an average escape latency of <20 s) in both young and old groups of mice as a function of 4 weeks of training. (C) In aged mice, performance deficits observed during standard place training were highly correlated with soluble Aβ levels in the hippocampus. (D) A significant correlation was also found between mean trials-to-criterion scores in old mice during week 4 and hippocampal soluble Aβ levels but not with Aβ plaque burden. In all figures, * indicates P < 0.05, and † indicates P < 0.005 (by ANOVA).