Memory deficits in Tg6799 mice with age. A, Spatial working memory of Tg6799 and nontransgenic littermate (Wild-type) mice was assessed by spontaneous alternation in the Y-maze (n = 12–20). Tg6799 mice showed normal alternation performance in the Y-maze at 2 months of age, but they performed poorly at 4–5 months of age (only slightly >50% chance levels) compared with nontransgenic littermate mice (F_(3,62) = 13.96; p < 0.01). B, The total number of arm entries was not different between Tg6799 and nontransgenic (Wild-type) control mice, indicating similar levels of motor and exploratory activity in the Y-maze (n = 12–21). Each column represents the mean ± SEM. **p < 0.01 versus nontransgenic compared by ANOVA and post hoc Fisher's PLSD test.