Fig. 2

HF diet caused a wider array of cognitive impairment in females compared to males. A Episodic-like memory was assessed in the novel object recognition test (NORT). Recognition index (% time spent with the novel object) was calculated. Performance not significantly greater than chance (50%, indicated by the red line) indicates impaired memory. B–D Spatial learning and memory was assessed using the Morris Water Maze (MWM). Five hidden trials (B) assessed spatial learning via pathlength to reach the target platform (shorter pathlength = better performance). Average pathlength over the 5 hidden trials (C) was longer (more impaired memory) in MxD females and AD females on a HF diet. Spatial memory was assessed in the probe trial (D), as % time spent in the target quadrant vs. chance (25%, indicated by the red line). Performance above 25% indicates intact memory. E The nest building task was used to assess activities of daily living. Nests were graded on 1–5 scale (average of scores by 3 experimenters blinded to treatment). Lower scores are indicative of impairment. Data are presented as mean + SEM except for nest building (median + interquartile range), +++p < 0.001 vs chance, +p < 0.05 vs. chance, **p < 0.01 effect of diet, ^p < 0.05 effect of dementia, ^^p < 0.01 effect of dementia, ^^^^p < 0.0001 effect of dementia, Red line = chance, 2-way ANOVA, (n = 5–11/group NOR, n = 8–13/group MWM, nest building)