FIGURE 3.

Long-term sucrose consumption alters episodic and spatial memory. (A) Experimental design of the testing of episodic and spatial memory in the novel-object recognition (NOR) and Morris-watermaze (MWM) tests. Animals consumed 25% sucrose for 8 weeks prior to behavioral testing and continued to be exposed to sucrose for a total of 12 weeks. Memory tests were conducted 3 weeks apart. Animals were assigned into two groups: sugar-withdrawn animals and water controls. (B–D) Long-term sucrose drinking animals interact less with a novel object across the duration of the test, compared to water controls (B), as confirmed by a reduction in the area-under-curve (AUC) (C). The 2 objects used alternatively in the novel-object-recognition test, which are discernible in shape, size and color, are pictured in panel (D). (E–G) Long-term sucrose consuming mice showed no alteration in their learning and swimming behavior to reach a visible platform (E), however, they showed an increased latency to reach the zone where the platform was previously placed (F) compared to water controls. Schematic drawing of the MWM apparatus used is depicted in panel (G). Data are presented as mean ± SEM; n = 8 mice/group. *p < 0.05, ***p < 0.001.