Figure 7.

TB protects 3×Tg mice from developing memory and neuromuscular deficits at 17 months.

Schematic depictions of representative travel traces captured during the NORT novel object probe stage four hours after the familiar object learning stage from the indicated groups of 3×Tg a). The yellow circles indicate placement of the novel object and its surrounding area, and the red lines trace the route of travel for a representative mouse during the 5 minute recording. Calculated NORT recognition indexes (RIs) indicating a lost preference in 17 month old (17mo) 3×Tg mice for the novel object, while 17 month old +TB (17mo+TB) treated mice retained novel object recognition b). The percentage of spontaneous alternations observed in the 3-arm Y-maze trial c) and the percentage of alterations in the 2-arm Y-maze trial d) are also shown. Non-parametric Spearman Correlation analysis plot demonstrates the linear association between % relative abundance of total butyrate-producing bacteria with NORT-RI e). Results from individual mice from all groups of 3×Tg are denoted by different colored circles (white: 2 months old; light gray: 12 months old; medium gray: 17 months old; and dark gray: 17 months old +TB). Spearman correlation coefficient was r = 0.5449, and the P value indicates significance at p = 0.0087. Neuromuscular function in 3×Tg mice was measured with the fore limb Grip Test, measuring the amount of force at which mice lose their grip on a wire mesh, and is depicted as grip strength f). The time to fall or latency when placed on an accelerating RotaRod apparatus was measured in seconds for 3×Tg mice g). Bar graphs and error bars represent mean scores ± SD, and data from individual mice are shown in closed circles. Statistics were calculated using ordinary one-way ANOVA with Tukey post-hoc comparisons test with single variance and are indicated as *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.