Figure 1
Acidified drinking water in Cln1R151X mice prevents the impairment in pole climbing ability. A group of Cln1R151X and wild-type (WT) male mice received acidified drinking water from weaning (21 days of age) and were compared to male mice that always had non-acidified drinking water. At 3 and 6 months of the age, a vertical pole was used to test the climb down (a,b) and turn downward (c,d) ability of mice. One day later, the same mice were also tested on an accelerating rotarod (from 0 to 48 rpm in 240 s) (e,f). (g,h) Weight of the mice at 3 and 6 months. Acidified drinking water in Cln1R151X mice prevented the impairment in pole climbing ability at 3 and 6 months of age (a,b). Acidified drinking water decreased the time to turn downward at both 3 and 6 months but the differences were not statistical significant (c,d). In line with our previous results1, acidified drinking water impaired the pole-descending ability of WT mice at 6 months (b). In the accelerating rotarod test, which measures motor coordination and balance, Cln1R151X mice receiving non-acidified drinking water performed poorly at both 3 and 6 months, and acidified water apparently had no effect on their rotarod performance (e,f). However, 6-month-old Cln1R151X mice that received acidified drinking water displayed a strange behavior in the rotarod test: they did not want to stay on the rod of the rotarod even when the rod was not moving. Therefore, their rotarod performance was confounded by their unwillingness to stay on the rod. The movement and home cage activity of these mice were normal (as observed by the experimenter during the behavioral tests and by animal care technicians daily in the vivarium), and these mice performed similarly to WT mice in the pole descending task (a,b). Columns and bars represent mean ± SEM (WT and Cln1R151X on non-acidified water: 14 and 19 mice, respectively; WT and Cln1R151X on acidified water: 10 and 18 mice, respectively). Two-way ANOVA analysis showed a significant interaction between the two factors, genotype and type of drinking water, for the time to climb down the pole at both 3 and 6 months (p = 0.0154 and p < 0.0001), and for weight at 3 months (p = 0.0465). Only the genotype had a significant effect on the time to turn downward on the pole (p < 0.0001 at 3 months, p = 0.0008 at 6 months), and on the rotarod test results (p < 0.0001 at both 3 and 6 months). In two-way ANOVA, Tukey’s post-test was used to calculate statistical significance in multiple comparisons. NS not significant (d).
