A. Starting at 30 days of age mice were placed, twice a week, on a rod at 12 rpm for 60 secs and the time remaining on the rod before falling was recorded. Not shown in the figure is the rotarod performance from 30 to 70 days of age, which was for all mice at maximum (60 s). All values are mean ±SEM. Statistical analysis was performed by ANOVA followed by post-hoc test (Tukey-Kramer), p<0.05 is considered significant. Significance (*) was reached for MEX vs. SED and HEX at 105 days of age. B. Demonstration of fitting the total data to a logistic function that combined the onset and slope of the decline. We used the R-factor ratio test, which is quite similar to an F-test to compare the fits for each set of parameters with the R-factor ratio determining the significance of the fits.