Figure 1.

Significantly greater white matter loss observed in rTg-DI compared to WT rats. Mean and 95% confidence bands for age-dependent volumetric changes of the grey matter (GM) (a), white matter (WM) (b) for WT (blue, filled circles) and rTg-DI rats (red, filled circles) extracted from proton-weighted magnetic resonance images acquired in vivo. Observations for the WT group have been shifted slightly left of the rTg-DI group at each age to more clearly display the data. Individual filled circles represent individual rats. Model estimates are presented as means (filled squares) with 95% pairwise confidence intervals (black bands) using generalized estimating equations (GEE). Mean differences were tested for rTg-DI vs. WT groups at each age group. For the GM compartment, the results revealed no significant volumetric differences between strains tested at each age. For WM volume, the mean profiles between rTg-DI and WT rats differed statistically across the age groups (p-value < 0.001).