Fig. 4

Principal component analysis (PCA) of differentially expressed proteins in the CSF of rTg-DI and WT rats. Data was centred and scaled prior to analysis. 45 proteins were significantly different (p ≤ 0.05) at 12 months of age between rTg-DI and WT models and were quantifiable in 100% of samples and used as input for PCA, using the expression levels of these proteins at ages 3 M, 6 M and 12 M respectively. Principal components 1/2 (PC1/2) accounted for 35.7/13.5% (3 M), 41.3/13.9% (6 M) and 49.5/15.5% (12 M) of total variance. Individual animals and probability ellipses are represented as dots and ellipses, with rTg-DI in red and WT in blue