Expression level of GFAP in four different models of amyloid disease. Pooled samples of total RNA isolated from the whole brains of diseased or age-matched control animals were used to determine relative GFAP expression levels by quantitative real-time PCR. The histograms represent the average of the means of three independent quantitative real-time PCR reactions, done in duplicate, ± standard deviation. All plotted data represent expression levels in diseased animals relative to gene expression levels in age and strain-matched control animals. A statistically significant increase in GFAP expression was observed in all terminal disease models (p = 3.44E-5 for Alzheimer's model, p = 0.000364 for VM BSE mice, p = 3.24E-5 for Hamster 263K 56 IC, p = 0.0068 for Hamster 263K IP, and p = 0.0014 for C57BL/6 ME7 mice).