Expression levels of interferon responsive genes 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 gene 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, for each gene ± standard deviation. All plotted data represent gene expression levels in diseased animals relative to gene expression levels in age and strain-matched control animals. The days post infection (dpi) indicated correspond to the times at which the onset of clinical symptoms and terminal stage disease are observed in the different model systems. At the onset of clinical symptoms (panel A) significantly higher expression levels of the three interferon responsive genes were observed in all the models of TSE disease via the IC route (p ≤ 0.008). No significant increase was observed in the hamster scrapie 263K 63 day IP sample or the similar disease stage transgenic mouse model of Alzheimer's disease. At the terminal stage of disease (panel B) the expression of the three interferon responsive genes was significantly increased in all rodent models of TSE disease (p ≤ 0.002) but not in the Alzheimer's disease model (p ≤ 0.32).