PrPSc is transported along axons from one brain region to another. Data from the thalamus (squares) and the neocortex (triangles) are shown. A. Syrian hamsters inoculated in the thalamus with the Sc237 prion strain become clinically ill at ~10 weeks. Measurements of rPrPSc were generated by Western blot analysis from dissected brain regions. B. CD1 mice inoculated in the thalamus with RML prions become clinically ill at ~20 weeks. rPrPSc was estimated by morphometry of brain regions on histoblots.