Fig. 1

Ability of current diagnostic criteria to identify the disorders as prion diseases as observed in the different models used in this study. We considered here that the diagnosis of prion disease is based on the presence of PK-resistant abnormal PrP in the brains of animals with possible prion disease. For each model, N ^e corresponds to the number of animals exposed to the sources of infectivity and N to the number of mice developing neurological impairments (% disease = N/N ^e × 100). The numbers within bars correspond to the percentages of neurologically affected animals without detectable PrP^res