Fig. 3.

Neuropathological characterization of ill Tg1014 mice inoculated with sCJD prions (A–D) and vCJD prions (E–P). Brain sections were taken from the Tg1014 mouse inoculated with sCJD prions shown in Fig. 1A, lane 2, and Tg1014 mice inoculated with vCJD prions shown in Fig. 1C, lanes 3, 8 and 9. Tg1014 mice inoculated with sCJD prions showed moderate vacuolation (A) and punctate deposits of PrP^Sc (B, C), which were not amyloid (D). Tg1014 mice inoculated with vCJD, harboring type 1 PrP^Sc, showed moderate vacuolation similar to sCJD inoculation (E) and occasional kuru-type amyloid plaques (F–H). In mice with type 2 PrP^Sc, little vacuolation was observed (I) but the kuru-type amyloid plaques were large (J, K) and stained positively with Thioflavin S (L). Intermediate neuropathology was observed in Tg1014 mice with mixed type 1 and type 2 PrP^Sc: vacuolation was mild to moderate (M) and a few amyloid plaques were observed (N–P). Sections were stained with H&E to visualize vacuoles (left column), anti-PrP R2 antibody to visualize PrP^Sc deposition (middle column), and Thioflavin S to identify amyloid (right column). Bar in panel O represents 50 μm and applies panels in the three left columns; bar in panel P represents 50 μm and applies to the right column.