Figure 4

Immunohistochemical staining and neuropathology in sCJD and CWD-inoculated tg66 mice. Whole brain sections stained with anti-prion protein antibody b3F4 are shown in A, E and I. The small rectangle shown in the whole brain sections depicts the region of thalamus shown at higher magnification on the right. Thalamus panels were stained with b3F4, H&E or GFAP (shown above each column). Tissues were stained with the anti-PrP antibody to detect PrP deposition, by H&E to look for spongiosis/vacuolation and general neuropathology, and anti-GFAP was used to detect activated astrocytes. A–D Are from a tg66 mouse infected with sCJD, E–H are from a normal, aged tg66 mouse and I–L are from an aged CWD-inoculated tg66 mouse. No pathology, spongiform lesions, or excessive astroglial activation was observed in any of the uninoculated or CWD-inoculated tg66 brains. PrPsen could be seen in all brains as a smooth brown blush using anti-PrP antibody b3F4. The scale bar in A is 1 mm and applies to A, E and I. The scale bar in L is 50 µm and applies to B–D, F–H, and J–L.