Immunohistochemical staining and neuropathology in sCJD and CWD-inoculated tgRM 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 tgRM mouse infected with sCJD, E–H are from a normal, aged tgRM mouse and I–L are from an aged CWD-inoculated tgRM mouse. No pathology, spongiform lesions, or excessive astroglial activation was observed in any of the uninoculated or CWD-inoculated tgRM brains. The PrPsen background staining seen in tg66 mice is not present in tgRM mice using the same staining methods. This is likely due to the lower PrPsen expression in tgRM mice. 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.