Fig. 5

Abnormal axonal pathology, dystrophic neurites and neuritic processes are prominent features of Tau4RTg2652 mice. Grossly dilated axons resembling axonal spheroids are abundant in the frontal cortex and are immunoreactive for MC1 (a) and the neurofilament marker SMI31 (b). (c,d) High power images of regions in a and b (designated by asterisk) demonstrating the dilated axons (arrows) and a neuronal cell body (arrowhead) immunoreactive for MC1 (c) and SMI31 (d). Abnormal axonal spheroids are also detectable by Bielschowsky silver stain (e). Neuritic processes (dot-like pattern of staining) and axonal spheroids (arrows) are immunoreactive for AT8 (f) and Alz50 (g) in the piriform cortex. One year old Tau4RTg2652 mice exhibit robust striatal tau pathology; MC1 immunoreactivity is visible in the white fiber tracts (pencil fibers) in the striatum (h). Dystrophic neurites in the striatum are immunoreactive for MC1 (i) and AT8 (j). Grossly dilated axons and dystrophic neurites are detectable in the pons (k,l) and spinal cord (m,n) and are immunoreactive for AT8 (k,n), MC1 (m) and are Bielschowsky silver stain positive (l). Scale bars = 100um (a,b,h) and 50um (c-g and i-n)