Chronic dosing of methylene blue leads to reductions in soluble tau but pathology is unaffected. (A) Half-brain lysates (no cerebellum) were analyzed for tau protein levels by Western blot. (B) Optical density of tau levels is shown as a percentage of control (saccharine treated rTg4510), *p < 0.05. (C) Representative images of immunoreactivity to a phosphorylated tau epitope (pS202/T205), the MC1 epitope (early tangles), and reactivity to the gallyas silver stain (late tangles) are shown. Scale bar, 200 μm. (D) High magnification images of immunohistochemistry. Scale bar, 20 μm. (E) Quantitation of the percent area of positive staining shows no statistical significance between the means of all stains.