(A) Analysis of free NGF levels in the brain, blood serum, and salivary gland from control mice, AD11 mice, and AD11 mice treated with LT4 or vehicle. (B) Total number of ChAT-positive neurons in control mice, AD11 mice, and AD11 mice treated with different concentrations of LT4. Immunohistochemical study: ChAT-positive neurons in (C) 2-month-old control mice, (D) AD11 untreated mice, and (E) LT4-treated AD11 mice. Hyperphosphorylated tau in (F) 2-month-old control mice, (G) untreated AD11 mice, and (H) LT4-treated AD11 mice. APP expression in (I) 2-month-old control mice, (J) untreated AD11 mice, and (K) LT4-treated AD11 mice. Arrows point to vessels heavily stained by the anti-APP antibody. (Scale bar = 200 μm.)