A. Brain lysates from 15, 18, 21, and 24 month old female Fyn+/+3xTg+/− and Fyn+/−3xTg+/− mice were Western blotted for Fyn. Female Fyn+/−3xTg+/− mice showed a 34% decrease at 15 months (p<0.001), a 39% decrease at 18 months (p<0.05), a 60% decrease at 21 months (p<0.01), and a non-significant decrease at 24 months. B. 18, 21, and 24 month old male Fyn+/+3xTg+/− and Fyn+/− 3xTg+/− mice were Western blotted for Fyn. Fyn+/−3xTg+/− mice had a 74% decrease in Fyn levels at 18 months (p<0.001), a 56% decrease at 21 months (p<0.05), and a 55% decrease at 24 months (p<0.01).