Previous studies have shown widespread amyloid but not tau pathology at 6 months of age in the hippocampus [3, 12, 13, 17], and behavioral studies using the Morris Water Maze have demonstrated memory retention deficits dependent upon the appearance of amyloid pathology at 6- but not 2-month-old 3xTg-AD mice [11]. This evidence concerns the gene MAPT and Alzheimer disease.