Other similar studies using AD animal models (APP-knockout mice, 3xTg-AD mice, and JNPL3 tauopathy mice) have revealed axonal transport disorders in the brain prior to the formation of Aβ plaques (2, 109), and the axonal transport of Mn2+ decreases with the pathological increase in the levels of the tau protein (110). This evidence concerns the gene MAPT and Alzheimer disease.