MAPT and tauopathy: Our own experiments were conducted in PS19 mice, a widely used model of tauopathy that exhibits neuronal loss and NFT-like phosphorylated tau inclusions;23 the timing of the appearance of NFTs depends on the genetic background of the mouse and its rearing environment.36 Under our conditions, 6-month-old PS19 mice show impaired path integration, accompanied by abundant AT8-positive neurons in the EC.