MAPT and Alzheimer disease: In multiple studies the neuronal loss has been estimated in transgenic AD models (carrying mutated familial AD genes or Tau gene) in brain areas affected in clinical AD especially the hippocampus; in single APP transgenic or double or triple transgenic (APP/PS1 or APP/PS2 or APP/PS1/TAU, etc.)experimental animals a slight to substantial neuronal loss was observed (Schmitz et al., 2004; Wirths and Bayer, 2010; Wirths and Zampar, 2020).