MAPT and Neurofibrillary tangles: They found that over-expressing wild-type human tau increases Aβ-plaque size and dystrophic neurite number but it did not cause Aβ-mediated synaptic loss and neuronal loss, while in another study by Umeda et al. [158], wild-type human tau expressing mice with high levels of human Aβ oligomers had neurofibrillary tangle pathology development and synapse loss at much older ages (18 months) which the difference between the result of these two studies can be due to the different ages examined and the role of age in cognitive deficits.