Consistent with findings from non-ERC MTL subregions, Aβ—in the absence of tau—induced hyperexcitability in the ERC circuits; however, co-expression of both Aβ and tau moderated the excitatory effects of Aβ on the ERC.52 This is broadly consistent with our findings of increased connectivity in the anterior MTL only during the preclinical stage of Alzheimer’s disease when tau levels are expected to be low. This evidence concerns the gene MAPT and Alzheimer disease.