The deposits of hippocampal tau are considered critical in cognitive decline because they are at the crossroad in the spread of pathogenic tau aggregates, from early deposits in transentorhinal cortex (Braak stages I–II) to major projections to the hippocampus where tau pathology gradually occurs in the CA1 region (Braak II), followed by spread to the limbic structures, inferior temporal neocortex (Braak III), the amygdala and thalamus (Braak IV), and finally propagation into the neocortex (Braak V–VI) [38,40]. Here, MAPT is linked to Mental deterioration.