When comparing the immunohistochemical markers used in the brain in AD with those in normal aging, we identified a typical pattern of changes characteristic of AD (Figure 8), observed in most of the studied regions and areas, characterized by an increase in the levels of Drp-1 and Mfn-2 markers and a decrease in the intensity of the Opa-1 marker (Figure 1), which causes a shift in mitochondrial dynamics towards mitochondrial fission (increase in Drp-1 marker) and apparently leads to increased organelle fragmentation and greater susceptibility to oxidative stress [29]. This evidence concerns the gene OPA1 and Alzheimer disease.