Since increased metal content can be a sign of degenerative cellular processes (e.g., cell condensation, apoptosis/necrosis, dystrophic mineralization of cell bodies or ferrugination, hyper-phosphorylation of p-tau fibrils or Fe-trapping by Aβ oligomers), this observation reinforces an interpretation of the neuronal ICHD measured via X-PCI-CT as intracellular protein and metal accumulations due to either neuron aging or to AD-linked neurodegeneration respectively in WT and 3xTgAD animals (more in Suppl. The gene discussed is MAPT; the disease is Alzheimer disease.