Ultrastructural changes in the frontal cortex and hippocampus in the ageing marmoset

The ultrastructure of the cells and capillaries of the frontal cortex and hippocampus was studied in marmosets to assess age-related changes. The appearances in the brains of four marmosets, more than 12 years of age, were compared with those of two young marmosets aged 26 and 21 months. There was widespread accumulation of lipofuscin in neurons, glial cells, perivascular macrophages and pericytes, but not in endothelial cells. Many of the nerve cell nuclei showed marked membrane infolding, alteration of nuclear morphology and occasional inclusions. A few degenerated and dystrophic axons containing abnormal organelles were seen. The capillaries displayed irregularly thickened and split basal laminae. No neurofibrillary tangles, neuritic plaques, amyloid deposits or granulovacuoles were present. These changes are compared to those occurring in other animal species and in man during ageing.