Histochemical and ultrastructural study of the human pineal gland in the course of aging.

A histochemical and ultrastructural study was carried out on the pineal gland of 2 day- to 86-year-old subjects. Specimens were obtained by stereotaxis in the course of neurosurgery; other specimens were autoptical pineal fragments. Histochemical and ultrastructural analyses showed lipofuscin pigments, frequently localized in the proximity of blood capillaries and of cytoplasmic microacervuli. The brain sand amount does not appear to be age-related because microacervuli are barely present or frequently absent in the oldest subjects. Its involvement in the secretory activity rather than in gland atrophy is also suggested. The close relationship between cytoplasmic microacervuli and intermediate filaments suggests a possible role of the cytoskeleton in the formation of the brain sand.