DEVELOPMENT OF FERRITIN-CONTAINING CELLS IN THE PENS AND CEREBELLUM OF THE HUMAN BRAIN

The distribution and development of ferritin-containing cells were studied in the pens and cerebellum of human fetuses up to adults, using an immunohistochemical method. The predominant cell type labeled with antiserum to ferritin in the pens and cerebellum was morphologically oligodendrocytes. In the pens, positive cells appeared at 21 weeks of gestation in the reticular formation, and longitudinal and transverse fibers, and at 25 weeks of gestation in pontine nuclei. They increased with age from 33 weeks to infancy. In the cerebellum, positive cells appeared at 25 weeks of gestation in the cerebellar white matter and granular layer. They increased from 29 to 40 weeks of gestation in the white matter, and to childhood in the granular layer. The time of appearance of positive cells in the pens and cerebellum is earlier than in the cerebrum, like myelination. This development of ferritin-positive glia may be related to maturation of oligodendrocytes as well as being the basis of myelination.