Immunocytochemical development of transferrin and ferritin immunoreactivity in the human pons and cerebellum

The distribution and development of transferrin-positive cells in the pons and cerebellum of human fetuses to adults were examined immunohistochemically, compared with those of ferritin-positive cells. Transferrin was present in oligodendrocytes, astrocytes, and neurons. Transferrin-positive neurons appeared at 18 weeks of gestation in Purkinje cells and the pontine reticular formation. In the pontine nuclei, transferrin-positive neurons appeared at 22 weeks of gestation. On the other hand, transferrin-positive glia also appeared at 18 weeks of gestation in the reticular formation, and at 24 weeks of gestation in the cerebellar white matter and pontine nuclei. Transferrin-positive glia and cells appeared earlier in the reticular formation of the pons than ferritin, but the order of its appearance was similar to that of ferritin and myelination. Because iron is involved in the syntheses and functions of dopamine, serotonin, and gamma-aminobutyric acid (GABA), transferrin may be carried for various iron uses from an early fetal stage.