Developmental immunohistochemistry of bifunctional protein in human brain

Immunohistochemical studies of a peroxisomal enzyme, bifunctional protein, were performed on human brains (occipital cortex, cerebellum, pons) from fetus to young adult. Bifunctional protein-positive neurons appeared at 23-25 weeks of gestation in the facial nuclei of pons, at 27-28 weeks in the occipital cortex and Purkinje cells of vermis, and at 36-38 weeks in the Purkinje cells of the cerebellar hemisphere and pontine nuclei. They then increased in number with gestational age. However, bifunctional protein-positive glia appeared early in the occipital deep white matter at 17-20 weeks of gestation, their appearance shifting from the deep to the superficial white matter with increasing age. These results suggest that bifunctional protein is closely related to neuronal maturation and gliogenesis of premyelination in the human brain during development as other peroxisomal enzymes.