Astrocytes in the postnatal central nervous system. From birth to 14 years of age. An immunohistochemical study on paraffin-embedded material.

The postnatal development of the fibrillary astrocyte in 25 children without any anamnestic or post mortem signs of disease were studied. The investigation was performed on basis of the immunoperoxidase method for glial fibrillary acidic protein (GFAP). The supporting function of the external glial limiting membrane, the glial vascular limiting membrane and the metabolic role of the astrocytes are stressed. During the postnatal myelination of the white matter the immature astrocyte changed into the mature form and a dense fibrous network developed. The radially oriented glial processes of the Bergmann astrocytes of the cerebellum guided the fetal external granular cells during the migration. In the brainstem we found minor variations of the dense fibrous astrocytic network both in children dead after accidents and in sudden infant death syndrome. These findings presumably demonstrate a normal pattern.