Autoradiographic analysis of sulfate metabolism in the cerebellum of the mouse

The metabolism of ³⁵S]sulfate in the cerebellum of young adult mice was studied by autoradiography. Labeled sulfate was concentrated in the cytoplasma near the nucleus of capillary endothelial cells, Bergmann glia, oligodendroglia, and Purkinje cells. A few neurons in the granular layer took up small amounts of radiosulfate. Utilization of inorganic sulfate by other cerebellar cells, with the possible exception of astrocytes, was negligible. This measns that production of sulfate materials in the cerebellum is not specifically a glial or neuronal function, but is a characteristic of certain glial cells and certain neurons, as well as the cells which line the capillary bed.

The sulfated compounds did not remain where they were produced. Instead, they were redistributed throughout all the layers of the cerebellum. Oligodendroglia deposited sulfated material in myelin, presumably in the form of sulfated lipids (sulfatides). In Purkinje cells the radioactive material (probably sulfated mucopolysaccharide) spread into the dendrites which ramify in the molecular layer. This indicates that the process of cytoplasmic flow occurs in dendrites as well as axons. Part of the labeling of the molecular layer could be accounted for by assuming a comparable process of cytoplasmic flow in the Bergmann glia.