Histochemistry of glutamate metabolizing enzymes in the rat cerebellar cortex

Applying catalytic enzyme histochemistry, glutamate dehydrogenase (GDH) and phosphate activated glutaminase (PAG) were demonstrated at the light microscopic level, and aspartate aminotransferase (AAT) was detected at the electron microscopic level. GDH staining appeared preferentially in glial cells (Bergmann glia and astrocytes), whereas AAT was localized only in neuronal structures. Cytoplasmic AAT was demonstrated in the perikarya and terminal plexus of basket cells, in the perikarya of stellate cells, in about 60% of the granule cells, in mossy fiber boutons, in numerous small boutons in the molecular layer, and in the axoplasm of numerous myelinated and unmyelinated fibers. PAG was observed in both neuronal structures (perikarya of granule and Purkinje cells) and in astrocytes and Bergmann glia.