LOCALIZATION OF NEURONAL AND GLIAL GLUTAMATE TRANSPORTERS

The cellular and subcellular distributions of the glutamate transporte r subtypes EAAC1, GLT-1, and GLAST in the rat CNS were demonstrated us ing anti-peptide antibodies that recognize the C-terminal domains of e ach transporter. On immunoblots, the antibodies specifically recognize proteins of 65-73 kDa in total brain homogenates, Immunocytochemistry shows that glutamate transporter subtypes are distributed differentia lly within neurons and astroglia. EAAC1 is specific for certain neuron s, such as large pyramidal cortical neurons and Purkinje cells, but do es not appear to be selective for glutamatergic neurons. GLT-1 is loca lized only to astroglia. GLAST is found in both neurons and astroglia. The regional localizations are unique to each transporter subtype. EA AC1 is highly enriched in the cortex, hippocampus, and caudate-putamen and is confined to pre- and postsynaptic elements. GLT-1 is distribut ed in astrocytes throughout the brain and spinal cord. CLAST is most a bundant in Bergmann glia in the cerebellar molecular layer brain, but is also present in the cortex, hippocampus, and deep cerebellar nuclei .