Localization of the glutamate transporter GLT-1 in rat and macaque monkey retinae

Antibodies directed against a glutamate transporter (GLT-1) purified from rat brain were applied to cryostat sections of rat and macaque monkey retinae. In the brain, GLT-1 expression is found mainly in astrocytes, and therefore it has been suggested that GLT-1 may be a glutamate transporter specific to glial cells. However, in the rat retina, cones and two distinct cone bipolar cell types were strongly immunoreactive. In the monkey retina, flat midget bipolars and one diffuse bipolar cell type (DB2)), were found to be labelled. Müller cells or astrocytes, the neuroglial cells of rat and monkey retinae, were not GLT-1-immunoreactive.