Glial and neuronal localization of ionotropic glutamate receptor subunit-immunoreactivities in the median eminence of female rats: GluR2/3 and GluR6/7 colocalize with vimentin, not with glial fibrillary acidic protein (GFAP).

Female rat median eminence was immunostained with anti-NR1, GluR1, GluR2/3, GluR6/7, or KA2. GluR2/3- and GluR6/7-immunoreactivities were detected in cells lining the basal portion of the third ventricle. To identify these cells as tanycytes, the median eminence was dual-immunostained with glutamate receptors and glial cytoskeletal marker proteins, such as vimentin or glial fibrillary acidic protein (GFAP). Both GluR2/3 and GluR6/7 were shown to colocalize with vimentin, not with GFAP. These results suggest the potential role for tanycytes in conducting glutamate signaling.