2024-03-28T14:30:27Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/517502023-01-19T03:10:04Zhdl_2115_20040hdl_2115_121Glutamate transporter GLT-1 is transiently localized on growing axons of the mouse spinal cord before establishing astrocytic expression.Yamada, K.Watanabe, M.Shibata, T.Nagashima, M.Tanaka, K.Inoue, Y.ATP-Binding Cassette Transporters/analysisAmino Acid SequenceAmino Acid Transport System X-AGAnimalsAntibody FormationAstrocytes/chemistryAxons/chemistryBiological Transport/physiologyEmbryonic and Fetal Development/physiologyImmunohistochemistryIn Situ HybridizationMiceMice, Inbred C57BLMolecular Sequence DataNerve Tissue Proteins/analysisNeurons/chemistryNeurons/ultrastructureSpinal Cord/chemistrySpinal Cord/embryologySpinal Cord/growth & developmentTime FactorsThe glutamate transporter GLT-1 is expressed in astrocytes of the mature brain and spinal cord. In the present study, we examined its expression in the developing mouse spinal cord. By in situ hybridization, 35S-labeled antisense oligonucleotide probes for GLT-1 mRNA consistently labeled the mantle zone/gray matter from embryonic day 11 through the adult stage. However, immunohistochemistry with a specific antibody visualized distinct regional and cellular localizations during the time between the fetal and postnatal stages. At fetal stages, GLT-1 immunoreactivity predominated in the marginal zone/white matter, observed as tiny puncta in cross-sections and as thin fibers in longitudinal sections. The GLT-1-immunopositive structures were also labeled for neuron-specific enolase, a glycolytic enzyme specific to postmitotic neurons and endocrine cells. By electron microscopy, GLT-1 immunoreactivity was detected in axons forming frequent enlargements and was focally localized on a small portion of the axolemma, particularly that facing adjacent axons. At early postnatal stages, GLT-1 disappeared from axons in white matter tracts and, instead, appeared in astrocytic processes surrounding various neuronal elements in the gray matter. Therefore, before switching to astrocytic expression, GLT-1 is transiently expressed in neurons and localized in differentiating axons. Together with our previous finding on the localization of glutamate transporter GLAST in radial glial fibers, GLT-1 and GLAST are thus localized during development on distinct directional cellular elements along which young neurons elongate their axons or move their cell bodies, respectively.Society for NeuroscienceJournal Articleapplication/pdfhttp://hdl.handle.net/2115/51750https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/51750/1/JN18-15_5706-5713.pdf0270-6474The Journal of neuroscience : the official journal of the Society for Neuroscience1815570657131998-08-01enginfo:pmid/9671661info:doi/10.1523/JNEUROSCI.18-15-05706.1998publisher