The glutamate transporter, GLT-1, is expressed in cultured hippocampal neurons.
There are multiple subtypes of Na+-dependent glutamate transporters. Several studies suggest that EAAC1 and EAAT4 are expressed in neurons, while GLT-1 and GLAST expression is thought to be restricted to glia. In the present study, expression of GLT-1 and EAAC1 was examined in cultured rat hippocampal neurons using single cell mRNA amplification and immunocytochemistry with subtype specific antibodies. GLT-1 and EAAC1 mRNAs were observed in all neurons examined. Neuronal phenotype was confirmed in these cells by expression of neurofilament (NF-L) mRNA and absence of glial fibrillary acidic protein (GFAP) mRNA. EAAC1 immunoreactivity was observed in essentially all cells which expressed neuron specific enolase (NSE) and GLT-1 immunoreactivity was detected in the majority (approximately 90%) of NSE-positive cells. Consistent with the glial expression of GLT-1, GLT-1 immunoreactivity was also observed in NSE-negative cells. These studies provide evidence that GLT-1 expression is not intrinsically restricted to glial cells, but can occur in neurons under certain circumstances.
Department of Neurology, Children's Hospital of Philadelphia, Children's Seashore House, University of Pennsylvania, 19104, USA. kayal@email.chop.edu
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Brooks-Kayal
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Munir
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Jin
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Robinson
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D027322:Amino Acid Transport System X-AG; D000818:Animals; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D006624:Hippocampus / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats
D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger