Differential expression patterns of three glutamate transporters (GLAST, GLT1 and EAAC1) in the rat main olfactory bulb.
Glutamate is the main neurotransmitter in the olfactory bulb. Therefore, glutamate transporters, which regulate the concentration of extracellular glutamate, might play pivotal roles in odor processing. In this study, we examined expressions of three glutamate transporters (GLAST, GLT1 and EAAC1) in the olfactory bulb using in situ hybridization and immunohistochemistry. EAAC1 mRNA was expressed in neurons, such as periglomerular cells, tufted cells, mitral cells and granule cells as shown before in other brain areas. In contrast, GLAST and GLT1 were found in glial cells throughout the olfactory bulb, with intenser expressions in the glomerular layer, external plexiform layer and internal plexiform layer where glutamatergic synapses are concentrated. In addition, using double staining immunohistochemistry we clearly showed that GLAST and GLT1 were expressed in astrocytes. Furthermore, we found that GLAST was also intensely expressed in the subependymal layer where precursor cells exist. These results suggest each glutamate transporter plays its unique role not only in glutamatergic neurotransmission but also in cell differentiation and migration in the olfactory bulb.
Utsumi
M
M
Department of Anatomy & Neuroscience, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Ohno
K
K
Onchi
H
H
Sato
K
K
Tohyama
M
M
D027322:Amino Acid Transport System X-AG / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation; D002465:Cell Movement; D027341:Excitatory Amino Acid Transporter 1; D027342:Excitatory Amino Acid Transporter 2 / Q000096:biosynthesis* / Q000235:genetics; D050580:Excitatory Amino Acid Transporter 3; D020869:Gene Expression Profiling; D050491:Glutamate Plasma Membrane Transport Proteins; D018698:Glutamic Acid / Q000502:physiology; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism*; D018034:Olfactory Receptor Neurons / Q000378:metabolism; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000378:metabolism; D027981:Symporters
D027322:Amino Acid Transport System X-AG; D002352:Carrier Proteins; D027341:Excitatory Amino Acid Transporter 1; D027342:Excitatory Amino Acid Transporter 2; D050580:Excitatory Amino Acid Transporter 3; D050491:Glutamate Plasma Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C493398:Slc1a1 protein, rat; C493392:Slc1a3 protein, rat; D027981:Symporters; D018698:Glutamic Acid