Abstract
Low extracellular glutamate content is maintained primarily by high- affinity sodium-dependent glutamate transport. Three glutamate transporter proteins have been cloned: GLT-1 and GLAST are astroglial, whereas EAAC1 is neuronal. The effects of axotomy on glutamate transporter expression was evaluated in adult rats following unilateral fimbria-fornix and corticostriatal lesions. The hippocampus and striatum were collected at 3, 7, 14, and 30 days postlesion. Homogenates were immunoblotted using antibodies directed against GLT-1, GLAST, EAAC1, and glial fibrillary acidic protein and assayed for glutamate transport by D-[3H]aspartate binding, GLT-1 immunoreactivity was decreased within the ipsilateral hippocampus and striatum at 14 days postlesion. GLAST immunoreactivity was decreased within the ipsilateral hippocampus and striatum at 7 and 14 days postlesion. No alterations in EAAC1 immunoreactivity were observed. D-[3H]Aspartate binding was decreased at 14 days postlesion within the ipsilateral hippocampus and at 7 and 14 days postlesion within the ipsilateral striatum. By 30 days postlesion, glutamate transporters and D-[3H]aspartate binding returned to control levels. This study demonstrates the down-regulation of primarily glial, and not neuronal, glutamate transporters following regional disconnection.
Original language | English (US) |
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Pages (from-to) | 2800-2803 |
Number of pages | 4 |
Journal | Journal of Neurochemistry |
Volume | 65 |
Issue number | 6 |
State | Published - Dec 1995 |
Keywords
- Corticostriatal pathway
- EAAC1
- Fimbria-fornix
- GLAST
- GLT-1
- Glutamate transporter
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Biochemistry