QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gundersen, V. Articles by Storm-Mathisen, J. Search for Related Content PubMed PubMed Citation Articles by Gundersen, V. Articles by Storm-Mathisen, J.

 Previous Article  |  Next Article 

Journal of Neuroscience, Vol 15, 4417-4428, Copyright © 1995 by Society for Neuroscience

ARTICLE

Quantification of excitatory amino acid uptake at intact glutamatergic synapses by immunocytochemistry of exogenous D-aspartate

V Gundersen, O Shupliakov, L Brodin, OP Ottersen and J Storm-Mathisen
Anatomical Institute, University of Oslo, Blindern, Norway.

To study the localization and efficiency of glutamate/aspartate membrane transport in the vicinity of intact glutamatergic synapses, the avascular lamprey spinal cord was incubated with D-aspartate, a metabolically inert transporter substrate. The exogenous D-aspartate was localized by immunocytochemistry after aldehyde fixation. Incubation at 50 or 500 microM D-aspartate for 1 hr caused a prominent D-aspartate labeling of glial processes at glutamatergic synapses, while presynaptic axons and postsynaptic dendrites remained unlabeled. The glial processes surrounding glutamatergic sensory axons with a predominantly tonical firing pattern contained significantly higher levels of D-aspartate than did processes surrounding glutamatergic reticulospinal axons, which fire rarely and in brief bursts. Preparations incubated for 10 hr with 500 microM D-aspartate showed D- aspartate immunolabeling in glia as well as in the two types of glutamatergic axon, but no evidence was obtained for uptake into synaptic vesicles. Nor was such evidence obtained after high-frequency electrical stimulation. The observations suggest that excitatory amino acids delivered diffusely to the extracellular space in the intact CNS are transported almost exclusively into glia. The avid uptake in glial processes, combined with their spatial arrangement around glutamatergic synapses, appears to limit the access of exogenous D-aspartate to the nerve terminal glutamate/aspartate transporter. In physiological conditions, the glial processes are likely to impede the exchange of glutamate between the synaptic cleft and the rest of the extracellular space. The transport was more efficient in glial processes located near tonically active synapses than in ones located near synapses releasing transmitter sporadically. D-Aspartate is not a substrate of vesicular glutamate transport sites at these intact synapses.

This article has been cited by other articles:

				M. Martire, P. Castaldo, M. D'Amico, P. Preziosi, L. Annunziato, and M. Taglialatela M Channels Containing KCNQ2 Subunits Modulate Norepinephrine, Aspartate, and GABA Release from Hippocampal Nerve Terminals J. Neurosci., January 21, 2004; 24(3): 592 - 597. [Abstract] [Full Text] [PDF]

				W. Chen, C. Aoki, V. Mahadomrongkul, C. E. Gruber, G. J. Wang, R. Blitzblau, N. Irwin, and P. A. Rosenberg Expression of a Variant Form of the Glutamate Transporter GLT1 in Neuronal Cultures and in Neurons and Astrocytes in the Rat Brain J. Neurosci., March 15, 2002; 22(6): 2142 - 2152. [Abstract] [Full Text] [PDF]

				J. C. Rekling, G. D. Funk, D. A. Bayliss, X.-W. Dong, and J. L. Feldman Synaptic Control of Motoneuronal Excitability Physiol Rev, April 1, 2000; 80(2): 767 - 852. [Abstract] [Full Text] [PDF]

				J. Masson, C. Sagne, M. Hamon, and S. E. Mestikawy Neurotransmitter Transporters in the Central Nervous System Pharmacol. Rev., September 1, 1999; 51(3): 439 - 464. [Abstract] [Full Text] [PDF]

				R. Ventura and K. M. Harris Three-Dimensional Relationships between Hippocampal Synapses and Astrocytes J. Neurosci., August 15, 1999; 19(16): 6897 - 6906. [Abstract] [Full Text] [PDF]

				V. Gundersen, F. A. Chaudhry, J. G. Bjaalie, F. Fonnum, O. P. Ottersen, and J. Storm-Mathisen Synaptic Vesicular Localization and Exocytosis of L-Aspartate in Excitatory Nerve Terminals: A Quantitative Immunogold Analysis in Rat Hippocampus J. Neurosci., August 15, 1998; 18(16): 6059 - 6070. [Abstract] [Full Text] [PDF]

				E. Masliah, J. Raber, M. Alford, M. Mallory, M. P. Mattson, D. Yang, D. Wong, and L. Mucke Amyloid Protein Precursor Stimulates Excitatory Amino Acid Transport. IMPLICATIONS FOR ROLES IN NEUROPROTECTION AND PATHOGENESIS J. Biol. Chem., May 15, 1998; 273(20): 12548 - 12554. [Abstract] [Full Text] [PDF]

				C. D. Weaver, V. Gundersen, and T. A. Verdoorn A High Affinity Glutamate/Aspartate Transport System in Pancreatic Islets of Langerhans Modulates Glucose-stimulated Insulin Secretion J. Biol. Chem., January 16, 1998; 273(3): 1647 - 1653. [Abstract] [Full Text] [PDF]

				O. Shupliakov, P. Löw, D. Grabs, H. Gad, H. Chen, C. David, K. Takei, P. De Camilli, and L. Brodin Synaptic Vesicle Endocytosis Impaired by Disruption of Dynamin-SH3 Domain Interactions Science, April 11, 1997; 276(5310): 259 - 263. [Abstract] [Full Text]

				D. Schachter and J. C. Sang Aortic leucine-to-glutamate pathway: metabolic route and regulation of contractile responses Am J Physiol Heart Circ Physiol, March 1, 2002; 282(3): H1135 - H1148. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help