| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
The Journal of Neurophysiology Vol. 83 No. 5 May 2000, pp. 2835-2843
Copyright ©2000 by the American Physiological Society
Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201
Diamond, Jeffrey S. and
Craig E. Jahr.
Synaptically Released Glutamate Does Not Overwhelm Transporters
on Hippocampal Astrocytes During High-Frequency Stimulation. J. Neurophysiol. 83: 2835-2843, 2000. In
addition to maintaining the extracellular glutamate concentration at
low ambient levels, high-affinity glutamate transporters play a direct
role in synaptic transmission by speeding the clearance of glutamate
from the synaptic cleft and limiting the extent to which transmitter
spills over between synapses. Transporters are expressed in both
neurons and glia, but glial transporters are likely to play the major
role in removing synaptically released glutamate from the extracellular
space. The role of transporters in synaptic transmission has been
studied directly by measuring synaptically activated,
transporter-mediated currents (STCs) in neurons and astrocytes. Here we
record from astrocytes in the CA1 region of hippocampal slices and
elicit STCs with high-frequency (100 Hz) stimulus trains of varying
length to determine whether transporters are overwhelmed by stimuli
that induce long-term potentiation. We show that, at near-physiological
temperatures (34°C), high-frequency stimulation (HFS) does not affect
the rate at which transporters clear glutamate from the extrasynaptic
space. Thus, although spillover between synapses during "normal"
stimulation may compromise the absolute synapse specificity of fast
excitatory synaptic transmission, spillover is not exacerbated during
HFS. Transporter capacity is diminished somewhat at room temperature (24°C), although transmitter released during brief, "theta burst" stimulation is still cleared as quickly as following a single stimulus,
even when transport capacity is partially diminished by pharmacological means.
This article has been cited by other articles:
|
|
 |
|
  K. Zheng, A. Scimemi, and D. A. Rusakov Receptor Actions of Synaptically Released Glutamate: The Role of Transporters on the Scale from Nanometers to Microns Biophys. J., November 15, 2008; 95(10): 4584 - 4596. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. C. Harney, D. E. Jane, and R. Anwyl Extrasynaptic NR2D-Containing NMDARs Are Recruited to the Synapse during LTP of NMDAR-EPSCs J. Neurosci., November 5, 2008; 28(45): 11685 - 11694. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Hires, Y. Zhu, and R. Y. Tsien Optical measurement of synaptic glutamate spillover and reuptake by linker optimized glutamate-sensitive fluorescent reporters PNAS, March 18, 2008; 105(11): 4411 - 4416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Djukic, K. B. Casper, B. D. Philpot, L.-S. Chin, and K. D. McCarthy Conditional Knock-Out of Kir4.1 Leads to Glial Membrane Depolarization, Inhibition of Potassium and Glutamate Uptake, and Enhanced Short-Term Synaptic Potentiation J. Neurosci., October 17, 2007; 27(42): 11354 - 11365. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Z. Harris and D. L. Pettit Extrasynaptic and synaptic NMDA receptors form stable and uniform pools in rat hippocampal slices J. Physiol., October 15, 2007; 584(2): 509 - 519. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Herman and C. E. Jahr Extracellular Glutamate Concentration in Hippocampal Slice J. Neurosci., September 5, 2007; 27(36): 9736 - 9741. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Gebhardt and S. G. Cull-Candy Influence of agonist concentration on AMPA and kainate channels in CA1 pyramidal cells in rat hippocampal slices J. Physiol., June 1, 2006; 573(2): 371 - 394. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Ennis, M. Zhu, T. Heinbockel, and A. Hayar Olfactory Nerve-Evoked, Metabotropic Glutamate Receptor-Mediated Synaptic Responses in Rat Olfactory Bulb Mitral Cells J Neurophysiol, April 1, 2006; 95(4): 2233 - 2241. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Christie and C. E. Jahr Multivesicular Release at Schaffer Collateral-CA1 Hippocampal Synapses J. Neurosci., January 4, 2006; 26(1): 210 - 216. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Rusakov, F. Saitow, K. P. Lehre, and S. Konishi Modulation of Presynaptic Ca2+ Entry by AMPA Receptors at Individual GABAergic Synapses in the Cerebellum J. Neurosci., May 18, 2005; 25(20): 4930 - 4940. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Wang and M. W. Quick Trafficking of the Plasma Membrane {gamma}-Aminobutyric Acid Transporter GAT1: SIZE AND RATES OF AN ACUTELY RECYCLING POOL J. Biol. Chem., May 13, 2005; 280(19): 18703 - 18709. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Diamond Deriving the Glutamate Clearance Time Course from Transporter Currents in CA1 Hippocampal Astrocytes: Transmitter Uptake Gets Faster during Development J. Neurosci., March 16, 2005; 25(11): 2906 - 2916. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. K. Bekar, M. E. Loewen, K. Cao, X. Sun, J. Leis, R. Wang, G. W. Forsyth, and W. Walz Complex Expression and Localization of Inactivating Kv Channels in Cultured Hippocampal Astrocytes J Neurophysiol, March 1, 2005; 93(3): 1699 - 1709. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Huang, L. Barakat, D. Wang, and A. Bordey Bergmann glial GlyT1 mediates glycine uptake and release in mouse cerebellar slices J. Physiol., November 1, 2004; 560(3): 721 - 736. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Khabour, J. Levenson, L. C. Lyons, L. S. Kategaya, J. Chin, J. H. Byrne, and A. Eskin Coregulation of Glutamate Uptake and Long-Term Sensitization in Aplysia J. Neurosci., October 6, 2004; 24(40): 8829 - 8837. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. H. Huang, S. R. Sinha, K. Tanaka, J. D. Rothstein, and D. E. Bergles Astrocyte Glutamate Transporters Regulate Metabotropic Glutamate Receptor-Mediated Excitation of Hippocampal Interneurons J. Neurosci., May 12, 2004; 24(19): 4551 - 4559. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. A. Fiacco and K. D. McCarthy Intracellular Astrocyte Calcium Waves In Situ Increase the Frequency of Spontaneous AMPA Receptor Currents in CA1 Pyramidal Neurons J. Neurosci., January 21, 2004; 24(3): 722 - 732. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. C. Mathews and J. S. Diamond Neuronal Glutamate Uptake Contributes to GABA Synthesis and Inhibitory Synaptic Strength J. Neurosci., March 15, 2003; 23(6): 2040 - 2048. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Reichelt and T. Knopfel Glutamate Uptake Controls Expression of a Slow Postsynaptic Current Mediated by mGluRs in Cerebellar Purkinje Cells J Neurophysiol, April 1, 2002; 87(4): 1974 - 1980. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Diamond Neuronal Glutamate Transporters Limit Activation of NMDA Receptors by Neurotransmitter Spillover on CA1 Pyramidal Cells J. Neurosci., November 1, 2001; 21(21): 8328 - 8338. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Zhou and H. K. Kimelberg Freshly Isolated Hippocampal CA1 Astrocytes Comprise Two Populations Differing in Glutamate Transporter and AMPA Receptor Expression J. Neurosci., October 15, 2001; 21(20): 7901 - 7908. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Barbour An Evaluation of Synapse Independence J. Neurosci., October 15, 2001; 21(20): 7969 - 7984. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. L. Kidd and J. T. R. Isaac Kinetics and Activation of Postsynaptic Kainate Receptors at Thalamocortical Synapses: Role of Glutamate Clearance J Neurophysiol, September 1, 2001; 86(3): 1139 - 1148. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
