Abstract
We have examined the potential role of spinal glial cells in the induction of C fiber-evoked long-term potentiation (LTP) in the spinal cord. Tetanic stimulation of the sciatic nerve induced longterm potentiation of C-fiber-evoked field potentials in the spinal dorsal horn in all rats. Following intrathecal fluorocitrate (1 nmol), a glial metabolic inhibitor, tetanic stimulation induced longterm depression (LTD) but not LTP. The effects of fluorocitrate were abolished by kynurenic acid or 2-amino-5-phosphonovaleric acid (AP-5), but not by 6,7-dinitroquinoxaline-2,3-dione (DNQX), picrotoxin or strychnine. These data suggest that spinal glial cells may modulate the central sensitization of nociceptive neurons via NMDA receptors.
Copyright 2002 Lippincott Williams & Wilkins
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Action Potentials / drug effects
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Action Potentials / physiology
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Animals
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Citrates / pharmacology
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Electric Stimulation
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Excitatory Amino Acid Antagonists / pharmacology
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Long-Term Potentiation / drug effects
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Long-Term Potentiation / physiology*
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Long-Term Synaptic Depression / drug effects
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Long-Term Synaptic Depression / physiology
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Male
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Nerve Fibers, Unmyelinated / drug effects
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Nerve Fibers, Unmyelinated / physiology*
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Neuroglia / drug effects
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Neuroglia / physiology*
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Nociceptors / drug effects
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Nociceptors / physiology*
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Pain / physiopathology*
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Posterior Horn Cells / drug effects
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Posterior Horn Cells / physiology*
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Rats
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Rats, Sprague-Dawley
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Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
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Receptors, N-Methyl-D-Aspartate / metabolism
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Sciatic Nerve / drug effects
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Sciatic Nerve / physiology
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Synaptic Transmission / drug effects
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Synaptic Transmission / physiology*
Substances
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Citrates
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Excitatory Amino Acid Antagonists
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Receptors, N-Methyl-D-Aspartate
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fluorocitrate