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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
2
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pubmed:dateCreated |
2009-3-3
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pubmed:abstractText |
The tetrodotoxin-resistant (TTX-R) voltage-gated Na(+) channels Na(v)1.8 and Na(v)1.9 are expressed by a subset of primary sensory neurons and have been implicated in various pain states. Although recent studies suggest involvement of TTX-R Na(+) channels in sensory synaptic transmission and spinal pain processing, it remains unknown whether TTX-R Na(+) channels are expressed and function presynaptically. We examined expression of TTX-R channels at sensory synapses formed between rat dorsal root ganglion (DRG) and spinal cord (SC) neurons in a DRG/SC co-culture system. Immunostaining showed extensive labeling of presynaptic axonal boutons with Na(v)1.8- and Na(v)1.9-specific antibodies. Measurements using the fluorescent Na(+) indicator SBFI demonstrated action potential-induced presynaptic Na(+) entry that was resistant to tetrodotoxin (TTX) but was blocked by lidocaine. Furthermore, presynaptic [Ca(2+)](i) elevation in response to a single action potential was not affected by TTX in TTX-resistant DRG neurons. Finally, glutamatergic synaptic transmission was not inhibited by TTX in more than 50% of synaptic pairs examined; subsequent treatment with lidocaine completely blocked these TTX-resistant excitatory postsynaptic currents. Taken together, these results provide evidence for presynaptic expression of functional TTX-R Na(+) channels that may be important for shaping presynaptic action potentials and regulating transmitter release at the first sensory synapse.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Anesthetics, Local,
http://linkedlifedata.com/resource/pubmed/chemical/Benzofurans,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Dlgh4 protein, rat,
http://linkedlifedata.com/resource/pubmed/chemical/Ethers, Cyclic,
http://linkedlifedata.com/resource/pubmed/chemical/Intracellular Signaling Peptides...,
http://linkedlifedata.com/resource/pubmed/chemical/Lidocaine,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Nerve Tissue Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Neuropeptides,
http://linkedlifedata.com/resource/pubmed/chemical/Scn11a protein, rat,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Tetrodotoxin,
http://linkedlifedata.com/resource/pubmed/chemical/sensory neuron specific (SNS)...,
http://linkedlifedata.com/resource/pubmed/chemical/sodium-binding benzofuran...
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0306-4522
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
17
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pubmed:volume |
159
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
559-69
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pubmed:dateRevised |
2010-8-16
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pubmed:meshHeading |
pubmed-meshheading:19162133-Action Potentials,
pubmed-meshheading:19162133-Anesthetics, Local,
pubmed-meshheading:19162133-Animals,
pubmed-meshheading:19162133-Animals, Newborn,
pubmed-meshheading:19162133-Benzofurans,
pubmed-meshheading:19162133-Biophysics,
pubmed-meshheading:19162133-Calcium,
pubmed-meshheading:19162133-Cells, Cultured,
pubmed-meshheading:19162133-Coculture Techniques,
pubmed-meshheading:19162133-Electric Stimulation,
pubmed-meshheading:19162133-Ethers, Cyclic,
pubmed-meshheading:19162133-Extracellular Fluid,
pubmed-meshheading:19162133-Ganglia, Spinal,
pubmed-meshheading:19162133-Intracellular Signaling Peptides and Proteins,
pubmed-meshheading:19162133-Ion Channel Gating,
pubmed-meshheading:19162133-Lidocaine,
pubmed-meshheading:19162133-Membrane Proteins,
pubmed-meshheading:19162133-Nerve Tissue Proteins,
pubmed-meshheading:19162133-Neuropeptides,
pubmed-meshheading:19162133-Patch-Clamp Techniques,
pubmed-meshheading:19162133-Presynaptic Terminals,
pubmed-meshheading:19162133-Rats,
pubmed-meshheading:19162133-Rats, Sprague-Dawley,
pubmed-meshheading:19162133-Sensory Receptor Cells,
pubmed-meshheading:19162133-Sodium,
pubmed-meshheading:19162133-Sodium Channel Blockers,
pubmed-meshheading:19162133-Sodium Channels,
pubmed-meshheading:19162133-Spinal Cord,
pubmed-meshheading:19162133-Synapses,
pubmed-meshheading:19162133-Tetrodotoxin
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pubmed:year |
2009
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pubmed:articleTitle |
Functional tetrodotoxin-resistant Na(+) channels are expressed presynaptically in rat dorsal root ganglia neurons.
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pubmed:affiliation |
Department of Pharmacology, University of Iowa, Carver College of Medicine, 2-250 BSB, 51 Newton Road, Iowa City, IA 52242, USA.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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