Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-11-16
pubmed:abstractText
The transient receptor potential (TRP) vanilloid type 1 (TRPV1) agonist, capsaicin, enhances glutamatergic spontaneous excitatory synaptic transmission in CNS neurons. Resiniferatoxin (RTX) has a much higher affinity for TRPV1 than capsaicin, but its ability to modulate excitatory transmission is unclear. We examined the effect of RTX on excitatory transmission using the whole-cell patch-clamp technique in substantia gelatinosa (SG) neurons of adult rat spinal cord slices. Bath-applied RTX dose-dependently increased the frequency, but not the amplitude, of spontaneous excitatory postsynaptic current (sEPSC), independent of its application time. In about a half of the neurons tested, this effect was accompanied by an inward current at -70 mV that was sensitive to glutamate-receptor antagonists. Repeated application of RTX did not affect excitatory transmission. RTX was more potent than capsaicin but showed similar efficacy. RTX activity could be blocked by capsazepine or SB-366791, a TRPV1 antagonist, but not tetrodotoxin, a Na(+)-channel blocker, and could be inhibited by pretreatment with capsaicin but not the TRPA1 agonist, allyl isothiocyanate. RTX enhances the spontaneous release of L-glutamate from nerve terminals with similar efficacy as capsaicin and produces a membrane depolarization by activating TRPV1 in the SG, with fast desensitization and slow recovery from desensitization. These results indicate a mechanism by which RTX can modulate excitatory transmission in SG neurons to regulate nociceptive transmission.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1873-7544
pubmed:author
pubmed:issnType
Electronic
pubmed:day
29
pubmed:volume
164
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1833-44
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Effect of resiniferatoxin on glutamatergic spontaneous excitatory synaptic transmission in substantia gelatinosa neurons of the adult rat spinal cord.
pubmed:affiliation
Department of Physiology, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan.
pubmed:publicationType
Journal Article, In Vitro