Potentiation of rabbit trigeminal responses to capsaicin in a low pH environment

Melissa E. Martenson, Susan Ingram, Thomas K. Baumann

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

The sensitivity of 35 adult rabbit trigeminal ganglion neurons to low pH (pH 6.0), 10 μM capsaicin (CAP) and 10 μM capsaicin at low pH (CAP@pH6.0) was studied using voltage-clamp whole-cell recording techniques. Neurons responded to pH 6.0 with a transient inward current, followed by a more slowlt activating (sustained) net inward current. Responses to capsaicin showed only a sustained current. Capsaicin caused an increase in membrane conductance, whereas responses to low pH were associated with either a net increase or decrease in conductance. A subset of neurons (n = 14) responded to CAP@pH6.0 with a sustained current which exceeded the sum of the peak sustained currents evoked by CAP and pH 6.0 applied singularly by approximately a factor of 4. The current was associated with a substantial increase in membrane conductance. The present results indicate that, in addition to a direct conductance activating effect, protons have the ability to enhance the current evoked by capsaicin.

Original languageEnglish (US)
Pages (from-to)143-147
Number of pages5
JournalBrain Research
Volume651
Issue number1-2
DOIs
Publication statusPublished - Jul 18 1994

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Keywords

  • Capsaicin
  • Chemosensitivity
  • Irritant
  • Neuron
  • Patch clamp
  • Proton
  • Sensitization
  • Somatosensory

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

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