VR1-, VRL-1- and P2X3 receptor-immunoreactive innervation of the rat temporomandibular joint

H. Ichikawa, T. Fukunaga, H. W. Jin, Masako Fujita, T. Takano-Yamamoto, T. Sugimoto

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

Immunohistochemistry for vanilloid receptor subtype 1 (VR1), vanilloid receptor 1-like receptor (VRL-1) and P2X3 receptor was performed in the rat temporomandibular joint (TMJ). Blood vessels in the articular disk and capsule, the synovial membrane and the fibrous tissue around the condylar process were innervated by VR1- or P2X3 receptor-immunoreactive (ir) nerve fibers. However, VRL-1-immunoreactivity (ir) could not be detected in the TMJ. Retrograde tracing and immunohistochemical methods revealed that 25%, 41% and 52% of TMJ neurons in the trigeminal ganglion (TG) exhibited VR1-, VRL-1- and P2X3 receptor-ir, respectively. VR1-ir TMJ neurons were mostly small to medium-sized, whereas VRL-1- and P2X3 receptor-ir TMJ neurons were predominantly medium-sized to large. In addition, 73%, 28% and 44% of VR1-, VRL-1- and P2X3 receptor-ir TMJ neurons, respectively, coexpressed calcitonin gene-related peptide (CGRP)-ir. The present study suggests that the TMJ has abundant nociceptors which respond to vanilloid compounds, protons, heat and extracellular ATP.

Original languageEnglish
Pages (from-to)131-136
Number of pages6
JournalBrain Research
Volume1008
Issue number1
DOIs
Publication statusPublished - May 15 2004

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Keywords

  • Immunohistochemistry
  • P2X3
  • Sensory systems
  • Somatic and visceral afferents
  • Temporomandibular joint
  • Trigeminal ganglion
  • VR1
  • VRL-1

ASJC Scopus subject areas

  • Neuroscience(all)

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