VR1-immunoreactive primary sensory neurons in the rat trigeminal ganglion

Brain Res. 2001 Jan 26;890(1):184-8. doi: 10.1016/s0006-8993(00)03253-4.


Immunohistochemistry for VR1, a nociceptive transducer for vanilloid compounds, protons and heat (>43 degrees C), was performed on the rat trigeminal ganglion (TG). The immunoreactivity (IR) was detected in 20% of TG cells and these neurons were mostly small- to medium-sized (mean+/-S.D. 427+/-189 microm(2)). Twenty-six percent of the TG neurons retrogradely labeled from the facial skin exhibited VR1-IR, while the IR was detected in only 8% of those labeled from the tooth pulp. Co-expression of VR1 was common among the calcitonin gene-related peptide-immunoreactive cutaneous neurons (63%) but not among the similar tooth pulp neurons (20%). The present study indicates that primary nociceptive neurons which respond to vanilloid compounds, protons and heat are abundant in the facial skin but not in the tooth pulp.

MeSH terms

  • Animals
  • Calcitonin Gene-Related Peptide / analysis
  • Cell Size
  • Dental Pulp / innervation
  • Immunohistochemistry
  • Male
  • Neurons, Afferent / chemistry*
  • Neurons, Afferent / cytology
  • Rats
  • Receptors, Drug / analysis*
  • Receptors, Drug / immunology
  • Skin / innervation
  • TRPV Cation Channels
  • Trigeminal Ganglion / chemistry*
  • Trigeminal Ganglion / cytology


  • Receptors, Drug
  • TRPV Cation Channels
  • TRPV1 receptor
  • Calcitonin Gene-Related Peptide