P2X3 is expressed by DRG neurons that terminate in inner lamina II

Eur J Neurosci. 1998 Nov;10(11):3470-8. doi: 10.1046/j.1460-9568.1998.00355.x.


The P2X3 receptor subunit, a member of the P2X family of ATP-gated ion channels, is almost exclusively localized in sensory neurons. In the present study, we sought to gain insight into the role of P2X3 and P2X3-containing neurons in sensory transmission, using immunohistochemical approaches. In rat dorsal root ganglia (DRG), P2X3-immunoreactivity (-ir) was observed in small- and medium-sized neurons. Approximately 40% of DRG neuronal profiles in normal rats contained P2X3-ir. In rats that had received neonatal capsaicin treatment, the number of P2X3-positive neurons was decreased by approximately 70%. Analysis of the colocalization of P2X3-ir with cytochemical markers of DRG neurons indicated that approximately 94% of the P2X3-positive neuronal profiles were labelled by isolectin B4 from Bandeiraea simplicifolia, while only 3% contained substance P-ir, and 7% contained somatostatin-ir. In dorsal horn of rat spinal cord, P2X3-ir was observed in the inner portion of lamina II and was reduced subsequent to dorsal rhizotomy, as well as subsequent to neonatal capsaicin treatment. Finally, P2X3-ir accumulated proximal to the site of sciatic nerve ligation, and was seen in nerve fibres in skin and corneal epithelium. In summary, our results suggest that P2X3 is expressed by a functionally heterogeneous population of BSI-B4-binding sensory neurons, and is transported into both central and peripheral processes of these neurons.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Capsaicin / toxicity
  • Epithelium, Corneal / innervation
  • Fluorescent Antibody Technique
  • Male
  • Microscopy, Confocal
  • Neurons / metabolism*
  • Neurons, Afferent / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Purinergic P2 / metabolism*
  • Receptors, Purinergic P2X3
  • Sciatic Nerve / metabolism
  • Skin / innervation
  • Spinal Cord / metabolism*
  • Spinal Nerve Roots / cytology
  • Spinal Nerve Roots / metabolism*


  • P2rx3 protein, rat
  • Receptors, Purinergic P2
  • Receptors, Purinergic P2X3
  • Capsaicin