Diversity of expression of the sensory neuron-specific TTX-resistant voltage-gated sodium ion channels SNS and SNS2

Mol Cell Neurosci. 2000 Apr;15(4):331-42. doi: 10.1006/mcne.1999.0828.


The differential distribution of two tetrodotoxin resistant (TTXr) voltage-gated sodium channels SNS (PN3) and SNS2 (NaN) in rat primary sensory neurons has been investigated. Both channels are sensory neuron specific with SNS2 restricted entirely to those small dorsal root ganglion (DRG) cells with unmyelinated axons (C-fibers). SNS, in contrast, is expressed both in small C-fiber DRG cells and in 10% of cells with myelinated axons (A-fibers). All SNS expressing A-fiber cells are Trk-A positive and many express the vanilloid-like receptor VRL1. About half of C-fiber DRG neurons express either SNS or SNS2, and in most, the channels are colocalized. SNS and SNS2 are found both in NGF-responsive and GDNF-responsive C-fibers and many of these cells also express the capsaicin receptor VR1. A very small proportion of small DRG cells express either only SNS or only SNS2. At least four different classes of A- and C-fiber DRG neurons exist, therefore, with respect to expression of these sodium channels.

Publication types

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

MeSH terms

  • Animals
  • Antibody Specificity
  • Biomarkers
  • Blotting, Western
  • Cell Line
  • Ganglia, Spinal / cytology
  • Humans
  • In Situ Hybridization
  • Intermediate Filament Proteins / analysis
  • Kidney / cytology
  • Male
  • Membrane Glycoproteins*
  • Molecular Sequence Data
  • NAV1.8 Voltage-Gated Sodium Channel
  • NAV1.9 Voltage-Gated Sodium Channel
  • Nerve Fibers / chemistry
  • Nerve Fibers / physiology
  • Nerve Fibers, Myelinated / chemistry
  • Nerve Fibers, Myelinated / physiology
  • Nerve Tissue Proteins / analysis
  • Neurofilament Proteins / analysis
  • Neurons, Afferent / chemistry*
  • Neurons, Afferent / physiology*
  • Neurons, Afferent / ultrastructure
  • Neuropeptides / analysis
  • Neuropeptides / genetics
  • Neuropeptides / immunology
  • Peripherins
  • RNA, Messenger / analysis
  • Rabbits
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Drug / analysis
  • Sequence Homology, Amino Acid
  • Sodium Channels / analysis*
  • Sodium Channels / genetics*
  • Sodium Channels / immunology
  • Tetrodotoxin


  • Biomarkers
  • Intermediate Filament Proteins
  • Membrane Glycoproteins
  • NAV1.8 Voltage-Gated Sodium Channel
  • NAV1.9 Voltage-Gated Sodium Channel
  • Nerve Tissue Proteins
  • Neurofilament Proteins
  • Neuropeptides
  • Peripherins
  • RNA, Messenger
  • Receptors, Drug
  • SCN10A protein, human
  • SCN11A protein, human
  • Scn10a protein, rat
  • Scn11a protein, rat
  • Sodium Channels
  • neurofilament protein H
  • Tetrodotoxin