Localization of 5-HT3 receptors in the rat spinal cord: immunohistochemistry and in situ hybridization

Neuroreport. 1995 Jan 26;6(2):257-61. doi: 10.1097/00001756-199501000-00008.


Specific antibodies raised against a fusion protein containing the amino acid sequence of the putative second intracellular loop of the cloned 5-HT3-A receptor subunit were used for the immunohistochemical visualization of 5-HT3 receptors in the rat spinal cord. A dense 5-HT3-like immunoreactivity was found in the superficial layers of the dorsal horn, which closely matched the labelling of 5-HT3 binding sites by [125I]iodo-zacopride. This immunostaining was markedly decreased following unilateral rhizotomy, consistently with a preferential location of 5-HT3 receptors on terminals of primary afferent fibres, and with the presence of 5-HT3 mRNA in dorsal root ganglia. However, a significant proportion of 5-HT3 receptors persisted after rhizotomy, and the corresponding mRNA was found in the dorsal horn of the spinal cord. 5-HT3 receptors are therefore also located on intrinsic neurones of the spinal cord.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Ganglia, Spinal / chemistry*
  • Immunohistochemistry
  • In Situ Hybridization
  • Male
  • Molecular Sequence Data
  • RNA, Messenger / analysis*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Serotonin / analysis*
  • Spinal Cord / chemistry*


  • RNA, Messenger
  • Receptors, Serotonin