Tooth pulp stimulation induces c-fos expression in the lateral habenular nucleus of the cat

Neuroreport. 1994 Nov 21;5(17):2397-400. doi: 10.1097/00001756-199411000-00046.


Detection of Fos protein expression by the peroxidase-antiperoxidase method was used to determine the area in the habenular (Hb) complex responding to electrical stimulation of the tooth pulp in the cat anaesthetized with pentobarbital. In the anaesthetic-injected group, the Fos-positive neurones were found bilaterally in the lateral Hb nucleus (HbL). Tooth pulp stimulation (intensity: 3 times the threshold for jaw-opening reflex) increased the number of positive neurones within the HbL by up to 300%, but did not induce any expression in the medical Hb nucleus. The increase in HbL was inhibited by morphine (2 mg kg-1, i.p.). These findings and the results of previous research suggest that HbL neurones are involved in defensive mechanisms by means of antinociception following noxious stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Dental Pulp / physiology*
  • Electric Stimulation
  • Female
  • Immunohistochemistry
  • Male
  • Morphine / pharmacology
  • Neurons / metabolism
  • Proto-Oncogene Proteins c-fos / metabolism*
  • Thalamus / cytology
  • Thalamus / physiology*
  • Tissue Distribution


  • Proto-Oncogene Proteins c-fos
  • Morphine