Sequential expression of JUN B, JUN D and FOS B proteins in rat spinal neurons: cascade of transcriptional operations during nociception

Neurosci Lett. 1991 Aug 19;129(2):221-4. doi: 10.1016/0304-3940(91)90466-7.


Expression of the immediate-early gene encoded proteins JUN B, JUN D and FOS B was investigated by immunocytochemistry in rat L5 spinal cord up to 24 h following stimulation of hind limb somatosensory nociceptors by noxious heat or injection of formalin. In both experimental protocols, JUN B, which did not show basal expression, reached maximum expression after 2 h and thereafter slowly decreased. In contrast, the expression of JUN D, which was present before stimulation in many spinal neurons, was increased after 4 h, reached its maximum after 8 h and thereafter remained elevated. FOS B which was absent under basal conditions reached its maximum between 4 h and 8 h and thereafter declined but was still present after 24 h. All immunoreactivities were restricted to the ipsilateral dorsal horn except JUN D which was also induced in the contralateral side after 8 h. The results are discussed in respect to their meaning for transcriptional operations of JUN and FOS proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Formaldehyde / pharmacology
  • Gene Expression Regulation
  • Hot Temperature
  • Immunohistochemistry
  • Male
  • Neurons / metabolism*
  • Nociceptors / metabolism
  • Pain / metabolism*
  • Pain / physiopathology
  • Proto-Oncogene Proteins c-fos / biosynthesis*
  • Proto-Oncogene Proteins c-jun / biosynthesis*
  • Rats
  • Rats, Inbred Strains
  • Spinal Cord / cytology
  • Spinal Cord / metabolism*
  • Transcription, Genetic


  • Proto-Oncogene Proteins c-fos
  • Proto-Oncogene Proteins c-jun
  • Formaldehyde