Use of Fos-related antigens (FRAs) as markers of neuronal activity: FRA changes in dopamine neurons during proestrus, pregnancy and lactation

Gloria E. Hoffman, Wei Wei Le, Rula Abbud, Wen Sen Lee, M. Susan Smith

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)


This manuscript describes the use of staining of Fos-related antigens (FRAs) as markers for changes in neuronal activity. The model system consisted of the tuberoinfundibular dopamine (TIDA) neurons located in the arcuate nucleus of the hypothalamus. Under normal conditions, these neurons are devoid of c-Fos staining even though the neurons are tonically active and can express FRAs. During specific neuroendocrine states the neurons undergo changes in activity, as described by other studies. At times when the activity is relatively high as in pregnancy and during proestrus, approximately 50%-60% of the TIDA neurons expressed FRA immunoreactivity. Moreover changes over the course of proestrus paralleled known shifts in TIDA activity (declining as the day progressed). At times when TIDA activity is suppressed, such as during lactation, FRA staining in TIDA neurons was markedly reduced or absent. Upon removal of the suckling stimulus, FRA staining rose to reach peak expression 12-24 h after pup removal (without coordinate induction of c-Fos). These data suggest that FRA staining can serve as a useful marker of activity in the TIDA neurons which permits not only assessment of stimulated activity but also suppressed function in the neurons. A cautionary note in using this approach along with acquisition of serial blood samples for hormone measurement is that surgical procedures for monitoring plasma hormone levels are associated with strong long-lived induction of FRAs (and c-Fos) in many neurons (including the TIDA neurons) that can canfound interpretation of FRA staining.

Original languageEnglish
Pages (from-to)207-215
Number of pages9
JournalBrain Research
Issue number2
Publication statusPublished - Aug 22 1994
Externally publishedYes


  • Arcuate nucleus
  • c-Fos
  • Hypothalamus
  • Immediate early gene product
  • Immunocytochemistry
  • Proto-oncogene

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)


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