C-fos expression in vasopressin and oxytocin neurons reveals functional heterogeneity within magnocellular neurons

Michelle M. Roberts, Alan G. Robinson, Mark D. Fitzsimmons, Fred Grant, Wen Sen Lee, Gloria E. Hoffman

Research output: Contribution to journalArticlepeer-review

87 Citations (Scopus)


The C-fos protein is rapidly induced in hypothalamic magnocellular nuclei following hemorrhage. We used specific antibodies directed against c-fos and either vasopressin (AVP) or oxytocin (OT) neurophysin to investigate c-fos activation in individual AVP and OT neurons. AVP and OT neurons expressed c-fos in response to hypovolemic stimuli. Following a protocol of incremental hemorrhage, AVP and OT neurons expressed c-fos with a graded response that correlated with stimulus intensity. As the volume of hemorrhage increased, there was an increase in the number of cells expressing c-fos as well as in the amount of c-fos immunoreactivity per cell. These increases correlated with the amount of hormone released into the peripheral blood. In addition, a differential pattern of activation for AVP neurons occurred in response to hemorrhagic stimuli. AVP neurons in the supraoptic nucleus (SON) had a lower threshold for response than those in the paraventricular nucleus (PVN). For OT, activation required a greater blood loss than AVP and c-fos expression encompassed both SON and PVN neurons. We conclude that c-fos expression is proportional to stimulus intensity and reveals functional heterogeneity among magnocellular neurons.

Original languageEnglish
Pages (from-to)388-400
Number of pages13
Issue number3
Publication statusPublished - 1993
Externally publishedYes


  • Magnocellular neurons
  • Neurohypophysis
  • Oxytocin
  • Paraventricular nucleus
  • Supraoptic nucleus
  • Vasopressin
  • c-fos

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'C-fos expression in vasopressin and oxytocin neurons reveals functional heterogeneity within magnocellular neurons'. Together they form a unique fingerprint.

Cite this