The suprachiasmatic nuclei (SCN) are intrinsic pacemakers which organize circadian rhythms in mammals. When the SCN of Long-Evans rats are surgically isolated and perifused in vitro, they retain the ability to express a 24 hr rhythm of neuronal firing rate. We find that the SCN are also capable of secreting the peptide vasopressin (VP) in a circadian pattern. The pattern of VP secretion is similar to that of SCN neuronal electrical activity measured during perifusate collection. The temporal profile of VP levels in SCN perifusate parallels that seen in cerebrospinal fluid, suggesting that the SCN might be both the pacemaker and a secretory contributor to this rhythm.

Original languageEnglish (US)
Pages (from-to)135-139
Number of pages5
JournalBrain Research Bulletin
Issue number1
StatePublished - Jul 1987


  • Brain slice
  • Circadian rhythms
  • Electrophysiology
  • Hypothalamus
  • Neuronal oscillator
  • nuclei Vasopressin
  • Suprachiasmatic

ASJC Scopus subject areas

  • General Neuroscience


Dive into the research topics of 'The hypothalamic suprachiasmatic nuclei: Circadian patterns of vasopressin secretion and neuronal activity in vitro'. Together they form a unique fingerprint.

Cite this