Identification of hypothalamic vasopressin and oxytocin neurons activated during the exercise pressor reflex in cats

Jianhua Li, Gregory A. Hand, Jeffrey T. Potts, Jere H. Mitchell

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Blood pressure and heart rate reflexly increase during static muscle contraction in anesthetized cats. Previous studies have demonstrated that vasopressin (AVP) and oxytocin (OT) may act as neuromodulators to regulate cardiovascular responses elicited by contraction of skeletal muscle. In this study, we tested the hypothesis that neurons containing AVP and OT in the paraventricular nucleus (PVN) and the supraoptic nucleus (SON) of the hypothalamus are activated during static muscle contraction. A laminectomy was performed to expose the spinal cord and the peripheral cut ends of L7 and S1 ventral roots were stimulated electrically to induce muscle contraction. Hypothalamic neurons activated during the muscle contraction were identified by Fos-like immunoreactivity (FLI). Static muscle contraction significantly increased FLI in the PVN and SON, compared with sham-operated cats. Double-staining of neurons in the PVN for AVP and OT showed that 22 ± 4% of the AVP and 26 ± 3% of the OT neurons in the PVN expressed FLI. In contrast, only 4 ± 1% of the AVP and 3 ± 1% of the OT neurons in the PVN were labeled with FLI in sham-operated animals. These results indicate that neurons in the PVN and SON of the hypothalamus were activated during static muscle contraction. Furthermore, as FLI was present in AVP and OT neurons, this suggests these neurons may constitute a part of the neural pathway involved in cardiovascular regulation during static muscle contraction.

Original languageEnglish (US)
Pages (from-to)45-51
Number of pages7
JournalBrain Research
Volume752
Issue number1-2
DOIs
StatePublished - Mar 28 1997

Keywords

  • c-Fos
  • cat
  • exercise pressor reflex
  • hypothalamus
  • oxytocin
  • static muscle contraction
  • vasopressin

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Identification of hypothalamic vasopressin and oxytocin neurons activated during the exercise pressor reflex in cats'. Together they form a unique fingerprint.

  • Cite this