c-Fos expression in the medulla induced by static muscle contraction in cats

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

Research output: Contribution to journalArticle

53 Scopus citations

Abstract

In this study, we examined Fos-like immunoreactivity (FLI) in the medulla after static muscle contraction induced by stimulation of L7 and S1 ventral roots of the spinal cord in anesthetized cats. The results show that FLI increases in the lateral reticular nucleus, nucleus of the solitary tract, lateral tegmental field, vestibular nucleus, subretrofacial nucleus, and A1 region of the medulla in comparison with these same areas in sham- operated animals (P < 0.05 in each region). In the rostral ventrolateral medulla, FLI distribution in neurons containing phenylethanolamine-N- methyltransferase(PNMT, the synthetic enzyme for epinephrine) was also observed utilizing double-labeling methods. The majority of neurons with PNMT also expressed FLI (66 ± 4%). These data are in contrast to the results from sham-operated animals showing that 24 + 3% of the neurons costained with PNMT (P < 0.05). Our findings indicate that expression of FLI can be used to identify neurons activated during static muscle contraction and support previous studies implicating the ventrolateral medulla as a critical region for expression of the exercise pressor reflex. Furthermore, neurons in the rostral ventrolateral medulla containing PNMT were activated during static muscle contraction.

Original languageEnglish (US)
Pages (from-to)H48-H56
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume272
Issue number1 41-1
DOIs
StatePublished - Jan 1 1997

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Keywords

  • exercise pressor reflex
  • heart rate
  • ventrolateral medulla

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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