Regression analysis between heart rate variability and baroreflex-related vagus nerve activity in rats

Terry B J Kuo, Ching J. Lai, Yu Ting Huang, Cheryl C H Yang

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61 Citations (Scopus)

Abstract

Introduction: Many previous studies have suggested that the high-frequency (HF) power of the heart rate variability may represent cardiac vagal activity although direct evidence of a correlation between the HF and vagal neuronal activity is still lacking. In the present study, we performed a regression analysis of the HF and vagal neurograms. Methods and Results: Experiments were carried out on adult male Sprague-Dawley rats anesthetized with a continuous infusion of pentobarbital sodium. The baroreflex-related vagus neuronal activities were obtained by nerve or single-fiber recordings. The transient baroreflex response was employed to alter vagus neuronal activities using a bolus injection of phenylephrine (PE). On-line power spectral analysis of the heart rate and a vagal neurogram was performed during the acute baroreflex response. During the test period, systemic arterial pressure immediately increased in response to the PE injection, after which the R-R interval (RR), HF (0.6-2.4 Hz), and vagus nerve and unit activities all dramatically increased. Both nerve and unit activities exhibited good correlations (r ≥ 0.7 in all nerve recordings and r ≥ 0.6 in 91% of single-fiber recordings) with the HF. There were insignificant differences between the right- and left-side baroreflex-related vagus nerve recordings. Conclusion: Our present study provides a direct linkage between the HF and vagus neuronal electrical activity in anesthetized rats.

Original languageEnglish
Pages (from-to)864-869
Number of pages6
JournalJournal of Cardiovascular Electrophysiology
Volume16
Issue number8
DOIs
Publication statusPublished - Aug 2005
Externally publishedYes

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Keywords

  • Baroreflex
  • Heart rate variability
  • Power spectral analysis
  • Single-fiber recordings
  • Vagus nerve recordings

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology

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