Verification of a Central Pacemaker in Brain Stem by Phase-Coupling Analysis Between HR Interval- and BOLD-Oscillations in the 0.10–0.15 Hz Frequency Band

Gert Pfurtscheller*, Andreas R. Schwerdtfeger, Beate Rassler, Alexandre Andrade, Gerhard Schwarz, Wolfgang Klimesch

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The origin of slow intrinsic oscillations in resting states of functional magnetic resonance imaging (fMRI) signals is still a matter of debate. The present study aims to test the hypothesis that slow blood oxygenation level-dependent (BOLD) oscillations with frequency components greater than 0.10 Hz result from a central neural pacemaker located in the brain stem. We predict that a central oscillator modulates cardiac beat-to-beat interval (RRI) fluctuations rapidly, with only a short neural lag around 0.3 s. Spontaneous BOLD fluctuations in the brain stem, however, are considerably delayed due to the hemodynamic response time of about ∼2–3 s. In order to test these predictions, we analyzed the time delay between slow RRI oscillations from thorax and BOLD oscillations in the brain stem by calculating the phase locking value (PLV). Our findings show a significant time delay of 2.2 ± 0.2 s between RRI and BOLD signals in 12 out of 23 (50%) participants in axial slices of the pons/brain stem. Adding the neural lag of 0.3 s to the observed lag of 2.2 s we obtain 2.5 s, which is the time between neural activity increase and BOLD increase, termed neuro-BOLD coupling. Note, this time window for neuro-BOLD coupling in awake humans is surprisingly of similar size as in awake head-fixed adult mice (Mateo et al., 2017).

Original languageEnglish
Article number922
JournalFrontiers in Neuroscience
Volume14
DOIs
Publication statusPublished - 28 Aug 2020

Keywords

  • BOLD oscillations
  • brain stem
  • central pacemaker
  • heart rate interval
  • neurovascular coupling

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint

Dive into the research topics of 'Verification of a Central Pacemaker in Brain Stem by Phase-Coupling Analysis Between HR Interval- and BOLD-Oscillations in the 0.10–0.15 Hz Frequency Band'. Together they form a unique fingerprint.

Cite this