title: Cerebral functional connectivity and Mayer waves in mice: Phenomena and separability.
abstract: Resting-state functional connectivity is a growing neuroimaging approach that analyses the spatiotemporal structure of spontaneous brain activity, often using low-frequency (<0.08 Hz) hemodynamics. In addition to these fluctuations, there are two other low-frequency hemodynamic oscillations in a nearby spectral region (0.1-0.4 Hz) that have been reported in the brain: vasomotion and Mayer waves. Despite how close in frequency these phenomena exist, there is little research on how vasomotion and Mayer waves are related to or affect resting-state functional connectivity. In this study, we analyze spontaneous hemodynamic fluctuations over the mouse cortex using optical intrinsic signal imaging. We found spontaneous occurrence of oscillatory hemodynamics ∼0.2 Hz consistent with the properties of Mayer waves reported in the literature. Across a group of mice (n = 19), there was a large variability in the magnitude of Mayer waves. However, regardless of the magnitude of Mayer waves, functional connectivity patterns could be recovered from hemodynamic signals when filtered to the lower frequency band, 0.01-0.08 Hz. Our results demonstrate that both Mayer waves and resting-state functional connectivity patterns can co-exist simultaneously, and that they can be separated by applying bandpass filters.
authors: 1 Department of Biomedical Engineering, Washington University in St Louis, St Louis, Missouri, USA.
authors: Jonathan R
authors: JR
authors: Bumstead
authors: 2 Department of Radiology, Washington University in St Louis, St Louis, Missouri, USA.
authors: Adam Q
authors: AQ
authors: Bauer
authors: 1 Department of Biomedical Engineering, Washington University in St Louis, St Louis, Missouri, USA.|2 Department of Radiology, Washington University in St Louis, St Louis, Missouri, USA.
authors: Patrick W
authors: PW
authors: Wright
authors: 1 Department of Biomedical Engineering, Washington University in St Louis, St Louis, Missouri, USA.|2 Department of Radiology, Washington University in St Louis, St Louis, Missouri, USA.|3 Department of Physics, Washington University in St Louis, St Louis, Missouri, USA.
authors: Joseph P
authors: JP
authors: Culver
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000098:blood supply* / Q000502:physiology*; D006439:Hemodynamics; D008297:Male; D051379:Mice; D009415:Nerve Net / Q000502:physiology*; D061848:Optical Imaging / Q000379:methods
keywords: Brain imaging; cerebral hemodynamics; cortical mapping; intrinsic optical imaging; neurovascular coupling