Dynamic resting state fMRI analysis in mice reveals a set of Quasi-Periodic Patterns and illustrates their relationship with the global signal

• Type of Material: Article
• Authors: Michaël E. Belloy, University of Antwerp; Maarten Naeyaert, University of Antwerp; Anzar Abbas, Emory University; Disha Shah, University of Antwerp; Verdi Vanreusel, University of Antwerp; Johan Van Audekerke, University of Antwerp; Shella Keilholz, Emory University; Georgios A. Keliris, University of Antwerp; Annemie Van der Linden, University of Antwerp; Marleen Verhoye, University of Antwerp
• Language: English
• Date: 2018-10-15
• Publisher: Elsevier: Creative Commons Licenses
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018 Elsevier Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neuroimage.2018.01.075
• Title of Journal or Parent Work: NeuroImage
• ISSN: 1053-8119
• Volume: 180
• Issue: Pt B
• Start Page: 463
• End Page: 484
• Grant/Funding Information: This work was supported by the interdisciplinary PhD grant (ID) BOF DOCPRO 2014 (granted to MV) and further partially supported by funding received from: the European Union’s Seventh Framework Programme (INMiND) (grant agreement 278850, granted to AVdL), the molecular Imaging of Brain Pathohysiology (BRAINPATH) and the Marie Curie Actions-Industry-Academia Partnerships and Pathways (IAPP) program (grant agreement 612360, granted to AVdL), Flagship ERA-NET (FLAG-ERA) FUSIMICE (grant agreement G.0D7651N), the Flemish Impulse funding for heavy scientific equipment (granted to AVdL), the Institute for the Promotion of Innovation by Science and Technology (IWT) in Flanders - D.S. is holder of an IWT PhD grant (grant agreement 131060) - and the Fund for Scientific Research Flanders (FWO) (grant agreements G.057615N and G.067515N).
• Keywords: Default mode network; Neurosciences & Neurology; Neuroimaging; BOLD FMRI; Dynamic rsfMRI; FUNCTIONAL CONNECTIVITY; Radiology, Nuclear Medicine & Medical Imaging; Medetomidine/isoflurane anesthesia; NEURONAL-ACTIVITY; Global signal regression; FLUCTUATIONS; Science & Technology; MOUSE; HUMAN BRAIN; Neurosciences; Life Sciences & Biomedicine; ANESTHESIA; Mouse; NEURAL ACTIVITY; Quasi-periodic pattern (QPP); SPATIOTEMPORAL DYNAMICS; DEFAULT MODE NETWORK
• Research Categories: Engineering, Biomedical; Biology, Animal Physiology; Biology, Neuroscience

Abstract

Time-resolved ‘dynamic’ over whole-period 'static’ analysis of low frequency (LF) blood-oxygen level dependent (BOLD) fluctuations provides many additional insights into the macroscale organization and dynamics of neural activity. Although there has been considerable advancement in the development of mouse resting state fMRI (rsfMRI), very little remains known about its dynamic repertoire. Here, we report for the first time the detection of a set of recurring spatiotemporal Quasi-Periodic Patterns (QPPs) in mice, which show spatial similarity with known resting state networks. Furthermore, we establish a close relationship between several of these patterns and the global signal. We acquired high temporal rsfMRI scans under conditions of low (LA) and high (HA) medetomidine-isoflurane anesthesia. We then employed the algorithm developed by Majeed et al. (2011), previously applied in rats and humans, which detects and averages recurring spatiotemporal patterns in the LF BOLD signal. One type of observed patterns in mice was highly similar to those originally observed in rats, displaying propagation from lateral to medial cortical regions, which suggestively pertain to a mouse Task-Positive like network (TPN) and Default Mode like network (DMN). Other QPPs showed more widespread or striatal involvement and were no longer detected after global signal regression (GSR). This was further supported by diminished detection of subcortical dynamics after GSR, with cortical dynamics predominating. Observed QPPs were both qualitatively and quantitatively determined to be consistent across both anesthesia conditions, with GSR producing the same outcome. Under LA, QPPs were consistently detected at both group and single subject level. Under HA, consistency and pattern occurrence rate decreased, whilst cortical contribution to the patterns diminished. These findings confirm the robustness of QPPs across species and demonstrate a new approach to study mouse LF BOLD spatiotemporal dynamics and mechanisms underlying functional connectivity. The observed impact of GSR on QPPs might help better comprehend its controversial role in conventional resting state studies. Finally, consistent detection of QPPs at single subject level under LA promises a step forward towards more reliable mouse rsfMRI and further confirms the importance of selecting an optimal anesthesia regime.