1 Department of Psychology, University of Montreal, Montreal, QC, Canada.
2 Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, QC, Canada.
3 McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
4 Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale (LIB), 75013 Paris, France.
5 Center for Advanced Research in Sleep Medicine, Montreal, QC, Canada.
6 School of Psychology, University of Ottawa, Ottawa, Ontario, Canada.
7 University of Ottawa Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada.
8 University of Ottawa Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
9 PERFORM Centre, Electrical and Computer Engineering Department, Concordia University, Montreal, Canada.
10 École de technologie supérieure, Department of Electrical Engineering, Montreal, Canada.

Beyond spindles: interactions between sleep spindles and boundary frequencies during cued reactivation of motor memory representations.

Sleep. 2018 Sep 01;41(9):

Authors: Laventure S, Pinsard B, Lungu O, Carrier J, Fogel S, Benali H, Lina JM, Boutin A, Doyon J

Abstract

There is now ample evidence that sleep spindles play a critical role in the consolidation of newly acquired motor sequences. Previous studies have also revealed that the interplay between different types of sleep oscillations (e.g. spindles, slow waves, sharp-wave ripples) promotes the consolidation process of declarative memories. Yet the functional contribution of this type of frequency-specific interactions to motor memory consolidation remains unknown. Thus, this study sought to investigate whether spindle oscillations are associated with low- or high-frequency activity at the regional (local) and interregional (connectivity) levels. Using an olfactory-targeted memory reactivation paradigm paired to a motor sequence learning task, we compared the effect of cuing (Cond) to no-cuing (NoCond) on frequency interactions during sleep spindles. Time-frequency decomposition analyses revealed that cuing induced significant differential and localized changes in delta (1-4 Hz) and theta (4-8 Hz) frequencies before, during, and after spindles, as well as changes in high-beta (20-30 Hz) during the spindle oscillation. Finally, coherence analyses yielded significant increases in connectivity during sleep spindles in both theta and sigma (11-17 Hz) bands in the cued group only. These results support the notion that the synchrony between spindle and associated low- or high-frequency rhythmic activity is an integral part of the memory reactivation process. Furthermore, they highlight the importance of not only measuring spindles' characteristics, but to investigate such oscillations in both time and frequency domains when assessing memory consolidation-related changes.

PMID: 30137521 [PubMed - in process]