A role for spindles in the onset of rapid eye movement sleep

• Published in: Nature communications Vol. 11; no. 1; p. 5247
• Main Authors: Bandarabadi, Mojtaba, Herrera, Carolina Gutierrez, Gent, Thomas C., Bassetti, Claudio, Schindler, Kaspar, Adamantidis, Antoine R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.10.2020; Nature Portfolio
• Subjects: 631/378/1385/519; 631/378/2620/1838; 631/378/2620/2618; 631/378/3920; 64/60; 9/30; 9/97; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-19076-2

Sleep spindle generation classically relies on an interplay between the thalamic reticular nucleus (TRN), thalamo-cortical (TC) relay cells and cortico-thalamic (CT) feedback during non-rapid eye movement (NREM) sleep. Spindles are hypothesized to stabilize sleep, gate sensory processing and consolidate memory. However, the contribution of non-sensory thalamic nuclei in spindle generation and the role of spindles in sleep-state regulation remain unclear. Using multisite thalamic and cortical LFP/unit recordings in freely behaving mice, we show that spike-field coupling within centromedial and anterodorsal (AD) thalamic nuclei is as strong as for TRN during detected spindles. We found that spindle rate significantly increases before the onset of rapid eye movement (REM) sleep, but not wakefulness. The latter observation is consistent with our finding that enhancing spontaneous activity of TRN cells or TRN-AD projections using optogenetics increase spindle rate and transitions to REM sleep. Together, our results extend the classical TRN-TC-CT spindle pathway to include non-sensory thalamic nuclei and implicate spindles in the onset of REM sleep. During NREM sleep, spindles emerge from thalamocortical interactions. Here the authors carry out multisite thalamic and cortical recordings in freely behaving mice, to investigate the role of other non-classical thalamic sites in sleep spindle generation.