[en] The circadian system orchestrates sleep timing and structure and is altered with increasing age. Sleep propensity, and particularly REM sleep is under strong circadian control and has been suggested to play an important role in brain plasticity. In this exploratory study, we assessed whether surface-based brain morphometry indices are associated with circadian sleep regulation and whether this link changes with age. Twenty-nine healthy older (55-82 years; 16 men) and 28 young participants (20-32 years; 13 men) underwent both structural magnetic resonance imaging and a 40-h multiple nap protocol to extract sleep parameters over day and night time. Cortical thickness and gyrification indices were estimated from T1-weighted images acquired during a classical waking day. We observed that REM sleep was significantly modulated over the 24-h cycle in both age groups, with older adults exhibiting an overall reduction in REM sleep modulation compared to young individuals. Interestingly, when taking into account the observed overall age-related reduction in REM sleep throughout the circadian cycle, higher day-night differences in REM sleep were associated with increased cortical gyrification in the right inferior frontal and paracentral regions in older adults. Our results suggest that a more distinctive allocation of REM sleep over the 24-h cycle is associated with regional cortical gyrification in aging, and thereby point towards a protective role of circadian REM sleep regulation for age-related changes in brain organization.
Reyt, Mathilde; GIGA-CRC in Vivo Imaging, University of Liège, Belgium ; Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology and Educational Sciences, University of Liège, Belgium
Berthomier, Christian; Physip, Paris, France
Muto, Vincenzo ; Université de Liège - ULiège > GIGA > GIGA CRC In vivo Imaging
Hammad, Grégory ; Université de Liège - ULiège > Département de Psychologie > Neuropsychologie
de Haan, Stella ; Université de Liège - ULiège > Département de Psychologie > Neuropsychologie
Dourte, Marine ; Université de Liège - ULiège > GIGA > GIGA CRC In vivo Imaging - Sleep and chronobiology ; UR2NF, Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
Taillard, Jacques; USR 3413 SANPSY CNRS, University of Bordeaux, France
Lambot, Eric ; Centre Hospitalier Universitaire de Liège - CHU > > Service de neurologie
Cajochen, Christian ; Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland and Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
Reichert, Carolin F; Institute of Primary Health Care (BIHAM), University of Bern, Switzerland
Maire, Micheline; Institute of Primary Health Care (BIHAM), University of Bern , Bern , Switzerland
Baillet, Marion ✱; Université de Liège - ULiège > Département de Psychologie > Neuropsychologie
Schmidt, Christina ✱; Université de Liège - ULiège > Département de Psychologie > Neuropsychologie