Age-related changes in sleep spindles characteristics during daytime recovery following a 25-hour sleep deprivation

Abstract

Objectives: The mechanisms underlying sleep spindles (~11–15 Hz; >0.5 s) help to protect sleep. With age, it becomes increasingly difficult to maintain sleep at a challenging time (e.g., daytime), even after sleep loss. This study compared spindle characteristics during daytime recovery and nocturnal sleep in young and middle-aged adults. In addition, we explored whether spindles characteristics in baseline nocturnal sleep were associated with the ability to maintain sleep during daytime recovery periods in both age groups.Methods: Twenty-nine young (15 women and 14 men; 27.3 y ± 5.0) and 31 middle-aged (19 women and 13 men; 51.6 y ± 5.1) healthy subjects participated in a baseline nocturnal sleep and a daytime recovery sleep after 25 hours of sleep deprivation. Spindles were detected on artifact-free Non-rapid eye movement (NREM) sleep epochs. Spindle density (nb/min), amplitude (μV), frequency (Hz), and duration (s) were analyzed on parasagittal (linked-ears) derivations.Results: In young subjects, spindle frequency increased during daytime recovery sleep as compared to baseline nocturnal sleep in all derivations, whereas middle-aged subjects showed spindle frequency enhancement only in the prefrontal derivation. No other significant interaction between age group and sleep condition was observed. Spindle density for all derivations and centro-occipital spindle amplitude decreased whereas prefrontal spindle amplitude increased from baseline to daytime recovery sleep in both age groups. Finally, no significant correlation was found between spindle characteristics during baseline nocturnal sleep and the marked reduction in sleep efficiency during daytime recovery sleep in both young and middle-aged subjects.Conclusion: These results suggest that the interaction between homeostatic and circadian pressure modulates spindle frequency differently in aging. Spindle characteristics do not seem to be linked with the ability to maintain daytime recovery sleep.

Effects of late‐night short‐sleep on in‐home polysomnography: relation to adult age and sex

“…The age by condition interaction was a main focus of the study and was significant for N3%. The lower N3% increase in the older group in response to LSS agrees with what could be expected based on previous work on full‐sleep after total sleep loss (Cajochen et al ., ; Lafortune et al ., ; Rosinvil et al ., ). In addition, the reduction in N2% was lower in the older group, which seems logical because of the modest increase in N3% in that group; the two sleep stages normally interact because N3 is scored when the EEG amplitude exceeds criterion (75 μ V) and N2 when it falls below the criterion.…”

“…One possible modifier of the response to LSS may be age, because older individuals have shorter total sleep time (TST), less sleep stage N3, less REM, and more stage N1 during full‐night sleep than young individuals (Bixler et al ., ; Moraes et al ., ; Ohayon et al ., ). Older individuals also show a somewhat lower N3 response to total sleep deprivation than younger ones (Cajochen et al ., ; Lafortune et al ., ; Rosinvil et al ., ). Delta power density decreases with age, while REM density is unaffected (Schwarz et al ., ).…”

Schizotypal traits are associated with sleep spindles and rapid eye movement in adolescence

“…Specifically, SWS and REM sleep may reflect levels of depression (Riemann, Berger, & Voderholzer, ) or compensation after insufficient sleep (Ong, Lo, Gooley, & Chee, ). These potential causes may further be reflected in the percentages of different sleep stages and spindle activity (Rosinvil et al., ). Sleep spindles vary in their morphology, or form, as well as their function across development (Clawson, Durkin, & Aton, ).…”

Acoustic enhancement of sleep slow oscillations in mild cognitive impairment

“…Given that spindles have been shown to play a role in memory consolidation during sleep and that previous studies of acoustic stimulation of slow waves have found concomitant changes in spindles, we also examined spindle changes in this study. Automated spindle detection (spindles between 9 and 16 Hz) was performed on channel Fpz for all ON and OFF intervals for stim and sham by adapting previously published methods that have also been employed in older adults . Additional details are described in Data S1.…”