Napping during night shift preserves normal neural activity in nurses with sleep deprivation: evidence from functional magnetic resonance imaging study.

BACKGROUND AND PURPOSE: Neuropsychological studies suggest that napping during night shifts may benefit nurses' brain functions and clinical performance. However, in vivo neuroimaging evidence remains scarce. This study aims to use resting-state functional magnetic resonance imaging (rs-fMRI) to investigate how night-shift napping modulates neural activity in nurses experiencing sleep deprivation (SD), addressing a critical gap in understanding the neurophysiological mechanisms underlying nap-induced recovery. METHODS: rs-fMRI was administered to 24 nurses during three sessions: rested wakefulness (RW), SD, and napping (NAP). Within a biological day, RW represented normal sleep duration, SD indicated an absence of sleep, and NAP referred to naps lasting less than two hours during the night. Amplitude of low-frequency fluctuations (ALFF) analysis was performed to assess spontaneous neural activity and reflect brain function. One-way repeated measures analysis of variance, followed by post hoc paired t-tests, was used to examine ALFF differences. RESULTS: A comparison between RW and SD revealed a significant SD-related reduction in ALFF, predominantly affecting the bilateral frontal and temporal cortices, insula, subcortical structures, and cerebellum, and a notable ALFF increase predominantly involving the bilateral occipital cortex, motor and sensory-related areas, parietal lobe, and several temporal regions (FWE-corrected P<0.05). When comparing RW with NAP sessions, the spatial extent of ALFF alterations was significantly reduced (FWE-corrected P<0.05). Additionally, comparison between SD and NAP sessions showed that NAP effectively mitigated the ALFF disturbances induced by SD. CONCLUSION: Night-shift napping may serve as an effective strategy for restoring disturbed neural activity and thereby preserving cognitive and perceptual brain functions. These findings provide novel neuroimaging evidence supporting napping as a neuroprotective strategy for sleep-deprived nurses.