Region-specific response to shortened sleep in childhood: Associations with performance and myelination

Abstract

Sleep is required for plasticity processes underlying brain maturation in animals. Sleep problems in childhood predict later psychological and social problems over and above demographic factors. Yet, it remains unknown how inadequate sleep in children affects brain activity and behavior and how developing neural networks drive this relationship. All-night high-density EEG (128 channels) was obtained in 13 healthy children (5–12 y, 6 f) during habitual sleep (HS) and restricted sleep (RS, 50% of HS via delayed bedtime). Myelin-specific mcDESPOT magnetic resonance imaging was recorded in all subjects. Reaction times (auditory oddball) task were measured before and after sleep in both conditions. Sleep restriction increased non-REM sleep EEG power, which was most pronounced in slow-wave activity (SWA, 1–4.5 Hz; RS/HS). This homeostatic response occurred within prefrontal and parieto-occipital regions. The parieto-occipital SWA increase was inversely related to myelin content in the optic radiation (partial [factor age] correlation r = −0.57, p = 0.03, 1-tailed). Overnight performance improvement in reaction time correlated with the prefrontal SWA increase ( r = 0.79 p = 0.02; partial [factor age] r = 0.81 p = 0.03, 1-tailed). These results provide evidence for increased sleep need in developing neural networks in children, and extend animal findings showing that sleep is a fundamental contributor to neurodevelopment. Long-term effects of insufficient sleep may negatively impact the development of the neural networks that are involved in the generation of sleep slow-waves.