Summary: Researchers report sleep deprivation affects the parietal and occipital lobes in children, along with myelin levels in the visual system.
Source: University of Zurich.
Sleep is vital for humans. If adults remain awake for longer than usual, the brain responds with an increased need for deep sleep. This is measured in the form of “slow wave activity” using electroencephalography (EEG). In adults, these deep-sleep waves are most pronounced in the prefrontal cortex – the brain region which plans and controls actions, solves problems and is involved in the working memory.
Sleep deprivation in children increases deep sleep in posterior brain regions
For the first time, researchers from UZH have now demonstrated that curtailed sleep in children also results in locally increased deep sleep. “However, a child’s brain reacts differently to acute sleep deprivation than an adult’s,” stresses Salome Kurth from the Pulmonary Clinic at University Hospital Zurich. “The deep-sleep effect doesn’t appear in the front regions of the brain like in adults, but rather in the back – in the parietal and occipital lobes.”
The team of researchers also discovered that the heightened need for sleep – measured as an increase in deep sleep – in children is associated with the myelin content in certain nerve fiber bundles: the optic radiation. This brain region is part of the visual system responsible for spatial perception and processing multi-sensorial input. The level of myelin – a fatty sheath around the nerve fibers, which accelerates the transfer of electrical signals – is a yardstick for brain maturity and increases in the course of childhood and adolescence. The new results now reveal that the higher the myelin content in a brain region, the more similar the deep-sleep effect is to adults.
Deep-sleep effect depends on extent of brain maturity
In order to study the effects of sleep deprivation in children a collaboration was launched with the University of Colorado Boulder (USA). The sleep researchers measured the brain activity in 13 healthy five to 12-year-olds as they slept. The EEG measurements with a total of 128 electrodes were conducted twice overnight at home with the families. On the first occasion, the children went to bed at their normal bedtime; the second time, they stayed awake until late and thus received exactly half the normal amount of sleep. The scientists also determined the myelin content in the brain with the aid of a recently developed, non-invasive magnetic resonance imaging technique.
“Our results show that the deep-sleep effect occurs specifically in a particular region of the brain and is linked to the myelin content,” sums up Kurth. According to the researcher, this effect might only be temporary, i.e. only occur during sensitive developmental phases in childhood or adolescence. The scientists assume that the quality of sleep is jointly responsible for the neuronal connections to develop optimally during childhood and adolescence. Consequently, it is important for a child to sleep sufficiently during this life phase. According to international guidelines, the recommended amount of sleep for children aged 6 to 13 is 9 to 11 hours per night.
Source: Salome Kurth – University of Zurich
Image Source: NeuroscienceNews.com image is credited to the researchers/Frontiers in Human Neuroscience.
Original Research: Full open access research for “Increased Sleep Depth in Developing Neural Networks: New Insights from Sleep Restriction in Children” by Salome Kurth, Douglas C. Dean, Peter Achermann, Jonathan O’Muircheartaigh, Reto Huber, Sean C. L. Deoni and Monique LeBourgeois in Frontiers in Human Neuroscience. Published online September 21 2016 doi:10.3389/fnhum.2016.00456
[cbtabs][cbtab title=”MLA”]University of Zurich “Developing Brain Regions in Children Hardest Hit by Sleep Deprivation.” NeuroscienceNews. NeuroscienceNews, 4 October 2016.
<https://neurosciencenews.com/sleep-deprivation-neurodevelopment-5198/>.[/cbtab][cbtab title=”APA”]University of Zurich (2016, October 4). Developing Brain Regions in Children Hardest Hit by Sleep Deprivation. NeuroscienceNew. Retrieved October 4, 2016 from https://neurosciencenews.com/sleep-deprivation-neurodevelopment-5198/[/cbtab][cbtab title=”Chicago”]University of Zurich “Developing Brain Regions in Children Hardest Hit by Sleep Deprivation.” https://neurosciencenews.com/sleep-deprivation-neurodevelopment-5198/ (accessed October 4, 2016).[/cbtab][/cbtabs]
Abstract
Increased Sleep Depth in Developing Neural Networks: New Insights from Sleep Restriction in Children
Brain networks respond to sleep deprivation or restriction with increased sleep depth, which is quantified as slow-wave activity (SWA) in the sleep electroencephalogram (EEG). When adults are sleep deprived, this homeostatic response is most pronounced over prefrontal brain regions. However, it is unknown how children’s developing brain networks respond to acute sleep restriction, and whether this response is linked to myelination, an ongoing process in childhood that is critical for brain development and cortical integration. We implemented a bedtime delay protocol in 5- to 12-year-old children to obtain partial sleep restriction (1-night; 50% of their habitual sleep). High-density sleep EEG was assessed during habitual and restricted sleep and brain myelin content was obtained using mcDESPOT magnetic resonance imaging. The effect of sleep restriction was analyzed using statistical non-parametric mapping with supra-threshold cluster analysis. We observed a localized homeostatic SWA response following sleep restriction in a specific parieto-occipital region. The restricted/habitual SWA ratio was negatively associated with myelin water fraction in the optic radiation, a developing fiber bundle. This relationship occurred bilaterally over parieto-temporal areas and was adjacent to, but did not overlap with the parieto-occipital region showing the most pronounced homeostatic SWA response. These results provide evidence for increased sleep need in posterior neural networks in children. Sleep need in parieto-temporal areas is related to myelin content, yet it remains speculative whether age-related myelin growth drives the fading of the posterior homeostatic SWA response during the transition to adulthood. Whether chronic insufficient sleep in the sensitive period of early life alters the anatomical generators of deep sleep slow-waves is an important unanswered question.
“Increased Sleep Depth in Developing Neural Networks: New Insights from Sleep Restriction in Children” by Salome Kurth, Douglas C. Dean, Peter Achermann, Jonathan O’Muircheartaigh, Reto Huber, Sean C. L. Deoni and Monique LeBourgeois in Frontiers in Human Neuroscience. Published online September 21 2016 doi:10.3389/fnhum.2016.00456
