Abstract
A good quality and amount of sleep are fundamental to preserve cognition and affect. New evidence also indicates that poor sleep is detrimental to brain myelination. In this study, we test the hypothesis that sleep quality and/or quantity relate to variability in cognitive and emotional function via the mediating effect of interindividual differences in proxy neuroimaging measures of white matter integrity and intracortical myelination. By employing a demographically and neuropsychologically well-characterized sample of healthy people drawn from the Human Connectome Project (n = 974), we found that quality and amount of sleep were only marginally linked to cognitive performance. In contrast, poor quality and short sleep increased negative affect (i.e. anger, fear, and perceived stress) and reduced life satisfaction and positive emotionality. At the brain level, poorer sleep quality and shorter sleep duration related to lower intracortical myelin in the mid-posterior cingulate cortex (p = 0.038), middle temporal cortex (p = 0.024), and anterior orbitofrontal cortex (OFC, p = 0.034) but did not significantly affect different measures of white matter integrity. Finally, lower intracortical myelin in the OFC mediated the association between poor sleep quality and negative emotionality (p < 0.05). We conclude that intracortical myelination is an important mediator of the negative consequences of poor sleep on affective behavior.
Highlights
Sleep is a naturally recurring state of the brain and body that occupies about one third of our lives
Out of the approximately n = 1,200 original sample from the Human Connectome Project (HCP) dataset, we employed all participants for which a T1/ T2-derived myelin map as well as valid diffusion magnetic resonance imaging (MRI) data were available, resulting in n = 974 participants
Chronic short sleep and poor sleep quality relate to negative emotionality but not cognitive performance
Summary
Sleep is a naturally recurring state of the brain and body that occupies about one third of our lives. Acute or chronic sleep loss in rodent models down-regulates several brain transcripts related to myelin function [6, 11, 12]. Our recent work has shown that ~5 days of sleep restriction in mice reduce myelin thickness and increase the length of Ranvier’s nodes in highly myelinated white matter tracts [7, 10]. Such changes have a profound impact on reducing the velocity of the signal propagation along axons [13], which in turn may represent the neurophysiological basis of the cognitive and emotional problems resulting from sleep deprivation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
