Literature Updates from March 2013

Effects of Insufficient Sleep on Circadian Rhythmicity and Expression Amplitude of the Human Blood Transcriptome

Twenty-six participants were exposed to 1 week of insufficient sleep (mean 5.7 hours/24 hours) and 1 week of sufficient sleep (mean 8.5 hours/ 24 hours). 10 whole blood RNA samples were obtained from each participant. Transcriptome analyses revealed 711 genes up and down-regulated in response to the sleep restriction condition, including genes implicated in circadian rhythm, sleep homeostasis, oxidative stress, and metabolism. Identified pathways may help elucidate mechanisms that underlie associations between insufficient sleep and disease risk.

A Pathway-Based Analysis on the Effects of Obstructive Sleep Apnea in Modulating Visceral Fat Transcriptome

Obstructive sleep apnea (OSA) is associated with metabolic dysregulation and systemic inflammation, which may be due to pathophysiologic effects of OSA on visceral adipose tissue. Eighteen patients (10 with OSA and 8 controls) underwent ventral hernia repair surgery during which time visceral fat biopsies were obtained. RNA and whole genome profiling revealed that OSA patients displayed an upregulation of proinflammatory NF-kB and the proteolytic ubiquitin/proteasome gene sets and a downreguatlion in peroxisome proliferator-activated receptor compared to controls.

Identification of a Dopamine Pathway That Regulates Sleep and Arousal in Drosophila

The dopamine pathways involved in sleep and arousal have not been well characterized. This is an elegant study using anatomically targeted genetic modifications in Drosophila to identify a specific dopamine-mediated arousal pathway. The authors found that activating a single dopamine neuron projecting to the dorsal fan-shaped body activates arousal via a DA1 receptor-mediated mechanism. They also demonstrated that this pathway is distinct from a dopamine pathway known to be involved in memory formation. These results encourage further work to identify the corresponding dopaminergic arousal pathway(s) in larger animals and humans.

Effects of Volatile Anesthetics on the Circadian Rhythms of Rat Hippocampal Acetylcholine Release and Locomotor Activity

This study revealed that the levels and circadian rhythms of hippocampal ACh release and locomotor activity were more sensitive to isoflurane anesthesia when administered during the dark phase. These findings suggest that anesthesia exerts differential effects on the regulation of circadian rhythms depending on the circadian phase.

Seasonal Variability in Paediatric Obstructive Sleep Apnoea

We identified more severe obstructive sleep apnoea in clinically referred children during winter and spring and suggest that inflammation from respiratory viruses may contribute to adenotonsillar hypertrophy, worsening airway obstruction.

Sleep Measurement and Monitoring in Children with Down Syndrome: A Review of the Literature, 1960–2010

The aim of this comprehensive review is to synthesize studies and present the historical context of evolving technologies, methodologies, and knowledge about SDB and DS. Future research opportunities and practice implications are discussed.

Sleep in Attention-Deficit/Hyperactivity Disorder in Children and Adults: Past, Present, and Future

In this review, we present a comprehensive and critical account of the research that has been carried out to investigate the association between sleep and ADHD, as well as discuss mechanisms that have been proposed to account for the elusive relationship between sleep disturbances, sleep disorders, and ADHD.

Sleep-Disordered Breathing in Preschool Children is Associated with Behavioral, But Not Cognitive, Impairments

SDB of any severity was associated with poorer behavior but not cognitive performance. The lack of significant cognitive impairment in this age group may have identified a “window of opportunity” where early treatment may prevent deficits arising later in childhood.