Novel method for high-throughput phenotyping of sleep in mice.

Assessment of sleep in mice currently requires initial implantation of chronic electrodes for assessment of electroencephalogram (EEG) and electromyogram (EMG) followed by time to recover from surgery. Hence, it is not ideal for high-throughput screening. To address this deficiency, a method of assessment of sleep and wakefulness in mice has been developed based on assessment of activity/inactivity either by digital video analysis or by breaking infrared beams in the mouse cage.

Consequences of comorbid insomnia symptoms and sleep-related breathing disorder in elderly subjects.

Background: The prevalence of sleep-related breathing disorder (SRBD) and insomnia symptoms increases considerably with advancing age, but little is known about their cooccurrence and their effects on daytime functioning when present together.

Methods: Older adults with (cases, n = 99) and without (controls, n = 100) symptoms of insomnia underwent 2 nights of in-laboratory polysomnography, daytime nap, and neurobehavioral testing and completed study questionnaires. Predictors of SRBD were identified (apnea-hypopnea index [indicating number of events per hour], > or =15).

Multiple mechanisms limit the duration of wakefulness in Drosophila brain.

The functions of sleep and what controls it remain unanswered biological questions. According to the two-process model, a circadian process and a homeostatic process interact to regulate sleep. While progress has been made in understanding the molecular and cellular functions of the circadian process, the mechanisms of the homeostatic process remain undiscovered.

Risk factors for excessive sleepiness in older adults.

Objective: To determine risk factors for excessive daytime sleepiness in older adults.

Methods: This is a cross-sectional study assessing multiple risk factors for excessive daytime sleepiness in older subjects (mean age, 78 years; range 65-98 years) with (n=149) and without (n=144) complaints of frequent excessive daytime sleepiness. Assessment of risk factors included full in-laboratory sleep studies.

Impaired performance in commercial drivers: role of sleep apnea and short sleep duration.

Sleepiness plays an important role in major crashes of commercial vehicles. Because determinants are likely to include inadequate sleep and sleep apnea, we evaluated the role of short sleep durations over 1 wk at home and sleep apnea in subjective sleepiness (Epworth Sleepiness Scale), objective sleepiness (reduced sleep latency as determined by the Multiple Sleep Latency Test), and neurobehavioral functioning (lapses in performance, tracking error in Divided Attention Driving Task) in commercial drivers. Studies were conducted in 247 of 551 drivers at higher risk for apnea and in 159 of 778 drivers at lower risk.

A novel gain-of-function mutant of the cyclic GMP-dependent protein kinase egl-4 affects multiple physiological processes in Caenorhabditis elegans.

cGMP-dependent protein kinases are key intracellular transducers of cell signaling. We identified a novel dominant mutation in the C. elegans egl-4 cGMP-dependent protein kinase (PKG) and show that this mutation causes increased normal gene activity although it is associated with a reduced EGL-4 protein level.

Sleepiness and relationships in obstructive sleep apnea.

This is a qualitative analysis of data from a multisite study of 156 participants with Obstructive Sleep Apnea (OSA). Participants completed a battery of tests, including the Functional Outcomes of Sleep Questionnaire (FOSQ) that contains an item assessing the impact of OSA on relationships. Approximately one third of participants wrote comments; they were predominately male, mean age 44.

Age-related changes in adenosine metabolic enzymes in sleep/wake regulatory areas of the brain.

The impact of age on the enzymatic activities of adenosine metabolic enzymes, i.e., adenosine deaminase, adenosine kinase, cytosolic- and ecto-5'-nucleotidase have been assessed in the brain sleep/wake regulatory areas of young, intermediate and old rats (2, 12 and 24 months, respectively).

Changes in symptoms of sleep-disordered breathing during pregnancy.

Background: Although incident snoring is common in pregnant women and has been proposed as a potential risk factor for adverse maternal-fetal outcomes, the development of sleep-disordered breathing during pregnancy has not been prospectively described.

Methods: Using the Apnea Symptom Score from the Multivariable Apnea Prediction Index and the Epworth Sleepiness Scale, we prospectively assessed symptoms of sleep-disordered breathing and daytime somnolence in 155 women to determine whether symptoms increased during pregnancy and the characteristics associated with increasing symptoms.

Results: We found that sleep-disordered breathing symptoms (Apnea Symptom Score, 0.

Advances in sleep-disordered breathing.

Since the original clarification of the obstructive nature of obstructive sleep apnea (OSA) in 1965, much has been learned about the disorder. It is a condition with a high prevalence with obesity as a major risk factor. It aggregates in families, a relationship that is not simply explained by obesity.

Family aggregation of upper airway soft tissue structures in normal subjects and patients with sleep apnea.

Rationale: Sleep apnea is believed to be a genetic disorder. Thus, we hypothesized that anatomic risk factors for sleep apnea would demonstrate family aggregation.

Objectives: We used volumetric magnetic resonance imaging in a sib pair "quad" design to study the family aggregation of the size of upper airway soft tissue structures that are associated with increased risk for obstructive sleep apnea.

Claustrophobia and adherence to CPAP treatment.

This study evaluated the effect of claustrophobia, an abnormal dread or fear of closed spaces, on adherence to continuous positive airway pressure (CPAP) therapy. The design was a secondary analysis of data from a prospective study of participants (N = 153) that completed 3 months of CPAP therapy from seven sleep disorders centers in the United States and Canada. A 15-item subscale adapted from the Fear and Avoidance Scale measured claustrophobic tendencies pre-CPAP treatment and again after 3 months.

Changes in upper airway size during tidal breathing in children with obstructive sleep apnea syndrome.

Unlabelled: We performed respiratory-gated magnetic resonance imaging to evaluate airway dynamics during tidal breathing in 10 children with obstructive sleep apnea syndrome (OSAS; age, 4.3 +/- 2.3 years) and 10 matched control subjects (age, 5.

Sleep deprivation induces the unfolded protein response in mouse cerebral cortex.

Little is known about the molecular mechanisms underlying sleep. We show the induction of key regulatory proteins in a cellular protective pathway, the unfolded protein response (UPR), following 6 h of induced wakefulness. Using C57/B6 male mice maintained on a 12:12 light/dark cycle, we examined, in cerebral cortex, the effect of different durations of prolonged wakefulness (0, 3, 6, 9 and 12 h) from the beginning of the lights-on inactivity period, on the protein expression of BiP/GRP78, a chaperone and classical UPR marker.

Differences in activity of cytochrome C oxidase in brain between sleep and wakefulness.

Study Objectives: Increased mRNA level of subunit 1 cytochrome c oxidase (COXI) during wakefulness and after short-term sleep deprivation has been described in brain. We hypothesized that this might contribute to increased activity of cytochrome oxidase (COX) enzyme during wakefulness, as part of the mechanisms to provide sufficient amounts of adenosine triphosphate to meet increased neuronal energy demands.

Design: COX activity was measured in isolated mitochondria from different brain regions in groups of rats with 3 hours of spontaneous sleep, 3 hours of spontaneous wake, and 3 hours of sleep deprivation.

Occupational screening for obstructive sleep apnea in commercial drivers.

Excluding the presence of obstructive sleep apnea in commercial drivers is valuable, as the syndrome may increase their risk of sleepiness-related accidents. Using polysomnography as the criterion standard, we prospectively compared accuracies of five strategies in excluding the presence of severe sleep apnea and, secondarily, any sleep apnea among 406 commercial drivers. These strategies were as follows: (1) symptoms; (2) body mass index; (3) symptoms plus body mass index; (4) a two-stage approach with symptoms plus body mass index for everyone, followed by oximetry for a subset; and (5) oximetry for all.

Glycogen in the brain of Drosophila melanogaster: diurnal rhythm and the effect of rest deprivation.

One function of sleep is thought to be the restoration of energy stores in the brain depleted during wakefulness. One such energy store found in mammalian brains is glycogen. Many of the genes involved in glycogen regulation in mammals have also been found in Drosophila melanogaster and rest behavior in Drosophila has recently been shown to have the characteristics of sleep.

Practice parameters for the use of portable monitoring devices in the investigation of suspected obstructive sleep apnea in adults.

Background: A variety of devices are used to evaluate patients with a potential diagnosis of obstructive sleep apnea (OSA). A committee comprised of members of the American Academy of Sleep Medicine, American Thoracic Society, and American College of Chest Physicians systematically evaluated data on the use of these devices and developed practice parameters.

Devices Reviewed: Three categories of portable monitoring (PM) devices were reviewed with regard to assessing the probability of identifying an apnea-hypopnea index (AHI) of greater or less than 15 in attended and unattended settings.

Self-efficacy in sleep apnea: instrument development and patient perceptions of obstructive sleep apnea risk, treatment benefit, and volition to use continuous positive airway pressure.

Study Objectives: The purpose of this study was to evaluate the Self-Efficacy Measure for Sleep Apnea (SEMSA) designed to assess adherence-related cognitions.

Design: Subjects completed the questionnaire prior to the initiation of continuous positive airway pressure (CPAP) treatment. Test-retest reliability of the instrument was evaluated by having a subset of subjects complete the SEMSA a second time at home, 1 week later, returning the questionnaire by mail.

Functional genomics of sleep.

Functional genomics is a systematic and high-throughput effort to analyze the functions of genes and gene products. Functional genomics is divided into gene- and phenotype-driven approaches. Gene-driven approaches to the functional genomics of sleep have demonstrated that transcripts of many genes change as a function of behavioral state.