Daily rhythm in DNA methylation and the effect of total sleep deprivation.

Numerous hormones and genes exhibit diurnal 24-hr rhythms that can also be affected by sleep deprivation. Here we studied diurnal rhythms in DNA methylation under a 24-hr sleep/wake cycle and a subsequent 29 hr of continual wakefulness (1 night of sleep deprivation). Fifteen healthy men (19-35 years) spent 3 days/nights in a sleep laboratory: (1) adaptation; (2) baseline; (3) total sleep deprivation day/night.

Benefits of nostalgic landmarks for people living with Alzheimer's disease.

Background: Emerging literature shows that nostalgia induced by autobiographical reflection and music confers psychological benefits to people living with dementia.

Objective: Our objective was to test the potential benefits of nostalgic landmarks for people living with Alzheimer's disease.

Methods: We displayed the landmarks as wall-mounted pictures within a virtual environment.

Short-term changes in human metabolism following a 5-h delay of the light-dark and behavioral cycle.

Experimental inversion of circadian and behavioral rhythms by 12 h adversely affects markers of metabolic health. We investigated the effects of a more modest 5-h delay in behavioral cycles. Fourteen participants completed an 8-day in-patient laboratory protocol, with controlled sleep-wake opportunities, light-dark cycles, and diet.

Exposing 24-hour cycles in bile acids of male humans.

Bile acids are trans-genomic molecules arising from the concerted metabolism of the human host and the intestinal microbiota and are important for digestion, energy homeostasis and metabolic regulation. While diurnal variation has been demonstrated in the enterohepatic circulation and the gut microbiota, existing human data are poorly resolved, and the influence of the host circadian system has not been determined. Using entrained laboratory protocols, we demonstrate robust daily rhythms in the circulating bile acid pool in healthy male participants.

Housing and Husbandry Factors Affecting Zebrafish () Novel Tank Test Responses: A Global Multi-Laboratory Study.

The reproducibility crisis in bioscience, characterized by inconsistent study results, impedes our understanding of biological processes and global collaborative studies offer a unique solution. This study is the first global collaboration using the zebrafish () novel tank test, a behavioral assay for anxiety-like responses. We analyzed data from 20 laboratories worldwide, focusing on housing conditions and experimental setups.

The effect of laboratory diet and feeding on growth parameters in juvenile zebrafish.

Despite being one of the most used laboratory species in biomedical, behavioral and physiological research, the nutritional requirements of zebrafish (Danio rerio) are poorly understood, and no standardized laboratory diet exists. Diet and feeding regimen can substantially impact the welfare of the fish and, in turn, experimental reproducibility. Consequently, the establishment of a standardized diet and feeding protocol for laboratory zebrafish is imperative to enhance animal welfare, guarantee research reproducibility and advance the economic and environmental sustainability of laboratory dietary practices.

The British Sleep Society position statement on Daylight Saving Time in the UK.

There is an ongoing debate in the United Kingdom and in other countries about whether twice-yearly changes into and out of Daylight Saving Time should be abolished. Opinions are divided about whether any abolition of Daylight Saving Time should result in permanent Standard Time, or year-long Daylight Saving Time. The British Sleep Society concludes from the available scientific evidence that circadian and sleep health are affected negatively by enforced changes of clock time (especially in a forward direction) and positively by the availability of natural daylight during the morning.

Protocol for investigating light/dark locomotion in larval stage zebrafish using a standardized behavioral assay.

Zebrafish (Danio rerio) larvae offer a unique avenue for high-throughput in vivo investigation. The light/dark locomotor assay is widely used but lacks experimental consistency. Here, we present a protocol for a standardized light/dark assay by describing the steps for plating, acclimatizing larvae, performing the assay, and preparing drug exposure solutions.

P-tau217 and other blood biomarkers of dementia: variation with time of day.

Plasma biomarkers of dementia, including phosphorylated tau (p-tau217), offer promise as tools for diagnosis, stratification for clinical trials, monitoring disease progression, and assessing the success of interventions in those living with Alzheimer's disease. However, currently, it is unknown whether these dementia biomarker levels vary with the time of day, which could have implications for their clinical value. In two protocols, we studied 38 participants (70.

Closed-loop auditory stimulation targeting alpha and theta oscillations during rapid eye movement sleep induces phase-dependent power and frequency changes.

Study Objectives: Alpha and theta oscillations characterize the waking human electroencephalogram (EEG) and can be modulated by closed-loop auditory stimulation (CLAS). These oscillations also occur during rapid eye movement (REM) sleep, but their function here remains elusive. CLAS represents a promising tool to pinpoint how these brain oscillations contribute to brain function in humans.

Reliable Contactless Monitoring of Heart Rate, Breathing Rate, and Breathing Disturbance During Sleep in Aging: Digital Health Technology Evaluation Study.

Background: Longitudinal monitoring of vital signs provides a method for identifying changes to general health in an individual, particularly in older adults. The nocturnal sleep period provides a convenient opportunity to assess vital signs. Contactless technologies that can be embedded into the bedroom environment are unintrusive and burdenless and have the potential to enable seamless monitoring of vital signs.

Sleep maintains excitatory synapse diversity in the cortex and hippocampus.

Insufficient sleep is a global problem with serious consequences for cognition and mental health. Synapses play a central role in many aspects of cognition, including the crucial function of memory consolidation during sleep. Interference with the normal expression or function of synapse proteins is a cause of cognitive, mood, and other behavioral problems in over 130 brain disorders.

A unified approach to investigating 4 dpf zebrafish larval behaviour through a standardised light/dark assay.

Zebrafish are a dynamic research model in the domains of neuropsychopharmacology, biological psychiatry and behaviour. Working with larvae ≤4 days post-fertilisation (dpf) offers an avenue for high-throughput investigation whilst aligning with the 3Rs principles of animal research. The light/dark assay, which is the most widely used behavioural assay for larval neuropharmacology research, lacks experimental reliability and standardisation.

HPA activity mediates the link between trait impulsivity and boredom.

Boredom, a complex emotional state with implications for mental health and well-being, has garnered attention across disciplines, yet remains relatively understudied in psychiatric research. Here, we explored the intricate relationship between trait-impulsivity, stress, and boredom across two studies. Participants completed self-report measures of trait-impulsivity and boredom and boredom-inducing tasks.

Model integration of circadian- and sleep-wake-driven contributions to rhythmic gene expression reveals distinct regulatory principles.

Analyses of gene-expression dynamics in research on circadian rhythms and sleep homeostasis often describe these two processes using separate models. Rhythmically expressed genes are, however, likely to be influenced by both processes. We implemented a driven, damped harmonic oscillator model to estimate the contribution of circadian- and sleep-wake-driven influences on gene expression.

A closed-loop auditory stimulation approach selectively modulates alpha oscillations and sleep onset dynamics in humans.

Alpha oscillations play a vital role in managing the brain's resources, inhibiting neural activity as a function of their phase and amplitude, and are changed in many brain disorders. Developing minimally invasive tools to modulate alpha activity and identifying the parameters that determine its response to exogenous modulators is essential for the implementation of focussed interventions. We introduce Alpha Closed-Loop Auditory Stimulation (αCLAS) as an EEG-based method to modulate and investigate these brain rhythms in humans with specificity and selectivity, using targeted auditory stimulation.

A Protocol for Evaluating Digital Technology for Monitoring Sleep and Circadian Rhythms in Older People and People Living with Dementia in the Community.

Sleep and circadian rhythm disturbance are predictors of poor physical and mental health, including dementia. Long-term digital technology-enabled monitoring of sleep and circadian rhythms in the community has great potential for early diagnosis, monitoring of disease progression, and assessing the effectiveness of interventions. Before novel digital technology-based monitoring can be implemented at scale, its performance and acceptability need to be evaluated and compared to gold-standard methodology in relevant populations.