Recent quotes:
Body clock off-schedule? Prebiotics may help: Dietary compounds shown to protect against jet lag-type symptoms -- ScienceDaily
Naturally abundant in many fibrous foods -- including leeks, artichokes and onions -- and in breast milk, these indigestible carbohydrates pass through the small intestine and linger in the gut, serving as nourishment for the trillions of bacteria residing there. The authors' previous studies showed that rats raised on prebiotic-infused chow slept better and were more resilient to some of the physical effects of acute stress. For the new study, part of a multi-university project funded by the Office of Naval Research, the researchers sought to learn if prebiotics could also promote resilience to body-clock disruptions from things like jet lag, irregular work schedules or lack of natural daytime light -- a reality many military personnel live with. "They are traveling all over the world and frequently changing time zones. For submariners, who can be underwater for months, circadian disruption can be a real challenge," said lead author Robert Thompson, a postdoctoral researcher in the Fleshner lab. "The goal of this project is to find ways to mitigate those effects."New study uncovers how a series of sleep loss impacts mental and physical wellbeing -- ScienceDaily
Participants reported a pile-up of angry, nervous, lonely, irritable and frustrated feelings as a result of sleep loss. They also experienced more physical symptoms, such as upper respiratory issues, aches, gastrointestinal problems and other health concerns. These negative feelings and symptoms were continuously elevated throughout consecutive sleep loss days and didn't return to baseline levels unless they had a night sleep of more than six hours.Sleep Deprivation Impairs Molecular Clearance From the Brain
One night of sleep deprivation impaired clearance of the tracer substance from most brain regions, including the cerebral cortex, white matter and limbic structures, as demonstrated on the morning of Day 2 after intervention (sleep deprivation/sleep). Moreover, the impaired cerebral clearance in the sleep deprivation group was not compensated by subsequent sleep from Day 2 to 3. The present results provide in vivo evidence that one night of total sleep deprivation impairs molecular clearance from the human brain, and that humans do not catch up on lost sleep.Research delves into link between test anxiety and poor sleep -- ScienceDaily
Hamilton and graduate student co-authors Ronald Freche and Ian Carroll and undergraduates Yichi Zhang and Gabriella Zeller surveyed the sleep quality, anxiety levels and test scores for 167 students enrolled in a statistics class at KU. Participants completed an electronic battery of measures and filled out Sleep Mood Study Diaries during the mornings in the days before a statistics exam. Instructors confirmed exam scores. The study showed "sleep and anxiety feed one another" and can hurt academic performance predictably.Sleep is vital to associating emotion with memory, study finds -- ScienceDaily
The researchers found that when they disrupted sleep after they showed the subjects an image and had given them a mild foot shock, there was no fear associated with the visual stimulus. Those with unmanipulated sleep learned to fear the specific visual stimulus that had been paired with the foot shock. "We found that these mice actually became afraid of every visual stimulus we showed them," Aton said. "From the time they go to the chamber where the visual stimuli are presented, they seem to know there's a reason to feel fear, but they don't know what specifically they're afraid of." This likely shows that, in order for them to make an accurate fear association with a visual stimulus, they have to have sleep-associated reactivation of the neurons encoding that stimulus in the sensory cortex, according to Aton. This allows a memory specific to that visual cue to be generated.The researchers think that at the same time, that sensory cortical area must communicate with other brain structures, to marry the sensory aspect of the memory to the emotional aspect.A sleep disorder associated with shift work may affect gene function: Going on holiday has a restorative effect on changes in DNA -- ScienceDaily
A total of 32 shift workers participated in the study, of whom 21 suffered from shift work disorder and 11 were in the control group. Dynamic changes to DNA methylation were investigated through a genome-wide analysis during work and after a holiday period. Changes to DNA methylation which affected gene function were identified in study subjects suffering from a sleep disorder caused by shift work. The findings demonstrated that rest and recovery during holiday periods also resulted in the restoration of DNA methylation in cases where changes had been observed during the work period. The study proved the dynamic nature of DNA methylation, which was particularly emphasised in the activity of NMDA glutamate receptors. The strongest evidence was gained from the GRIN2C receptor: the methylation level of a specific CpG base pair in the regulatory region was lower during the work period in subjects suffering from shift work disorder. However, this change was reversed after the holiday period.Day-to-day variability in sleep parameters and depression risk: a prospective cohort study of training physicians | npj Digital Medicine
Within individuals, increased TST (b = 0.06, p < 0.001), later wake time (b = 0.09, p < 0.001), earlier bedtime (b = − 0.07, p < 0.001), as well as lower day-to-day shifts in TST (b = −0.011, p < 0.001) and in wake time (b = −0.004, p < 0.001) were associated with improved next-day mood.The science of siestas: New research reveals the genetic basis for daytime napping -- ScienceDaily
For this study, the MGH researchers and their colleagues used data from the UK Biobank, which includes genetic information from 452,633 people. All participants were asked whether they nap during the day "never/rarely," "sometimes" or "usually." The GWAS identified 123 regions in the human genome that are associated with daytime napping. A subset of participants wore activity monitors called accelerometers, which provide data about daytime sedentary behavior, which can be an indicator of napping. This objective data indicated that the self-reports about napping were accurate. "That gave an extra layer of confidence that what we found is real and not an artifact," says Dashti. Several other features of the study bolster its results. For example, the researchers independently replicated their findings in an analysis of the genomes of 541,333 people collected by 23andMe, the consumer genetic-testing company. Also, a significant number of the genes near or at regions identified by the GWAS are already known to play a role in sleep. One example is KSR2, a gene that the MGH team and collaborators had previously found plays a role in sleep regulation.Ancient echoes: Moonlight affects human sleep patterns | YaleNews
nt’s sleep duration across the lunar cycle ranged from 20 minutes to more than 90 minutes with little difference between the three indigenous groups, according to the study. Changes in the time that people fell asleep varied from a half hour to 80 minutes, the study found. The findings among the college students were consistent with these ranges. In all cases, people went to bed latest, and slept the least amount of time, three to five days before a full moon, according to the study. Interviews with Toba/Qom individuals indicated that moonlit nights are a particularly rich period for social activities, and elders reported that sufficient moonlight enables nighttime hunting and fishing, according to the study.Fruit-fly study sheds light on why vibrations help rock baby to sleep | by Psych News Daily | Dec, 2020 | Medium
The flies’ sleep duration is longer when they are “rocked,” and intrusive lights are less likely to wake them up. Vibrations also make the fruit flies sleep better — they are more alert afterwards, and behave as if they had slept longer than they actually had. This in turn lets them function better, even when they have had less sleep.Blue-light glasses improve sleep and workday productivity, study finds -- ScienceDaily
Across two studies, researcher collected data from 63 company managers and 67 call center representatives at Brazil-based offices for a U.S. multinational financial firm and measured task performance from clients. Participants were randomly chosen to test glasses that filtered blue light or those that were placebo glasses. "Employees are often required to work early mornings, which may lead to a misalignment between their internal clock and the externally controlled work time," the researchers said, adding that their analyses showed a general pattern that blue-light filtration can have a cumulative effect on key performance variables, at least in the short term. "Blue-light exposure should also be of concern to organizations," Guarana said. "The ubiquity of the phenomenon suggests that control of blue-light exposure may be a viable first step for organizations to protect the circadian cycles of their employees from disruption."Past your bedtime? Inconsistency may increase risk to cardiovascular health -- ScienceDaily
Researchers at the University of Notre Dame studied the correlation between bedtime regularity and resting heart rate (RHR) and found that individuals going to bed even 30 minutes later than their usual bedtime presented a significantly higher resting heart rate that lasted into the following day. "We already know an increase in resting heart rate means an increased risk to cardiovascular health," said Nitesh Chawla, the Frank M. Freimann professor of Computer Science and Engineering at Notre Dame, director of the Center for Network and Data Science and a lead author of the study. "Through our study, we found that even if you get seven hours of sleep a night, if you're not going to bed at the same time each night, not only does your resting heart rate increase while you sleep, it carries over into the next day."
Sleep has been conceptualized as “activity-dependent”, hence a response to prior waking experience, and proposed to be “the price the brain pays for plasticity during wakefulness”. We here propose that at the level of neuronal networks, particularly those arising from isolated embryonic thalamocortical cells maintained in culture, it represents a default mode of functioning. We show that cell assemblies in ex vivo cultures express powerful sleep specific patterns of oscillatory activity, as well as metabolic and molecular signatures of the sleep state.