Chapter 14. Biological Rhythms, Sleep, and Dreaming

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By Lisa L. Lewis To any observers, the electrodes were the most visible sign that the Stanford Summer Sleep Camp was a bit out of the ordinary. Joe Oliveira, one of the original campers, recalls that right after check-in, four electrodes were glued to his hair, two taped next to his eyes, and several more by his chin. The electrodes remained in place the whole time. Long cords came out of them that were, “very small, like an iPhone charger,” he told me. During the day, the cords were often tied back and taped together into a compact bundle at the back of his head. The “trodes” (as the campers were called because of their electrode ponytails) attracted their fair share of weird looks on their outings around the university campus. And there was something else peculiar: Like clockwork, every two hours, they all returned to the dorm for “nap tests,” according to Mary Carskadon, who was pursuing her doctorate in neuro- and biobehavioral sciences at Stanford University. In their darkened dorm rooms, all the campers — a mix of kids and teens — would lie quietly for 20 minutes and attempt to fall asleep. Meanwhile, technicians in a nearby control room monitored their brainwaves, eye movements, and chin-muscle activity being transmitted from their electrodes via the cords, which had been plugged into a box near the headboard that had cables linked to a polysomnograph machine in the other room. There, a continuous paper trail issued forth mapping the campers’ data. When the time was up, the campers were roused and unplugged. The counselors recorded their vital signs, then plugged their wires into a second box closer to the dorm room desk and ran the campers through a short series of tests to measure their recall, attention span, and other aspects of alertness and cognitive functioning. Tom Harvey, who worked as a counselor/technician at the camp for several years, recalled a mix of “math tests and memory tests and ‘can you suffer through boredom’ tests.”

Keyword: Sleep; Development of the Brain
Link ID: 28381 - Posted: 06.25.2022

By Oliver Whang The sleep debt collectors are coming. They want you to know that there is no such thing as forgiveness, only a shifting expectation of how and when you’re going to pay them back. You think of them as you lie in bed at night. How much will they ask for? Are you solvent? You fall asleep, then wake up in a cold sweat an hour later. You fall asleep, then wake up, drifting in and out of consciousness until morning. As most every human has discovered, a couple nights of bad sleep is often followed by grogginess, difficulty concentrating, irritability, mood swings and sleepiness. For years, it was thought that these effects, accompanied by cognitive impairments like lousy performances on short-term memory tests, could be primarily attributed to a chemical called adenosine, a neurotransmitter that inhibits electrical impulses in the brain. Spikes of adenosine had been consistently observed in sleep-deprived rats and humans. Adenosine levels can be quickly righted after a few nights of good sleep, however. This gave rise to a scientific consensus that sleep debt could be forgiven with a couple of quality snoozes — as reflected in casual statements like “I’ll catch up on sleep” or “I’ll be more awake tomorrow.” But a review article published recently in the journal Trends in Neurosciences contends that the folk concept of sleep as something that can be saved up and paid off is bunk. The review, which canvassed the last couple of decades of research on long term neural effects of sleep deprivation in both animals and humans, points to mounting evidence that getting too little sleep most likely leads to long-lasting brain damage and increased risk of neurodegenerative disorders like Alzheimer’s disease. © 2022 The New York Times Company

Keyword: Sleep
Link ID: 28380 - Posted: 06.25.2022

Killian Fox Born in Aldershot in 1959, Russell Foster is a professor of circadian neuroscience at Oxford and the director of the Nuffield Laboratory of Ophthalmology. For his discovery of non-rod, non-cone ocular photoreceptors he received numerous awards including the Zoological Society scientific medal. His latest book – the first he has written without a co-author – is Life Time: The New Science of the Body Clock, and How It Can Revolutionize Your Sleep and Health. What is circadian neuroscience? It’s the fundamental understanding of how our biology ticks on a 24-hour basis. But also it’s bigger than that – it’s an understanding of how different structures interact within the brain and how different genes and their protein products generate a complex behaviour. And that is then embedded throughout our entire biology. Is it an exciting field? What’s happened over the past 25 years has been a move into understanding how these internal 24-hour oscillations are generated and I think it’s one of the amazing success stories in biomedicine. One of the great aims of neuroscience is identifying different bits of the brain with different functions and here we’ve got one: the suprachiasmatic nucleus (SCN), with 50,000 cells, is the master circadian pacemaker. If you don’t have that, then all of our 24-hour rhythms just disappear. How did you first get interested in circadian research? It was largely through photoreceptors. During my second year as an undergraduate – I did zoology at Bristol – I was reading the extraordinary The Life of Vertebrates by JZ Young and I came across a bit about lampreys. They have a parietal third eye, which mammals don’t have; we only have ocular photoreceptors, whereas fish, reptiles, birds, all have multiple photoreceptors. And I just thought: wow, this is so cool. For my PhD, I was trying to understand how light is detected and measured to regulate the seasonal biology of birds. Then I started to address what seemed a simple question: how are the clocks of mammals regulated? We don’t have weird photoreceptors, we have visual cells that grab light in a fraction of a second and then forget it. So how can that light sensory system also be used to gather light information over long periods of time – dawn-dusk detectors? Way back in the early 1990s, we suggested that there was [an undiscovered photoreceptor] in the eye and there was a huge outcry. © 2022 Guardian News & Media Limited

Keyword: Biological Rhythms; Sleep
Link ID: 28379 - Posted: 06.25.2022

By Anna Gibbs Turns out there is rest for the wicked: Sleepy mosquitoes are more likely to catch up on missed z’s than drink blood, a new study finds. Most people are familiar with the aftermath of a poor night’s sleep. Insects also suffer; for instance, drowsy honeybees struggle to perform their signature waggle dance, and weary fruit flies show signs of memory loss. In the case of sleep-deprived mosquitoes, they give up valuable time for feeding in favor of sleeping overtime, researchers report June 1 in Journal of Experimental Biology. The preference for dozing over dining is surprising given that “we know that mosquitoes love blood a lot,” says Oluwaseun Ajayi, a disease ecologist at the University of Cincinnati. Scientists have long been interested in mosquitoes’ circadian rhythms, the internal clock that determines their sleep and awake times (SN: 10/2/17). Knowing when a mosquito is awake — and biting — is important for understanding and limiting disease transmission. For instance, malaria, often transmitted by nocturnal mosquitoes, is kept under control by slinging netting around beds. But new research suggests that mosquitoes that feed during the day may also spread the disease. It’s challenging to study sleeping bloodsuckers in the lab. That’s partly because awake mosquitoes are aroused by the presence of a meal — the experimenter. And when mosquitoes do fall asleep, they look rather similar to peers that are merely resting to conserve energy. © Society for Science & the Public 2000–2022.

Keyword: Sleep; Evolution
Link ID: 28359 - Posted: 06.09.2022

The Associated Press NEW YORK — Researchers are drawing attention to a rise in poisonings in children involving the sleep aid melatonin — including a big jump during the pandemic. Last year, U.S. poison control centers received more than 52,000 calls about children consuming worrisome amounts of the dietary supplement — a six-fold increase from about a decade earlier. Most such calls are about young children who accidentally got into bottles of melatonin, some of which come in the form of gummies for kids. Parents may think of melatonin as the equivalent of a vitamin and leave it on a nightstand, said Dr. Karima Lelak, an emergency physician at Children's Hospital of Michigan and the lead author of the study published Thursday by the Centers for Disease Control and Prevention. "But really it's a medication that has the potential to cause harm, and should be put way in the medicine cabinet," Lelak said. An increasingly popular over-the-counter sleep aid Melatonin is a hormone that helps control the body's sleep cycle. It has become a popular over-the-counter sleeping aid, with sales increasing 150% between 2016 and 2020, the authors said. In the U.S., melatonin is sold as a supplement, not regulated as a drug. Because melatonin is unregulated, the U.S. Food and Drug Administration doesn't have oversight over the purity of ingredients or the accuracy of dosage claims. Other researchers have found that what's on the label may not match what's actually in the bottle, and some countries have banned the sale of over-the-counter melatonin. © 2022 npr

Keyword: Biological Rhythms; Sleep
Link ID: 28351 - Posted: 06.04.2022

By Peter Kendall As he gets ready for sleep each night, Don Tucker slips on an electrode cap and checks a little computer on his bedside table. Many workers at the private lab, run by the professor emeritus at the University of Oregon, follow the same routine. The experimental device monitors the nightly voyage through sleep. After sensing light sleep for a few minutes, it pulses electric current through the scalp and skull, nudging the brain into that nirvana known as deep sleep. The goal is not just a more restful slumber. Groundbreaking discoveries made in the past decade have revealed that the brain has a power-washing system that switches into high gear during deep sleep, flushing away harmful waste. This nightly cleanup is part of the restorative power of sleep and revives concentration, memory and motor skills. As we age, however, this cleansing system gets sloppier, and it can begin to leave behind some of the metabolic detritus of the day, including the amyloid beta proteins found in the plaque that characterize Alzheimer’s disease and other devastating neurological disorders. The controversial approval of an Alzheimer’s drug reignites the battle over the underlying cause of the disease The stunning revelation in 2012 of this previously unknown brain infrastructure — dubbed the glymphatic system — has ushered in a new age of research and invention not only about sleep but also aging, dementia and brain injury. Nearly 300 research papers were published last year on the glymphatic system. © 1996-2022 The Washington Post

Keyword: Sleep
Link ID: 28346 - Posted: 06.01.2022

If you’ve ever been put under anaesthesia, you might recall the disorienting feeling of blinking your eyes one moment and the next, waking up hours later. Now, findings from a new study illustrate just how profoundly general anaesthesia alters the state of the brain as it induces and maintains unconsciousness. It’s the first paper to track travelling brain waves in subjects all the way through the process of losing to regaining consciousness. An interdisciplinary team has found that the commonly used anaesthetic, propofol, substantially alters how different frequencies of brain waves travel along the cortex – the surface of the brain – and the research has been published in the Journal of Cognitive Neuroscience. Unconsciousness induced by propofol may be in part due to an increase in the strength and direction of slow delta traveling brain waves that disrupt higher-frequency waves associated with cognition. “The rhythms that we associate with higher cognition are drastically altered by propofol,” explains senior author Earl Miller, professor of neuroscience with the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology (MIT) in the US. “The beta traveling waves seen during wakefulness are pushed aside, redirected by delta traveling waves that have been altered and made more powerful by the anaesthetic,” he says. “The deltas come through like a bull in a china shop.” Conscious brains show a mixture of brain waves of different frequencies, which rotate or travel straight in various directions: you could think of them like the numerous waves on a choppy ocean.

Keyword: Sleep
Link ID: 28314 - Posted: 05.04.2022

By Elizabeth Preston On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t gotten any more hours of sleep than a typical Western city-dweller who stayed up doom-scrolling on their smartphone. Research has shown that people in non-industrial societies — the closest thing to the kind of setting our species evolved in — average less than seven hours a night, says evolutionary anthropologist David Samson at the University of Toronto Mississauga. That’s a surprising number when you consider our closest animal relatives. Humans sleep less than any ape, monkey or lemur that scientists have studied. Chimps sleep around 9.5 hours out of every 24. Cotton-top tamarins sleep around 13. Three-striped night monkeys are technically nocturnal, though really, they’re hardly ever awake — they sleep for 17 hours a day. Samson calls this discrepancy the human sleep paradox. “How is this possible, that we’re sleeping the least out of any primate?” he says. Sleep is known to be important for our memory, immune function and other aspects of health. A predictive model of primate sleep based on factors such as body mass, brain size and diet concluded that humans ought to sleep about 9.5 hours out of every 24, not seven. “Something weird is going on,” Samson says. Research by Samson and others in primates and non-industrial human populations has revealed the various ways that human sleep is unusual. We spend fewer hours asleep than our nearest relatives, and more of our night in the phase of sleep known as rapid eye movement, or REM. The reasons for our strange sleep habits are still up for debate but can likely be found in the story of how we became human. Graph shows average time spent sleep of different primate species. Humans sleep the least at seven hours per night; the three-striped night monkey sleeps the most at nearly 17 hours. © 2022 Annual Reviews

Keyword: Sleep; Evolution
Link ID: 28310 - Posted: 04.30.2022

By Michele Lent Hirsch Sleep problems are a hallmark of modern American life — perhaps never more so than recently. In 2016, the Centers for Disease Control and Prevention found that a third of Americans were getting too little sleep at night. But then came the stressors of the pandemic, job losses, disrupted schedules and closed schools, which kept record numbers of Americans up at night or unable to wake up in the morning. As many as 2 in 3 Americans reported getting either too much or too little sleep, in a survey from the American Psychological Association during the pandemic’s second year. And the insomnia of the past two years may be stubbornly hanging on: Many people continue having more trouble falling asleep or staying asleep or have seen unusual shifts in their sleep schedules. All of this is taking a toll. “These different types of sleep changes seem to be closely related to [problems with] mental health,” says Karianne Dion, a graduate student in clinical psychology at the University of Ottawa. Research she co-wrote, published in the Journal of Sleep Research in 2021, found “worse symptoms of stress, anxiety, and depression” among those who are sleeping less or going to bed later and waking up later than before. Researchers have long known that anxiety and depression can lead to sleeplessness, while sleeping poorly can increase the likelihood of anxiety and depression. But a good night’s rest is also critical for a strong immune system, as well as for health overall. Insufficient sleep over time is associated with a greater risk of diabetes, high blood pressure and heart disease, according to the CDC. It can lead to memory and cognitive issues as well. So how can we get the sleep we need? Here’s how to solve seven common problems that can interfere with your rest and your health. © 1996-2022 The Washington Post

Keyword: Sleep
Link ID: 28303 - Posted: 04.27.2022

Kayt Sukel Each night, as you transition into deep sleep from wakefulness, your body undergoes a remarkable transformation. Your muscles relax. Your breathing slows. Your temperature and blood pressure drop. Even your brain activity changes, decelerating into slow, coordinated waves. Despite these remarkable physiological changes, scientists are now learning that the brain is far from idle during sleep. Rather, it remains hard at work, facilitating memory and learning while uncoupled from the external world. “For a long time, we believed that being awake all day depleted you and that sleep was what was required to restore and reinvigorate the whole body, including the brain,” says Robert Stickgold, a pioneering sleep researcher at Harvard Medical School. “It turns out that rest has very little to do with the function of sleep—rather, our brain is sorting and consolidating the information we learned during the day so we can better access it when it’s needed.” Anyone who has ever pulled an all-nighter knows the effect that sleep deprivation can have on cognitive function, including one’s ability to learn and retain new information. Yet, over the last few decades, neuroscientists across the globe have learned that sleep plays an integral role in memory—and it is a role that is highly conserved across the animal kingdom. To better understand how sleep helps us remember, these researchers have been working to characterize not only the physiological changes observed during sleep, but also the neural mechanisms underlying them. Nearly every animal on earth, from fruit flies to non-human primates, experiences some form of sleep, a naturally recurring state of altered consciousness and inhibited sensory activity. And while the exact amount of time spent in slumber, and the patterns of neural activity, differ from animal to animal, humans are no different. We need sleep to thrive. © 2022 The Dana Foundation.

Keyword: Sleep; Learning & Memory
Link ID: 28285 - Posted: 04.16.2022

Yue Leng Doctors often recommend “power naps” as a way to compensate for a poor night’s sleep and help keep alert until bedtime. But for older adults, extensive power naps could be an early sign of dementia. Research on how napping affects cognition in adults has had mixed results. Some studies on younger adults suggest that napping is beneficial to cognition, while others on older adults suggest it may be linked to cognitive impairment. However, many studies are based on just a single self-reported nap assessment. This methodology may not be accurate for people with cognitive impairment who may not be able to reliably report when or how long they napped. As an epidemiologist who studies sleep and neurodegeneration in older adults, I wanted to find out if changes in napping habits foreshadow other signs of cognitive decline. A study my colleagues and I recently published found that while napping does increase with age, excessive napping may foreshadow cognitive decline. Sleep may play a significant role in Alzheimer’s development. The link between daytime napping and dementia Sleep disturbance and daytime napping are known symptoms of mild to moderate Alzheimer’s disease and other forms of dementia in older adults. They often become more extreme as the disease progresses: Patients are increasingly less likely to fall asleep and more likely to wake up during the night and feel sleepy during the day. © 2010–2022, The Conversation US, Inc.

Keyword: Alzheimers; Sleep
Link ID: 28256 - Posted: 03.30.2022

By Erin Blakemore From the streetlights outside our bedrooms to the lamps and devices inside, sleeping with some amount of light has become a way of life for many. That may not be such a bright idea. Research suggests that sleeping in a moderately lit room could affect metabolic and cardiovascular health compared with snoozing in a room with dimmer light. We don’t need more sleep. We just need more darkness. In a study published in PNAS, researchers at Northwestern University had two groups of 10 young adults sleep in differently lit rooms. One group slept in rooms with dim light for two nights; the other slept one night in a room with dim night and the next in a room with moderate overhead light — about the equivalent of an overcast day. Participants wore heart monitors at night. In the morning, they did a variety of glucose tests. Both groups got the same amount of sleep but their bodies experienced very different nights. Both groups responded well to insulin the first night, when they both slept in dim lighting. On the second night, however, the group sleeping in brighter lighting didn’t respond as well to insulin. The dim light sleepers’ insulin resistance scores fell about 4 percent on the second night, while the bright sleepers’ rose about 15 percent. Their heart rates were faster on the bright night, too. The heightened heart rate and other measures led the researchers to conclude that light activates the sympathetic nervous system, which usually dominates bodily functions during the day.

Keyword: Sleep; Biological Rhythms
Link ID: 28252 - Posted: 03.26.2022

Hannah Devlin Science corespondent Taking long naps could be a precursor of Alzheimer’s disease, according to a study that tracked the daytime sleeping habits of elderly people. The findings could help resolve the conflicting results of the effects of napping on cognition in older adults, with some previous studies highlighting the benefits of a siesta on mood, alertness and performance on mental tasks. The latest study suggests that an increase over time in naps was linked to a higher chance of developing mild cognitive impairment or Alzheimer’s. The scientists think it is more likely that excessive napping could be an early warning sign, rather than it causing mental decline. “It might be a signal of accelerated ageing,” said Dr Yue Leng, an assistant professor of psychiatry at the University of California San Francisco. “The main takeaway is if you didn’t used to take naps and you notice you’re starting to get more sleepy in the day, it might be a signal of declining cognitive health.” The scientists tracked more than 1,000 people, with an average age of 81, over several years. Each year, the participants wore a watch-like device to track mobility for up to 14 days. Each prolonged period of non-activity from 9am to 7pm was interpreted as a nap. The participants also underwent tests to evaluate cognition each year. At the start of the study 76% of participants had no cognitive impairment, 20% had mild cognitive impairment and 4% had Alzheimer’s disease. For participants who did not develop cognitive impairment, daily daytime napping increased by an average 11 minutes a year. The rate of increase doubled after a diagnosis of mild cognitive impairment to a total of 24 minutes and nearly tripled to a total of 68 minutes after a diagnosis of Alzheimer’s disease, according to the research published in the journal Alzheimer’s and dementia. © 2022 Guardian News & Media Limited

Keyword: Alzheimers; Sleep
Link ID: 28244 - Posted: 03.19.2022

By Veronique Greenwood Sharks are celebrated for their apparently ceaseless motion — a small handful of species such as great white sharks must even swim to breathe, keeping water washing over their gills. Still, all that moving doesn’t preclude sharks from having a rest. Sleep across the animal kingdom manifests itself in many peculiar ways, like the birds whose brains sleep one half at a time or the bats that spend almost every hour of their day snoozing. And in a paper published in Current Biology on Wednesday, researchers confirmed that the draughtsboard shark, a small nocturnal shark native to New Zealand, appears to be sleeping during periods of calm, reporting that their metabolism and posture change significantly during these bouts of repose. They do, however, in a creepy touch, keep their eyes open for a lot of it. Further research will be required to demonstrate that other kinds of sharks catch underwater z’s like the draughtsboard shark. But the new study supports the hypothesis that one reason organisms might have evolved sleep is as a tool for conserving energy. Draughtsboard sharks were identified last year as sleepers by this same group of researchers based in New Zealand and Australia. They watched captured sharks carefully in tanks and tested their responses to disturbances during their restful periods. (These sharks are not among those that swim to breathe; they hang out on the ocean floor and pump water over their gills.) The team found that it was more difficult to prompt the sharks into movement if they had been still for a long time, suggesting they were in fact sleeping. This time, said Craig Radford, a professor of marine science at the University of Auckland and an author of the new paper, the researchers were looking to compare the sharks’ metabolisms during these periods of calm, defined as being still for longer than five minutes, with when they were resting for shorter periods and when they were actively swimming. They used a specially built tank with instruments that let them monitor how much oxygen the sharks were using, a way to indirectly measure metabolism. Seven sharks each spent 24 hours in the tank, and the researchers found that these states were indeed quite different. © 2022 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 28234 - Posted: 03.11.2022

ByKelly Servick In 1997, Laura Gould put her 15-month-old daughter, Maria, down for a nap and returned to find her unresponsive. She had died suddenly, with no clues to explain the tragedy besides a fever the night before. When her daughter’s body was sent to the medical examiner’s office, “I thought they’d call me in an hour and tell me what happened … like on TV,” Gould says. Months later, neither that office nor independent pathologists had an explanation. “I hated ending it with ‘the autopsy was inconclusive, go on and live your life now,’” she says. “It just didn’t really feel like that was an option.” Gould co-founded a nonprofit foundation to support grieving parents, raise research funds, and increase awareness of sudden unexplained death in childhood (SUDC), a term used for children older than 12 months. In the United States, roughly 400 deaths fall into this category each year—about one-quarter as many as are labeled sudden infant death syndrome (SIDS). Two recent genetic analyses, one funded in part by Gould’s SUDC Foundation, now suggest potential causes for at least a small fraction of cases: mutations in genes associated with epilepsy, heart arrhythmias, and neurodevelopmental disorders. “Having this data is important,” says Marco Hefti, a neuropathologist at the University of Iowa Carver College of Medicine who was not involved in the new studies. SUDC is not a single disease, but “a grab bag of different things—and the more of those different things you can pull out, the better for everybody.” Neither study can say with certainty that a mutation is responsible for a child’s death. But the findings provide a basis for animal studies that could reveal how the genetic changes interfere with vital functions. They might also inform future child death investigations and potentially even screening programs to prevent deaths. Research on SUDC has lagged that on the more common and better known SIDS. Yet, biologically, SIDS and SUDC “may be part of a spectrum,” says Ingrid Holm, a medical geneticist at Boston Children’s Hospital. In both, death often occurs during sleep, and researchers suspect contributors including undetected heart defects, metabolic disorders, and central nervous system abnormalities. The children who die are roughly 10 times more likely than the average child to have a history of febrile seizures—convulsions that come with fevers in young children, notes neurologist Orrin Devinsky of New York University (NYU) Langone Health. © 2022 American Association for the Advancement of Science.

Keyword: Sleep; Genes & Behavior
Link ID: 28200 - Posted: 02.12.2022

Ian Sample Science editor People who develop Alzheimer’s disease can experience sleep disturbances years before the condition takes hold, but whether one causes the other, or something more complex is afoot, has always proved hard for scientists to determine. Now, researchers in the US have shed light on the mystery, in work that raises hopes for new therapies, and how “good sleep hygiene” could help to tackle the disease and its symptoms. The findings show that humans’ 24-hour circadian clock controls the brain’s ability to mop up wayward proteins linked to Alzheimer’s disease. If the scientists are right, the work would explain, at least in part, how disruption to circadian rhythms and sleep disturbances might feed into the onset and progression of Alzheimer’s disease, and how preventing such disruption might stave off the condition. “Circadian disruption is correlated with Alzheimer’s diagnosis and it has been suggested that sleep disruptions could be an early warning sign of Alzheimer’s disease,” said Dr Jennifer Hurley, who led the research at Rensselaer Polytechnic Institute, in New York. Alzheimer’s takes hold when connections are lost between nerve cells in the brain. The disease is progressive and linked to abnormal plaques and tangles of proteins that steadily build up in the brain. The disease is the most common cause of dementia and affects more than half a million people in the UK, a figure that is set to rise. To keep the brain healthy, immune cells called microglia seek out and destroy troublesome proteins that threaten to accumulate in the brain. One type of protein targeted by the cells is called amyloid beta, a hallmark of Alzheimer’s. © 2022 Guardian News & Media Limited

Keyword: Alzheimers; Sleep
Link ID: 28197 - Posted: 02.12.2022

Ian Sample Science editor Getting an hour or so more sleep each night can help people to cut calories, according a small clinical trial in overweight adults. Researchers in the US found that people who typically slept for less than 6.5 hours a night shed an average of 270 calories from their daily intake when they got an extra 1.2 hours of sleep. Sustained over three years, the reduction in calories could lead people to lose about 12kg (26lbs) without changing their diet during the day, the scientists believe. Some participants in the study consumed 500 fewer calories a day after improving their sleep. The study was not designed to look at weight loss, but researchers noticed the fall in calories within two weeks of patients changing their sleep patterns. “If healthy sleep habits are maintained over longer duration, this would lead to clinically important weight loss over time,” said Dr Esra Tasali, of the University of Chicago’s sleep centre. “Many people are working hard to find ways to decrease their caloric intake to lose weight – well, just by sleeping more, you may be able to reduce it substantially.” The trial studied 80 adults aged 21 to 40 with a body mass index between 25 and 29.9, meaning they were overweight. Half of the participants were randomly assigned to receive personalised sleep hygiene counselling aimed at extending the amount of time they slept each night. © 2022 Guardian News & Media Limited

Keyword: Sleep; Obesity
Link ID: 28191 - Posted: 02.09.2022

By Amelia Nierenberg A couple of glasses of wine or a few drinks in the evening will probably make you fall asleep faster than normal. Who among us hasn’t left the dishes for the next morning or neglected a skin-care routine after a dinner party or festive night out? But even if you thud into dreamland, there’s a good chance that too much alcohol will mean a fitful night of sleep. That’s because alcohol disrupts what’s known as your sleep architecture, the normal phases of deeper and lighter sleep we go through every night. A night of drinking can “fragment,” or interrupt, these patterns, experts say, and you may wake up several times as you ricochet through the usual stages of sleep. “You pay for it in the second half of the night,” said Dr. Jennifer Martin, a psychologist and professor of medicine at the University of California, Los Angeles. Alcohol is “initially sedating, but as it’s metabolized, it’s very activating.” Here’s how it breaks down. In the first half of the night, when fairly high levels of alcohol are still coursing through your bloodstream, you’ll probably sleep deeply and dreamlessly. One reason: In the brain, alcohol acts on gamma-aminobutyric acid, or GABA, a neurotransmitter that inhibits impulses between nerve cells and has a calming effect. Alcohol can also suppress rapid eye movement, or REM sleep, which is when most dreaming occurs. Later in the night, as alcohol levels drop, your brain kicks into overdrive. You may toss and turn as your body undergoes a rebound arousal. “As the levels decline, you’re going to get more issues with the fragmentation,” said Dr. R. Nisha Aurora, a member of the board of directors of the American Academy of Sleep Medicine. You’ll also probably have more vivid or stressful dreams and — because fitful sleep means that you’re waking up more regularly — you are more likely to remember them.

Keyword: Sleep; Drug Abuse
Link ID: 28183 - Posted: 02.02.2022

By Amelia Nierenberg Most people think of melatonin as a natural nod-off aid, kind of like chamomile tea in pill form. Even the name of the popular dietary supplement sounds sleepy — that long “o” sound almost makes you yawn mid-word. But melatonin is also a hormone that our brains naturally produce, and hormones, even in minuscule amounts, can have potent effects throughout the body. “There are some clinical uses for it, but not the way that it’s marketed and used by the vast majority of the general public,” said Jennifer Martin, a psychologist and professor of medicine at the University of California, Los Angeles. Experts strongly urge people to consult their doctor or a sleep specialist before taking melatonin, in part because the supplement does not address many underlying health problems that may be disrupting sleep. Anxiety can cause insomnia, as can a host of other potentially serious ailments, such as sleep apnea, restless legs syndrome or mood disorders like depression, that may require medical treatment. Melatonin, however, is relatively inexpensive and readily available at local pharmacies in the United States (in other countries it typically requires a prescription), and many people will go out and buy it on their own. So what’s the best approach to taking melatonin? Here’s what experts had to say. During the day, the brain’s pea-sized pineal gland remains inactive. A few hours before our natural sleep time, as it starts to get dark outside and the light entering our retina fades, the gland switches on to flood the brain with melatonin. “Melatonin is sometimes called the ‘hormone of darkness’ or ‘vampire hormone,’” because it comes out at night, said Matthew Walker, a professor of neuroscience and psychology at the University of California, Berkeley, and the author of the book “Why We Sleep.” As levels of melatonin rise, levels of cortisol, the stress hormone, fall. Respiration slows. Soon, our eyelids begin to droop. Instead of a lights-out trigger, melatonin acts more like a dimmer switch, turning the day functions off and switching night functions on. So taking a melatonin supplement is sort of like taking a dose of sunset, tricking your body into feeling like it’s nighttime. It doesn’t put you to sleep as much as it tells the body that it’s time to sleep. © 2022 The New York Times Company

Keyword: Biological Rhythms; Sleep
Link ID: 28158 - Posted: 01.19.2022

Leyland Cecco A whistleblower in the Canadian province of New Brunswick has warned that a progressive neurological illness that has baffled experts for more than two years appears to be affecting a growing number of young people and causing swift cognitive decline among some of the afflicted. Speaking to the Guardian, an employee with Vitalité Health Network, one of the province’s two health authorities, said that suspected cases are growing in number and that young adults with no prior health triggers are developing a catalog of troubling symptoms, including rapid weight loss, insomnia, hallucinations, difficulty thinking and limited mobility. The official number of cases under investigation, 48, remains unchanged since it was first announced in early spring 2021. But multiple sources say the cluster could now be as many as 150 people, with a backlog of cases involving young people still requiring further assessment. “I’m truly concerned about these cases because they seem to evolve so fast,” said the source. “I’m worried for them and we owe them some kind of explanation.” At the same time, at least nine cases have been recorded in which two people in close contact – but without genetic links – have developed symptoms, suggesting that environmental factors may be involved. One suspected case involved a man who was developing symptoms of dementia and ataxia. His wife, who was his caregiver, suddenly began losing sleep and experiencing muscle wasting, dementia and hallucinations. Now her condition is worse than his. A woman in her 30s was described as non-verbal, is feeding with a tube and drools excessively. Her caregiver, a nursing student in her 20s, also recently started showing symptoms of neurological decline. © 2021 Guardian News & Media Limited

Keyword: Movement Disorders; Alzheimers
Link ID: 28140 - Posted: 01.05.2022