Chapter 14. Biological Rhythms, Sleep, and Dreaming

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By Karen Zraick and Sarah Mervosh Are you sabotaging your sleep in your quest to improve it? Many new tools are becoming available to monitor your sleep or help you achieve better sleep: wearable watches and bands; “nearable” devices that you can place on your bed or nightstand; and apps that work by monitoring biometric data, noise and movement. They can remind you to start winding down, or generate a report on your night’s slumber. But some sleep specialists caution that these apps and devices may provide inaccurate data and can even exacerbate symptoms of insomnia. Fiddling with your phone in bed, after all, is bad sleep hygiene. And for some, worrying about sleep goals can make bedtime anxiety even worse. There’s a name for an unhealthy obsession with achieving perfect sleep: orthosomnia. It was coined by researchers from Rush University Medical School and Northwestern University’s Feinberg School of Medicine in a 2017 case study published in the Journal of Clinical Sleep Medicine. Dr. Kelly Baron, one of the paper’s authors and the director of the University of Utah’s behavioral sleep medicine program, said that sleep trackers can be helpful in identifying patterns. She herself tracks her bedtime with a Fitbit. But she said she had noticed a trend of patients complaining based on unverified scores, even for things like the amount of deep sleep, which varies by individual. “People were putting a lot of stock in what it was telling them,” she said. “Like, ‘I’m afraid I’m not getting enough deep sleep. There’s something wrong with me.’” As gadgets proliferate, so do concerns The flood of data and buzzwords can easily become confusing: sleep debt percentages, heart rate dips, sleep rhythms, graphs of sleep disruption and comparisons to other users. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26327 - Posted: 06.14.2019

By Jane E. Brody How did you sleep last night? If you’re over 65, I hope it was better than many others your age. In a study by the National Institute on Aging of over 9,000 Americans aged 65 and older, more than half said they had difficulty falling asleep or staying asleep. Many others who believe they spend an adequate number of hours asleep nonetheless complain of not feeling rested when they get up. Chronic insomnia, which affects 5 percent to 10 percent of older adults, is more than just exhausting. It’s also linked to an increased risk of developing hypertension, Type 2 diabetes, heart attack, depression, anxiety and premature death. It may also be a risk factor for dementia, especially Alzheimer’s disease. Studies based on more than 1,700 men and women followed over many years by researchers at Pennsylvania State University College of Medicine found that the risk of developing hypertension was five times greater among those who slept less than five hours a night and three and a half times greater for those who slept between five and six hours. But there was no increased risk among those who regularly slept six or more hours. Likewise, the risk of developing diabetes was three times greater for the shortest sleepers and twice as great for those who slept between five and six hours. People with insomnia often complain that they can’t concentrate or focus and have memory problems. While the evidence for this is inconsistent, the Penn State studies showed that people with insomnia are more likely to perform poorly on tests of processing speed, switching attention and visual memory. And most studies have shown that insomnia impairs cognitive performance, a possible risk factor for mild cognitive impairment and dementia. © 2019 The New York Times Company

Keyword: Sleep; Alzheimers
Link ID: 26315 - Posted: 06.10.2019

Hannah Devlin Science correspondent Smartphone sleep-tracking apps are making people so anxious and obsessed about their sleep that they are developing insomnia, a leading neurologist has said. Speaking at the Cheltenham science festival, Dr Guy Leschziner, a sleep disorder specialist and consultant at Guy’s hospital in London, said a growing preoccupation with getting enough sleep was backfiring. “We’ve seen a lot of people who have developed significant insomnia as a result of either sleep trackers or reading certain things about how devastating sleep deprivation is for you,” Leschziner said before his talk. A high proportion of patients seeking treatment for insomnia turn up at his clinic with data about their sleep patterns and are often reluctant to delete the app, he said. “It’s rather difficult to dissuade them from using it.” Most apps have not been clinically validated and only track movement, so do not provide insight into the quality of sleep, he added. “My view of sleep trackers is fairly cynical. If you wake up feeling tired and you’ve had an unrefreshing night’s sleep then you know you’ve got a problem,” he said. “If you wake up every day and feel refreshed, are awake throughout the day and are ready to sleep at the same time every night then you’re probably getting enough sleep for you and you don’t need an app to tell you that.” Similar concerns were highlighted in a series of case studies published last year by a team in Chicago that described patients whose micromanagement of sleep using apps had led to a disorder called orthosomnia. © 2019 Guardian News & Media Limited

Keyword: Sleep
Link ID: 26314 - Posted: 06.10.2019

Laura Sanders In a nighttime experiment called the Dream Catcher, people’s dreams slipped right through the net. Looking at only the brain wave activity of sleeping people, scientists weren’t able to reliably spot a dreaming brain. The details of that leaky net, described May 27 at bioRxiv.org, haven’t yet been reviewed by other scientists. And the results are bound to be heavily scrutinized, as they run counter to earlier work that described signs of dreams in neural data. The experimental design matters, because scientists suspect that dreams hold clues about the deepest mystery of the mind — consciousness itself. The brain can create rich tapestries of awareness even in the complete absence of incoming information. Studying these instances of brain-created consciousness, which include dreaming, mind-wandering and daydreaming, “is a powerful way to understand the relationship between the brain and the mind,” says study coauthor Naotsugu Tsuchiya of Monash University in Clayton, a town near Melbourne, Australia. Tsuchiya and his colleagues analyzed data generated from nine people who slept overnight in a laboratory while wearing an electrode cap that measured brain waves. The researchers focused on a stage of sleep called non-REM sleep. (Dreams are so abundant during REM sleep that researchers would have been hard-pressed to find enough instances of nondream sleep to use as a comparison.) To identify dreams, researchers employed an irritating method: They would wake up a person once he or she had entered non-REM sleep, and ask whether the person had been dreaming. To keep the experiment free from unintentional biases, the project relied on two teams of researchers: data collectors and data analyzers. Once the collectors had gathered brain wave data on both dreams and nondreams, the data was handed over to Tsuchiya and other data analyzers without any clues about the subjects, including whether they were dreaming. |© Society for Science & the Public 2000 - 2019.

Keyword: Sleep
Link ID: 26298 - Posted: 06.04.2019

By Amitha Kalaichandran, M.D. It was 11 p.m. and my 5-year-old patient was sleeping peacefully in her hospital bed, snuggled up with her mother and several stuffed animals. Her breathing was quiet and soft. Her bedside heart rate monitor, which glowed a faint yellow in the dark hospital room, was turned to “silent.” “Sorry, I have to take a listen to her heart,” I whispered to her mother, tapping her shoulder lightly. Her mother and I had a good relationship: I had served as an advocate for her daughter several times during her seven-week stay in the ward. She had a rare disease that had been a medical mystery for many months, but she would be transferred to a more specialized center soon. I hated to wake her, but recently, when I had offered to wait to examine a child until after a nap, my attending physician had scolded: “You can’t care about that. If you do, you’ll never examine them. They have to get used to it — they’re in the hospital, after all.” But the poor girl was tired. She was poked three times a day for blood and taken to the M.R.I. or CT scanner at various times. I completed my exam: her vital signs, her heart, perfusion (how well her heart was pumping blood to her body), and palpated her abdomen to check her liver and spleen (which were enlarged, but no more than they had been). She seemed stable. I backed out slowly. The next morning, the girl’s mother mentioned that it had taken another hour for her to fall asleep again. Was there anything that we could do to allow her to sleep through the night? Wouldn’t a good night’s sleep help with her condition? She had a point. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26297 - Posted: 06.04.2019

By Jane E. Brody When a child is born with a rare disorder that few doctors recognize or know how to manage, it can pay big dividends for parents to be proactive, learn everything they can about the condition, and with expert medical guidance, come up with the best way to treat it. That is the approach Lara C. Pullen of Chicago adopted when her son, Kian Tan, was born 15 years ago last month at 7½ pounds, seemingly well-formed and healthy. But within 24 hours, Dr. Pullen, who already had two daughters, said Kian had stopped moving, wouldn’t nurse and felt as floppy as a rag doll. Two and a half weeks later, a genetic test showed that Kian had Prader-Willi syndrome, a genetic disorder that occurs once in every 15,000 to 25,000 live births. While at first it is a struggle to get enough food into these babies because they’re too weak to suck, within two or three years their main symptom is an insatiable appetite that results in extreme obesity unless the child, who is driven by constant hunger, is kept from sneaking and stealing food. Prader-Willi syndrome is caused by the failed expression of several genes on chromosome 15 derived from the child’s father. The genes are either missing or inactivated by a mistake that occurs during sperm development or, in some cases, the father’s entire chromosome 15 is not inherited by the fetus. The disorder is only rarely inherited, but when a father has Prader-Willi syndrome caused by a deletion in chromosome 15, there’s a 50 percent chance each child he fathers will inherit the defective chromosome. In addition to an excessive appetite, its range of symptoms includes short stature, sleep apnea, extreme daytime sleepiness, visual defects, underdeveloped genital organs, poor coordination, mild to moderate intellectual disability, speech problems, a high tolerance for pain, temper tantrums, obsessive behaviors and blood sugar irregularities. © 2019 The New York Times Company

Keyword: Obesity; Genes & Behavior
Link ID: 26292 - Posted: 06.03.2019

By Gian Gastone Mascetti One of the most striking features of living organisms, both animals and plants, is the way their physiology and behavior have adapted to follow the fluctuations of daily light and nocturnal darkness. A clock in the brain synchronized to environmental cues generates biological changes that vary over a 24-hour cycle—circadian rhythms (from the Latin words circa and diem, meaning “about” and “a day,” respectively). In this way, the earth’s rotation is reproduced in the dynamics of our neuronal circuits. The sleep-wakefulness cycle is a typical circadian rhythm. Wakefulness is characterized by sensory activity and movement; during sleep the senses lose touch with their surroundings, and movements subside. This periodic loss of consciousness appears on electroencephalogram (EEG) recordings as a clear signature: deep sleep consists of slow oscillations of high amplitude. Wakefulness, in contrast, is made up of fast, low-amplitude oscillations. Much about sleep remains a mystery, however. Why would an animal shut down basic sensory and motor activity for hours on end, leaving itself a target for predators? This question becomes more acute in aquatic mammals, which need to regulate breathing and body temperature while they sleep. Remarkably, some animals have solved this problem by developing the ability to sleep with one half their brain while remaining vigilant with the other—a behavior known as unihemispheric slow-wave sleep (USWS). Still others engage in USWS under some circumstances but put both hemispheres to bed when necessary. Marine mammals, bird species and possibly reptiles enter a half-on/half-off state, sometimes keeping one eye open during these intervals. Recently researchers have even discovered a vestigial form of unihemispheric sleep in humans. © 2019 Scientific American

Keyword: Sleep; Laterality
Link ID: 26290 - Posted: 06.03.2019

By Jane E. Brody Although the woman in her 50s had been effectively treated for depression, she remained plagued by symptoms that often accompany it: fatigue, sleepiness and lethargy, even though she thought she was getting enough sleep. With depression no longer causing her persistent symptoms, her psychiatrist advised her to consult a sleep specialist. Sure enough, a night in the sleep lab at the University of Pennsylvania’s Perelman School of Medicine revealed that while the woman was supposedly asleep, she experienced micro-awakenings about 18 times an hour, resulting in sleep that restored neither body nor brain. All night long, she would stop breathing for more than 10 seconds at a time, followed by a mini-arousal and a snore as she gasped for breath to raise the depleted oxygen level in her blood. Diagnosis: Obstructive sleep apnea, an increasingly common yet often missed or untreated condition that can result in poor quality of life, a risk of developing heart disease, stroke, diabetes and even cancer, and perhaps most important of all, a threefold increased risk of often-fatal motor vehicle accidents. Obstructive sleep apnea afflicts about 9 percent of women and 24 percent of men, most of them middle-aged or older, yet as many as 9 in 10 adults with this treatable condition remain undiagnosed, according to the American Academy of Sleep Medicine. The condition is on the rise because the most frequent cause is obesity, which continues its unrelenting climb among American adults. Sleep apnea afflicts more than two people in five who have a body mass index of more than 30, and three in five adults with metabolic syndrome, Dr. Sigrid C. Veasey and Dr. Ilene M. Rosen wrote in The New England Journal of Medicine in April. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26272 - Posted: 05.28.2019

Bryan Clark Last spring, a study set the internet ablaze with sensational headlines promising an early death for those with nontraditional sleep schedules. It wasn’t the conclusion of the study, or its researchers. But in the bombastic world of science reporting, it didn’t really matter. Originally published in the journal Chronobiology International, the study looked at the chronotypes — a means of classifying one’s predisposition for sleeping at certain hours — of more than 430,000 people over a six-and-a-half-year period. Scouring data from the National Health Service in England and the NHS Central Register in Scotland, researchers sought to find out what, if any, negative health impacts awaited those with a night-owl schedule. After sorting nearly half a million people into four groups — definite larks (larks are early birds, those most likely to rise with the sun), definite owls (those more likely to retire to bed with the sun than to wake with it), moderate larks and moderate owls — researchers reported some troubling findings. More than 10,000 participants died during the study period. Of those deaths, the bulk seemed to be the result of natural causes. The study didn’t necessarily seek to link death with sleep deprivation, but rather to “comorbidity” — the occurrence in one person of two or more conditions, such as psychological or neurological disorders, diabetes and the like. With each incremental shift toward a night-owl schedule, comorbidities became more common, increasing the risk of an early death. But while saying that night owls are going to die early makes for an eye-catching headline, the real story isn’t quite that simple. The story behind the study It’s evident that owls’ nontraditional schedules put them at risk of significant health problems. Nearly every study on this chronotype has returned troubling findings. © 2019 The New York Times Company

Keyword: Biological Rhythms
Link ID: 26267 - Posted: 05.24.2019

By Benedict Carey Federal health regulators announced on Tuesday that they would require manufacturers of sleeping pills such as Ambien and related drugs to post strongly worded warnings in boxes on labels and patient guides. The Food and Drug Administration, in what it called a safety announcement, noted that the drugs’ side effects included risky behaviors, such as sleepwalking and sleep driving, that can lead to injury and even death. The F.D.A. singled out Ambien and two other popular sleep aids, Lunesta and Sonata, as well as three formulations of zolpidem, the generic name for Ambien. The boxed warnings — the most prominent form of warning required by the agency — must list side effects such as sleepwalking and sleep driving, in which people using the drugs take risks without being fully awake. The agency said such reactions were rare but could lead to injuries or death; it advised doctors not to prescribe the drugs to people who have had such side effects in the past. “Patients, stop taking your insomnia medicine and contact your health care professional right away if you experience a complex sleep behavior where you engage in activities while you are not fully awake,” the agency’s safety alert said, “or if you do not remember activities you have done while taking the medicine.” Prescriptions for sleeping pills grew to more than 20 million in 2010 from 5.3 million in 1999, according to national estimates. About one in eight people with sleeping difficulty report using the drugs; among people of retirement age, more than a third report taking a sleeping aid. The F.D.A. warned about such effects in 2007, after doctors reported that some patients were having strange nighttime experiences, mostly while taking zolpidem (Ambien), the first of the so-called z-drugs. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26193 - Posted: 05.01.2019

By Nicholas Bakalar The most common cause of injury deaths in babies under a year old is unintentional suffocation, and almost all of these deaths are preventable, a new report found. Researchers used a federal government case registry to look at the causes of infant deaths by injury between 2011 and 2014. Of 1,812 sudden and unexpected infant deaths over the period, about 14 percent were caused by accidental suffocation. Of these, 69 percent were caused by soft bedding, 19 percent were overlay deaths, in which a caregiver rolled over on the baby, and 12 percent happened when the infant was trapped between two objects, usually the mattress and a wall. The analysis appears in Pediatrics. About 71 percent of the overlay deaths occurred in an adult’s bed, as did 49 percent of the soft bedding deaths, where blankets, pillows or soft toys covering the airway were the most common cause. The American Academy of Pediatrics recommends that babies be put to sleep on their backs, that the crib have no soft bedding or soft objects, and that adults never sleep in the same bed with a baby. “This paper supports the A.A.P. recommendations,” said the lead author, Alexa B. Erck Lambert, an epidemiologist with the Centers for Disease Control and Prevention. “And it shows that these deaths by suffocation could have been avoided if the babies had been placed properly.” © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26171 - Posted: 04.25.2019

Allison Aubrey An estimated 40% of adults in the U.S. snore. And, men, you tend to out-snore women. (Yes, this may explain why you get kicked or shoved at night!) And despite the myth that snoring is a sign of deep sleep, there's really no upside to it. "Snoring really does not demonstrate anything good, " says Erich Voigt, an ear, nose, and throat doctor and sleep specialist at New York University Langone Health. "You can have beautifully deep sleep in a silent sleep." Snoring is never great news, but often it's harmless (other than the pain your sleeping partner may feel). In some cases, though, it's a sign of something serious. When we sleep, if the air that moves through our nose and mouth has a clear passage, we can sleep silently. But when the airways are narrowed, we snore. "Snoring is basically a vibration of the tissues inside of the airway," Voigt explains — that is, the roof of the mouth and the vertical folds of tissue that surround the tonsils. A lot of factors can contribute to snoring, says Voigt. We can control some of the underlying triggers. For instance, drinking alcohol is linked to snoring. Alcohol tends to make the tissues within our mouths swell a bit, and alcohol can also change the quality of sleep. "Your brain is sedated from alcohol, so the combination can make you snore worse," Voigt says. © 2019 npr

Keyword: Sleep
Link ID: 26165 - Posted: 04.23.2019

By Christopher Ingraham Sleep scientist Matthew Walker has observed that “human beings are the only species that deliberately deprive themselves of sleep for no apparent gain.” We stay up late to watch our favorite TV shows. We wake up early to get to work or school on time. And twice a year we change our clocks, to the bewilderment of our circadian rhythms. We also set up conflicts between our natural and social clocks in other, less obvious ways, a fact underscored in research published this month in the Journal of Health Economics. It turns out, the study found, that living on the wrong side of a time zone’s boundary can have negative consequences on a person’s health and wallet. The culprit? More natural light in the evening hours. To understand the study, co-authored by Osea Giuntella of the University of Pittsburgh and Fabrizio Mazzonna of the Universita della Svizzera Italiana, it is important to understand how time zones affect local sunset times. Traveling east to west, sunrise and sunset times get later, as the map above shows. Panama City, Fla., for instance, is located on the far eastern end of the Central time zone, while Pecos, Tex., sits on the far western side. This week, the sun set in Panama City about 7:12 p.m. Central time. In Pecos, it set more than an hour later, at 8:25 p.m. Sunset is a powerful biological trigger: The fading of natural light causes the body to release melatonin, a hormone that induces drowsiness. As a result, people on the eastern side of a time zone, where the sun sets earlier, tend to go to bed earlier than those on the western side. The data below, derived from about 1 million users of the now-defunct sleep tracker Jawbone, illustrates this point, showing how bedtimes shift from east to west, with a sharp reset happening once you cross into a new time zone. © 1996-2019 The Washington Post

Keyword: Biological Rhythms; Sleep
Link ID: 26161 - Posted: 04.22.2019

By James Gallagher Health and science correspondent, BBC News Widely held myths about sleep are damaging our health and our mood, as well as shortening our lives, say researchers. A team at New York University trawled the internet to find the most common claims about a good night's kip. Then, in a study published in the journal Sleep Health, they matched the claims to the best scientific evidence. They hope that dispelling sleep myths will improve people's physical and mental health and well-being. So, how many are you guilty of? Myth 1 - You can cope on less than five hours sleep This is the myth that just won't go away. Former British Prime Minister Margaret Thatcher famously had a brief four hours a night. German Chancellor Angela Merkel has made similar claims, and swapping hours in bed for extra time in the office is not uncommon in tales of business or entrepreneurial success. Yet the researchers said the belief that less than five hours shut-eye was healthy, was one of the most damaging myths to health. "We have extensive evidence to show sleeping five hours or less consistently, increases your risk greatly for adverse health consequences," said researcher Dr Rebecca Robbins. These included cardiovascular diseases, such as heart attacks and strokes, and shorter life expectancy. Instead, she recommends everyone should aim for a consistent seven to eight hours of sleep a night. Thatcher: Can people get by on four hours' sleep? Myth 2 - Alcohol before bed boosts your sleep The relaxing nightcap is a myth, says the team, whether it's a glass of wine, a dram of whisky or a bottle of beer. © 2019 BBC

Keyword: Sleep
Link ID: 26146 - Posted: 04.16.2019

Kate Kellaway Alice Robb is an American science journalist who has written for the Washington Post and the New Republic. Her new book, Why We Dream, encourages us to rethink the importance of dreams and to become dream interpreters ourselves. Writing a book about dreams turned you into a “magnet for confessions”. Why are people compelled to talk about dreams? It is a natural impulse because dreams are emotional, affect moods, feel profound. What is unusual is that we live in a culture where we’re expected to forget our dreams. We have this cliche that it is boring to talk about dreams. Between 1970 and 2000 you note that no research about dreaming was published in the top US journal, Science. Is that because it was looked down upon as a topic or the technical challenges involved in studying it? For most of the 20th century, researchers who wanted to study dreams had to rely on people’s descriptions of them – not the most perfect form of evidence. It didn’t help that psychologists were trying very hard to have their discipline seen as a “real” science; they were trying to distance themselves from Freud, who had put dreams at the centre of psychoanalysis. I think this is a case of technological advances enabling a shift in attitude. Once scientists saw that it was possible to study dreams with neuroimaging, they were able to start asking questions about what’s going on in the brain when we dream. There were a couple of big breakthroughs in the 1990s and early 2000s that helped make dreams a valid topic of scientific inquiry. Neuroscientist Matt Wilson discovered that rats’ brains kept working as they slept, replaying a maze they had run through during the day. And Robert Stickgold, a psychiatrist at Harvard, found that people who played Tetris in the lab would dream of the game at night. © 2019 Guardian News & Media Limited

Keyword: Sleep
Link ID: 26138 - Posted: 04.15.2019

By Steph Yin For animals that hibernate, making it to spring is no small feat. Torpor — the state of reduced bodily activity that occurs during hibernation — is not restful. By the time they emerge, hibernating animals are often sleep-deprived: Most expend huge bursts of energy to arouse themselves occasionally in the winter so their body temperatures don’t dip too low. This back-and-forth is exhausting, and hibernators do it with little to no food and water. By winter’s end, some have shed more than half their body weight. But just because it’s spring doesn’t mean it’s time to celebrate. Spring means getting ready for the full speed of summer — and after spending a season in slow motion, that requires some ramping up. Here’s a look at what different animals have on the agenda after coming out of winter’s slumber. Black bears emerge from their dens in April, but stay lethargic for weeks. During this so-called walking hibernation, they sleep plenty and don’t roam very far. Though they have lost up to one-third of their body weight over winter, they don’t have a huge appetite right away — their metabolism is not yet back to normal. They snack mostly on pussy willows and bunches of snow fleas. In January or February, some females give birth, typically to two or three cubs. New mothers continue to hibernate, but they go in and out of torpor, staying alert enough to respond to their cubs’ cries. When they emerge from their dens, mama bears find trees with rough bark that her cubs can easily climb for safety. © 2019 The New York Times Company

Keyword: Biological Rhythms
Link ID: 26112 - Posted: 04.04.2019

Laura Sanders SAN FRANCISCO — Seizures during sleep can scramble memories — a preliminary finding that may help explain why people with epilepsy sometimes have trouble remembering. The sleeping brain normally rehashes newly learned material, a nocturnal rehearsal that strengthens those memories. Neuroscientist Jessica Creery and her colleagues forced this rehearsal by playing certain sounds while nine people with epilepsy learned where on a screen certain pictures of common objects were located. Then, while the subjects later slept, the researchers played the sounds to call up some of the associated memories. This sneaky method of strengthening memories, called targeted memory reactivation, worked as expected for five people who didn’t have seizures during the process. When these people woke up, they remembered the picture locations reactivated by a tone better than those that weren’t reactivated during sleep, said Creery, of Northwestern University in Evanston, Ill. She presented the research March 25 at the annual meeting of the Cognitive Neuroscience Society. The opposite was true, however, for four people who had mild seizures, detected only by electrodes implanted deep in the brain, while they slept. For these people, memory reactivation during sleep actually worsened memories, making the reactivated memories weaker than the memories that weren’t reactivated during sleep. The combination of seizures and memory reactivation “seems like it’s actually scrambling the memory,” Creery says, a finding that suggest that seizures somehow accelerate forgetting. |© Society for Science & the Public 2000 - 2019

Keyword: Sleep; Epilepsy
Link ID: 26083 - Posted: 03.27.2019

By Marlene Cimons It can be difficult to sleep while pregnant. Any number of issues can interrupt sleep, including the frequent need to urinate, back pain, abdominal discomfort and shortness of breath, among others. Moreover, disruptive sleep during pregnancy can be risky for the fetus, contributing to curbing growth. But a recent study suggests that excessive, undisturbed sleep may be a problem, too. Sleeping continuously for nine or more hours may be related to the danger of late stillbirth, that is, the loss or death of a baby before or during delivery. “There’s been a lot of public attention paid to sleep deprivation and its impact on health, but not as much to lengthy — perhaps too much — sleep, especially when it comes to pregnancy,” said Louise O’Brien, research associate professor in the neurology sleep disorders center and in obstetrics and gynecology at the University of Michigan. “Women often worry when they wake up several times during the night when they are pregnant, but it may be protective in this case.” O’Brien and her colleagues analyzed online surveys from 153 women who had experienced a late stillbirth (on or after 28 weeks of pregnancy) during the month previous to answering the questionnaire and 480 women with an ongoing third-trimester pregnancy or who had recently delivered a live born baby during the same period. The findings, recently published in the journal Birth, suggest a connection between long periods of undisturbed maternal sleep and stillbirth, independent of other risk factors. Stillbirth affects about 1 percent of all pregnancies, or about 24,000 annually in the United States, many of them unexplained, according to the Centers for Disease Control and Prevention. © 1996-2019 The Washington Post

Keyword: Sleep
Link ID: 26073 - Posted: 03.25.2019

Allison Aubrey There are lots of reasons why many of us don't get the recommended seven hours or more of sleep each night. Travel schedules, work deadlines, TV bingeing and — a big one — having young children all take a toll. Research published recently in the journal Sleep finds that up to six years after the birth of a child, many mothers and fathers still don't sleep as much as they did before their child was born. For parents, there's just less time in the day to devote to yourself. So, can you catch up on sleep? That partly depends on how much sleep you've missed. A study in the current issue of Current Biology points to just how quickly the adverse effects of sleep deprivation can kick in. Researchers at the University of Colorado Boulder recruited a bunch of young, healthy adults who agreed to a stay in a sleep lab. Some were allowed to sleep no more than five hours per night for five consecutive days. "After five days, people [gained] as much as 5 pounds," says study author Christopher Depner, who studies the links between sleep loss and metabolic diseases. Lack of sleep can throw off the hormones that regulate appetite, he explains, so people tend to eat more. Depner and his colleagues also documented a decrease in insulin sensitivity among the sleep-deprived participants. "In some people, it decreased to a level where they'd be considered pre-diabetic," he says. Presumably, that rise in blood sugar would be only temporary in these young, healthy people. But it's a striking indicator of how much a lack of sleep can influence metabolism. © 2019 npr

Keyword: Sleep
Link ID: 26072 - Posted: 03.25.2019

Emery N. Brown, Francisco J. Flores General anesthetics work by altering the activity of specific neurons in the brain. One main class of these drugs, which includes propofol and the ether-derivative sevoflurane, work primarily by increasing the activity of inhibitory GABAA receptors, while a second class that includes ketamine primarily blocks excitatory NMDA receptors. The GABAA receptor is a channel that allows chloride ions to flow into the neuron, decreasing the voltage within the cell relative to the extracellular space. Such hyper­polarization decreases the probability that the neuron will fire. Propofol and sevoflurane increase the chloride current going into the cell, making the inhibition more potent. The NMDA receptor allows sodium and calcium ions to flow into the cell, while letting potassium ions out, increasing the voltage within the cell relative to the extra­cellular space and increasing the probability of neural firing. Ketamine blocks this receptor, decreasing its excitatory actions. Anesthetics’ interactions with neural receptors alter how neurons work, and as a consequence, how different brain regions communicate. These alterations manifest as highly structured oscillations in brain activity that are associated with the dramatic behavioral changes characteristic of general anesthesia. © 1986 - 2019 The Scientist

Keyword: Sleep
Link ID: 26048 - Posted: 03.19.2019