Chapter 14. Biological Rhythms, Sleep, and Dreaming

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Nicola Davis Many people complain they do not get enough sleep, and it seems they are right to be concerned. Researchers have found that adults under the age of 65 who get five or fewer hours of sleep for seven days a week have a higher risk of death than those who consistently get six or seven hours’ shut-eye. However the effect of short sleeps over a few days may be countered by a later lie-in. The research found that individuals who managed just a few hours’ sleep each day during the week but then had a long snooze at weekends had no raised mortality risk, compared with those who consistently stuck to six or seven hours a night. “Sleep duration is important for longevity,” said Torbjörn Åkerstedt, first author of the study, at the Stress Research Institute, Stockholm University, and Karolinska Institute, also in the Swedish capital. The study, published in the Journal of Sleep Research, is based on data from more than 38,000 adults, collected during a lifestyle and medical survey conducted throughout Sweden in 1997. The fate of participants was followed for up to 13 years, using a national death register. Åkerstedt said researchers had previously looked at links between sleep duration and mortality but had focused on sleep during the working week. “I suspected there might be some modification if you included also weekend sleep, or day-off sleep.” Once factors such as gender, body mass index, smoking, physical activity and shift work, were taken into account, the results revealed that those under the age of 65 who got five hours of sleep or under that amount seven days a week had a 65% higher mortality rate than those getting six or seven hours’ sleep every day. But there was no increased risk of death for those who slept five or fewer hours during the week but then managed eight or more hours’ sleep on weekend days. 'Western society is chronically sleep deprived': the importance of the body's clock © 2018 Guardian News and Media Limited

Keyword: Sleep; Neuroimmunology
Link ID: 25007 - Posted: 05.23.2018

/ By Lynne Peeples Reaching behind a low bookshelf slightly taller than a typical 5-year-old — and one topped with a Seattle Seahawks gnome and stuffed kangaroo — Sara Barbee presses a button labeled “Alert.” Intense bluish light fills her classroom, and nearly all 17 kindergarteners respond with a collective “Whoooaaaaa.” Barbee, their teacher here at Renton Park Elementary School, walks back to the front of the classroom and ushers the students to sit “crisscross applesauce” on the perimeter of a brightly colored alphabet rug. Front-and-center rests a water tank atop a small blue table, which Barbee uses to teach her students about the buoyancy of objects in water. Indeed, it’s not the buoyancy lesson that has drawn me to this school just outside of Seattle, but those funky new lights, which are designed to mimic the shifting colors and intensities of the rising and setting sun. Scientists believe that exposure to bright, blue-rich white light during the day, and to softer, amber hues at night, helps restore the human body’s natural circadian rhythm, a deeply ingrained, physiological drumbeat that, many experts argue, has been disrupted to ill-effect by our constant exposure to standard incandescent or fluorescent lighting — and more recently, to the relentless glow of electronic screens. These are not, of course, new ideas, and doctors have long prescribed light boxes and related paraphernalia for seasonal affective disorder and other forms of depression. But it’s only now, proponents say — amid innovations in light-emitting diode, or LED, technology; amid calls for more energy-efficient lighting infrastructure overall; and amid a renaissance in scientific understanding of how human eyes, brains, and internal clocks interrelate — that a public health revolution, driven by more thoughtful lighting infrastructure, has the potential to unfold. Copyright 2018 Undark

Keyword: Biological Rhythms; Depression
Link ID: 25003 - Posted: 05.21.2018

Michaeleen Doucleff Six months ago, Melissa Nichols brought her baby girl, Arol, home from the hospital. And she immediately had a secret. "I just felt guilty and like I didn't want to tell anyone," says Nichols, who lives in San Francisco. "It feels like you're a bad mom. The mom guilt starts early, I guess." Across town, first-time mom Candyce Hubbell has the same secret — and she hides it from her pediatrician. "I don't really want be lectured," she says. "I know what her stance will be on it." The way these moms talk about their secret, you might think they're putting their babies in extreme danger. Perhaps drinking and driving with the baby in the car? Or smoking around the baby? But no. What they're hiding is this: They hold the baby at night while they sleep together in the bed. Here in the U.S., this is a growing trend among families. More moms are choosing to share a bed with their infants. Since 1993, the practice in the U.S. has grown from about 6 percent of parents to 24 percent in 2015. But the practice goes against medical advice in the U.S. The American Academy of Pediatrics is opposed to bed-sharing: It "should be avoided at all times" with a "[full-]term normal-weight infant younger than 4 months," the AAP writes in its 2016 recommendations for pediatricians. The organization says the practice puts babies at risk for sleep-related deaths, including sudden infant death syndrome, accidental suffocation and accidental strangulation. About 3,700 babies die each year in the U.S. from sleep-related causes. © 2018 npr

Keyword: Sleep; Development of the Brain
Link ID: 25002 - Posted: 05.21.2018

Nicola Davis People who experience disrupted 24-hour cycles of rest and activity are more likely to have mood disorders, lower levels of happiness and greater feelings of loneliness, research suggests. While the study does not reveal whether disruptions to circadian rhythms are a cause of mental health problems, a result of them or some mixture of the two, the authors say the findings highlight the importance of how we balance rest and activity. “Because people have these 24-hour patterns of living nowadays and because by 2050 two-thirds of the world’s population will live in cities where circadian disruption is much more likely, it is quite a big public health issue. How do we take account of our natural patterns of rest and activity and how do we design cities or jobs to protect people’s mental health?” said Daniel Smith, professor of psychiatry at the University of Glasgow and lead author of the research. Writing in the journal Lancet Psychiatry, a team of researchers from Scotland, Ireland and Sweden report how they carried out the largest study of its kind to date by harnessing data from the UK BioBank, a research endeavour that has collected health information on 500,000 participants, aged between 37 and 73, since 2006. To explore the link between mental health and the 24-hour cycles of sleep and activity known as circadian rhythms, the team looked at data from more than 91,000 participants who had worn a wrist-based activity tracker for a week at some point between 2013 and 2015. © 2018 Guardian News and Media Limited

Keyword: Biological Rhythms; Depression
Link ID: 24988 - Posted: 05.17.2018

By Dana G. Smith You don’t remember it, but you woke up at least 100 times last night. These spontaneous arousals, lasting less than 15 seconds each, occur roughly every five minutes and don’t seem to affect how well-rested you feel. They are unrelated to waking up from a bad dream or your partner tossing and turning. Instead, they seem to be linked to some internal biological mechanism. Frequently waking up throughout the night may have protected early humans from predators by increasing their awareness of their surroundings during sleep. “The likelihood someone would notice an animal is higher [if they] wake up more often,” says Ronny Bartsch, a senior lecturer in the Department of Physics at Bar-Ilan University in Israel. “When you wake up, you’re more prone to hear things. In deep sleep, you’re completely isolated.” Sleep scientists, however, have been stumped as to what triggers these nocturnal disruptions. In a new Science Advances paper Bartsch proposes an innovative hypothesis that spontaneous arousals are due to random electrical activity in a specific set of neurons in the brain—aptly named the wake-promoting neurons. Even when you are asleep your brain cells continuously buzz with a low level of electrical activity akin to white noise on the radio. Occasionally, this electrical clamor reaches a threshold that triggers the firing of neurons. The new paper suggests that when random firing occurs in the wake-promoting neurons, a person briefly jerks awake. But this is countered by a suite of sleep-promoting neurons that helps one quickly fall back to sleep. © 2018 Scientific American

Keyword: Sleep
Link ID: 24932 - Posted: 05.02.2018

by Lenny Bernstein White House physician Ronny L. Jackson allegedly provided travelers on White House trips with Ambien, a prescription sedative that is widely regarded as a safe drug that poses little risk of addiction. Nearly 30 million Americans take it for it insomnia — the vast majority of them in its generic form, zolpidem — for a single night or for longer periods of sleeplessness. But that doesn't mean a physician can hand out the drug “like candy,” as Sen. Jon Tester (D-Mont.) said Jackson did, without inquiring about other medications a patient might be taking, drug history or other medical issues, experts said. “Any physician prescribing a controlled substance should have a doctor-patient relationship, just because of knowing the other health problems and the other medications,” said Cathy Goldstein, an assistant professor of neurology at the University of Michigan School of Medicine and a physician at the Michigan Medicine Sleep Disorders Center. Taking Ambien, “you could get hurt. You could be disruptive, especially if you're using it with alcohol.” Ambien and the stimulant Provigil, which Tester said Jackson dispensed to help travelers awaken, are Schedule IV controlled substances in the government's five-category ranking of drugs' risk of abuse. But like any medication, they pose some risk, particularly in certain groups. © 1996-2018 The Washington Post

Keyword: Sleep
Link ID: 24903 - Posted: 04.26.2018

By RUTH MARGALIT Harvey Karp, the pediatrician, parenting expert and inventor-slash-entrepreneur, cuts an unimposing figure. Lean and agile, with wispy dark hair, blue-rimmed glasses and a bounce in his step, Karp hugs like the Angeleno he has become and deadpans like the New Yorker he once was. Gray has infiltrated his beard and his eyes are a little hooded, but he still makes for a young 66. He used to dress only in blue button-up shirts with matching sweater vests and bulbous ties in a seemingly self-conscious take on the Nutty Professor, but he has graduated to a darker navy, with slim-fitting jeans, an occasional blazer and a pair of Converse or laceless Vans: his transformation into a hip West Coast chief executive — Prius included — complete. Karp is the author of “The Happiest Baby on the Block,” the 2002 book on newborn sleeping and soothing techniques that has sold more than a million copies and remains on Amazon’s 10 best-selling parenting books — a “category killer,” in the words of its publisher. An accompanying DVD, released the following year, is the most watched child-rearing DVD ever. These days, Karp, who no longer practices medicine, is hoping to capitalize on the trust he has won from parents and sell them on his new product: a $1,160 robotic bassinet called SNOO that he invented with his wife, Nina Montée, and for which they have raised $30 million in two rounds of funding. One Saturday afternoon last summer, Karp found himself riding an empty elevator to the 10th story of a boxy high-rise on Manhattan’s East Side, on a speaking tour to promote the four-figure bed that he is convinced could prevent postpartum depression by improving babies’ — and parents’ — sleep. © 2018 The New York Times Company

Keyword: Sleep
Link ID: 24893 - Posted: 04.24.2018

Lynne Peeples Carole Godain remembers a lot of the little details from the clinical trial she took part in nine years ago. There was the blue button she pushed to get her chemotherapy drugs, and the green light that came on to confirm that the medication was dripping into her veins. Then, of course, there was the hour — 10:00 p.m. without fail, for every treatment. By all accounts, Godain’s own time was running short. The first treatment for her colon cancer had failed, and her last body scan had revealed 27 tumours growing inside her liver. So the psychologist from Tours, France, jumped at the opportunity to take part in a trial at Paul Brousse hospital in Villejuif, which aimed to test whether delivering drugs at a specific time of day might make them more effective or reduce their toxic side effects. Ideally, it would accomplish both. “I was interested in increasing my chances of being cured,” says Godain. Today, at the age of 43, she is cancer-free. And Francis Lévi, the oncologist who treated Godain, says that although such an amazing result is anomalous, emerging evidence should encourage more interest in the concept of chronotherapy — scheduling treatments so that they provide the most help and do the least harm. More than four decades of studies describe how accounting for the body’s cycle of daily rhythms — its circadian clock — can influence responses to medications and procedures for everything from asthma to epileptic seizures. Research suggests that the majority of today’s best-selling drugs, including heartburn medications and treatments for erectile dysfunction, work better when taken at specific times of day. “When you give a medication, you always know the dose,” says Lévi, who also now works at Warwick Medical School in Coventry, UK, where he leads a team associated with INSERM, the French national biomedical research agency. “We have found that the timing is sometimes more important than the dose.” © 2018 Macmillan Publishers Limited

Keyword: Biological Rhythms
Link ID: 24877 - Posted: 04.18.2018

by Robby Berman She was wide awake and it was nearly two in the morning. When asked if everything was alright, she said, “Yes.” Asked why she couldn’t get to sleep she said, “I don’t know.” Neuroscientist Russell Foster of Oxford might suggest she was exhibiting “a throwback to the bi-modal sleep pattern." Research suggests we used to sleep in two segments with a period of wakefulness in-between. A. Roger Ekirch, historian at Virginia Tech, uncovered our segmented sleep history in his 2005 book At Day’s Close: A Night in Time’s Past. There’s very little direct scientific research on sleep done before the 20th century, so Ekirch spent years going through early literature, court records, diaries, and medical records to find out how we slumbered. He found over 500 references to first and second sleep going all the way back to Homer’s Odyssey. “It’s not just the number of references—it is the way they refer to it as if it was common knowledge,” Ekirch tells BBC. "He knew this, even in the horror with which he started from his first sleep, and threw up the window to dispel it by the presence of some object, beyond the room, which had not been, as it were, the witness of his dream." — Charles Dickens, Barnaby Rudge (1840) Here’s a suggestion for dealing with depression from English ballad 'Old Robin of Portingale': "And at the wakening of your first sleepe/You shall have a hott drinke made/And at the wakening of your next sleepe/Your sorrowes will have a slake." Two-part sleep was practiced into the 20th century by people in Central America and Brazil and is still practiced in areas of Nigeria. © Copyright 2007-2018 & BIG THINK

Keyword: Sleep
Link ID: 24856 - Posted: 04.12.2018

By NICHOLAS BAKALAR Morning people may live longer than night owls, a new study suggests. Researchers studied 433,268 people, aged 38 to 73, who defined themselves as either “definite morning” types, “moderate morning” types, “moderate evening” types or “definite evening” types. They followed their health for an average of six-and-a-half years, tracking cause of death with death certificates. The study is in Chronobiology International. After controlling for age and sex, smoking, body mass index, sleep duration and other variables, they found that compared with “definite morning” types, “definite evening” types had a 10 percent increased risk of dying from any cause. Each increase from “morningness” to “eveningness” was associated with an increased risk for disease. Night owls were nearly twice as likely as early risers to have a psychological disorder and 30 percent more likely to have diabetes. Their risk for respiratory disease was 23 percent higher and for gastrointestinal disease 22 percent higher. The lead author, Kristen L. Knutson, an associate professor of neurology at Northwestern University, said that while being a night owl is partly genetic, people can make adjustments — gradually making bedtime earlier, avoiding using smartphones before bed, and eventually moving themselves out of the “night owl zone.” Although the reasons for their increased mortality remain unclear, she said, “Night owls should know that there may be some health consequences.” © 2018 The New York Times Company

Keyword: Biological Rhythms
Link ID: 24854 - Posted: 04.12.2018

By Danna Staaf "You're doing your surgery, but you don't know if the animal still feels it and you've just stolen its ability to respond," says biologist Robyn Crook of San Francisco State University (SFSU) in California. Until recently, researchers working with octopuses, squids, and other cephalopods routinely faced this dilemma, an ethical and, in some cases, legal challenge to studying these intelligent creatures in the laboratory. But Crook has now shown that both ordinary alcohol and magnesium chloride are effective anesthetics—crucial information for scientists pursuing cephalopod research. Cephalopods might not seem to be ideal laboratory animals. They're exclusively marine, so a complex seawater system is needed to keep them alive, and they're disinclined to stay put—octopuses can escape through minuscule holes, while squids may jet right out of their tanks. But their unique biology and behavior have made them indispensable to researchers in many fields. Studies of the squid's giant axon helped spawn modern neuroscience decades ago, and the light organ of the bobtail squid (Euprymna scolopes) powered a revolution in the study of symbiotic host-microbe interactions. Today, some researchers are studying how the animals accomplish their striking feats of regeneration, while others use them in ecotoxicology studies; cephalopods even guide research into the origins of consciousness. Because of their complex brains, cephalopods became the first invertebrates to be protected by laboratory animal laws. In 1991, the Canadian Council on Animal Care decided to extend the standards for vertebrate care to cephalopods, meaning, among other things, that researchers have to get ethical approval for their studies and must use anesthesia, when possible, for procedures that could cause pain. Since then, the United Kingdom, New Zealand, and some Australian states have passed similar regulations. The biggest expansion of cephalopod rights came in 2013, when an EU-wide directive gave them the same protections as vertebrates in scientific studies in 28 countries. © 2018 American Association for the Advancement of Science. A

Keyword: Animal Rights; Sleep
Link ID: 24823 - Posted: 04.06.2018

By KAREN BARROW Creepy-crawly, itchy, tingly, aching legs — while different people may describe restless leg syndrome differently the results are the same: sleepless nights and restless days. What is it like to be diagnosed with R.L.S.? Six men and women speak about their experiences. Lynne Kaiser, an artist, believes she has had restless leg syndrome for most of her life. She recalls waking up in the middle of the night as a child to take a hot bath or fill a hot water bottle to try to relieve the prickly sensations in her legs. It wasn’t until recently that a specialist confirmed the diagnosis. Today, Mrs. Kaiser advocates for R.L.S. patients. Dopaminergic medications, as well as art and needlework, help her to “get in a tunnel” where she can be distracted from the uncomfortable sensations, she said. Mrs. Kaiser says the symptoms of R.L.S. strained her relationship with her husband. He couldn’t understand why she couldn’t just relax in bed with him, or why she would get up at night to stretch her legs or sit in a scalding hot bath. Because of R.L.S., Mrs. Kaiser finds it difficult to travel. She also knows that R.L.S. medications tend to lose their effectiveness over time, so she focuses on how good she feels today. “I really try not to think about the future,” she said. Dr. David Rye, a professor of neurology at Emory University in Atlanta, discovered that he had restless leg syndrome several years after he began researching the disease. He says that many in the medical community believe that R.L.S. is a psychological disease rather than a physical ailment. However, Dr. Rye and his colleagues were among the first to discover a gene variant linked to R.L.S. Genetic factors help to explain why R.L.S. is so much more prevalent among Caucasians than other ethnicities. © 2018 The New York Times Company

Keyword: Sleep
Link ID: 24799 - Posted: 03.29.2018

by Ariana Eunjung Cha) Sally Clark lost both her infant sons shortly after their births. In 1996, 11-week-old Christopher fell unconscious after being put to bed and never woke up. Two years later, 8-week-old Harry was found dead slumped forward in his bouncy chair. Doctors initially concluded the first boy had died of sudden infant death syndrome (SIDS) — in which a seemingly healthy baby dies without warning and without an obvious cause. But after Clark's second child died, prosecutors in the United Kingdom charged her with murder and put her on trial. According to scholars analyzing the widely publicized case, Clark was wrongly convicted based on a statistic. An expert witness for the prosecution claimed the chance of two cases of SIDS, in an affluent family like hers, was astronomically high — 1 in 73 million. Her defenders said the numbers assumed that SIDS strikes at random, even though we had no idea back then whether that was true. An important study published Wednesday in the Lancet shows a link between SIDS and a rare genetic mutation that would make some families more vulnerable than others — providing a possible explanation for situations like Clark's. The research involved 278 infants who died of SIDS, also called “crib death” or “cot death,” and 729 healthy controls. Four of those who died of SIDS had a variant of a gene called SCN4A associated with an impairment of breathing muscles, while no babies in the control group had it. Authors Michael Hanna from the United Kingdom's Medical Research Council's Center for Neuromuscular Diseases and Michael Ackerman from the Mayo Clinic in the United States wrote that these mutations are typically found in fewer than 5 out of 100,000 people. © 1996-2018 The Washington Post

Keyword: Sleep; Genes & Behavior
Link ID: 24795 - Posted: 03.29.2018

By KAREN BARROW Narcolepsy is a sleep disorder that causes excessive sleepiness and frequent daytime sleep attacks. What is it like to never feel fully rested? Three women discuss the realities of living with a sleep disorder. Kailey Profeta learned she had narcolepsy at age 9 after her mother noticed she was unusually tired and had inexplicably gained a lot of weight. Kailey was home-schooled for several years while she and her family learned what combinations of medicines and behavioral adjustments worked to keep her on a normal sleep schedule. She now takes a medicine every night that helps her sleep, but leaves her nauseated in the morning. To cope, she eats breakfast in bed and takes other medications to help her stay awake during the day. Kailey goes home from school every day during third period to take a nap, and she rests again after school. Kailey, who wants to be a fashion designer, works at a bridal boutique during the summer and on weekends. She said that most of her friends understand when she has to rest, but that being a teenager with narcolepsy is not always easy. Patricia A. Higgins suffers from narcolepsy with cataplexy – sudden muscle weakness that causes her to fall and feel temporarily paralyzed. She first began falling from cataplexy as a teenager, and the condition reached its worst point when she was 32; she remembers falling 17 times in one weekend. Getting the correct diagnosis was a struggle. Ms. Higgins went from doctor to doctor and was told at various times that she had a seizure disorder and a psychiatric condition. Eventually, a sleep study confirmed that she had narcolepsy. Narcolepsy has disrupted Ms. Higgins’s work and family life. She is married and the mother of three children, but she left her job as a nurse and cannot drive. She volunteers regularly with the Narcolepsy Network, a support and information group for narcoleptics. © 2018 The New York Times Company

Keyword: Narcolepsy
Link ID: 24774 - Posted: 03.21.2018

To understand the link between aging and neurodegenerative disorders such as Alzheimer’s disease, scientists from the National Institutes of Health compared the genetic clocks that tick during the lives of normal and mutant flies. They found that altering the activity of a gene called Cdk5 appeared to make the clocks run faster than normal, and the flies older than their chronological age. This caused the flies to have problems walking or flying later in life, to show signs of neurodegeneration, and to die earlier. “We tried to untangle the large role aging appears to play in some of the most devastating neurological disorders,” said Edward Giniger, Ph.D., senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke and the senior author of the study published in Disease Models & Mechanisms. “Our results suggest that neurodegenerative disorders may accelerate the aging process.” On average, the normal flies in this study lived for 47 days. To create a genetic clock, Dr. Giniger’s team measured the levels of every gene encoded in messenger RNA molecules from cells from the heads and bodies of flies at 3, 10, 30, and 45 days after birth. This allowed the researchers to use advanced analysis techniques to search for the genes that seemed to be sensitive to aging, and create a standard curve, or timeline, that described the way they changed. When they performed the same experiments on 10-day-old mutant flies and compared the results with the standard curve, they found that the flies were “older” than their chronological age. Altering Cdk5 activity made the brains of the flies appear genetically to be about 15 days old and their bodies to be about 20 days old.

Keyword: Biological Rhythms
Link ID: 24748 - Posted: 03.14.2018

Children and adults who spend a lot of time outside in the summer may be less likely to develop multiple sclerosis years later, a U.S. study suggests. Sun exposure is thought to lessen the risk of MS, a chronic disease in which a person's immune system targets nerve cells in the brain and spinal cord, leading to damage. It is estimated Canada may have among the highest prevalence of MS in the world. While the disease is common, little is known about its causes. But for more than 10 years, sun exposure has been thought to be linked to MS risk. Previously, researchers focused on how UV-B rays from sunlight seem protective during childhood years. Now, University of British Columbia neurology professor Helen Tremlett and her co-authors have taken a broader view, extending the association into adulthood. In Wednesday's online issue of the journal Neurology, Tremlett and her team report combing through data on 151 women with MS and 235 others of similar age without the disease who were all participating in the Nurses' Health Study based in Boston. The long-running U.S. study is one of the largest investigations into risk factors such as diet, hormones, and environment for major chronic diseases in women. "We found that just generally going out in the summer was a beneficial thing and didn't matter so much if you were exposing yourself to direct sunlight. It was just going out in the summer that was associated with a reduced risk," Tremlett said in an interview. ©2018 CBC/Radio-Canada.

Keyword: Multiple Sclerosis; Biological Rhythms
Link ID: 24731 - Posted: 03.08.2018

Bruce Bower People have evolved to sleep much less than chimps, baboons or any other primate studied so far. A large comparison of primate sleep patterns finds that most species get somewhere between nine and 15 hours of shut-eye daily, while humans average just seven. An analysis of several lifestyle and biological factors, however, predicts people should get 9.55 hours, researchers report online February 14 in the American Journal of Physical Anthropology. Most other primates in the study typically sleep as much as the scientists’ statistical models predict they should. Two long-standing features of human life have contributed to unusually short sleep times, argue evolutionary anthropologists Charles Nunn of Duke University and David Samson of the University of Toronto Mississauga. First, when humans’ ancestors descended from the trees to sleep on the ground, individuals probably had to spend more time awake to guard against predator attacks. Second, humans have faced intense pressure to learn and teach new skills and to make social connections at the expense of sleep. As sleep declined, rapid-eye movement, or REM — sleep linked to learning and memory (SN: 6/11/16, p. 15) — came to play an outsize role in human slumber, the researchers propose. Non-REM sleep accounts for an unexpectedly small share of human sleep, although it may also aid memory (SN: 7/12/14, p. 8), the scientists contend. “It’s pretty surprising that non-REM sleep time is so low in humans, but something had to give as we slept less,” Nunn says. |© Society for Science & the Public 2000 - 2018.

Keyword: Sleep; Evolution
Link ID: 24728 - Posted: 03.07.2018

Alice M. Gregory, Erin Leichman, Jodi Mindell Pairing the words “baby” and “sleep” can evoke strong emotions. Those who have had limited contact with little ones might interpret this word-combination as implying deep and prolonged slumber. For others, this union of words may elicit memories of prolonged periods of chaotic sleep (or what can feel like no sleep at all). Coping with the way babies sleep can be difficult. It’s not that babies don’t sleep. In fact, they sleep more than at any other stage of life. It’s more an issue of when they sleep. Newborns start by sleeping and waking around the clock. This is not always easy for parents. There is even research suggesting that in adults waking repeatedly at night can feel as bad as getting hardly any sleep in terms of attentional skills, fatigue levels and symptoms of depression. As to why infants wake at night, this is best explained by thinking about the two things that govern our sleep: the homeostatic and circadian processes. The crux of the homeostatic process is the straightforward idea that the longer we have been awake the greater our sleep drive (and the more sleepy we feel). It may take an adult an entire day to build up enough sleep drive to fall asleep at bedtime, but an infant may only need an hour or two of wakefulness before being able to drift off to sleep. The second process is circadian, which works like a clock. Adults typically feel more awake during the morning hours and sleepy at night, regardless of when we last slept. In very young babies this process is not yet developed. This means that sleep is more likely to occur at different points across the 24-hour day. © 2018 Guardian News and Media Limited

Keyword: Sleep; Development of the Brain
Link ID: 24713 - Posted: 03.01.2018

Amelia Hill For a serious examination of the devastating and incurable disability that is narcolepsy, Henry Nicholls’s book, Sleepy Head, is a surprisingly funny account. There is the obvious, if somewhat cruel, humour to be found in stories of people falling asleep in surprising places: in a small boat sailing around the Farne Islands, with the freezing North Sea cascading over the gunwale; while scuba diving; on a rollercoaster; at the dentist’s; on the back of a horse; on a surfboard. But there are other extremely funny insights that Nicholls gives into the crepuscular world that narcoleptics inhabit: his laconic fretting over the etiquette of attending a CBT group for insomniacs, which he discovers he also suffers from while researching the book. “A narcoleptic attending an insomnia clinic could be seen as the height of insensitivity,” he deadpans. Then there’s the attempt to solve sleep apnoea by learning the didgeridoo. (Didgetherapy, since you ask. It involves acrylic didgeridoos and is, apparently, quite effective.) Misjudging his tone entirely, I arrive at our interview expecting a garrulous chat. I’m particularly excited that I opened Nicholls’s book thinking I was pretty special to be able to share with him the fact that my father also had narcolepsy – and close his book having realised that five of my closest family members (including myself) have had diagnosable sleep disorders ranging from sleep apnoea to night terrors to – my own thrilling self-realisation – an episode of hypnagogic hallucination and sleep paralysis. © 2018 Guardian News and Media Limited

Keyword: Narcolepsy; Sleep
Link ID: 24697 - Posted: 02.26.2018

By Catherine Offord River-dwelling populations of the Central American fish species Astyanax mexicanus sleep for more than 10 hours each day. But eyeless, cave-dwelling members of the same species barely sleep at all, and show no obvious health or developmental problems as a result. Now, researchers in the U.S. and in France have identified the signaling pathway behind this difference, offering a glimpse into the processes regulating sleep duration in vertebrates. The findings were published yesterday (February 6) in two papers in eLife. In one study, researchers at Florida Atlantic University compared the brains of cave-dwelling A. mexicanus with their surface-living cousins. They found that the number of neurons producing hypocretin—a neuropeptide linked to sleep-disorders such as narcolepsy when dysregulated—was significantly higher in the cave dwellers. What’s more, inhibiting hypocretin signaling genetically or pharmacologically increased cavefish’s sleep duration by several hours, while having minimal effect on surface-living fish. “These findings suggest that differences in hypocretin production may explain variation in sleep between animal species, or even between individual people,” study coauthor Alex Keene of Florida Atlantic University’s Brain Institute says in a statement. “It may also provide important insight into how we might build a brain that does not need to sleep.” © 1986-2018 The Scientist

Keyword: Sleep; Vision
Link ID: 24632 - Posted: 02.08.2018