Chapter 10. Biological Rhythms and Sleep

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By Helen Macdonald I found a dead common swift once, a husk of a bird under a bridge over the River Thames, where sunlight from the water cast bright scribbles on the arches above. I picked it up, held it in my palm, saw the dust in its feathers, its wings crossed like dull blades, its eyes tightly closed, and realized that I didn’t know what to do. This was a surprise. Encouraged by books, I’d always been the type of Gothic amateur naturalist who preserved interesting bits of the dead. I cleaned and polished fox skulls; disarticulated, dried and kept the wings of roadkill birds. But I knew, looking at the swift, that I could not do anything like that to it. The bird was suffused with a kind of seriousness very akin to holiness. I didn’t want to leave it there, so I took it home, swaddled it in a towel and tucked it in the freezer. It was in early May the next year, as soon as I saw the first returning swifts flowing down from the clouds, that I knew what I had to do. I went to the freezer, took out the swift and buried it in the garden one hand’s-width deep in earth newly warmed by the sun. Swifts are magical in the manner of all things that exist just a little beyond understanding. Once they were called the “Devil’s bird,” perhaps because those screaming flocks of black crosses around churches seemed pulled from darkness, not light. But to me, they are creatures of the upper air, and of their nature unintelligible, which makes them more akin to angels. Unlike all other birds I knew as a child, they never descended to the ground. When I was young, I was frustrated that there was no way for me to know them better. They were so fast that it was impossible to focus on their facial expressions or watch them preen through binoculars. They were only ever flickering silhouettes at 30, 40, 50 miles an hour, a shoal of birds, a pouring sheaf of identical black grains against bright clouds. There was no way to tell one bird from another, nor to watch them do anything other than move from place to place, although sometimes, if the swifts were flying low over rooftops, I’d see one open its mouth, and that was truly uncanny, because the gape was huge, turning the bird into something uncomfortably like a miniature basking shark. Even so, watching them with the naked eye was rewarding in how it revealed the dynamism of what before was merely blankness. Swifts weigh about 1½ ounces, and their surfing and tacking against the pressures of oncoming air make visible the movings of the atmosphere. © 2020 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 27391 - Posted: 07.29.2020

By Baland Jalal Imagine waking up in the middle of the night to an unearthly figure with blood dripping down its fangs. You try to scream, but you can’t. You can’t move a single muscle! If this sounds familiar, you’ve probably experienced an episode of sleep paralysis, which involves the inability to move or speak upon falling asleep or awakening and is often coupled with hallucinations. About one in five people have had sleep paralysis at least once. But despite its prevalence, it has largely remained a mystery. For centuries, cultures across the world have attributed these hallucinations to black magic, mythical monsters, even paranormal activity. Scientists have since dismissed such explanations, yet these cultural beliefs persist. In fact, my and my colleagues’ research, conducted over roughly a decade in six different countries, suggests that beliefs about sleep paralysis can dramatically shape the physical and psychological experience, revealing a striking type of mind-body interaction. Sleep paralysis is caused by what appears to be a basic brain glitch at the interface between wakefulness and rapid eye movement (REM) sleep. During REM, you have intensely lifelike dreams. To prevent you from acting out these realistic dreams (and hurting yourself!), your brain has a clever solution: it temporarily paralyzes your entire body. Indeed, your brain has a “switch” (a handful of neurochemicals) that tilts you between sleep and wakefulness. Sometimes the “switch” fails, however—your brain inadvertently wakes up while your body is still under the “spell” of REM paralysis, leaving you stuck in a paradoxical state between parallel realities: wakefulness and REM sleep. During sleep paralysis, the crisp dreams of REM “spill over” into waking consciousness like a dream coming alive before your eyes—fanged figures and all. © 2020 Scientific American

Keyword: Sleep
Link ID: 27367 - Posted: 07.16.2020

By Nicholas Bakalar Artificial outdoor light at night may disrupt adolescents’ sleep and raise the risk for psychiatric disorders, a new study suggests. Researchers tracked the intensity of outdoor light in representative urban and rural areas across the country using satellite data from the National Oceanic and Atmospheric Administration. They interviewed more than 10,123 adolescents living in these neighborhoods about their sleep patterns, and assessed mental disorders using well-validated structured scales. They also interviewed the parents of more than 6,000 of the teenagers about their children. The study, in JAMA Psychiatry, found that the more intense the lighting in your neighborhood, the more sleep was disrupted and the greater the risk for depression and anxiety. After adjustment for other factors such as sex, race, parental education and population density, they found that compared with the teenagers in the one-quarter of neighborhoods with the lowest levels of outdoor light, those in the highest went to bed, on average, 29 minutes later and reported 11 fewer minutes of sleep. Adolescents living in the most intensely lit neighborhoods had a 19 percent increased risk for bipolar illness, and a 7 percent increased risk for depression. The study is observational, and does not prove cause and effect. The senior author, Kathleen R. Merikangas, a senior investigator with the National Institute of Mental Health, said that future policy changes could make a difference. In the meantime, she said, “At least as individuals, we ought to try to minimize exposure to light at night.” © 2020 The New York Times Company

Keyword: Sleep; Biological Rhythms
Link ID: 27362 - Posted: 07.15.2020

By Anna Goldfarb It’s understandable that you may be struggling to fall asleep these days. Our world has been turned upside down, so it is especially hard to unplug from the day and get the high-quality sleep your body needs. “Almost every single patient I’m speaking with has insomnia,“ said Dr. Alon Y. Avidan, a professor and vice chair in the department of neurology at the David Geffen School of Medicine at the University of California, Los Angeles, and director of the U.C.L.A. Sleep Disorders Center. “Especially now with Covid-19, we have an epidemic of insomnia. We call it Covid-somnia.” An increase in anxiety in both children and adults is affecting our ability to fall asleep. Additionally, our lifestyles have changed drastically as people observe sheltering in place guidelines. With more people staying indoors, it can mean they are not getting enough light exposure. “Without light exposure in the morning,” Dr. Avidan said, people “lose the circadian cues that are so fundamentally important in setting up appropriate and normal sleep-wake time.” There are nonmedical ways to help you sleep better: Meditation, turning off screens early in the night, warm showers and cool bedrooms can help your body rest better. But if these options don’t work, or if you are ready for the next step, you may have considered trying melatonin supplements. These pills are commonplace enough that you have most likely heard of them and seen them in your local pharmacy. Here’s what you need to know about the pros and cons of using melatonin supplements for sleeping difficulties. What is melatonin? Melatonin is a hormone that helps regulate sleep timing. It is produced in the pea-size pineal gland, which is nestled in the middle of your brain and syncs melatonin production with the rising and setting of the sun. According to the National Sleep Foundation, the gland remains inactive during the day but switches on around 9 p.m. (when it’s generally dark) to flood the brain with melatonin for the next 12 hours. © 2020 The New York Times Company

Keyword: Sleep; Biological Rhythms
Link ID: 27360 - Posted: 07.14.2020

Research shows that adolescents who live in areas that have high levels of artificial light at night tend to get less sleep and are more likely to have a mood disorder relative to teens who live in areas with low levels of night-time light. The research was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health, and is published in JAMA Psychiatry. “These findings illustrate the importance of joint consideration of both broader environmental-level and individual-level exposures in mental health and sleep research,” says study author Diana Paksarian, Ph.D., a postdoctoral research fellow at NIMH. Daily rhythms, including the circadian rhythms that drive our sleep-wake cycles, are thought to be important factors that contribute to physical and mental health. The presence of artificial light at night can disrupt these rhythms, altering the light-dark cycle that influences hormonal, cellular, and other biological processes. Researchers have investigated associations among indoor artificial light, daily rhythms, and mental health, but the impact of outdoor artificial light has received relatively little attention, especially in teens. In this study, Paksarian, Kathleen Merikangas, Ph.D., senior investigator and chief of the Genetic Epidemiology Research Branch at NIMH, and coauthors examined data from a nationally representative sample of adolescents in the United States, which was collected from 2001 to 2004 as part of the National Comorbidity Survey Adolescent Supplement (NCS-A). The dataset included information about individual-level and neighborhood-level characteristics, mental health outcomes, and sleep patterns for a total of 10,123 teens, ages 13 to 18 years old.

Keyword: Biological Rhythms; Depression
Link ID: 27348 - Posted: 07.08.2020

By Richard Sandomir Dr. William Dement, whose introduction to the mysteries of slumber as a postgraduate student in the 1950s led him to become an eminent researcher of sleep disorders and to preach the benefits of a good night’s sleep, died on June 17 in Stanford, Calif. He was 91. His son, Nick, a physician, said the cause was complications of a heart procedure. Dr. Dement spent his working life as a popular professor in the department of psychiatry at Stanford University, where he started what is believed to be the world’s first successful sleep disorders clinic. He taught a class on sleep and dreams that drew as many as 1,200 students. When he awakened dozing students with spritzes from a water gun, Dr. Dement gave them extra credit if they recovered and shouted, “Drowsiness is red alert!” — his rallying cry to make sleep deprivation a public health priority. Drowsiness was the last step before falling asleep, he often said. Sleep deprivation put people at a higher risk of an accident on the road, diminished their productivity, increased the likelihood of their making mistakes, made them irritable and actually hurt their ability to fall asleep. “Bill Dement was an evangelist about sleep,” Dr. Rafael Pelayo, a Stanford psychiatry professor who succeeded Dr. Dement in leading the sleep class, said in a phone interview. “He felt that not enough people knew about sleep disorders, and he thought of his students as multipliers who would tell the world about them.” Dr. Dement’s expertise led to his appointment as chairman of a federal commission on sleep disorders. The commission reported in 1992 that 40 million Americans had undiagnosed, untreated, mistreated or chronic sleep problems — findings that led Congress to establish the National Center on Sleep Disorders Research, within the National Institutes of Health, in 1993. When Dr. Dement testified on Capitol Hill five years later about the sleep center’s progress, he said he was pleased with its research but disappointed that the government had not sounded loud enough alarms about the serious, sometimes fatal, consequences of unhealthful sleep. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27333 - Posted: 06.29.2020

Kerry Grens William Dement, whose research and leadership were integral to the expansion of sleep science and medicine in the 20th century, died June 17 at age 91. He made fundamental contributions to understanding the phases of sleep and the array of sleep disorders people experience. In 1970, he launched one of the first sleep disorders clinic in the world. “William Dement was a force of nature. A pioneering researcher and clinician, and a legendary teacher, his passion to uncover sleep’s secrets and to share these discoveries was unquenchable,” Lloyd Minor, the dean of Stanford University School of Medicine, where Dement was a faculty member for half a century, says in a university obituary. “Not only did he make great contributions to Stanford, but his efforts directly led to the birth and development of the field of sleep medicine.” Dement was born in Wenatchee, Washington, in 1928. He served in the US Army in Japan and earned his bachelor’s degree from the University of Washington. At the University of Chicago, where he received a PhD and an MD, Dement worked with Nathaniel Kleitman to describe the physiology of rapid eye movement (REM) sleep and its relationship to dreaming. “The groundbreaking research and use of polysomnography by Kleitman, [Eugene] Aserinsky, and Dement in the U.S., and by Michel Jouvet in France, laid the foundation for the fields of sleep and circadian science and clinical sleep medicine,” according to a memoriam by the American Academy of Sleep Medicine (AASM), the first professional organization for sleep disorders that Dement helped launch in 1975. © 1986–2020 The Scientist.

Keyword: Sleep
Link ID: 27322 - Posted: 06.26.2020

by Laura Dattaro Children with autism are more likely than typical children to have had problems falling asleep as infants, according to a new study1. These infants also have more growth in the hippocampus, the brain’s memory hub, from age 6 to 24 months. The study is the first to link sleep problems to altered brain development in infants later diagnosed with autism. Sleep difficulties are common in autistic children: Nearly 80 percent of autistic preschoolers have trouble sleeping2. But little is known about the interplay between sleep and brain development in early life, says lead investigator Annette Estes, director of the UW Autism Center at the University of Washington in Seattle. The researchers examined the sleep patterns and brain scans of infants who have autistic older siblings, a group known as ‘baby sibs.’ Baby sibs are 20 times as likely to be diagnosed with autism as are children in the general population, and they often show signs of autism early in life. The study shows an association between sleep problems and brain structure in babies who have autism. But it is too early to say whether sleep troubles contribute to brain changes and autism traits or vice versa, or whether some common factor underlies all three, Estes says. It is also not clear what, if any, connection exists between these findings and the well-documented sleep problems in older autistic children. © 2020 Simons Foundation

Keyword: Autism; Sleep
Link ID: 27314 - Posted: 06.22.2020

By Simon Makin on June 15, 2020 A well-worn science-fiction trope imagines space travelers going into suspended animation as they head into deep space. Closer to reality are actual efforts to slow biological processes to a fraction of their normal rate by replacing blood with ice-cold saline to prevent cell death in severe trauma. But saline transfusions or other exotic measures are not ideal for ratcheting down a body’s metabolism because they risk damaging tissue. Coaxing an animal into low-power mode on its own is a better solution. For some animals, natural states of lowered body temperature are commonplace. Hibernation is the obvious example. When bears, bats or other animals hibernate, they experience multiple bouts of a low-metabolism state called torpor for days at a time, punctuated by occasional periods of higher arousal. Mice enter a state known as daily torpor, lasting only hours, to conserve energy when food is scarce. The mechanisms that control torpor and other hypothermic states—in which body temperatures drop below 37 degrees Celsius—are largely unknown. Two independent studies published in Nature on Thursday identify neurons that induce such states in mice when they are stimulated. The work paves the way toward understanding how these conditions are initiated and controlled. It could also ultimately help find methods for inducing hypothermic states in humans that will prove useful in medical settings. And more speculatively, such methods might one day approximate the musings about suspended animation that turn up in the movies. One of the two studies was conducted by neuroscientist Takeshi Sakurai of the University of Tsukuba in Japan and his colleagues. It began with a paradoxical finding about a peptide called QRFP. The team showed that injecting it into animals actually increased their activity. But when the researchers switched on neurons that were making the peptide in mice, they got a surprise. “The mice stayed still and were very cold: the opposite to what they expected,” says Genshiro Sunagawa, of the RIKEN Center for Biosystems Dynamics Research in Japan, who co-led the study. The animals’ metabolic rate (measured by oxygen consumption), body temperature, heart rate and respiration all dropped. © 2020 Scientific American,

Keyword: Sleep
Link ID: 27307 - Posted: 06.17.2020

Ruth Williams Research teams in the US and Japan have each discovered independently and by unrelated routes a population of hypothalamic neurons in mice that induce the low body temperature, reduced metabolism, and inactivity characteristic of hibernation and torpor. The two papers are published today (June 11) in Nature. “Trying to pin down which neurons are involved with initiating torpor and hibernation . . . is certainly something that biologists have been interested in for several years now,” says biologist Steven Swoap of Williams College who was not involved in the research. “Both of [the teams] come at it from a different angle and almost end up in the same place, so they complement each other in that way, which is pretty nice,” he adds. Hibernation and daily torpor are both forms of mammalian suspended animation and share a number of features. Both involve significant, but regulated, drops in body temperature, metabolism, heart rate, breathing rate, and activity, and both are thought to be ways of preserving energy when food is scarce. While hibernation lasts for weeks or months, however, daily torpor lasts several hours each day. Why some mammals such as bears and certain primates and rodents have the ability to enter periods of dormancy while others don’t is unknown. But the diversity of hibernator species suggests that the biological mechanisms controlling such states may also be preserved, albeit unused, in non-hibernating species. This tantalizing possibility sparks ideas of sending dormant astronauts on extended space journeys as well as more down-to-earth notions of temporarily lowering body temperature and metabolism to preserve tissues in patients with, for example, traumatic injuries. © 1986–2020 The Scientist.

Keyword: Sleep
Link ID: 27300 - Posted: 06.13.2020

Ruth Williams In the hippocampus of the adult mouse brain, newly formed cells that become activated by a learning experience are later reactivated in the REM phase of sleep, according to a study in Neuron today (June 4). The authors show this reactivation is necessary for fortifying the encoding of the memory. “It is a very cool paper,” writes neuroscientist Sheena Josselyn of the University of Toronto in an email to The Scientist. “This is the first study to causally link new neurons to sleep-dependent memory consolidation. I am sure it will have a broad impact on scientists studying memory, sleep as well as those interested in adult neurogenesis,” she says. Josselyn was not involved in the study. In the adult mammalian brain, most cells do not replicate. But, deep in the center of the organ, in a particular region of the hippocampus called the dentate gyrus, new neurons continue to be born at a slow rate throughout the lifetime of the animal. This neurogenesis is thought to be important for memory formation among other cognitive tasks. Indeed, if the activities of mouse adult-born neurons (ABNs) are perturbed during a learning experience, the animal will not memorize the event as effectively as it does when these cells are left alone. Learning is just one part of forming a memory, however. For memories to last, sleep, and in particular REM sleep, is essential. “Sleep deprivation generally decreases neurogenesis,” writes neuroscientist Masanori Sakaguchi of the International Institute for Integrative Sleep Medicine at the University of Tsukuba in an email to The Scientist. The question was, says Sakaguchi, “is there any function of adult-born neurons during sleep?” To find out, Sakaguchi’s team first examined the activity of mouse ABNs after a learning experience—a contextual fear conditioning in which the animals’ feet were shocked as they explored a particular cage—and during subsequent sleep. Using miniaturized microscopes attached to the skulls of freely moving mice and fluorescent markers to track ABN activities, the team showed that the ABNs that had been activated after the context-shock learning event were more likely to then be reactivated during the animals’ next REM phases of sleep. © 1986–2020 The Scientist

Keyword: Neurogenesis; Sleep
Link ID: 27298 - Posted: 06.10.2020

By Lisa Sanders, M.D. “I know what Danny has,” said the boy’s aunt to the boy’s mother, her sister-in-law. Her voice on the phone cracked with excitement. “I saw someone just like him on TV!” This was last fall, and Danny was 18. He had been a medical mystery since he was 7 months old. His mother recalled that she had just finished changing his diaper and picked him up when she heard him make a strange clicking noise, his mouth opening and closing oddly. And then his head flopped back as she held him. She hurried to the living room of their Queens home to show her husband, but by the time she got there, Danny was fine. Those sudden episodes of clicking and collapse happened again and again, eventually occurring more than 100 times a day. His first doctors thought these episodes could be tiny seizures. But none of the antiseizure medications they prescribed helped. Then, when Danny was 8, and almost too big for his mother to catch when he slow-motion slumped to the floor, his parents found a doctor who was willing to explore a different diagnosis and treatment. Could this be a rare disease known as cataplexy? In this disorder, patients have episodes of sudden weakness in the skeletal muscles of the body. In some, cataplexy may affect only the face or neck, causing the eyelids to droop or the head to fall forward. But in others, it can also affect the entire body. These episodes are often triggered by strong emotion, which was the case for Danny. Cataplexy is usually part of another rare disorder, narcolepsy, in which the normal control of sleep and wakefulness is somehow lost. Those with narcolepsy have sudden episodes of sleep that invade their waking hours and transient periods of wakefulness that disrupt their sleep. © 2020 The New York Times Company

Keyword: Sleep; Epilepsy
Link ID: 27290 - Posted: 06.08.2020

Allison Aubrey Sleep makes everything easier, even in these difficult days. Why then is it so hard to get? For most of us, right now, it takes work to settle our minds so we can rest. From medication to melatonin to putting on fuzzy socks, we all have routines we hope will help us drift off into sleep. And for good reason. "You've just got to gradually bring the brain and the body down, sort of from that altitude of wakefulness onto the hard, safe landing pad of sleep at night," says Matthew Walker, a sleep researcher at the University of California, Berkeley and the author of Why We Sleep. Don't count sheep Not only will counting sheep not help you fall asleep faster, but a study by Allison Harvey at UC Berkeley found that it actually "made it harder to fall asleep, and it took you longer to fall asleep." Do use calming mental imagery Harvey found that other types of mental imagery, however, are conducive to sleep. Walker suggests imagining a pleasant walk you've taken before, "like a hike in the woods or if it's a walk down on a beach that you do on vacation." Mentally navigating that walk, he says, "tended to hasten the speed of the onset of sleep." Try relaxation and meditation apps as training wheels "I'm a big fan of those things," says Chris Winter, a neurologist and sleep researcher in Charlottesville, Virginia. These apps can train you to meditate — to clear away regrets about the past and worries about the future so you can learn to be in the moment. "The ability to settle your mind and initiate sleep is a skill," Winter says. "The more you practice it, the better you'll get at it and the more confident you become." Melatonin has mixed results © 2020 npr

Keyword: Sleep; Stress
Link ID: 27289 - Posted: 06.08.2020

Veronique Greenwood Inside a series of tubes in a bright, warm room at Harvard Medical School, hundreds of fruit flies are staying up late. It has been days since any of them have slept: The constant vibrations that shake their homes preclude rest, cling as they might to the caps of the tubes for respite. Not too far away in their own tubes live other sleepless flies, animated with the calm persistence of those consigned to eternal day. A genetic tweak to certain neurons in their brains keeps them awake for as long as they live. They do not live long. The shaken flies and the engineered flies both die swiftly — in fact, the engineered ones survive only half as long as well-rested controls. After days of sleeplessness, the flies’ numbers tumble, then crash. The tubes empty out. The lights shine on. We all know that we need sleep to be at our best. But profound sleep loss has more serious and immediate effects: Animals completely deprived of sleep die. Yet scientists have found it oddly hard to say exactly why sleep loss is lethal. Sleep is primarily seen as a neurological phenomenon, and yet when deprived creatures die, they have a puzzlingly diverse set of failures in the body outside the nervous system. Insufficient sleep in humans and lab animals, if chronic, sets up health problems that surface over time, such as heart disease, high blood pressure, obesity and diabetes. But those conditions are not what slays creatures that are 100% sleep deprived within days or weeks. What does sleep do that makes it deadly to go without? Could answering that question explain why we need sleep in the first place? Under the pale light of the incubators in Dragana Rogulja’s lab at Harvard Medical School, sleepless flies have been living and dying as she pursues the answers. Simons Foundation © 2020

Keyword: Sleep; Neuroimmunology
Link ID: 27285 - Posted: 06.06.2020

Patti Neighmond Having trouble getting to sleep these days? You're not alone. For people with a history of insomnia, sleep problems are magnified right now. And many who never struggled before are suddenly experiencing interruptions in their nightly rest or difficulty falling asleep. It's pretty typical that in moments of anxiety, sleep suffers, but the situation we're all living through today means the anxiety never stops, says neurologist and sleep specialist Dr. Douglas Kirsch, past president of the American Academy of Sleep Medicine. For occasional insomnia, the problems go away when the specific trigger is resolved. But now, he says, there's no resolution or relief from "the constant inflow of anxiety-provoking news." And that spells trouble for sleep. Family doctors and sleep specialists say many people who are feeling grief, frustration and anxiety, whether about the pandemic, financial worries or racial inequalities and unrest in the U.S., are finding themselves unable to sleep. And it's not just the worry. It's the interrupted schedules and isolation of the pandemic too. Here's why it's not all in your head and what they say you can do about it. We're suffering "collective social anxiety" — tame it to sleep better Before the pandemic, Arlene Rentas, a busy currency trader in Charlotte, N.C., kept a regular schedule and slept like clockwork. She would awaken at 5:30 in the morning and be out the door by 7 a.m., home by 8 p.m. and, after a quick run, in bed around 10 p.m. © 2020 npr

Keyword: Sleep; Stress
Link ID: 27276 - Posted: 06.03.2020

By Christina Caron For the Langstaff family, the bedtime routine had become more like a bedtime marathon. “My son has struggled with sleep from the moment he was born,” Anna Langstaff, the head of a Montessori school in Portland, Ore., said of her 6-year-old son, Henry. “We used to joke that he was like a little knight fighting a dragon called sleep.” When Henry was a toddler, dimming the lights and other bedtime cues simply sent him into “battle mode” she said. “He’d start yelling, ‘No bed! No bed!’” After years of struggling with what had become a two-hour bedtime routine, the Langstaffs turned to their pediatrician, who recommended a chocolate containing melatonin, a hormone secreted by a pea-size organ in the brain called the pineal gland that helps regulate the body’s internal clock and induces sleepiness. “It was like magic,” she said. Now Henry falls asleep at 7:30 p.m. and continues to wake up at the same time he always has, shortly before 6 a.m., Langstaff said. “Magic” — “game changer” — these are words frequently used by parents describing how melatonin helps their children fall asleep. An online survey of 933 parents with children under 18 conducted by YouGov for The New York Times in May found that only about a third had kids who were struggling with sleep issues in the past year. But among those parents, almost half had given melatonin to their children. © 2020 The New York Times Company

Keyword: Sleep; Hormones & Behavior
Link ID: 27253 - Posted: 05.18.2020

Diana Kwon As Earth rotates around its axis, the organisms that inhabit its surface are exposed to daily cycles of darkness and light. In animals, light has a powerful influence on sleep, hormone release, and metabolism. Work by Takaomi Sakai, a neuroscientist at Tokyo Metropolitan University, and his team suggests that light may also be crucial for forming and maintaining long-term memories. The puzzle of how memories persist in the brain has long been of interest to Sakai. Researchers had previously demonstrated, in both rodents and flies, that the production of new proteins is necessary for maintaining long-term memories, but Sakai wondered how this process persisted over several days given cells’ molecular turnover. Maybe, he thought, an environmental stimulus, such as the light-dark cycles, periodically triggered protein production to enable memory formation and storage. Sakai and his colleagues conducted a series of experiments to see how constant darkness would affect the ability of Drosophila melanogaster to form long-term memories. Male flies exposed to light after interacting with an unreceptive female showed reduced courtship behaviors toward new female mates several days later, indicating they had remembered the initial rejection. Flies kept in constant darkness, however, continued their attempts to copulate. The team then probed the molecular mechanisms of these behaviors and discovered a pathway by which light activates cAMP response element-binding protein (CREB)—a transcription factor previously identified as important for forming long-term memories—within certain neurons found in the mushroom bodies, the memory center in fly brains. © 1986–2020 The Scientist.

Keyword: Learning & Memory; Biological Rhythms
Link ID: 27248 - Posted: 05.16.2020

By Alexandra Jacobs THE SHAPELESS UNEASE A Year of Not Sleeping By Samantha Harvey As if in unwitting aid of the malady they address, books about insomnia tend to be very dull indeed. Many are stuffed with statistics and unhelpful suggestions, like one of those oversize polyester-plumped sham pillows you see on the fancier beds — and just as likely to be flung in frustration to the floor. Samantha Harvey’s memoir of sleeplessness is more like a small and well-worn eiderdown quilt: It might not cover everything, but it both cools and warms, lofts and lulls, settling gradually on its inhabitant with an ethereal solidity. Harvey is a well-regarded novelist in the United Kingdom, and perhaps the only part of this book that feels a little lumpy and uncomfortable is her working out in its pages an O. Henry-like short story about a husband who loses his wedding ring while robbing an A.T.M. More compelled by her predicament, namely stretch after stretch of not only little sleep (or “petite nuit,” as the French more melodiously put it) but no sleep at all, I found it difficult to care about this fictional character, or figure out if his crime and punishment represented anything larger about what disenchanted millennials have taken to describing as “late-stage capitalism.” Not for nothing does the author’s own experience take place in 2016, that epoch of political shock during which a majority of her compatriots voted to leave the European Union, a.k.a. Brexit (“Why isn’t it called Ukexit,” Harvey wonders with the petty irritability of the sleep-deprived), and Donald J. Trump was elected over the pond. That these events have since been outdone by arrival of the coronavirus pandemic, with its attendant sleep disorders, only amplifies this small volume’s relevance and power. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27242 - Posted: 05.12.2020

A small study funded by the National Institutes of Health suggests that sleep problems among children who have a sibling with autism spectrum disorder (ASD) may further raise the likelihood of an ASD diagnosis, compared to at-risk children who do not have difficulty sleeping. Previous research has shown that young children who have a sibling with ASD are at a higher risk for also being diagnosed with the condition. The study appears in The American Journal of Psychiatry. If confirmed by other studies, the findings may give clinicians a tool to identify sleep problems early and provide interventions to reduce their effects on the health and development of children with autism. The findings may also provide insights into the potential role of sleep problems in the development of ASD. The study was conducted by Annette M. Estes, Ph.D., of the University of Washington Autism Center in Seattle, and colleagues in the NIH Autism Centers of Excellence Infant Brain Imaging Study Network. NIH funding was provided by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Institute of Mental Health. “The results are a promising lead,” said Alice Kau, Ph.D., of NICHD’s Intellectual and Developmental Disabilities Branch. “If confirmed by more in-depth studies, patterns of sleep disturbance in early life might be used to pinpoint increased risk for ASD among young children already at risk because they have a sibling with ASD.” The researchers analyzed data from a long-term study of children who do and do not have siblings with ASD. When the children were 6 and 12 months of age, parents were asked to respond to an infant temperament questionnaire that asks how much difficulty their child has falling asleep at bedtime and falling back to sleep after waking up during the night. At these time intervals, the children also received MRI scans to track their brain development. At 24 months, the children were assessed for ASD.

Keyword: Autism; Sleep
Link ID: 27238 - Posted: 05.08.2020

African Americans with severe sleep apnea and other adverse sleep patterns are much more likely to have high blood glucose levels — a risk factor for diabetes — than those without these patterns, according to a new study funded in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. The findings suggest that better sleep habits may lead to better blood glucose control and prove beneficial for type 2 diabetes prevention and diabetes management in African Americans, who are at higher risk for type 2 diabetes than other groups. They also point to the importance of screening for sleep apnea to help fight the potential for uncontrolled blood sugar in this high-risk group, the researchers said. Previous studies have linked disturbed sleep patterns, including sleep apnea, to increased blood glucose levels in white and Asian populations. But this new study is one of the few to use objective measurements to link these disturbed sleep patterns to increased blood glucose levels in black men and women, the researchers said. Their findings appear online on April 28 in the Journal of the American Heart Association. “The study underscores the importance of developing interventions to promote regular sleep schedules, particularly in those with diabetes,” said Yuichiro Yano, M.D., Ph.D., the lead study author and a researcher in the Department of Family Medicine and Community Health at Duke University. “It also reaffirms the need to improve the screening and diagnosis of sleep apnea, both in African Americans and other groups.”

Keyword: Sleep
Link ID: 27219 - Posted: 04.29.2020