Chapter 14. Biological Rhythms, Sleep, and Dreaming

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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

By Simon Makin Around a third of people complain of some sleeplessness, and one in 10 meets diagnostic criteria for clinical insomnia. The costs, in terms of well-being, physical health and productivity, are enormous. From twin studies, researchers know the inability to fall or stay asleep has a genetic component, but the identities of the culprits were mostly unknown. Now, two studies published Monday in Nature Genetics provide first peeks at the biological basis of insomnia, implicating specific brain regions and biological processes, and revealing links with heart disease and psychiatric disorders like depression. Both are genome-wide association studies (GWASs), which examine DNA from many thousands of individuals to determine where genetic markers related to health, disease or a particular trait reside. The first study, from a team led by geneticist Danielle Posthuma of Vrije University Amsterdam, analyzed the genomes of over 1.3 million people, making it the largest GWAS of any complex trait to date. They used data from the UK Biobank, a large, long-term genetics project, and from the direct-to-consumer genetics company 23andMe to identify 202 areas of the genome linked to insomnia, implicating 956 genes, a big advance from the seven found previously. “I’m pretty confident the vast majority of these are real,” says geneticist Stephan Ripke, a GWAS expert at the Berlin Institute of Health who was not involved in either study. “But we need to confirm this in more, separate cohorts from different countries and researchers.” © 2019 Scientific American

Keyword: Sleep; Genes & Behavior
Link ID: 26028 - Posted: 03.13.2019

Catherine Offord One of the functions of sleep may be to repair DNA damage that has built up in the brain during waking hours, according to a study published yesterday (March 5) in Nature Communications. By using time-lapse imaging to observe the brains of zebrafish, researchers in Israel found that chromosome dynamics associated with DNA repair increased in neurons during sleep, and that sleep deprivation prevented this repair from happening efficiently. Study coauthor Lior Appelbaum of Bar-Ilan University notes in a statement that sleep is found across the animal kingdom and that this repair role might be one of the reasons “sleep has evolved and is so conserved.” To study what is going on in individual neurons during sleep, Appelbaum and colleagues genetically engineered zebrafish larvae to have fluorescent chromosomes in their neurons. They then used a high-resolution microscope to monitor the movements of those chromosomes when the transparent fish were awake and asleep. The researchers found that when the fish were awake, chromosomes were relatively static and accumulated double-strand breaks. But once the zebrafish went to sleep, the chromosomes became more dynamic, and the DNA damage began dissipating. Further experiments showed that manipulating zebrafish sleep could influence the repair process. For example, keeping the fish awake by tapping on their tank promoted the accumulation of more double-strand breaks, while inducing sleep with a drug pumped through the tank allowed the cells to repair their DNA. © 1986 - 2019 The Scientist

Keyword: Sleep
Link ID: 26019 - Posted: 03.09.2019

By Carolyn Y. Johnson The negative health effects of skimping on sleep during the week can’t be reversed by marathon weekend sleep sessions, according to a sobering new study. Researchers have long known that routine sleep deprivation can cause weight gain and increase other health risks, including diabetes. But for those who force themselves out of bed bleary-eyed every weekday after too few hours of shut-eye, hope springs eternal that shutting off the alarm on Saturday and Sunday will repay the weekly sleep debt and reverse any ill effects. The research, published in Current Biology, crushes those hopes. Despite complete freedom to sleep in and nap during a weekend recovery period, participants in a sleep laboratory who were limited to five hours of sleep on weekdays gained nearly three pounds over two weeks and experienced metabolic disruption that would increase their risk for diabetes over the long term. While weekend recovery sleep had some benefits after a single week of insufficient sleep, those gains were wiped out when people plunged right back into their same sleep-deprived schedule the next Monday. “If there are benefits of catch-up sleep, they’re gone when you go back to your routine. It’s very short-lived,” said Kenneth Wright, director of the sleep and chronobiology laboratory at the University of Colorado at Boulder, who oversaw the work. “These health effects are long-term. It’s kind of like smoking once was — people would smoke and wouldn’t see an immediate effect on their health, but people will say now that smoking is not a healthy lifestyle choice. I think sleep is in the early phase of where smoking used to be.” Clifford Saper, head of neurology at Beth Israel Deaconess Medical Center, called the study “convincing and fascinating.” © 1996-2019 The Washington Post

Keyword: Sleep
Link ID: 25995 - Posted: 03.01.2019

By Roni Caryn Rabin Cannabidiol, or CBD, a nonintoxicating component of the marijuana plant, is touted as a magic bullet that eases pain, anxiety, insomnia and depression. Salves, sprays, tinctures and oils containing CBD are marketed as aphrodisiacs that boost desire; as balms for eczema, pimples and hot flashes; and even as treatments for serious diseases like diabetes and multiple sclerosis. Unlike THC, or tetrahydrocannabinol, the “psychoactive” component of the cannabis plant, CBD won’t get you “high.” But scientists know little about what it can do: Most of the information about CBD’s effects in humans is anecdotal or extrapolated from animal studies, and few rigorous trials have been conducted. “It is a kind of a new snake oil in the sense that there are a lot of claims and not so much evidence,” said Dustin Lee, an assistant professor in psychiatry and behavioral sciences at Johns Hopkins University who is planning a human trial of CBD for use in quitting smoking. The Food and Drug Administration has approved some drugs made from synthetic substances similar to THC to treat poor appetite and nausea in people with A.I.D.S. or cancer. But so far, the F.D.A. has approved only one drug containing CBD, Epidiolex, after clinical trials found it reduced seizures in children with two rare, severe forms of epilepsy. “There’s a lot of hype about everything about CBD,” said Dr. Orrin Devinsky, the director of the NYU Langone Comprehensive Epilepsy Center, who led the Epidiolex studies and went out of his way to say the drug’s effect was “not miraculous.” “There is certainly data that it has a variety of anti-inflammatory effects, but whether that translates into improving human health is unknown. Does it help people with eczema, rheumatoid arthritis or ulcerative colitis? We don’t know. There is a good theoretical basis, but the studies have not been done.” © 2019 The New York Times Company

Keyword: Drug Abuse; Sleep
Link ID: 25988 - Posted: 02.27.2019

By Michael Price Insomnia, often blamed on stress or bad sleep habits, may instead be closely linked to depression, heart disease, and other physiological disorders, a pair of deep dives into the human genome now reveals. “Both studies are very well done,” says psychologist Philip Gehrman of the University of Pennsylvania’s Perelman School of Medicine, who researches sleep behavior. Still, he stresses, much more work remains before the genetic connections to insomnia can be translated to new therapies for patients. Insomnia costs the U.S. workforce more than $63 billion each year in lost productivity, according to some estimates. It’s also incredibly common: As much as a third of the worldwide population suffers from insomnia-related symptoms at any given time. Yet the disorder remains poorly understood. In one new paper reported today in Nature Genetics, researchers led by geneticist Danielle Posthuma of Vrije Universiteit in Amsterdam conducted a genome-wide association study (GWAS), which looks for links between shared sequences of DNA and particular behaviors or clinical symptoms. The group analyzed the genomes of more than 1 million people, which the authors say is the largest GWAS to date. The data came from UK Biobank, a long-running, enormous U.K. genetics study, and the private genetics firm 23andMe. The prevalence of insomnia in the people covered by both databases was about 30%, which is in line with estimates for the general population. © 2019 American Association for the Advancement of Science

Keyword: Sleep; Depression
Link ID: 25986 - Posted: 02.26.2019

By Veronique Greenwood Sleep — that absurd, amazing habit of losing consciousness for hours on end — is so universal across the animal kingdom that we usually assume it is essential to survival. Now, however, scientists who repeatedly disturbed the sleep of more than a thousand fruit flies are reporting that less slumber may be necessary for sustaining life than previously thought, at least in one species. A handful of studies involving dogs and cockroaches going back to the late 19th century suggest that being deprived of sleep can result in a shortened life span. But the methods behind some of these studies can make it difficult to say whether the test subjects were harmed by sleep deprivation itself, or by the stress of the treatment they were given — such as being shaken constantly. The new study took a milder approach, in hope of seeing the true effects of sleep deprivation. The automated system the researchers developed for monitoring the flies kept track of their movements with cameras, scoring any extended period without movement as sleep. When they were not being awakened repeatedly, the males slept about 10 hours a day, females about five on average. To keep the flies awake, the researchers equipped the system with tiny motors that would gently tip the flies any time they went still for at least 20 seconds. With this method, researchers deprived flies of rest over the course of their entire lifetimes, tipping them hundreds of times a day such that if they were snoozing during those periods of stillness, they might have been able to sleep around 2.5 hours a day on average. “When the results came from that experiment, it was very surprising,” said Giorgio Gilestro, a professor at Imperial College London who is a co-author of the study, which was published Wednesday in Science Advances. © 2019 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 25978 - Posted: 02.21.2019

The brain function of very late risers and "morning larks" during the hours of the working day is different, according to a study. Researchers scanned the brains of night owls with a bedtime of 02:30 and a wake time of 10:15, along with early risers. The tests - performed between 08:00 and 20:00 - found night owls had less connectivity in brain regions linked to maintaining consciousness. They also had poorer attention, slower reactions and increased sleepiness. Researchers said it suggested that night owls were disadvantaged by the "constraints" of the typical working day. They called for more research to understand the health implications of night owls performing on a work or school schedule to which they are not naturally suited. Scientists took 38 people who were either night owls or morning larks (people who went to bed just before 23:00 and woke at 06:30) and investigated their brain function at rest using magnetic resonance imaging (MRI) scans. The volunteers then carried out a series of tasks at various times, from 08:00 to 20:00, and were asked to report on their levels of sleepiness. Morning larks were least sleepy and had their fastest reaction time in the early morning tests. They were also found to perform significantly better at this time than night owls. In contrast, night owls were least sleepy and had their fastest reaction time at 20:00, although they did not do significantly better than the larks at this time. The brain connectivity in the regions that predicted better performance and lower sleepiness was significantly higher in larks at all time points, suggesting connectivity in late risers is impaired throughout the whole working day, researchers said. © 2019 BBC

Keyword: Biological Rhythms
Link ID: 25967 - Posted: 02.15.2019

By Kelly Servick Rough sleep is bad for your mind—and your heart. It can increase the risk of clogged arteries, which can lead to stroke or heart attacks. But how these two things are connected has been a mystery. Now, a study in mice reveals a link, based on signals the brain sends to bone marrow. If the story holds true in humans, the mechanism could help explain the connection between sleep and other conditions, from obesity to cancer. “Not everyone who is sleep-deprived develops cardiovascular disease,” says Namni Goel, a behavioral neuroscientist at the University of Pennsylvania Perelman School of Medicine in Philadelphia who was not involved in the work. The new mouse work “opens the door for human studies” that could sort out who is most at risk. In many forms of cardiovascular disease, fatty deposits build up on artery walls (a condition called atherosclerosis) and can rupture to cause a stroke or heart attack. Immune cells—in particular, white blood cells called monocytes—also play a key role. They flock to sites where these deposits have damaged blood vessels and they spawn cells that can contribute to the growing plaque. To follow up on the known connection between sleep and heart disease, immunologist Filip Swirski of Harvard Medical School and Massachusetts General Hospital in Boston wanted to explore whether sleep somehow triggered an immune process that spurs this dangerous buildup. © 2019 American Association for the Advancement of Science

Keyword: Sleep; Learning & Memory
Link ID: 25965 - Posted: 02.14.2019

By C. Claiborne Ray Q. What keeps squirrels from gaining huge amounts of weight as they gorge on acorns and nuts each fall? A. In fact, many squirrels do achieve huge weight gain ahead of the privations of winter. Common gray squirrels may increase their weight by 25 percent in the harvest season. But not because they hibernate — they don’t. Winter foraging is hard, and gray squirrels tend to spend the winter months mostly in their nests. But they must make forays every few days to seek squirreled-away food and other nourishment. Among hibernating squirrels, much of the stored nourishment is needed to survive the cold season without foraging. A study of the Arctic ground squirrel found extreme weight gains during the active season: 42 percent among males and 63 percent among females. They slow their activity drastically before hibernating in order to maintain peak mass. While some do emerge from winter lighter, a significant share of their fat stores may remain. © 2019 The New York Times Company

Keyword: Obesity; Biological Rhythms
Link ID: 25952 - Posted: 02.12.2019

By Jill U. Adams A lot of people out there don’t get enough sleep — more than 1 in 3 American adults, according to the Centers for Disease Control and Prevention. If you’re one of them, you probably know there are two main treatments for improving sleep: behavioral methods and medications. When you’re desperate for a good night’s sleep, medications sure do sound appealing. But there are caveats with them all — the prescription pills, the over-the-counter products and the herbal supplements. Before describing the medications in detail, I’ll remind you that the prevailing wisdom is that cognitive behavioral therapy, which involves changing habits and bedtime rituals, is the first-line treatment for insomnia. Sleep experts say CBT is more effective and longer lasting than medication for most people — but maybe you’re not most people. “There’s clearly a subset of patients who don’t improve with CBT,” says Andrew Krystal, who directs the sleep research program at the University of California at San Francisco. There’s also a problem with access, he says, as CBT requires effort. Even some of the seemingly simple online versions have fees attached. Another thing to consider before looking at medications is that sleep troubles often result from something else, such as sleep apnea or depression. Also, alcohol and caffeine intake can interfere with good sleep, as can certain medications, says Constance Dunlap, a D.C. psychiatrist in private practice. A doctor can help you rule out or address these issues. “I get a lot of information,” Dunlap says. © 1996-2019 The Washington Post

Keyword: Sleep; Drug Abuse
Link ID: 25951 - Posted: 02.11.2019