Chapter 10. Biological Rhythms and Sleep

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By KAREN WEINTRAUB Q. For working parents, it’s difficult to find time to exercise during the week, and early morning is often the only time slot available. Is it better for my overall health to get eight hours of sleep per night during the week but not have time to exercise, or to get six and a half to seven hours of sleep per night and fit in a morning workout? A. “That’s a terrible choice,” said Dr. Charles Czeisler, a sleep expert at Brigham and Women’s Hospital and Harvard Medical School in Boston. Both sleep and exercise are key components of a healthy lifestyle and shouldn’t be pitted against each other, Dr. Czeisler said. Sleep is important for workouts, he noted, reducing the risk of injury and allowing muscles to recover from exercise. Lack of sleep weakens the immune system, making people more likely to become sick — which means missing workouts. Sacrificing sleep has also been tied to weight gain, cardiovascular disease and diabetes, among other health problems. Of course, regular exercise provides a lot of benefits, too, including sounder sleep. Dr. Czeisler also noted that going to bed late, particularly if you’re using electronic devices and sitting under bright lights before bedtime, shifts the body’s circadian rhythms later. But people still need around eight hours of sleep per night. So if you get up after six and a half hours to work out, “you’re essentially exercising during your biological night,” he said. Research from Northwestern University suggests that muscle cells also have circadian rhythms, and that they perform and recover much better during the biological daytime than the biological night. “So, getting up during your biological night to exercise is counterproductive,” Dr. Czeisler said. © 2017 The New York Times Company

Keyword: Sleep
Link ID: 24406 - Posted: 12.08.2017

Terry Gross This is FRESH AIR. I'm Terry Gross. Here's how my guest describes his work. He writes, (reading) I am an anesthesiologist. I erase consciousness, deny memories, steal time, immobilize the body. I alter heart rate, blood pressure and breathing, and then I reverse these effects. I eliminate pain during a procedure, and I prevent it afterwards. I care for sick people, and I have saved lives, but it's rare that I'm the actual healer. That's from the opening of Dr. Henry Jay Przybylo's new memoir, "Counting Backwards: A Doctor's Notes On Anesthesia." He specializes in pediatric anesthesiology and estimates he treats about 1,000 children a year from micropreemies (ph) to teenagers. He's dealt with benign conditions, like the removal of a skin mole, as well as potentially fatal ones, like clipping a cerebral artery aneurism and heart transplants. He's also an associate professor at the Northwestern University School of Medicine. Dr. Przybylo, welcome to FRESH AIR. Your book is called "Counting Backwards." So why do anesthesiologists ask patients to count backwards from 100? HENRY JAY PRZYBYLO: You know, I'm not sure. I searched the Internet and everything to try and find the answer to that, and the closest I can come to is that around 1940s, we came up - medicines were developed to induce anesthesia that were given through veins - IV - and they were extremely quick-acting. And I think sometime, some anesthesiologist somewhere just wanted to see how long it would take and asked the patient to start counting backwards from a hundred, realizing they never made it out of the 90s before they were anesthetized, and I think that just stuck. © 2017 npr

Keyword: Sleep
Link ID: 24375 - Posted: 11.29.2017

Patricia Neighmond As the months grow colder and darker, many people find themselves somewhat sadder and even depressed. Bright light is sometimes used to help treat the symptoms of seasonal affective disorder, or SAD. Researchers are now testing light therapy to see if it also can help treat depression that's part of bipolar disorder. It's unclear how lack of light might cause the winter blues, although some suggest that the dark days affect the production of serotonin in the skin. The idea with light therapy for depression is to replace the sunshine lost with a daily dose of bright white artificial light. (Antidepressants, psychotherapy and Vitamin D help, too, according to the National Institute of Mental Health.) The light box is actually more like a screen, the size of your average desktop computer. Some people call it a "happy box." To test its usefulness in treating bipolar disorder, researchers at the Feinberg School of Medicine, Northwestern University enrolled 46 patients who had at least moderate bipolar depression. Half of participants were assigned to receive bright light therapy. The other half received a dim red placebo light. They also kept taking their regular medication. © 2017 npr

Keyword: Biological Rhythms; Schizophrenia
Link ID: 24368 - Posted: 11.27.2017

Mariah Quintanilla WASHINGTON, D.C. — If it takes you a while to recover from a few lost hours of sleep, be grateful you aren’t an orb weaver. Three orb-weaving spiders — Allocyclosa bifurca, Cyclosa turbinata and Gasteracantha cancriformis — may have the shortest natural circadian rhythms discovered in an animal thus far, researchers reported November 12 at the Society for Neuroscience’s annual meeting. Most animals have natural body clocks that run closer to the 24-hour day-night cycle, plus or minus a couple hours, and light helps reset the body’s timing each day. But the three orb weavers’ body clocks average at about 17.4, 18.5 and 19 hours respectively. This means the crawlers must shift their cycle of activity and inactivity — the spider equivalent of wake and sleep cycles — by about five hours each day to keep up with the normal solar cycle. “That’s like flying across more than five time zones, and experiencing that much jet lag each day in order to stay synchronized with the typical day-night cycle,” said Darrell Moore, a neurobiologist at East Tennessee State University in Johnson City. “Circadian clocks actually keep us from going into chaos,” he added. “Theoretically, [the spiders] should not exist.” For most animals, internal clocks help them perform recurring daily activities, like eat, sleep and hunt, at the most appropriate time of day. Previous studies have shown that animals that are out of sync with the 24-hour solar cycle are usually less likely to produce healthy offspring than those that aren’t. |© Society for Science & the Public 2000 - 2017.

Keyword: Biological Rhythms; Evolution
Link ID: 24328 - Posted: 11.15.2017

By VERONIQUE GREENWOOD When people tell you, “wake up and smell the roses,” they might be giving you bad advice. Your sense of smell may fluctuate in sensitivity over the course of 24 hours, in tune with our circadian clocks, with your nose best able to do its job during the hours before you go to sleep, according to a study published last month. The work, reported in the journal Chemical Senses, is part of a larger push to explore whether adolescents’ senses of taste and smell influence obesity. Rachel Herz, a sensory researcher at Brown University, and her colleagues designed this study to see if there might be times of day when the sense of smell was more powerful — perhaps making food smell particularly inviting. For the experiment, 37 adolescents ranging in age from 12 to 15 came into a lab for a very long sleepover party. For nine days, they followed a strict schedule to allow researchers to focus on the circadian clock, which helps control wake and sleep, but also influences other processes in the body, including metabolism. While more research is needed to test whether the results fully apply to adults, Dr. Herz says that as you grow up, the makeup of the smell receptors inside your nose doesn’t seem to change, although there is evidence your body clock may. The team kept track of where the teenagers were in their circadian cycle by measuring their saliva’s levels of melatonin, a hormone that rises and falls regularly over the course of the day. Every few hours, the children took a scent test, sniffing different concentrations of a chemical that smells like roses. The researchers recorded the lowest concentration they could detect at each time point. When the results were tallied up, the researchers saw a range of responses. “Nobody has the same nose,” Dr. Herz said. Some adolescents had only very mild changes in sensitivity, while sensitivity altered dramatically in others. Averaged together, however, the results showed that overall the circadian clock does affect smell, and that the times when the children’s noses were most sensitive tended to correspond to the evening, with an average peak of 9 p.m. © 2017 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Biological Rhythms
Link ID: 24311 - Posted: 11.09.2017

Jon Hamilton When people don't get enough sleep, certain brain cells literally slow down. A study that recorded directly from neurons in the brains of 12 people found that sleep deprivation causes the bursts of electrical activity that brain cells use to communicate to become slower and weaker, a team reports online Monday in Nature Medicine. The finding could help explain why a lack of sleep impairs a range of mental functions, says Dr. Itzhak Fried, an author of the study and a professor of neurosurgery at the University of California, Los Angeles. "You can imagine driving a car and suddenly somebody jumps in front of the car at night," Fried says. "If you are sleep-deprived, your cells are going to react in a different way than in your normal state." The finding comes from an unusual study of patients being evaluated for surgery to correct severe epilepsy. As part of the evaluation, doctors place wires in the brain to find out where a patient's seizures are starting. That allows Fried and a team of scientists to monitor hundreds of individual brain cells, often for days. And because patients with epilepsy are frequently kept awake in order to provoke a seizure, the scientists had an ideal way to study the effects of sleep deprivation. In the study, all the patients agreed to categorize images of faces, places and animals. Each image caused cells in areas of the brain involved in perception to produce distinctive patterns of electrical activity. "These are the very neurons [that] are responsible for the way you process the world in front of you," Fried says. © 2017 npr

Keyword: Sleep; Attention
Link ID: 24301 - Posted: 11.07.2017

Teens are getting less sleep than they did before smartphones became commonplace, prompting concerns about potentially serious health consequences, researchers say. A study published in the current issue of the journal Sleep Medicine examined data from two surveys of U.S. adolescents conducted over many years and including questions about how many hours of sleep they got. Almost 370,000 adolescents participated. The researchers focused on how much sleep teens reported getting in the years from 2009 to 2015, "when the mobile technology really saturated the market among adolescents," said Zlatan Krizan, a psychologist specializing in sleep and social behaviour at Iowa State University and co-author of the study. Zlatan Krizan, a psychology researcher specializing in sleep, personality and social behaviour at Iowa State University, was one of the authors of a recent study that showed a trend of teens getting less sleep over the years they started using smartphones. (Iowa State University) Krizan and his colleagues found that teens were 16 to 17 per cent more likely to report getting less than seven hours of sleep a night in 2015 than they were in 2009. The recommended amount of sleep for 13 to 18-year-olds is eight to 10 hours per night, according to the U.S. Centers for Disease Control and Prevention. ©2017 CBC/Radio-Canada.

Keyword: Sleep; Development of the Brain
Link ID: 24273 - Posted: 11.01.2017

By Dr Michael Mosley BBC Thanks to the clocks going back, many of us managed to grab a little bit of extra shut-eye over the weekend. And that's no bad thing because, as a country, we seem to be chronically sleep-deprived. According to the Sleep Council, the average Briton gets six-and-a-half hours sleep a night, which for most people is not enough. Lots of studies have shown that cutting back on sleep, deliberately or otherwise, can have a serious impact on our bodies. A few nights of bad sleep can really mess with our blood sugar control and encourage us to overeat. It even messes with our DNA. A few years ago, Trust Me I'm a Doctor did an experiment with Surrey University, asking volunteers to cut down on their sleep by an hour a night for a week. Dr Simon Archer, who helped run the experiment, found that getting an hour's less sleep a night affected the activity of a wide range of our volunteers' genes (around 500 in all) including some which are associated with inflammation and diabetes. Disturbed nights So the negative effects on our bodies of sleep deprivation are clear. But what effect does lack of sleep have on our mental health? To find out Trust Me teamed up with sleep scientists at the University of Oxford to run a small experiment. This time, we recruited four volunteers who normally sleep soundly. We fitted them with devices to accurately monitor their sleep and then, for the first three nights of our study, let them get a full, undisturbed eight hours. For the next three nights, however, we restricted their sleep to just four hours.

Keyword: Sleep
Link ID: 24272 - Posted: 11.01.2017

Christopher French, Alice M Gregory and Dan Denis Of all the sleep disorders, “exploding head syndrome” (EHS) has arguably the most intriguing name. EHS has been described as “a sensory parasomnia characterised by the perception of loud noises and/or a sense of explosion in the head when transitioning to or from sleep. These noises are not associated with significant pain, but lead to abrupt arousal and feelings of fright”. Although this phenomenon was first described as long ago as 1876, it was not given its colourful title until 1988. Despite its long history, it has received very little systematic research attention, with most of our knowledge being based upon small samples of case histories as opposed to large-scale investigations. We, the authors of this piece, along with the world’s leading authority on EHS, Dr Brian Sharpless of Argosy University, Northern Virginia, are hoping to rectify that situation by carrying out a large-scale survey of EHS. We’re also interested in the equally intriguing phenomenon of sleep paralysis, which involves a temporary period of paralysis occurring between sleep and wakefulness, often accompanied by hallucinations. If you have ever experienced either EHS or sleep paralysis, or even if you haven’t, we would love to hear from you. In addition to explosions, other types of loud noise perceived during episodes of EHS include gunshots, fireworks, thunder, doors slamming, clapping, shouting, and the clash of cymbals. There can also be beeps, buzzing and video static. This may be accompanied by “electrical” sensations, palpitations, breathing difficulties, sweating, seeing a flash of light, and twitching. Perhaps unsurprisingly, intense fear caused by the belief that something is seriously wrong is often reported. © 2017 Guardian News and Media Limited

Keyword: Sleep
Link ID: 24268 - Posted: 10.31.2017

By Angela Clow, Nina Smyth, October is a dismal time of year. The clocks go back, which accelerates the onset of darker evenings and the “shorter days” inevitably lead to calls for the tradition of putting clocks forward or backward to stop. Of course, the annual return to Greenwich Mean Time (GMT) from British Summer Time (BST) doesn’t make the days any shorter, it merely shifts an hour of available daylight from the evening to the morning. For many, lighter evenings are a priority and little attention is given to the benefits of lighter mornings. Arguments over clock changes tend to revolve around benefits for easier travel in lighter evenings. Nevertheless research suggests that holding onto lighter mornings might have hitherto unforeseen advantages. Light in the morning – more than any other time of day – leads to powerful brain-boosting effects, helping us to function as best we can, despite the approaching winter. All life on Earth has evolved around the 24-hour cycle of light and dark. An obvious sign is our desire for night-time sleep, but most biological functions are fine-tuned around day and night. Our bodies are honed to environmental light via a biological chain reaction. Light intensity is detected by special cells in the retina and this information is relayed to the internal body clock, located deep in a part of the brain called the suprachiasmatic nucleus. This sits in the hypothalamus, responsible for regulation of internal body processes using the endocrine system, which is linked to hormone secretion, via the pituitary gland. We are unaware of these light messages as they have nothing to do with conscious vision. Their sole job is to internalise information about environmental light intensity. © 2017 Scientific American,

Keyword: Biological Rhythms
Link ID: 24261 - Posted: 10.30.2017

By Rachel Schraer & Joey D'Urso People across the UK will wake up having gained an hour's sleep on Sunday morning, as the clocks go back heralding darker evenings and shorter days. But how much do we know about sleep and its impact on our lives, from our health and mood, to how long we'll live? 1. We're told to get our eight hours We often hear that we should all be getting eight hours' sleep a night. Organisations from the NHS to the US National Sleep Foundation recommend it. But where does this advice come from? Studies carried out around the world, looking at how often diseases occur in different groups of people across a population, have come to the same conclusion: both short sleepers and long sleepers are more likely to have a range of diseases, and to live shorter lives. But it's hard to tell whether it is short sleep that is causing disease or whether it is a symptom of a less healthy lifestyle. Short sleepers are generally defined as those who regularly get less than six hours' sleep and long sleepers generally more than nine or 10 hours' a night. Pre-puberty, children are recommended to get as much as 11 hours' sleep a night, however, and up to 18 hours a day for newborn babies. Teenagers should sleep for up to 10 hours a night. Shane O'Mara, professor of experimental brain research at Trinity College Dublin, says that, while it's difficult to tell whether poor sleep is a cause or a symptom of poor health, these relationships feed off each other. © 2017 BBC.

Keyword: Sleep
Link ID: 24253 - Posted: 10.28.2017

Nicola Davis Patients undergoing open heart surgery in the afternoon have a lower risk of potentially fatal complications than those undergoing operations in the morning, new research suggests. The study found that events including heart attacks and heart failure were less common among those who had undergone a valve replacement operation in the afternoon. The finding appears to be linked to the ability of the heart tissue to recover after being starved of blood supply during surgery – an effect the researchers say is influenced by the cells’ biological or “circadian” clock. Overweight patients less likely to die in hospital after heart operations Read more While the study suggests patients might fare better if they undergo afternoon surgery, Professor David Montaigne, first author of the research from the University of Lille in France, said it also highlighted another approach to reduce complications. “We have to find a drug that can alter the circadian clock to induce a jet lag,” he said, noting that it could also help to improve patient outcomes for heart attacks and organ transplantation. Writing the in Lancet, Montaigne and colleagues report how they looked at the outcomes of 596 patients, half of whom had valve surgery in the morning, and half in the afternoon. While 18% of morning surgery patients experienced a major cardiac event – such as a heart attack or heart failure –in the following 500 days, only 9% of those who had afternoon surgery experienced such events. © 2017 Guardian News and Media Limited

Keyword: Biological Rhythms
Link ID: 24251 - Posted: 10.27.2017

By DOUGLAS QUENQUA Bad news, bears. Hibernation is no longer the coolest thing animals do to survive the winter. As cold weather approaches, tiny mole-like creatures known as red-toothed shrews will shrink their own heads, reducing their skull and brain mass by as much as 20 percent, according to new research published Monday in Current Biology. When warm weather returns, they will regrow the region nearly to its original size, giving new meaning to the phrase “spring ahead.” Though it is not yet clear why the shrews go down a few sizes for the winter, the authors of the study speculate that the reduced head and brain size helps them conserve energy when resources are scarce. “These tiny mammals cannot migrate long distances to avoid winter, nor can they enter any kind of energy-saving state” like hibernation, said Javier Lazaro, a doctoral student at the Max Planck Institute for Ornithology in Germany and an author of the study. They also have high metabolic rates and very little fat stored in their bodies. “Therefore, they starve within a few hours if they do not hunt constantly.” The researchers say the shrinkage is a survival strategy. “Brain tissue is energetically very expensive, so reducing overall brain size might decrease energy demands and thus food requirements,” he said. The shrews’ reduction in size doesn’t only affect the head. Several major organs lose mass in winter, and the spine shortens, as well. Overall, the shrews in the study reduced their body mass by about 18 percent from July to February. Previous research had hinted that all shrew species might undergo a reduction in body and head mass during the winter. There is even a term for it, Dehnel’s Phenomenon, named after the Polish zoologist who conducted that research, August Dehnel. © 2017 The New York Times Company

Keyword: Biological Rhythms
Link ID: 24236 - Posted: 10.24.2017

Henry Nicholls One of my first jobs was to keep a lookout for lions. There are some occupations that are not suitable for someone with untreated narcolepsy and this is probably one of them. I was 22, a recent zoology graduate studying meerkats in the Kalahari desert in South Africa. We worked in pairs, one of us on foot, walking with meerkats, the other in the jeep scanning the horizon for danger. On many occasions, I awoke with the imprint of the steering wheel on my forehead, realising that meerkats and colleague had wandered out of sight. I would look for signs of life and, as the panic grew, signs of death. I can tell this story now only because no one got eaten. I have not always been like this. For the first 20 years of my life, I had a healthy relationship with sleep. Shortly after my 21st birthday, though, I began to experience symptoms of narcolepsy, a rare disorder thought to affect about one in every 2,500 people. If people know one thing about narcolepsy, it’s that it involves frequent bouts of uncontrollable sleepiness. This is true, but the condition is so much more disabling, often accompanied by cataplexy (where a strong emotion causes loss of muscle tone and a ragdoll-like collapse), trippy dreams, sleep paralysis, frightening hallucinations and, paradoxically, fractured night-time sleep. There is no cure. Yet. In the Kalahari, back in 1995, I was new to these symptoms. I had little sense of the incalculable toll that fighting a never-ending battle against sleep would take on mind, body and soul. I was not alone. Few family doctors had heard of the condition, let alone encountered a sufferer. Some neurologists knew what to look for, but many did not. Not even sleep specialists could explain why this disorder would suddenly strike, with peak onset at around 15 years of age. © 2017 Guardian News and Media Limited

Keyword: Narcolepsy
Link ID: 24235 - Posted: 10.24.2017

By Daisy Grewal Despite its importance for health and well-being, many American adults find it difficult to consistently get enough sleep. Approximately 50 to 70 million Americans suffer from a sleep disorder, according to the Center for Disease Control and Prevention. Sleep disturbances are particularly common in older adults and involve a variety of problems including difficulties falling or staying asleep, interrupted breathing, and restless leg syndrome. A person’s racial background can influence their likelihood of developing a sleep disorder, with a greater number of African Americans reporting sleep disturbances compared to White Americans. Beyond its effects on health, not getting enough sleep can lead to car accidents, medical errors, or other mistakes on the job. To encourage better sleep, the medical community encourages adults to engage in good “sleep hygiene” such as limiting or avoiding caffeine and nicotine, avoiding naps during the day, turning off electronics an hour before bed, exercising, and practicing relaxation before bedtime. It is also well-known that mental health is closely linked to sleep; insomnia is more common in people suffering from depression or anxiety. A recent study now raises the possibility that sleep could be affected by the degree to which someone feels like their life is purposeful or meaningful. Arlener Turner, Christine Smith, and Jason Ong of the Northwestern University School of Medicine found that people who reported having a greater sense of purpose in life also reported getting better sleep – even when taking into consideration age, gender, race, and level of education. © 2017 Scientific American

Keyword: Sleep; Attention
Link ID: 24217 - Posted: 10.19.2017

Amy Maxmen For the first time, researchers have cured the deadly neurological disease sleeping sickness using pills instead of a combination of intravenous infusions and pills. The investigators presented the results from final clinical trials on 17 October at the European Congress on Tropical Medicine and International Health in Antwerp, Belgium, providing hope that the treatment will help to eliminate the malady within a decade. The oral therapy — called fexinidazole — cured 91% of people with severe sleeping sickness, compared with 98% who were treated with the combination therapy. It also cured 99% of people in an early stage of the disease who would typically undergo a spinal tap, to determine whether they needed infusions. The relative ease of the treatment with fexinidazole means that if approved, it might save more lives than the current option, say the investigators leading the phase 3 trial, the final phase of testing before the drug goes to regulators for approval. Sleeping sickness is endemic to Africa and generally infects extremely poor people who live in remote regions. The sick often suffer from the disease for years before seeking treatment, causing them and those caring for them to miss work and spend their savings on traditional medicines. Trekking to a hospital and remaining there for intravenous infusions is costly as well. © 2017 Macmillan Publishers Limited,

Keyword: Sleep
Link ID: 24216 - Posted: 10.19.2017

By NICHOLAS BAKALAR Lack of sleep may raise the risk for gestational diabetes. Gestational diabetes — abnormally high blood sugar that develops during pregnancy — can lead to excessive birth weight, preterm birth or respiratory distress in the baby, among other problems. It can also increase the mother’s risk for Type 2 diabetes later in life. Researchers pooled data from eight studies involving 17,595 women. Seven of the studies depended on self-reports of sleep, and one measured sleep duration. After adjusting for variables such as age, body mass index and ethnicity, they found that women who slept less than 6.25 hours a night were almost three times as likely to have gestational diabetes as those who slept more. The study is in Sleep Medicine Reviews. The reasons for the link are not known, but the authors suggest that hormonal changes in pregnancy as well as systematic inflammation tied to lack of sleep can lead to insulin resistance and high blood glucose levels. But the study is observational and does not prove a causal relationship between poor sleep and gestational diabetes. “Minimizing sleep disruption is important — limiting caffeine, avoiding electronics at bedtime and so on,” said the lead author, Dr. Sirimon Reutrakul, an associate professor of medicine at the University of Illinois at Chicago. “It’s another factor that may influence overall health. But it’s easier said than done.” © 2017 The New York Times Company

Keyword: Sleep; Sexual Behavior
Link ID: 24215 - Posted: 10.19.2017

By Virginia Morell Dog owners often wonder what—if anything—is going on when their pooches are sleeping. It turns out they may be learning, according to a new study. Researchers in Hungary trained 15 pet dogs to sit and lie down using English phrases instead of the Hungarian they already knew. Afterward, the scientists attached small electrodes to the dogs’ heads to record their brain activity while they slept. Electroencephalograms (EEGs) showed that during 3-hour naps, the dogs’ brains experienced brief, repeated moments of “slow-wave” brain activity, lasting 0.5 to 5 seconds. These bursts—called sleep spindles because they look like a train of fast, rhythmic waves on EEG recordings—occur during non-REM sleep and are known to support memory, learning, general intelligence, and healthy aging in humans and rats. But this is the first time they’ve been studied in detail in dogs. Like those of humans and rats, the dogs’ sleep spindles occur in short cycles in the 9-hertz to 16-hertz range; in humans and rats, these cycles are associated with memory consolidation. The scientists also discovered that the number of spindle sessions per minute correlated with how well the dogs learned their new, foreign vocabulary, the researchers report this week in Scientific Reports. And—just like in humans—females had more spindle sessions per minute than males and performed better during testing. About 30% of the females learned the new words, compared to about 10% of the males. That suggests, the researchers say, that dogs can serve as models to better understand the function of our own sleep spindles. © 2017 American Association for the Advancement of Science

Keyword: Sleep; Learning & Memory
Link ID: 24191 - Posted: 10.14.2017

By DANIEL E. SLOTNIK Dr. Michel Jouvet, a neurophysiologist who discovered the region of the brain that controls rapid eye movement, and who helped define REM sleep as a unique state of consciousness common to humans and animals alike, was found dead on Oct. 3 in Villeurbanne, France. He was 91. Pierre-Hervé Luppi, a fellow researcher who worked with Dr. Jouvet for many years, said he had died overnight at a hospital. The curious physiological phenomenon known as REM sleep was first reported in the early 1950s by Eugene Aserinsky and Nathaniel Kleitman, researchers at the University of Chicago. They noticed that people who appeared to be sleeping soundly sometimes moved their fully lidded eyes, and that electroencephalogram recordings showed that brain activity during periods of eye movement was closer to that of someone awake than someone unconscious. They and another colleague, William C. Dement, eventually determined that sleepers had intermittent periods of REM during which they often dreamed. Dr. Jouvet was a researcher at the University of Lyon in France, studying how sleeping cats react to stimuli, before he turned his attention to REM in the late 1950s. In deep, or slow-wave, sleep, both cats and humans show slight muscle tension and low brain activity. But Dr. Jouvet found that during periods of REM sleep the muscles of cats were completely slack, even though their brain waves suggested physical activity. He called the REM state “paradoxical sleep,” since the brain is active even though the body is virtually still. © 2017 The New York Times Company

Keyword: Sleep
Link ID: 24177 - Posted: 10.12.2017

By Leslie Kaufman It is 7 p.m. on a spring Friday, and the Highland Hospital emergency room in Oakland, one of the busiest trauma centers in northern California, is expecting. When the patient—a young bicyclist hit by a car—arrives, blood is streaming down his temples. From a warren of care rooms, a team of nearly a dozen doctors and nurses materializes and buzzes around the patient. Amelia Breyre, a first-year resident who looks not much older than a college sophomore, immediately takes charge. As soon as the team finishes immobilizing the victim, Breyre must begin making split-second decisions: X-ray? Intubate? Transfusion? She quickly determines there is no internal bleeding or need for surgery and orders up neck X-rays after bandaging the patient’s head. Breyre will make a half-dozen similar critical choices tonight. Highland, a teaching hospital, is perhaps the most selective emergency-medical residency in the nation. To be here, she must be outstanding. To succeed, though, she must stay sharp. That quality of focus—amid the chaos and battered ­humanity that comes through Highland’s doors—is itself in need of urgent care. Andrew Herring, an emergency-room doctor who supervises Breyre and 40 other residents, is worried about the team. ER doctors are shift workers, and their hours are spread over a dizzying, ever-changing schedule of mornings, afternoons, and nights that total 20 ­different shifts a month. That’s meant to equally distribute the burden of nocturnal work across an entire team of physicians. But despite those good intentions, Herring says, the result is that every single one of them is exhausted and sleep ­deprived. That’s dangerous for doctor and patient alike.

Keyword: Biological Rhythms
Link ID: 24165 - Posted: 10.09.2017