By Meghan Rosen The patient arrived at the hospital one hot night in Masi-Manimba, an agricultural town unfurled along the Democratic Republic of the Congo’s Lukula River. He couldn’t speak, he couldn’t walk, he was conscious but “barely could make … gestures,” says Béatrice Kasita, a nurse who was there when he came in. She remembers his deformed posture, how his body curved into a fetal position. He was also unusually drowsy — a telltale sign of his illness. The patient, a 27-year-old man, had been brought in by a medical team screening villagers for sleeping sickness, a deadly parasitic disease spread via the bite of a blood-feeding fly. Since the first case report in the late 14th century, the illness has ebbed and flowed in sub-Saharan Africa. Across the continent, the predominant form of sleeping sickness shows up in about two dozen countries, most cases now occurring in the DRC. The disease is a nightmarish scourge that can maim the brain and ultimately kill. But today, cases hover near an all-time low. In 2021, the World Health Organization reported just 747 cases of the predominant form, down from more than 37,000 in 1998. That precipitous plunge came out of decades of work, millions of screenings, spinal taps upon spinal taps, toxic treatments and the rapid rise of safer though often burdensome ones, countless IV infusions, long hospital days and nights, medicine lugged to remote villages, and communities on constant alert for sleeping sickness’s insidious symptoms. Now, a promising drug has fanned hope for halting transmission of the disease. Called acoziborole, the drug is taken by mouth in just a single dose. Kasita’s patient, who arrived at the hospital in June 2017, was among the first to try it. © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28715 - Posted: 03.23.2023

By Katherine Harmon Courage We all might wish for minds as retentive as a hard drive. Memory file created. Saved. Ready for access at any time. But don’t yet go wishing for the memory performance of AI. Artificial neural networks are prone to a troublesome glitch known, evocatively, as catastrophic forgetting. These seemingly tireless networks can keep learning tasks day and night. But sometimes, once a new task is learned, any recollection of an old task vanishes. It’s as if you learned to play tennis decently well, but after being taught to play water polo, you suddenly had no recollection of how to swing a racket. This apparent network overload put an idea in the head of Maxim Bazhenov, a professor who studies computational neuroscience and sleep at the University of California San Diego School of Medicine. Perhaps the spiking neural networks he was working with simply needed a rest. In natural sleep, he had seen that the same basic brain processes occur in humans and in honeybees, working over information accumulated during waking moments. “That machinery presumably was doing something useful” in order to be conserved across evolutionary paths, he says. So, he thought, why not try a similar state for the machines. The idea was to simply provide the artificial neural networks with a break from external stimuli, to instruct them to go into a sort of rest state. Like the dozing human brain, the networks were still active, but instead of taking in new information, they were mulling the old stuff, consolidating, surfacing patterns.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory and Learning
Link ID: 28709 - Posted: 03.18.2023

Kevin Rawlinson It is no mystery that a good night’s sleep and a lie-in can improve your day. But researchers are suggesting that, far from just being enjoyable, quality sleep may even add years to people’s lives. Men who regularly sleep well could live almost five years longer than those who do not, while women could benefit by two years, research suggests. And they could also enjoy better health during their lives. Researchers found that young people who had better sleep habits were less likely to die early. But the researchers said their findings indicated quantity of sleep was not in itself enough to achieve the possible health benefits – quality of sleep is also important. Good sleep was based on five different factors: ideal sleep duration of seven to eight hours a night; difficulty falling asleep no more than two times a week; trouble staying asleep no more than two times a week; not using any sleep medication; and feeling well rested after waking up at least five days a week. The findings suggested that about 8% of deaths from any cause could be attributed to poor sleep patterns. Dr Frank Qian, an internal medicine resident physician at Beth Israel Deaconess Medical Center in Boston, America, said: “We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality.” © 2023 Guardian News & Media Limited

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28679 - Posted: 02.25.2023

By Dani Blum There are a few tried and true pieces of advice that sleep doctors always give for battling insomnia: Watch those alcoholic drinks at dinner, cut the afternoon coffee, stop scrolling before bed. And please, they beg: Keep your sleep schedule consistent. Flip-flopping between wake-up times — jolting awake at 7:30 on a Friday morning and then dozing until the afternoon on Saturday — wreaks havoc on our internal body clocks. Sleep experts refer to this as “social jet lag,” said Dr. Sabra Abbott, a sleep medicine specialist at the Northwestern Feinberg School of Medicine. Similar to changing time zones, heading to bed at vastly different times from night to night may throw off your circadian rhythm. And still, as anyone who’s worked a night shift, taken care of a toddler or fumbled back home after a party might tell you: Going to bed and waking up at the same times is easier said than done. “It’s a luxury, right?” said Kelsie Full, a behavioral epidemiologist and an assistant professor at Vanderbilt University Medical Center. Dr. Full is the lead author of a new study that tied irregular sleep to an early marker of cardiovascular disease. Researchers examined a week’s worth of sleep data from 2,000 adults over 45 and found that those who slept varying amounts each night and went to bed at different times were more likely to have hardened arteries than those with more regular sleep patterns. People whose overall sleep amounts varied by two or more hours from night to night throughout the week — getting five hours of sleep on Tuesday, say, and then eight hours on Wednesday — were particularly likely to have high levels of calcified fatty plaque built up in their arteries, compared with those who slept the same number of hours each night. The study could not confirm that inconsistent sleep patterns definitively caused the heart issues, Dr. Full said. And the findings don’t necessarily mean that the occasional late night or very early morning should be off the table. © 2023 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28676 - Posted: 02.22.2023

By Kristen French George Church looks like he needs a nap. I’m talking to him on Zoom, and his eyelids have grown heavy, inclining toward slumber. Or maybe my mind is playing tricks on me. He assures me he is wide awake. But sleeping and waking life are often blurred for Church. One of the world’s most imaginative scientists, Church is a narcoleptic. A rare disorder, narcolepsy causes sudden attacks of sleep, and Church has fallen asleep in some unfortunate circumstances—at The World Economic Forum, just a few feet away from Microsoft founder Bill Gates, for instance. He also had to give up driving due to the risk that a bout of sleepiness will strike while he is behind the wheel. But Church, a Harvard geneticist known for his pathbreaking contributions to numerous fields—from genetics to astrobiology to biomedicine—says the benefits of his condition outweigh the inconveniences. Many of his wildest and most prescient ideas come from his narcoleptic naps. “The fact is, I fall asleep several times a day, and so almost everything comes from there,” Church says. His idea for a quick and simple way to “read” DNA—which resulted in the first commercial genome sequence, of the human pathogen H. pylori—came from a narcoleptic nap. He also conceived of editing genomes with CRISPR and building new genomes with off-the-shelf molecules during narcoleptic naps. More recently, in December, a wild idea for a space probe that could reach distant stars within just 20 years, at one-fifth the speed of light, came to him after a narcoleptic nap. He proposed that these lightning-speed interstellar missions could be launched by microbes and powered by laser sails. The ideas that come to him are often the result of collisions of unexpected images in his head. “I try to turn science fiction into science fact,” Church tells me. © 2023 NautilusNext Inc.,

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Higher Cognition
Link ID: 28648 - Posted: 02.01.2023

By Susan Milius As tiny glass frogs fall asleep for the day, they take almost 90 percent of their red blood cells out of circulation. The colorful cells cram into hideaway pockets inside the frog liver, which disguises the cells behind a mirrorlike surface, a new study finds. Biologists have known that glass frogs have translucent skin, but temporarily hiding bold red blood brings a new twist to vertebrate camouflage (SN: 6/23/17). “The heart stopped pumping red, which is the normal color of blood, and only pumped a bluish liquid,” says evolutionary biochemist Carlos Taboada of Duke University, one of the discoverers of the hidden blood. What may be even more amazing to humans — prone to circulatory sludge and clogs — is that the frogs hold almost all their red blood cells packed together for hours with no blood clots, says co-discoverer Jesse Delia, now at the American Museum of Natural History in New York City. Wake the frog up, and cells just unpack themselves and get circulating again. Hiding those red blood cells can double or triple the transparency of glass frogs, Taboada, Delia and colleagues report in the Dec. 23 Science. That greenish transparency can matter a lot for the snack-sized frogs, which spend the day hiding like little shadows on the undersides of the leaves high in the forest canopy. A photo on the left showing a sleeping female glass frog with most of her red blood cells tucked into her liver. While the photo on the right shows the frog while awake with blood circulating and less transparent. What got Delia wondering about transparency was a photo emergency. He had studied glass frog behavior, but had never even seen them asleep. “They go to bed, I go to bed — that was my life for years,” he says. When he needed some charismatic portraits, however, he put some frogs in lab dishes and at last saw how the animals sleep the day away. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28610 - Posted: 12.24.2022

Max Barnhart In 2004, when physician Dr. Wilfried Mutombo began treating patients diagnosed with sleeping sickness, the available treatments were themselves horrific and sometimes deadly. "The widely available treatment then was an arsenic-based drug, and it was toxic. It could kill up to 5% of patients," he says. "I lost two of my patients. They were young, and that was a very bad experience. Sleeping sickness is an often fatal disease caused by a parasite where infected people become prone to sleeping all day and night as the disease progresses. It's endemic to 36 countries in Africa, but most cases occur in the Democratic Republic of the Congo. Now, a new oral drug has emerged that is 95% effective at curing sleeping sickness with just one dose. The results of clinical trials for this new drug, acoziborole, were published in The Lancet Infectious Diseases on Nov. 29. It has the potential to drastically change the way sleeping sickness is treated and help the World Health Organization (WHO) reach its goal of eliminating sleeping sickness by 2030. There are two kinds of sleeping sicknesses, both caused by Trypanosoma parasites. The most common form of the disease, and the one treated by this new drug, is caused by Trypanosoma brucei gambiense. Humans are the primary reservoir for the parasite, and it is spread to others by tsetse flies. WHO estimates there were roughly 300,000 cases per year in the late '90s, but the number of cases has now dropped to fewer than 1,000 cases per year. © 2022 npr

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28577 - Posted: 12.03.2022

By Sandra G. Boodman The first time it happened, Erin Bousquet was a high school freshman who had been diagnosed with strep throat, a common infection in her family. After three days on an antibiotic, she wasn’t getting better, so the 14-year-old was prescribed a second drug. A day or two later, Kristen Bousquet noticed worrisome changes in her oldest child. Erin seemed “lethargic and out of it,” her mother recalled. She was irritable, her pupils looked dilated, and much of what she said made no sense. Most alarming was Erin’s newfound ability to sleep for up to 20 hours at a time. “It was quite scary,” Kristen recalled. “At first we thought she was joking.” That bizarre episode, which occurred in September 2017, has been followed by 11 more, each lasting an average of 10 days. Between episodes, Erin’s behavior is normal. For 2 1/2 years she and her parents, who live in Lincoln, Neb., consulted pediatric neurologists, a neurosurgeon, an obstetrician-gynecologist and other specialists in a largely fruitless search to identify the condition that drastically alters her personality and temporarily shuts down her life two or three times a year. The diagnosis, made in March 2020, was an enormous relief. But it has required the Bousquets to cope with continued uncertainty because so little is known about Erin’s disorder. “The hardest thing for me are the things I’ve missed out on,” said Erin, a 19-year-old sophomore at the University of Nebraska at Lincoln. They include a high school basketball championship, her 18th birthday, a family Christmas trip to Colorado and the start of her sophomore year of college. Erin slept through them all. Because her symptoms — disorientation and prolonged sleep — can be signs of a serious, even life-threatening, illness, the staff at the urgent care clinic where Erin had been treated for strep told her mother to take her to an emergency room. A test for infectious mononucleosis, a contagious virus common among adolescents and young adults that causes profound fatigue was negative and a quick neurological exam was normal. Erin was sent home.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28567 - Posted: 11.23.2022

By Christina Jewett By 2015, Philips Respironics knew its breathing devices had a problem: Foam inside the CPAP machines, which help people with sleep apnea breathe at night, was breaking off into black flecks and blowing into the mouths and noses of users. The company did nothing at the time. Years went by as complaints mounted, and the company made cursory efforts to examine the problem, according to an investigation conducted later by the Food and Drug Administration. But it was not until April of last year, the company has claimed, that it realized the flaking foam contained potentially cancer-causing particles, setting off the largest and most disruptive medical device recall in more than a decade. Nearly a year and a half after the recall that involved more than five million devices worldwide, millions of American have endured a long wait for a device. Many have been forced to find alternative methods to ensure they can breathe at night without becoming deprived of oxygen or risking a heart attack. Others have been outraged by unexpected illness, suspicious that a device meant to help them actually caused harm. The U.S. Justice Department is now negotiating the terms of a consent decree with Philips, underscoring the deep concern about what the company knew — or should have known — before millions of people received devices that many believe caused devastating illnesses. A decree would likely require the company to document the steps it would take to prevent such a failure in the future. Doug Shiffler, a retired tech executive in Utah, is one of hundreds of people suing the company. His wife began using the device in 2018, when there were no public warnings of possible problems with the machines, and developed a persistent cough. By mid-2020, Joleen Shiffler was diagnosed with an aggressive lung cancer that baffled her doctors, although a direct link between her disease and the Philips device had not been established. Ms. Shiffler, 60, died within the year. “Why weren’t we informed that there was an issue?” Mr. Shiffler asked. If they had known, “I might be standing right beside Joleen instead of mourning her loss.” © 2022 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28551 - Posted: 11.16.2022

By Jackie Rocheleau For people haunted by recurring nightmares, untroubled sleep would be a dream come true. Now in a small experiment, neuroscientists have demonstrated a technique that, for some, may chase the bad dreams away. Enhancing the standard treatment for nightmare disorder with a memory-boosting technique cut down average weekly nightmares among a few dozen people from three to near zero, researchers report online October 27 in Current Biology. “The fact that they could actually make a big difference in the frequency of those nightmares is huge,” says Gina Poe, a neuroscientist at UCLA who wasn’t involved in the study. People with nightmare disorder fear the night not for the monsters under the bed, but the monsters in their dreams. Frequent, terrifying dreams disturb sleep and even affect well-being in waking life. The go-to nightmare disorder treatment is imagery rehearsal therapy, or IRT. In this treatment, patients reimagine nightmares with a positive spin, mentally rehearsing the new story line while awake. It reduces nightmares for most but fails for nearly a third of people. To boost IRT’s power, neuroscientist Sophie Schwartz of the University of Geneva and her colleagues leveraged a learning technique called targeted memory reactivation, or TMR. In this technique, a person focuses on learning something while a sound plays, and that same cue plays again during sleep. Experiencing the cue during sleep, which is important for memory storage, may reactivate and strengthen the associated memory (SN: 10/3/19). In the new study, the researchers gave 36 people with nightmare disorder training in IRT, randomly assigning half of them to rehearse their revised nightmares in silence. The other half rehearsed while a short piano chord, the TMR cue, played every 10 seconds for five minutes. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28532 - Posted: 10.28.2022

WASHINGTON — A massive recall of millions of sleep apnea machines has stoked anger and frustration among patients, and U.S. officials are weighing unprecedented legal action to speed a replacement effort that is set to drag into next year. Sound-dampening foam in the pressurized breathing machines can break down over time, leading users to potentially inhale tiny black particles or hazardous chemicals while they sleep, manufacturer Philips warned in June 2021. Philips initially estimated it could repair or replace the units within a year. But with the recall expanding to more than 5 million devices worldwide, the Dutch company now says the effort will stretch into 2023. That's left many patients to choose between using a potentially harmful device or trying risky remedies, including removing the foam themselves, buying second-hand machines online or simply going without the therapy. The devices are called continuous positive airway pressure, or CPAP, machines. They force air through a mask to keep passageways open during sleep. Untreated sleep apnea can cause people to stop breathing hundreds of times per night, leading to dangerous drowsiness and increased heart attack risk. The problem is more common in men than women, with estimates ranging from 10% to 30% of adults affected. Most patients are better off using a recalled device because the risks of untreated sleep apnea still outweigh the potential harms of the disintegrating foam, physicians say. But doctors have been hard pressed to help patients find new machines, which generally cost between $500 and $1,000, and were already in short supply due to supply chain problems. © 2022 npr

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28523 - Posted: 10.26.2022

Nicola Davis Science correspondent Playing sounds while you slumber might help to strengthen some memories while weakening others, research suggests, with experts noting the approach might one day help people living with traumatic recollections. Previous work has shown that when a sound is played as a person learns an association between two words, the memory of that word association is boosted if the same sound is played while the individual sleeps. Now researchers have found fresh evidence the approach could also be used to weaken such memories. “We can an actually induce forgetting of specific material whilst people are asleep,” said Dr Aidan Horner, co-author of the study from the University of York. Advertisement Writing in the journal Learning & Memory, Horner and colleagues report how 29 participants were shown pairs of words on a computer screen, one of which was an object word, such as bicycle, while the other was either a place word, such as office, or a person, such as David Beckham. The process was repeated for 60 different object words, and in the course of the process both possible pairings were shown, resulting in 120 associations. As the pairs flashed up, participants heard the object word being spoken out loud. The team tested the participants on a subset of the associations, presenting them with one of the words and asking them to select a paired word from a list of six options. Participants then spent a night in the team’s sleep laboratory. Once they had entered a particular sleep state – as judged by electrodes placed on their heads – they were played audio of 30 of the object words. The team tested participants on the word associations the next day. The results reveal participants’ ability to recall the first word they had learned to pair with an object word was boosted if audio of the latter was played as they slept, compared with if it was not played. However, their ability to recall the second word they learned to associate with the same object decreased relative to the audio-free scenario. © 2022 Guardian News & Media Limited

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory and Learning
Link ID: 28516 - Posted: 10.19.2022

By Erin Blakemore Empathy and generosity are two traits that arguably make the world go ‘round. But a study suggests that the willingness to help collapses when people get too little — or poor — sleep. To see how sleep affects how much humans help one another, researchers conducted three experiments designed to examine the issue from the individual to the societal scale. Their results are published in PLOS Biology. In the first experiment, researchers performed functional magnetic resonance imaging scans of the brain and asked questions to 24 adults after eight hours of sleep and after a night with no sleep. When they were well rested, the participants scored well on a helping behavior test. But after sleep deprivation, 78 percent had less of a desire to help others, even when it came to friends and family. The scans showed that areas of the brain associated with social cognition — our thought processes related to other people — were less active with sleep deprivation. The second experiment tracked 136 healthy adults over four nights and asked them questions about helping the following day. The effect held for them, too, and those who reported worse sleep quality scored worse on the tests. Just one hour of extra sleep each night can lead to better eating habits To test the effects on a societal level, the researchers then looked at a database of 3 million charitable donations given between 2001 and 2016. They found that immediately following the beginning of daylight saving time — a notorious sleep disrupter — donations dropped 10 percent. The effect wasn’t found in data from Hawaii or Arizona, however; neither observe DST. Nor did the shift back to standard time have such an association with donations.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28503 - Posted: 10.08.2022

By Deborah Balthazar It’s a frustration many parents know all too well: You’ve finally lulled your crying baby to sleep, so you put them down in their crib … and the wailing begins again. Science may have a trick for you. Carrying a crying infant for about five minutes, then sitting for at least another five to eight minutes can calm and lull the baby to sleep long enough to allow a parent to put the child down without waking them, researchers report September 13 in Current Biology. Some of those same researchers previously showed that carrying a crying baby soothes the child and calms a racing heart rate (SN: 4/18/13). For the new study, the team looked at what it takes to get that crying baby to nod off and stay asleep. The researchers put heart rate monitors on 21 crying babies, ranging in age from newborns to 7 months old. The team also took videos of the infants, monitoring their moods as their mothers carried them around a room, sat holding them and laid them in a crib. That allowed the team to observe how the babies responded to different environments, whether they were crying, fussy, alert or drowsy, heartbeat by heartbeat. “We tested the physiology behind these things that tend to be kind of common knowledge, though it’s not really well understood why they work,” says Gianluca Esposito, a developmental psychologist at the University of Trento in Italy. The babies’ heart rates slowed and they stopped crying when their mothers picked them up and carried them around for five minutes. Some infants even fell asleep. But the researchers also noticed that the babies tended to respond to the movement of the parent, whether they were in deep sleep or not. For instance, a baby’s heart rate quickened if a parent turned quickly while walking or tried to put the baby down. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory and Learning
Link ID: 28494 - Posted: 10.01.2022

By Jackie Rocheleau After experimenting on a hen, his dog, his goldfish, and himself, dentist William Morton was ready. On Oct. 16, 1846, he hurried to the Massachusetts General Hospital surgical theater for what would be the first successful public test of a general anesthetic. His concoction of sulfuric ether and oil from an orange (just for the fragrance) knocked a young man unconscious while a surgeon cut a tumor from his neck. To the onlooking students and clinicians, it was like a miracle. Some alchemical reaction between the ether and the man’s brain allowed him to slip into a state akin to light sleep, to undergo what should have been a painful surgery with little discomfort, and then to return to himself with only a hazy memory of the experience. General anesthesia redefined surgery and medicine, but over a century later it still carries significant risks. Too much sedation can lead to neurocognitive disorders and may even shorten lifespan; too little can lead to traumatic and painful wakefulness during surgery. So far, scientists have learned that, generally speaking, anesthetic drugs render people unconscious by altering how parts of the brain communicate. But they still don’t fully understand why. Although anesthesia works primarily on the brain, anesthesiologists do not regularly monitor the brain when they put patients under. And it is only in the past decade that neuroscientists interested in altered states of consciousness have begun taking advantage of anesthesia as a research tool. “It’s the central irony” of anesthesiology, says George Mashour, a University of Michigan neuroanesthesiologist, whose work entails keeping patients unconscious during neurosurgery and providing appropriate pain management. Mashour is one of a small set of clinicians and scientists trying to change that. They are increasingly bringing the tools of neuroscience into the operating room to track the brain activity of patients, and testing out anesthesia on healthy study participants. These pioneers aim to learn how to more safely anesthetize their patients, tailoring the dose to individual patients and adjusting during surgery. They also want to better understand what governs the transitions between states of consciousness and even hope to crack the code of coma. © 2022 NautilusThink Inc, All rights reserved.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 4: Development of the Brain
Link ID: 28480 - Posted: 09.17.2022

Michael Heithaus Could you explain how fish sleep? Do they drift away on currents, or do they anchor themselves to a particular location when they sleep? – Laure and Neeraj, New York From the goldfish in your aquarium to a bass in a lake to the sharks in the sea – 35,000 species of fish are alive today, more than 3 trillion of them. All over the world, they swim in hot springs, rivers, ponds and puddles. They glide through freshwater and saltwater. They survive in the shallows and in the darkest depths of the ocean, more than five miles down. If those trillions of fish, three major types exist: bony fish, like trout and sardines; jawless fish, like the slimy hagfish; and sharks and rays, which are boneless – instead, they have skeletons made of firm yet flexible tissue called cartilage. And all of them, every last one, needs to rest. Whether you’re a human or a haddock, sleep is essential. It gives a body time to repair itself, and a brain a chance to reset and declutter. As a marine biologist, I’ve always wondered how fish can rest. After all, in any body of water, predators are all over the place, lurking around, ready to eat them. But somehow they manage, like virtually all creatures on Earth. See the mysterious spot off the coast of Mexico where sharks take a nap. How they do it Scientists are still learning about how fish sleep. What we do know: Their sleep is not like ours. © 2010–2022, The Conversation US, Inc.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28465 - Posted: 09.07.2022

By Rebecca Sohn Distinctive bursts of sleeping-brain activity, known as sleep spindles, have long been generally associated with strengthening recently formed memories. But new research has managed to link such surges to specific acts of learning while awake. These electrical flurries, which can be observed as sharp spikes on an electroencephalogram (EEG), tend to happen in early sleep stages when brain activity is otherwise low. A study published in Current Biology shows that sleep spindles appear prominently in particular brain areas that had been active in study participants earlier, while they were awake and learning an assigned task. Stronger spindles in these areas correlated with better recall after sleep. “We were able to link, within [each] participant, exactly the brain areas used for learning to spindle activity during sleep,” says University of Oxford cognitive neuroscientist Bernhard Staresina, senior author on the study. Staresina, Marit Petzka of the University of Birmingham in England and their colleagues devised a set of tasks they called the “memory arena,” which required each participant to memorize a sequence of images appearing inside a circle. While the subjects did so, researchers measured their brain activity with an EEG, which uses electrodes placed on the head. Participants then took a two-hour nap, after which they memorized a new image set—but then had to re-create the original image sequence learned before sleeping. During naps, the researchers recorded stronger sleep spindles in the specific brain areas that had been active during the pre-sleep-memorization task, and these areas differed for each participant. This suggested that the spindle pattern was not “hardwired” in default parts of the human brain; rather it was tied to an individual's thought patterns. The researchers also observed that participants who experienced stronger sleep spindles in brain areas used during memorization did a better job re-creating the images' positions after the nap. © 2022 Scientific American

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory and Learning
Link ID: 28460 - Posted: 09.03.2022

Steven Strogatz Dreams are so personal, subjective and fleeting, they might seem impossible to study directly and with scientific objectivity. But in recent decades, laboratories around the world have developed sophisticated techniques for getting into the minds of people while they are dreaming. In the process, they are learning more about why we need these strange nightly experiences and how our brains generate them. In this episode, Steven Strogatz speaks with sleep researcher Antonio Zadra of the University of Montreal about how new experimental methods have changed our understanding of dreams. Steven Strogatz (00:03): I’m Steve Strogatz, and this is The Joy of Why, a podcast from Quanta Magazine that takes you into some of the biggest unanswered questions in math and science today. (00:13) In this episode, we’re going to be talking about dreams. What are dreams exactly? What purpose do they serve? And why are they often so bizarre? We’ve all had this experience: You’re dreaming about something fantastical, some kind of crazy story with a narrative arc that didn’t actually happen, with people we don’t necessarily know, in places we may have never even been. Is this just the brain trying to make sense of random neural firing? Or is there some evolutionary reason for dreaming? Dreams are inherently hard to study. Even with all the advances in science and technology, we still haven’t really found a way to record what someone else is dreaming about. Plus, as we all know, it’s easy to forget our dreams as soon as we wake up, unless we’re really careful to write them down. But even with all these difficulties, little by little, dream researchers are making progress in figuring out how we dream and why we dream. (01:11) Joining me now to discuss all this is Dr. Antonio Zadra, a professor at the University of Montreal and a researcher at the Center for Advanced Research in Sleep Medicine. His specialties include the study of nightmares, recurrent dreams and lucid dreaming. He’s also the coauthor of the recent book When Brains Dream, exploring the science and mystery of sleep. Tony, thank you so much for joining us today. Strogatz (01:39): I’m very excited to talk to you about this. So let’s start with thinking about the science of dreams as you and your colleagues see it today. Why are dreams so hard to study? All Rights Reserved © 2022

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 28454 - Posted: 08.27.2022

Yuta Senzai Massimo Scanziani Does rapid eye movement during sleep reveal where you’re looking at in the scenery of dreams, or are they simply the result of random jerks of our eye muscles? Since the discovery of REM sleep in the early 1950s, the significance of these rapid eye movements has intrigued and fascinated scores of scientists, psychologists and philosophers. REM sleep, as the name implies, is a period of sleep when your eyes move under your closed eyelids. It’s also the period when you experience vivid dreams. We are researchers who study how the brain processes sensory information during wakefulness and sleep. In our recently published study, we found that the eye movements you make while you sleep may reflect where you’re looking in your dreams. Past studies have attempted to address this question by monitoring the eye movements of people as they slept and waking them up to ask what they were dreaming. The goal was to find a possible connection between the content of a dream just before waking up (say, a car coming in from the left) and the direction the eyes moved at that moment. Unfortunately, these studies have led to contradictory results. It could be that some participants inaccurately reported dreams, and it’s technically difficult to match a given eye movement to a specific moment in a self-reported dream. We decided to bypass the problem of dream self-reporting. Instead, we used a more objective way to measure dreams: the electrical activity of a sleeping mouse brain. Mice, like humans and many other animals, also experience REM sleep. Additionally, they have a sort of internal compass in their brains that gives them a sense of head direction. When the mouse is awake and running around, the electrical activity of this internal compass precisely reports its head direction, or “heading,” as it moves in its environment. © 2010–2022, The Conversation US, Inc.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 7: Vision: From Eye to Brain
Link ID: 28453 - Posted: 08.27.2022

By Sujata Gupta Lack of sleep has been linked to heart disease, poor mood and loneliness (SN: 11/15/16). Being tired could also make us less generous, researchers report August 23 in PLOS Biology. The hour of sleep lost in the switch over to Daylight Savings Time every spring appears to reduce people’s tendency to help others, the researchers found in one of three experiments testing the link between sleep loss and generosity. Specifically, they showed that average donations to one U.S.-based nonprofit organization dropped by around 10 percent in the workweek after the time switch compared with four weeks before and after the change. In Arizona and Hawaii, states that do not observe Daylight Savings Time, donations remained unchanged. With over half of the people living in parts of the developed world reporting that they rarely get enough sleep during the workweek, the finding has implications beyond the week we spring forward, the researchers say. “Lack of sleep shapes the social experiences we have [and] the kinds of societies we live in,” says neuroscientist Eti Ben Simon of the University of California, Berkeley. To test the link between sleep loss and generosity, Ben Simon and her team first brought 23 young adults into the lab for two nights. The participants slept through one night and stayed awake for another night. In the mornings, participants completed a standardized altruism questionnaire rating their likelihood of helping strangers or acquaintances in various scenarios. For instance, participants rated on a scale from 1 to 5, with 1 for least likely to help and 5 for most likely, whether they would give up their seat on a bus to a stranger or offer a ride to a coworker in need. Participants never read the same scenario more than once. Roughly 80 percent of participants showed less likelihood of helping others when sleep-deprived than when rested. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28444 - Posted: 08.24.2022