By Elise Cutts On a summer night in the Bay of Naples, hordes of worms swam upward from the seagrass toward the water’s surface under the light of a waning moon. Not long before, the creatures began a gruesome sexual metamorphosis: Their digestive systems withered, and their swimming muscles grew, while their bodies filled with eggs or sperm. The finger-length creatures, now little more than muscular bags of sex cells, fluttered to the surface in unison and, over a few hours, circled each other in a frantic nuptial dance. They released countless eggs and sperm into the bay — and then the moonlit waltz ended in the worms’ deaths. The marine bristle worm Platynereis dumerilii gets only one chance to mate, so its final dance had better not be a solo. To ensure that many worms congregate at the same time, the species synchronizes its reproductive timing with the cycles of the moon. How can an undersea worm tell when the moon is at its brightest? Evolution’s answer is a precise celestial clock wound by a molecule that can sense moonbeams and sync the worms’ reproductive lives to lunar phases. No one had ever seen how one of these moonlight molecules worked. Recently, however, in a study published in Nature Communications, researchers in Germany determined the different structures that one such protein in bristle worms takes in darkness and in sunlight. They also uncovered biochemical details that help explain how the protein distinguishes between brighter sunbeams and softer moonglow. It’s the first time that scientists have determined the molecular structure of any protein responsible for syncing a biological clock to the phases of the moon. “I’m not aware of another system that has been looked at with this degree of sophistication,” said the biochemist Brian Crane of Cornell University, who was not involved in the new study. © 2023 An editorially independent publication supported by the Simons Foundation.

Keyword: Biological Rhythms; Evolution
Link ID: 29062 - Posted: 12.22.2023

By Cathleen O’Grady Why do some children learn to talk earlier than others? Linguists have pointed to everything from socioeconomic status to gender to the number of languages their parents speak. But a new study finds a simpler explanation. An analysis of nearly 40,000 hours of audio recordings from children around the world suggests kids speak more when the adults around them are more talkative, which may also give them a larger vocabulary early in life. Factors such as social class appear to make no difference, researchers report this month in the Proceedings of the National Academy of Sciences. The paper is a “wonderful, impactful, and much needed contribution to the literature,” says Ece Demir-Lira, a developmental scientist at the University of Iowa who was not involved in the work. By looking at real-life language samples from six different continents, she says, the study provides a global view of language development sorely lacking from the literature. Most studies on language learning have focused on children in Western, industrialized nations. To build a more representative data set, Harvard University developmental psychologist Elika Bergelson and her collaborators scoured the literature for studies that had used LENA devices: small audio recorders that babies can wear—tucked into a pocket on a specially made vest—for days at a time. These devices function as a kind of “talk pedometer,” with an algorithm that estimates how much its wearer speaks, as well as how much language they hear in their environment—from parents, other adults, and even siblings. The team asked 18 research groups across 12 countries whether they would share their data from the devices, leaving them with a whopping 2865 days of recordings from 1001 children. Many of the kids, who ranged from 2 months to 4 years old, were from English-speaking families, but the data also included speakers of Dutch, Spanish, Vietnamese, and Finnish, as well as Yélî Dnye (Papua New Guinea), Wolof (Senegal), and Tsimané (Bolivia). Combining these smaller data sets gave the researchers a more powerful, diverse sample.

Keyword: Language; Development of the Brain
Link ID: 29061 - Posted: 12.22.2023

Alex Johnson The holiday season is upon us, and with it, opportunities to indulge in festive treats. The proverbial saying “you eat with your eyes first” seems particularly relevant at this time of year. The science behind eating behavior, however, reveals that the process of deciding what, when and how much to eat is far more complex than just consuming calories when your body needs fuel. Hunger cues are only part of why people choose to eat. As a scientist interested in the psychology and biology that drives eating behavior, I’m fascinated with how the brain’s experiences with food shape eating decisions. Food-related visual cues can shape feeding behaviors in both people and animals. For example, wrapping food in McDonald’s packaging is sufficient to enhance taste preferences across a range of foods – from chicken nuggets to carrots – in young children. Visual food-related cues, such as presenting a light when food is delivered, can also promote overeating behaviors in animals by overriding energy needs. In fact, a whole host of sensory stimuli – noises, smells and textures – can be associated with the pleasurable consequences of eating and influence food-related decisions. This is why hearing a catchy radio jingle for a food brand, seeing a television ad for a restaurant or walking by your favorite eatery can shape your decision to consume and sometimes overindulge.

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 29060 - Posted: 12.22.2023

Emily Baumgaertner This is not a work of art. It’s an image of microscopic blood flow in a rat’s brain, taken with one of many new tools that are yielding higher levels of detail in brain imaging. Here are seven more glorious images from neuroscience research → © 2023 The New York Times Company

Keyword: Brain imaging
Link ID: 29059 - Posted: 12.22.2023

By Ann Gibbons Louise hadn’t seen her sister or nephew for 26 years. Yet the moment she spotted them on a computer screen, she recognized them, staring hard at their faces. The feat might have been impressive enough for a human, but Louise is a bonobo—one who had spent most of her life at a separate sanctuary from these relatives. The discovery, published today in the Proceedings of the National Academy of Sciences, reveals that our closest primate cousins can remember the faces of friends and family for years, and sometimes even decades. The study, experts say, shows that the capability for long-term social memory is not unique to people, as was long believed. “It’s a remarkable finding,” says Frans de Waal, a primatologist at Emory University who was not involved with the work. “I’m not even sure we humans remember most individuals we haven’t seen for 2 decades.” The research, he says, raises the possibility that other animals can also do this and may remember far more than we give them credit for. Trying to figure out whether nonhuman primates remember a face isn’t simple. You can’t just ask them. So in the new study, comparative psychologist Christopher Krupenye at Johns Hopkins University and colleagues used eye trackers, infrared cameras that noninvasively map a subject’s gaze as they look at images of people or objects. The scientists worked with 26 chimpanzees and bonobos living in three zoos or sanctuaries in Europe and Japan. The team showed the animals photos of the faces of two apes placed side by side on the screen at the same time for 3 seconds. Some images were of complete strangers; some were of close friends, foes, or family members who had once lived in their same social groups, but whom they hadn’t seen in years.

Keyword: Attention; Learning & Memory
Link ID: 29058 - Posted: 12.19.2023

By Andrew Jacobs An autopsy report released by the Los Angeles County medical examiner on Friday said the death of “Friends” actor Matthew Perry, who was found face down and unresponsive in a hot tub at his home on Oct. 28, resulted from the “acute effects” of ketamine, an anesthetic with psychedelic properties. Ketamine has become increasingly popular as a therapy for treatment-resistant depression and other mental health issues. It is also used recreationally. Mr. Perry had publicly acknowledged his long struggle with alcohol and drug use, but the report said he had been sober for 19 months and little was known about his relationship to ketamine. What is ketamine, and is it legal? Ketamine is an injectable, short-acting dissociative anesthetic that can have hallucinogenic effects at certain doses. It distorts perceptions of sight and sound and makes users feel detached from pain and their surroundings. Developed as a battlefield anesthetic in the 1960s, ketamine has been legal since 1970 for use in both people and animals. It is frequently used as an anesthetic for children, especially in the developing world. But the psychiatric use of ketamine is still unapproved and unregulated, although it is increasingly used off label for treating depression, suicidal ideation and chronic pain In 2019, the Food and Drug Administration approved a derivative of ketamine called esketamine in a nasal spray for treatment-resistant depression. Ketamine has the potential for abuse, which may lead to moderate or low physical dependence or high psychological dependence, but experts consider it a safe medication. Those who use it recreationally often snort the drug in powder form or administer it intranasally by spray. © 2023 The New York Times Company

Keyword: Drug Abuse
Link ID: 29057 - Posted: 12.19.2023

Robin McKie, Science Editor People in Britain could benefit from a key medical breakthrough next year. They may be given access to the first drugs ever developed to slow the impact of Alzheimer’s disease. The first of these medicines – lecanemab – was recently approved in the US and Japan, where treatments using it have already been launched. A second drug, donanemab, is expected to follow soon, and next year it is anticipated that the UK medical authorities will consider both of them for approval in Britain. The prospect has raised hopes that, after years of effort, scientists may be closing in on ways to directly tackle the UK’s dementia crisis. About a million people are living with the condition in this country, and this is expected to rise to about 1.7 million by 2040 – with potentially grim consequences. Last year dementia took the lives of 66,000 people in England and Wales, and it is now the leading cause of death in Britain, with Alzheimer’s accounting for two-thirds of cases. Until now doctors have only been able to prescribe medicines that help patients manage their symptoms, so the arrival of the first drugs that treat the actual cause of the condition has been welcomed – although experts have warned that their use should be treated with some caution. “The new drugs slow down the development of Alzheimer’s by six months to a year and are useful only for those in the early stages of the condition, so they are certainly not miracle medicines,” said David Thomas, head of policy at Alzheimer’s Research UK. “However, after decades of research, they are the first to improve patients’ lives directly, and that is a justifiable cause for excitement. If nothing else, they suggest we are probably on the right road to tackling Alzheimer’s.” © 2023 Guardian News & Media Limited

Keyword: Alzheimers
Link ID: 29056 - Posted: 12.19.2023

By Mark MacNamara The notion of boxing as the “sweet science” is often thought to have been coined in 1956 by the great New Yorker writer A.J. Liebling. He used the term as the title of his definitive book on the sport, but he took it—with much appreciation—from a British sportswriter, Pierce Egan. In 1813, Egan wrote about the “sweet science of bruising” in his master work, Boxiana. The book is a collection of magazine pieces set in a bloody, bare-knuckled world opposite Jane Austen’s. As for the “sweet science,” no one ever really defines it. A carefully thrown knockout punch to a sweet spot on the chin is one possible derivation. There’s also the play on a science with so little apparent sweetness. But that’s not it. The sweet science Liebling and Egan describe had more to do with British principles of “stoic virtues,” “generosity,” and “true courage”—altogether, life in a contradictory place. It’s a square ring, after all, where sometimes hope transcends the specter of an awful inevitability. Or so I’ve come to think, on a journey I’ve begun in the past year, exploring how the sweet science can be used as a treatment for Parkinson’s disease—that increasingly common degenerative disorder of the nervous system, tied to a loss of the brain chemical dopamine, which is involved in movement, memory, motivation, and cognition. Someone told her she moved like a wavy wind sock outside a used car lot. “Exactly how I feel,” she said. In October 2022, a longtime tennis partner noticed something “strange” in my stride, along with a noisy shuffle. “Fatigue,” I replied with pique. The truth is I’m 75 and had known something might not be right for years, particularly the ominous hand tremors, as well as the night-of-the-living-dead gait and a facial expression to match. Add severe anxiety in public places and bizarre nightmares, some quite disturbing. © 2023 NautilusNext Inc.,

Keyword: Parkinsons
Link ID: 29055 - Posted: 12.19.2023

By Sandra G. Boodman His plane was coming in for a landing at Philadelphia International Airport when Allen M. Weiss, a marketing professor at the University of Southern California, felt a spasm of pain pierce his left cheek near his nose. “It was really weird,” recalled Weiss, then director of Mindful USC, a group of meditation-based programs at the Los Angeles university. “My face froze up.” Within minutes the pain disappeared and the final leg of Weiss’s December 2015 trip home to California was uneventful. But over the next few months the sensation recurred in the same spot. At first the unpredictable pain was fairly mild and merely bothersome; later it became an excruciating daily torment. Several years after the pain first occurred Weiss, who had consulted dentists, oral pain experts and an otolaryngologist, was given a diagnosis that ended up being correct. But his complicated medical history, a radiology report that failed to describe an important finding and a cryptic warning by one of his doctors delayed effective treatment for three more years. “It was completely confusing,” Weiss said. In June 2023 he underwent surgery that has significantly reduced his pain and improved the quality of his life. N. Nicole Moayeri, the Santa Barbara, Calif., neurosurgeon who operated on Weiss, said a protracted search for a diagnosis and treatment is not unusual for those suffering from Weiss’s uncommon malady. “I commonly see people who’ve had multiple dental procedures for years” when the problem was not in their mouths, Moayeri said. “It’s really shocking to me that so many people suffer” with this for so long. After three months of intermittent pain following the flight, Weiss consulted his internist. For reasons that are unclear, the doctor told Weiss the cause was probably psychological, not physical, and that it wasn’t serious. He sent Weiss to an ear, nose and throat specialist whom he saw in March 2016. She performed an exam and ordered a CT scan that revealed a deviated septum, a typically painless condition estimated to affect up to 80 percent of the population in which the bone or cartilage that divides the nostrils is off-center. A moderate or severe deviation can contribute to the development of sinus infections, headaches and breathing problems. But Weiss had none of these. And a deviated septum didn’t explain the spasms of pain.

Keyword: Pain & Touch
Link ID: 29054 - Posted: 12.19.2023

By Yasemin Saplakoglu In the 16th century, the Belgian cartographer Abraham Ortelius created the world’s first modern atlas — a collection of maps that he called “The Theater of the World.” The maps, drawn by Ortelius and others, detailed what was at the time the best knowledge of the world’s continents, cities, mountains, rivers, lakes and oceans and helped usher in a new understanding of global geography. Similarly, the creation of cell atlases — maps of organs and bodies constructed cell by cell — is heralding a new era in our understanding of biology. Powerful sequencing and imaging technologies invented in the last decade are revealing with unprecedented detail the composition of human organs and tissues, from the pancreas and liver to the placenta, as well as those of other animals like the mouse and fruit fly. With these new tools, researchers can fingerprint individual cells based on which genes they are expressing. That information has revealed subtle and unsuspected distinctions among cells and has begun to illuminate how the diversity of cell types can be essential to the healthy functioning of organs. “We’re at this amazing point in time in science where we’re now able to understand the composition of these cell types,” said Steve Quake, a bioengineer and biophysicist at Stanford University who helped develop the technologies that make cell atlases possible. “It’s changed the way we understand how human biology works.” Two cell atlas efforts, part of the National Institutes of Health’s $250 million brain cell census, that just released their findings illustrate the excitement bubbling up in the field. Today in Nature, a coalition of laboratories published nine studies that collectively form a detailed atlas of the mouse brain — the most comprehensive mammalian brain atlas to date. It describes more than 5,300 types of cells found throughout the organ. How these cells are distributed and are related to one another suggests many intriguing ideas about the evolution of the mammalian brain. All Rights Reserved © 2023

Keyword: Development of the Brain; Brain imaging
Link ID: 29053 - Posted: 12.16.2023

By Carl Zimmer Neanderthals were morning people, a new study suggests. And some humans today who like getting up early might credit genes they inherited from their Neanderthal ancestors. The new study compared DNA in living humans with genetic material retrieved from Neanderthal fossils. It turns out that Neanderthals carried some of the same clock-related genetic variants as do people who report being early risers. Since the 1990s, studies of Neanderthal DNA have exposed our species’ intertwined history. About 700,000 years ago, our lineages split apart, most likely in Africa. While the ancestors of modern humans largely stayed in Africa, the Neanderthal lineage migrated into Eurasia. About 400,000 years ago, the population split in two. The hominins who spread west became Neanderthals. Their cousins to the east evolved into a group known as Denisovans. The two groups lived for hundreds of thousands of years, hunting game and gathering plants, before disappearing from the fossil record about 40,000 years ago. By then, modern humans had expanded out of Africa, sometimes interbreeding with Neanderthals and Denisovans. And today, fragments of their DNA can be found in most living humans. Research carried out over the past few years by John Capra, a geneticist at the University of California, San Francisco, and other scientists suggested that some of those genes passed on a survival advantage. Immune genes inherited from Neanderthals and Denisovans, for example, might have protected them from new pathogens they had not encountered in Africa. Dr. Capra and his colleagues were intrigued to find that some of the genes from Neanderthals and Denisovans that became more common over generations were related to sleep. For their new study, published in the journal Genome Biology and Evolution, they investigated how these genes might have influenced the daily rhythms of the extinct hominins. © 2023 The New York Times Company

Keyword: Biological Rhythms; Evolution
Link ID: 29052 - Posted: 12.16.2023

By Jaimie Seaton It’s not uncommon for Veronica Smith to be looking at her partner’s face when suddenly she sees his features changing—his eyes moving closer together and then farther apart, his jawline getting wider and narrower, and his skin moving and shimmering. Smith, age 32, has experienced this phenomenon when looking at faces since she was four or five years old, and while it’s intermittent when she’s viewing another person’s face, it’s more constant when she views her own. “I almost always experience it when I look at my own face in the mirror, which makes it really hard to get ready because I’ll think that I look weird,” Smith explains. “I can more easily tell that I’m experiencing distortions when I’m looking at other people because I know what they look like.” Smith has a rare condition called prosopometamorphopsia (PMO), in which faces appear distorted in shape, texture, position or color. (PMO is related to Alice in Wonderland syndrome, or AIWS, which distorts the size perception of objects or one’s own body.) PMO has fascinated many scientists. The late neurologist and writer Oliver Sacks co-wrote a paper on the condition that was published in 2014, the year before he died. Brad Duchaine, a professor of psychological and brain sciences at Dartmouth College, explains that some people with it see distortions that affect the whole face (bilateral PMO) while others see only the left or right half of a face as distorted (hemi-PMO). “Not surprisingly, people with PMO find the distortions extremely distressing. Over the last century, approximately 75 cases have been reported in the literature. However, little is known about the condition because cases with face distortions have usually been documented by neurologists who don’t have expertise in visual neuroscience or the time to study the cases in depth,” Duchaine says. For 25 years Duchaine’s work has focused on prosopagnosia (face blindness), but after co-authoring a study on hemi-PMO that was published in 2020, Duchaine shifted much of his lab’s work to PMO. © 2023 SCIENTIFIC AMERICAN,

Keyword: Attention; Vision
Link ID: 29051 - Posted: 12.16.2023

By Joseph Howlett Garter snakes have something in common with elephants, orcas, and naked mole rats: They form social groups that center around females. The snakes have clear “communities” composed of individuals they prefer hanging out with, and females act as leaders that tie the groups together and guide their members’ movements, according to the most extensive field study of snake sociality ever carried out. “This is an important first step in understanding how a community of snakes is organized in the wild,” says Gordon Burghardt, an ecologist at the University of Tennessee, Knoxville, who was not involved in the research. Other experts agree: “This is a big deal,” says integrative biologist Robert Mason of Oregon State University. “It’s a whole new avenue of research that I don’t think people have really given any thought to.” Ecologists had long assumed snakes are antisocial loners that hang out together only for core functions such as mating and hibernation. However, in 2020, Morgan Skinner, a behavioral ecologist at Wilfrid Laurier University, and collaborators showed in laboratory experiments that captive garter snakes have “friends”—specific snakes whose company they prefer over others. Still, studies of wild snakes were lacking “because they’re so secretive and difficult to find,” Skinner says. Then he learned that the Ontario Ministry of Transportation had funded an unprecedented long-term study of a huge population of Butler’s garter snakes (Thamnophis butleri) in Windsor, Canada. Ecologists began to monitor the flute-size slitherers in 2009 to keep them safe from nearby road construction. They regularly captured snakes in the 250-hectare study area, using identifying markings to track more than 3000 individuals over a 12-year span—about the lifetime of a garter snake. “We were mainly monitoring the population after they were relocated, to make sure they were thriving,” says Megan Hazell, a biologist with the consulting firm WSP, who led the field research as a graduate student at Queen’s University.

Keyword: Evolution; Sexual Behavior
Link ID: 29050 - Posted: 12.16.2023

By Oshan Jarow Sometimes when I’m looking out across the northern meadow of Brooklyn’s Prospect Park, or even the concrete parking lot outside my office window, I wonder if someone like Shakespeare or Emily Dickinson could have taken in the same view and seen more. I don’t mean making out blurry details or more objects in the scene. But through the lens of their minds, could they encounter the exact same world as me and yet have a richer experience? One way to answer that question, at least as a thought experiment, could be to compare the electrical activity inside our brains while gazing out upon the same scene, and running some statistical analysis designed to actually tell us whose brain activity indicates more richness. But that’s just a loopy thought experiment, right? Not exactly. One of the newest frontiers in the science of the mind is the attempt to measure consciousness’s “complexity,” or how diverse and integrated electrical activity is across the brain. Philosophers and neuroscientists alike hypothesize that more complex brain activity signifies “richer” experiences. The idea of measuring complexity stems from information theory — a mathematical approach to understanding how information is stored, communicated, and processed —which doesn’t provide wonderfully intuitive examples of what more richness actually means. Unless you’re a computer person. “If you tried to upload the content onto a hard drive, it’s how much memory you’d need to be able to store the experience you’re having,” Adam Barrett, a professor of machine learning and data science at the University of Sussex, told me. Another approach to understanding richness is to look at how it changes in different mental states. Recent studies have found that measures of complexity are lowest in patients under general anesthesia, higher in ordinary wakefulness, and higher still in psychedelic trips, which can notoriously turn even the most mundane experiences — say, my view of the parking lot outside my office window — into profound and meaningful encounters.

Keyword: Consciousness
Link ID: 29049 - Posted: 12.16.2023

By Carl Zimmer Why do we grow old and die? In the 19th century, the German biologist August Weismann argued that the machinery of life inevitably wore out with time. Death had evolved “for the need of the species,” he declared. It cleared away weak, old individuals so they wouldn’t compete with young ones. That explanation never made sense to George Williams, an American evolutionary biologist. Natural selection acts only on the genes that are passed down from one generation to the next. What happens at the end of an animal’s life can have no effect on the course of evolution. It occurred to Williams that growing old might instead be an inescapable side effect of natural selection. In 1957, he proposed a new theory: Genetic mutations that increased an animal’s fertility could also cause harm late in life. Over many generations, those mutations would create a burden that would lead eventually to death. A new study, published on Friday in the journal Science Advances, bolsters Williams’s theory using a trove of human DNA. Researchers found hundreds of mutations that could boost a young person’s fertility and that were linked to bodily damage later in life. Smaller studies in the past had already offered some support for Williams’s theory. In 2007, for example, a team of researchers studying a tiny worm found a pair of mutations that lengthened the creature’s life while cutting down its average number of offspring. But Jianzhi Zhang, an evolutionary biologist at the University of Michigan, was not satisfied with these experiments. “These are case studies,” he said. “We don’t know if in the entire genome there are lots of such mutations.” Dr. Zhang tapped into the UK Biobank, a database containing genetic material from half a million volunteers in Britain, along with information on their health and life experiences. The biobank has permitted scientists to uncover subtle links between genetic variations and thousands of traits such as high blood pressure, schizophrenia and a habit of smoking. Working with Dr. Erping Long, a medical researcher now at the Chinese Academy of Sciences, Dr. Zhang pored over the database for information about reproduction and longevity. The scientists found that the genetic variations linked to fertility, such as the number of children a volunteer had, were also linked to a shorter life span. © 2023 The New York Times Company

Keyword: Development of the Brain; Evolution
Link ID: 29048 - Posted: 12.16.2023

Maria Godoy What do you do when you can't get your kids to settle down to go to sleep? For a growing number of parents, the answer is melatonin. Recent research shows nearly one in five school-age children and adolescents are now using the supplement on a regular basis. Pediatricians say that's cause for alarm. "It is terrifying to me that this amount of an unregulated product is being utilized," says Dr. Cora Collette Breuner, a professor of pediatrics at the University of Washington. Melatonin is a hormone produced by your brain that helps regulate sleep-wake cycles. It's also sold as a dietary supplement and is widely used as a sleep aid. Sponsor Message Lauren Hartstein, a postdoctoral researcher who studies sleep in early childhood at the University of Colorado, Boulder, says she first got an inkling of melatonin's growing use in children and adolescents while screening families to participate in research. "All of a sudden last year, we noticed that there was a big uptick in the number of parents who were regularly giving [their kids] melatonin," Hartstein says. Hartstein and her colleagues wanted to learn more about just how widely melatonin is being used in kids. So they surveyed the parents of nearly 1,000 children between the ages of 1 to 14 across the country. She was surprised by just how many kids are taking the supplement. "Nearly 6% of preschoolers, [ages] 1 to 4, had taken it, and that number jumped significantly higher to 18% and 19% for school-age children and pre-teens," she says. As Hartstein and her co-authors recently reported in the journal JAMA Pediatrics, most of the kids that were using melatonin had been on it for a year or longer. And 1 in 4 kids were taking it every single night. © 2023 npr

Keyword: Biological Rhythms; Sleep
Link ID: 29047 - Posted: 12.16.2023

By Tosin Thompson Last month saw the first-ever approval of a gene therapy that uses the CRISPR–Cas9 gene-editing tool, a treatment for the blood conditions sickle-cell disease and β-thalassaemia that works by precisely cutting out a faulty gene in people’s stem cells. Now, researchers in search of new treatments for Alzheimer’s disease are hoping to deploy similar strategies against forms of the disease that are caused by genetic mutations. Although there are now some treatments that slow the progression of Alzheimer’s, these often don’t benefit people who are in the later stages or who have mutations that raise the risk of the disease. “CRISPR therapies could potentially be a one-and-done cure, which no other drug can match,” says Subhojit Roy, a neuroscientist at the University of California, San Diego. But he adds that there is a long way to go before these therapies could be deployed against such a complex condition. “Cutting and pasting a gene is much harder to do in the brain using current technology.” Alzheimer’s is the most common form of dementia, a health issue of global concern. More than 55 million people are affected by dementia, and this figure is projected to nearly triple by 2050. “We do not fully understand how the brain works, which makes the challenge of understanding and treating brain diseases like Alzheimer’s very difficult,” says Tara Spires-Jones, who studies neurodegeneration at the University of Edinburgh, UK. Much of Alzheimer’s research is driven by the amyloid hypothesis, the idea that the build-up of amyloid-β proteins in the brain, which eventually form clumps called plaques, is the main cause of the disease. Amyloid plaques trigger another brain protein, called tau, to clump together and spread inside neurons. It is usually well into this process that symptoms such as memory loss start to appear. Usually, the more tau is present, the more severe the symptoms are. © 2023 Springer Nature Limited

Keyword: Alzheimers; Genes & Behavior
Link ID: 29046 - Posted: 12.13.2023

By Roberta McLain Dreams have fascinated people for millennia, yet we struggle to understand their purpose. Some theories suggest dreams help us deal with emotions, solve problems or manage hidden desires. Others postulate that they clean up brain waste, make memories stronger or deduce the meaning of random brain activity. A more recent theory suggests nighttime dreams protect visual areas of the brain from being co-opted during sleep by other sensory functions, such as hearing or touch. David Eagleman, a neuroscientist at Stanford University, has proposed the idea that dreaming is necessary to safeguard the visual cortex—the part of the brain responsible for processing vision. Eagleman’s theory takes into account that the human brain is highly adaptive, with certain areas able to take on new tasks, an ability called neuroplasticity. He argues that neurons compete for survival. The brain, Eagleman explains, distributes its resources by “implementing a do-or-die competition” for brain territory in which sensory areas “gain or lose neural territory when inputs slow, stop or shift.” Experiences over a lifetime reshape the map of the brain. “Just like neighboring nations, neurons stake out their territory and chronically defend them,” he says. Eagleman points to children who have had half their brain removed because of severe health problems and then regain normal function. The remaining brain reorganizes itself and takes over the roles of the missing sections. Similarly, people who lose sight or hearing show heightened sensitivity in the remaining senses because the region of the brain normally used by the lost sense is taken over by other senses. Reorganization can happen fast. Studies published in 2007 and 2008 by Lotfi Merabet of Harvard Medical School and his colleagues showed just how quickly this takeover can happen. The 2008 study, in which subjects were blindfolded, revealed that the seizing of an idle area by other senses begins in as little as 90 minutes. And other studies found that this can occur within 45 minutes. When we sleep, we can smell, hear and feel, but visual information is absent—except during REM sleep. © 2023 SCIENTIFIC AMERICAN,

Keyword: Sleep; Vision
Link ID: 29045 - Posted: 12.13.2023

By Gina Kolata Dr. Edward Lewis, a pediatrician in Rochester, N.Y., has seen hundreds of children with obesity over the years in his medical practice. He finally may have a treatment for their medical condition — the powerful weight loss drug Wegovy. But that does not mean Dr. Lewis is prescribing it. Nor are most other pediatricians. “I am reluctant to prescribe medications we don’t use on a day-to-day basis,” Dr. Lewis said. And, he added, he is disinclined to use “a medicine that is a relative newcomer to the scene in kids.” Regulators and medical groups have all said that these drugs are appropriate for children as young as 12. But like Dr. Lewis, many pediatricians hesitate to prescribe Wegovy to young people, fearful that too little is known about long term effects, and mindful of past cases when problems emerged years after a drug was approved. Twenty-two percent of adolescents age 12 to 19 have obesity. Research shows that most are unlikely to ever overcome the condition — advice to diet and exercise usually has not helped. The reason, obesity researchers say, is that obesity is not caused by a lack of will power. Instead, it is a chronic disease characterized by an overwhelming desire to eat. Of particular concern to doctors are the 6 percent of children and adolescents with severe obesity, which is defined as having a body mass index at or above 120 percent of the 95th percentile for height and weight. “We are not talking about kids who are mildly overweight,” said Susan Yanovski, co-director of the office of obesity research at the National Institute of Diabetes and Digestive and Kidney Diseases. Such extreme obesity in adolescents, she said, often has “a really severe course.” These teenagers develop diabetes, heart disease, high blood pressure, kidney failure and eye damage much earlier than adults with obesity. “It is terrifying,” Dr. Yanovski added. The seriousness of health outcomes for obese teenagers motivated the American Academy of Pediatrics to recommend weight loss drugs like Wegovy for adolescents in January, after the Food and Drug Administration approved it for people age 12 and older. When that happened, experts in obesity medicine were elated, knowing full well the scope of the problem. “We said, Wow, we finally have something we can offer,” Dr. Yanovski said. Still, drugs like Wegovy are new, and the impediments to using them are snowballing. Doctors also worry about the dearth of data on long-term safety. And those who want to prescribe Wegovy say that they are beset by roadblocks put up by health insurers along with severe and continuing drug shortages. © 2023 The New York Times Company

Keyword: Obesity
Link ID: 29044 - Posted: 12.13.2023

Perspective by Michael Varnum and Ian Hohm A growing body of research in psychology and related fields suggests that winter brings some profound changes in how people think, feel and behave. The natural and cultural changes that come with winter often occur simultaneously, making it challenging to tease apart the causes underlying these seasonal swings. Live well every day with tips and guidance on food, fitness and mental health, delivered to your inbox every Thursday. We recently conducted an extensive survey of these findings with research colleagues Alexandra Wormley, a social psychologist at Arizona State University, and Mark Schaller, a psychologist at the University of British Columbia. Wintertime blues and a long winter’s nap Do you find yourself feeling down in the winter months? You’re not alone. As the days grow shorter, the American Psychiatric Association estimates that about 5 percent of Americans will experience a form of depression known as seasonal affective disorder, or SAD. People experiencing SAD tend to have feelings of hopelessness, decreased motivation to take part in activities they generally enjoy, and lethargy. Even those who don’t meet the clinical threshold for this disorder may see increases in anxiety and depressive symptoms. Scientists link SAD and more general increases in depression in the winter to decreased exposure to sunlight, which leads to lower levels of the neurotransmitter serotonin. Consistent with the idea that sunlight plays a key role, SAD tends to be more common in more northern regions of the world, such as Scandinavia and Alaska, where the days are shortest and the winters longest. Humans, special as we may be, are not unique in showing some of these seasonally linked changes. For instance, our primate relative the Rhesus macaque shows seasonal declines in mood.

Keyword: Biological Rhythms; Depression
Link ID: 29043 - Posted: 12.13.2023