By Traci Watson New clues have emerged in the mystery of how the brain avoids ‘catastrophic forgetting’ — the distortion and overwriting of previously established memories when new ones are created. A research team has found that, at least in mice, the brain processes new and old memories in separate phases of sleep, which might prevent mixing between the two. Assuming that the finding is confirmed in other animals, “I put all my money that this segregation will also occur in humans”, says György Buzsáki, a systems neuroscientist at New York University in New York City. That’s because memory is an evolutionarily ancient system, says Buzsáki, who was not part of the research team but once supervised the work of some of its members. The work was published on Wednesday in Nature1. Scientists have long known that, during sleep, the brain ‘replays’ recent experiences: the same neurons involved in an experience fire in the same order. This mechanism helps to solidify the experience as a memory and prepare it for long-term storage. To study brain function during sleep, the research team exploited a quirk of mice: their eyes are partially open during some stages of slumber. The team monitored one eye in each mouse as it slept. During a deep phase of sleep, the researchers observed the pupils shrink and then return to their original, larger size repeatedly, with each cycle lasting roughly one minute. Neuron recordings showed that most of the brain’s replay of experiences took place when the animals’ pupils were small. That led the scientists to wonder whether pupil size and memory processing are linked. To find out, they enlisted a technique called optogenetics, which uses light to either trigger or suppress the electrical activity of genetically engineered neurons in the brain. First, they trained engineered mice to find a sweet treat hidden on a platform. Immediately after these lessons, as the mice slept, the authors used optogenetics to reduce bursts of neuronal firing that have been linked to replay. They did so during both the small-pupil and large-pupil stages of sleep. © 2025 Springer Nature Limited

Keyword: Learning & Memory; Sleep
Link ID: 29615 - Posted: 01.04.2025

By Ellen Barry Kevin Lopez had just stepped out of his house, on his way to meet his girlfriend for Chinese food, when it happened: He began to hallucinate. It was just a flicker, really. He saw a leaf fall, or the shadow of a leaf, and thought it was the figure of a person running. For a moment, on a clear night last month, this fast-moving darkness seemed to hurtle in his direction and a current of fear ran through him. He climbed into the car, and the door shut and latched behind him with a reassuring thunk. “It’s nothing,” he said. “I don’t know why — I think there’s a person there.” Light had always caused problems for Kevin when symptoms of schizophrenia came on. He thought that the lights were watching him, like an eye or a camera, or that on the other side of the light, something menacing was crouched, ready to attack. But over time, he had found ways to manage these episodes; they passed, like a leg cramp or a migraine. That night, he focused on things that he knew were real, like the vinyl of the car seat and the chill of the winter air. He was dressed for a night out, with fat gemstones in his ears, and had taken a break from his graduate coursework in computer science at Boston University. A “big bearish, handsome nerd” is the way he styled himself at 24. For the past four years, Kevin has been part of a living experiment. Shortly after he began hallucinating, during his junior year at Syracuse University, his doctors recommended him for an intensive, government-funded program called OnTrackNY. It provided him with therapy, family counseling, vocational and educational assistance, medication management and a 24-hour hotline. © 2025 The New York Times Company

Keyword: Schizophrenia; Stress
Link ID: 29614 - Posted: 01.04.2025

Nicola Davis Science correspondent Standing patiently on a small fluffy rug, Calisto the flat-coated retriever is being fitted with some hi-tech headwear. But this is not a new craze in canine fashion: she is about to have her brainwaves recorded. Calisto is one of about 40 pet dogs – from newfoundlands to Tibetan terriers – taking part in a study to explore whether their brainwaves synchronise with those of their owners when the pair interact, a phenomenon previously seen when two humans engage with each other. The researchers behind the work say such synchronisation would suggest person and pet are paying attention to the same things, and in certain circumstances interpreting moments in a similar way. In other words, owner and dog really are on the same wavelength. Dr Valdas Noreika of Queen Mary, University of London said he got the idea for the study after working on similar experiments with mothers and their babies, where such synchronisation has also been seen. “Owners modulate their language in a similar way as parents modulate when they speak to children,” he said. “There are lots of similarities. That could be one of the reasons why we get so attached to dogs – because we already have these cognitive functions and capacities to attach with someone who is smaller or requires help or attention.” Hints of an emotional bond between humans and their dogs stretch into the distant past: researchers have previously discovered the 14,000-year-old remains of a puppy buried in Germany alongside a man and a woman: the analysis suggested the young dog had been nursed through several periods of illness, despite having no particular use. © 2025 Guardian News & Media Limited o

Keyword: Brain imaging; Attention
Link ID: 29613 - Posted: 01.04.2025

By Roni Caryn Rabin Alcohol is a leading preventable cause of cancer, and alcoholic beverages should carry a warning label as packs of cigarettes do, the U.S. surgeon general said on Friday. It is the latest salvo in a fierce debate about the risks and benefits of moderate drinking as the influential U.S. Dietary Guidelines for Americans are about to be updated. For decades, moderate drinking was said to help prevent heart attacks and strokes. That perception has been embedded in the dietary advice given to Americans. But growing research has linked drinking, sometimes even within the recommended limits, to various types of cancer. Labels currently affixed to bottles and cans of alcoholic beverages warn about drinking while pregnant or before driving and operating other machinery, and about general “health risks.” But alcohol directly contributes to 100,000 cancer cases and 20,000 related deaths each year, the surgeon general, Dr. Vivek Murthy, said. He called for updating the labels to include a heightened risk of breast cancer, colon cancer and at least five other malignancies now linked by scientific studies to alcohol consumption. “Many people out there assume that as long as they’re drinking at the limits or below the limits of current guidelines of one a day for women and two for men, that there is no risk to their health or well-being,” Dr. Murthy said in an interview. “The data does not bear that out for cancer risk.” Only Congress can mandate new warning labels of the sort Dr. Murthy recommended, and it’s not clear that the incoming administration would support the change. © 2025 The New York Times Company

Keyword: Drug Abuse
Link ID: 29612 - Posted: 01.04.2025

By Carl Zimmer In our digital age, few things are more irritating than a slow internet connection. Your web browser starts to lag. On video calls, the faces of your friends turn to frozen masks. When the flow of information dries up, it can feel as if we are cut off from the world. Engineers measure this flow in bits per second. Streaming a high-definition video takes about 25 million bps. The download rate in a typical American home is about 262 million bps. Now researchers have estimated the speed of information flow in the human brain: just 10 bps. They titled their study, published this month in the journal Neuron, “The unbearable slowness of being.” “It’s a bit of a counterweight to the endless hyperbole about how incredibly complex and powerful the human brain is,” said Markus Meister, a neuroscientist at the California Institute of Technology and an author of the study. “If you actually try to put numbers to it, we are incredibly slow.” Dr. Meister got the idea for the study while teaching an introductory neuroscience class. He wanted to give his students some basic numbers about the brain. But no one had pinned down the rate at which information flows through the nervous system. Dr. Meister realized that he could estimate that flow by looking at how quickly people carry out certain tasks. To type, for example, we look at a word, recognize each letter and then sort out the sequence of keys to press. As we type, information flows into our eyes, through our brains and into the muscles of our fingers. The higher the flow rate, the faster we can type. In 2018, a team of researchers in Finland analyzed 136 million keystrokes made by 168,000 volunteers. They found that, on average, people typed 51 words a minute. A small fraction typed 120 words a minute or more. Dr. Meister and his graduate student, Jieyu Zheng, used a branch of mathematics known as information theory to estimate the flow of information required to type. At 120 words a minute, the flow is only 10 bits a second. © 2024 The New York Times Company

Keyword: Attention
Link ID: 29611 - Posted: 12.28.2024

By Sarah DeWeerdt A few months ago, Sergiu Paşca, professor of psychiatry and behavioral sciences at Stanford University, shared his lab’s new work at the Gordon Research Conference on Thalamocortical Interactions. His talk concerned assembloids, lab-grown combinations of spherical organoids that mimic different parts of the nervous system. Paşca showed a video depicting waves of calcium signals traveling along a line of organoids modeling sensory neurons; the dorsal root ganglia of the spinal cord; a subcortical structure called the thalamus; and, finally, the cerebral cortex. In the audience, Audrey Brumback, assistant professor of neurology and pediatrics at the University of Texas at Austin, felt something move through her own subcortical structures as she watched the video: a visceral feeling of awe. “I just thought, ‘Holy crap, this is amazing,’” she recalls. “‘The future is now.’” The work, described in a preprint posted on bioRxiv in March, is part of a series of recent studies from Paşca’s lab that highlight the potential of assembloids to help researchers understand brain development at the circuit level, and how these circuits go awry in autism and other neurodevelopmental conditions. Autism, after all, involves differences in how various parts of the brain connect with each other, Brumback points out. “So to be able to model that in vitro is exactly what we need to be doing to be able to understand these network dysfunction disorders,” she says. For example, a lack of synchrony between the cortex and the thalamus is known to be associated with autism and schizophrenia, whereas too much synchrony between the two regions is implicated in absence seizures in epilepsy. Using a two-part assembloid representing this pair of brain structures, Paşca and his team probed the roots of these alterations in a study published 16 October in Neuron. © 2024 Simons Foundation

Keyword: Development of the Brain
Link ID: 29610 - Posted: 12.28.2024

By Emily Baumgaertner When President-elect Donald J. Trump mused in a recent television interview about whether vaccines cause autism — a theory that has been discredited by dozens of scientific studies — autism researchers across the country collectively sighed in frustration. But during the interview, on NBC’s “Meet The Press,” Mr. Trump made one passing comment with which they could agree: “I mean, something is going on,” he said, referring to skyrocketing rates of autism. “I think somebody has to find out.” What is going on? Autism diagnoses are undeniably on the rise in the United States — about 1 in 36 children have one, according to data the Centers for Disease Control and Prevention collected from 11 states, compared with 1 in 150 children in 2000 — and researchers have not yet arrived at a clear explanation. They attribute most of the surge to increased awareness of the disorder and changes in how it is classified by medical professionals. But scientists say there are other factors, genetic and environmental, that could be playing a role too. Autism spectrum disorder, as it is officially called, is inherently wide-ranging, marked by a blend of social and communication issues, repetitive behaviors and thinking patterns that vary in severity. A mildly autistic child could simply struggle with social cues, while a child with a severe case could be nonverbal. There is no blood test or brain scan to determine who has autism, just a clinician’s observations. Because there is no singular cause of autism, scientists say there is therefore no singular driver behind the rise in cases. But at the heart of the question is an important distinction: Are more people exhibiting the traits of autism, or are more people with such traits now being identified? It seems to be both, but researchers really aren’t sure of the math. More than 100 genes have been associated with autism, but the disorder appears to result from a complex combination of genetic susceptibilities and environmental triggers. The C.D.C. has a large-scale study on the risk factors that can contribute to autism, and researchers have examined dozens of potential triggers, including pollution, exposure to toxic chemicals and viral infections during pregnancy. © 2024 The New York Times Company

Keyword: Autism
Link ID: 29609 - Posted: 12.28.2024

By Dave Philipps A van full of U.S. Special Operations veterans crossed the border into Mexico on a sunny day in July to execute a mission that, even to them, sounded pretty far out. Listen to this article with reporter commentary Over a period of 48 hours, they planned to swallow a psychedelic extract from the bark of a West African shrub, fall into a void of dark hallucinations and then have their consciousness shattered by smoking the poison of a desert toad. The objective was to find what they had so far been unable to locate anywhere else: relief from post-traumatic stress disorder and traumatic brain injury symptoms. “It does sound a little extreme, but I’ve tried everything else, and it didn’t work,” said a retired Army Green Beret named Jason, who, like others in the van, asked that his full name not be published because of the stigma associated with using psychedelics. A long combat career exposed to weapons blasts had left him struggling with depression and anger, a frayed memory and addled concentration. He was on the verge of divorce. Recently, he said, he had put a gun to his head. “I don’t know if this will work,” Jason said of psychedelic therapy. “But at this point, I have nothing to lose.” Psychedelic therapy trips like this are increasingly common among military veterans. For years, psychedelic clinics in Mexico were a little-known last-ditch treatment for people struggling with drug addiction. More recently, veterans have found that they also got lasting relief from mental health issues they had struggled with since combat. No one tracks how many veterans seek psychedelic treatment in Mexico. Clinic owners estimate they now treat a few thousand American veterans a year, and say the number is steadily growing. Many of the veterans have free access to the U.S. veterans’ health care system but find standard treatments for combat-related mental health issues to be ineffective. The Department of Veterans Affairs announced this month that, for the first time in more than 50 years, it would fund research into psychedelic therapy. But while the research is conducted, the treatments will remain inaccessible to most veterans, perhaps for years. © 2024 The New York Times Company

Keyword: Stress; Drug Abuse
Link ID: 29608 - Posted: 12.21.2024

By Mitch Leslie It’s a dismaying thought during a holiday season full of cookies and big meals, but severely restricting calories consumed is one of the best supported strategies for a healthier, longer life. Slicing food consumption stretches the lives of animals in lab experiments, and similar deprivation seems to improve health in people, although almost no one can sustain such a calorie-depleted diet for long. Now, researchers in China studying animals on lean rations have identified a molecule made by gut bacteria that delivers some of the same benefits. When given on its own, the molecule makes flies and worms live longer and refurbishes age-weakened muscles in mice, all without leaving the animals hungry. Although the molecule’s effects in people remain unclear, the discovery is “a really important step forward,” says gerontologist Richard Miller of the University of Michigan, who wasn’t connected to the research. The work, reported in two studies today in Nature, “is very thorough.” Research over the past 90 years has shown that calorie restriction—which to scientists typically means a diet with between 10% and 50% fewer calories than normal—can extend longevity in organisms as diverse as yeast, nematodes, and mice. One experiment also found an effect in monkeys. Trials to test whether calorie restriction increases human life span would take too long, but participants in the 2-year CALERIE trial, which ran from 2007 to 2010 and aimed to cut calorie intake by 25%, enjoyed a slew of improvements, including lower levels of low-density lipoprotein cholesterol, increased sensitivity to insulin, and a 10% reduction in weight. However, the trial also illustrates what makes calorie restriction so challenging: Participants on average cut their caloric intake by only half the experiment’s goal. So, scientists have been hunting for molecules that trigger health-promoting, longevity-stretching effects without privation. To identify new candidates, molecular biologist and biochemist Sheng-Cai Lin of Xiamen University and colleagues took a systematic approach, analyzing the levels of more than 1200 metabolic molecules in blood samples from calorically restricted mice and from counterparts with no dietary limits. They discovered that just over 200 molecules became more abundant when food was in short supply.

Keyword: Obesity
Link ID: 29607 - Posted: 12.21.2024

By Terence Monmaney The road switches back and forth again and again as it climbs into Montchavin, perched in the French Alps at 4,100 feet above sea level. The once-sleepy mountainside village, developed into a ski resort in the 1970s, is dotted with wooden chalet-style condo buildings and situated in the midst of a vast downhill complex known as Paradiski, one of the world’s largest. Well known to skiers and alpinistes, Montchavin also has grabbed the attention of medical researchers as the site of a highly unusual cluster of a devastating neurological disease, amyotrophic lateral sclerosis. ALS, brought about by the progressive loss of nerve function in the brain, spinal cord and motor neurons in the limbs and chest, leading to paralysis and death, is both rare and rather evenly distributed across the globe: It afflicts two to three new people out of 100,000 per year. Though Montchavin is flooded with visitors in winter and summer, the year-round resident population is only a couple hundred, and neighboring villages aren’t much bigger, so the odds are strongly against finding more than just a few ALS patients in the immediate area. Yet physicians have reported 14. The first of the village patients to arouse suspicion in Emmeline Lagrange, the neurologist who has led the investigation into the problem, was a woman in her late thirties, a ski instructor and ski lift ticket-checker originally from Poland who worked in the offseason at the local tourism office. It was 2009. A physician in Montchavin had referred the woman to Lagrange, who practices at Grenoble University Hospital, 84 miles southwest of the village. Lagrange diagnosed ALS and recalls phoning the Montchavin physician to explain the consequences: “The first thing she said was, ‘I certainly know what it is. It’s the fourth case in the village. My neighbor died of ALS 20 years ago and two friends of hers are still victims of the disease.’”

Keyword: ALS-Lou Gehrig's Disease ; Neurotoxins
Link ID: 29606 - Posted: 12.21.2024

By Calli McMurray, Angie Voyles Askham, Claudia López Lloreda, Shaena Montanari Neuroscience can sometimes feel like an old mouse club—but it wasn’t always that way. In the 1960s and ’70s, neuroscientists routinely put on their field boots to search for the “animal that was expert at doing the task that you were interested in studying,” says Eve Marder, university professor of biology at Brandeis University. “People studied insects and annelids and mollusks and every kind of animal imaginable. And if they could have studied elephants, they would have.” Many fundamental—and Nobel-prize-winning—discoveries emerged from this approach. Recording from the squid’s giant axon, for example, revealed how action potentials work; experiments in sea slugs illuminated the molecular changes that drive learning and memory; work in barn owls unraveled sound localization; and studies in horseshoe crabs first exposed lateral inhibition in photoreceptors. But by the end of the 20th century, model diversity had fallen out of vogue. A small band of neuroethologists continued to explore animals off the beaten path, but the majority of neuroscientists soon jumped over to standard animal models, Marder says. Many of today’s common model organisms—including the mouse, zebrafish, roundworm and fruit fly—soared in popularity because they are cheap, easy to work with and quick to raise in a lab. The invention of molecular and genetic tools tailored to these species only increased their appeal, as did attention from the U.S. federal government. In 1999, the National Institutes of Health (NIH) published a list of 13 canonical model organisms for biomedical research, and in 2004 the organization’s “road map” encouraged the use of research animals for which genetic tools were available. Now, two decades later, a non-model organism “renaissance” is underway, says Ishmail Abdus-Saboor, associate professor of biological sciences at Columbia University, as a growing number of neuroscientists step outside of the model organism box. This shift is largely due to cost reductions and technological advances in “species-neutral” techniques, says Sam Reiter, assistant professor of computational neuroethology at the Okinawa Institute of Science and Technology, such as high-throughput extracellular recordings, machine-learning-based behavioral tracking, genome and transcriptome sequencing, and gene-editing tools. “This lets researchers quickly reach close to the cutting edge, even if working on an animal where little is known.” © 2024 Simons Foundation

Keyword: Evolution
Link ID: 29605 - Posted: 12.21.2024

By Emily McLaughlin Three days after our baby was born, my husband and I brought our newborn daughter home to our house in Tarrytown, New York. I was 32, fit and healthy, and had had an uneventful pregnancy. But on the second afternoon back home, while nursing, a thunderclap headache struck. The pounding in my temple literally brought me to my knees. I tried to tough it out, but it didn’t go away. That evening, I called my doctor. Since I was low-risk with normal blood pressure, she suggested rest and hydration. Then in the middle of that night, while I was still in debilitating pain, dark spots started to float across my vision. As my husband rushed me to the hospital, he asked me a few simple questions as he drove: Did you page the doctor? How’s your nausea? My answers came out in slow motion at first, then turned into a stutter, before they finally stopped. At the hospital, an emergency brain scan showed an intracerebral hemorrhage in the right frontal lobe — the site of executive functioning, creativity and emotion. The next thing I remember is waking in the Neuro-ICU of a nearby hospital — paralyzed on the left side, unable to smile, process time or even read the sign telling nurses I wasn’t allowed to swallow in case the muscles in my mouth were affected and I choked. I couldn’t get the words out to ask if I’d be trapped in my head for good. Ten days later, on blood pressure and antiseizure meds, I was finally allowed to go home to my newborn. It felt like I needed more care than she did. With only one strong, normally working arm, I couldn’t cradle my baby. A constant headache made it impossible to stand. Doctors said the headaches might last a year, until the blood in my brain reabsorbed. My left leg worked, but poor balance made even walking around the house difficult. The left half of my face couldn’t move, and my speech came out weak and slowly. I could not connect emotion to the rhythm of my words. I delivered questions as flat, imperative statements.

Keyword: Stroke; Hormones & Behavior
Link ID: 29604 - Posted: 12.21.2024

By Marla Broadfoot Everyone has heard that it’s vital to get seven to nine hours of sleep a night, a recommendation repeated so often it has become gospel. Get anything less, and you are more likely to suffer from poor health in the short and long term — memory problems, metabolic issues, depression, dementia, heart disease, a weakened immune system. But in recent years, scientists have discovered a rare breed who consistently get little shut-eye and are no worse for wear. Natural short sleepers, as they are called, are genetically wired to need only four to six hours of sleep a night. These outliers suggest that quality, not quantity, is what matters. If scientists could figure out what these people do differently it might, they hope, provide insight into sleep’s very nature. “The bottom line is, we don’t understand what sleep is, let alone what it’s for. That’s pretty incredible, given that the average person sleeps a third of their lives,” says Louis Ptáček, a neurologist at the University of California San Francisco. Scientists once thought sleep was little more than a period of rest, like powering down a computer in preparation for the next day’s work. Thomas Edison called sleep a waste of time — “a heritage from our cave days” — and claimed to never sleep more than four hours a night. His invention of the incandescent lightbulb encouraged shorter sleep times in others. Today, a historically high number of US adults are sleeping less than five hours a night. But modern sleep research has shown that sleep is an active, complicated process we don’t necessarily want to cut short. During sleep, scientists suspect that our bodies and brains are replenishing energy stores, flushing waste and toxins, pruning synapses and consolidating memories. As a result, chronic sleep deprivation can have serious health consequences.

Keyword: Sleep; Genes & Behavior
Link ID: 29603 - Posted: 12.14.2024

By Calli McMurray A strong, long-lasting sensory stimulus—be it visual, auditory, olfactory or tactile—triggers plasticity in the neurons that respond to it. But as a scientist long interested in temperature, Jan Siemens wondered: Does the same principle apply to prolonged heat? In mammals, the body changes when temperatures soar—blood vessels dilate, heat-generating brown adipose tissue shuts off, the heart rate lowers, locomotion slows—but it wasn’t clear if the brain played a role in these changes, or even changed itself, says Siemens, professor of pharmacology at the University of Heidelberg. Siemens and his team started a search for heat-induced neuronal plasticity in the ventromedial preoptic area of the hypothalamus (VMPO) in mice. They chose the region because of its involvement in regulating body temperature and generating fever; neurons there receive temperature information downstream from cells innervating the skin, whereas others are themselves warm-sensitive. They identified cells to target by measuring the expression of c-FOS, a gene that is activated by neuronal activity, after housing the mice at 36 degrees Celsius for up to eight hours. At first, however, their investigative trail went cold. In brain slices, those warm-responding cells showed only slight and inconsistent changes in synaptic plasticity. “That was actually quite humbling and disappointing,” Siemens says. But then they made a “serendipitous observation,” he says: A subgroup of neurons expressing the leptin receptor became almost constantly active after four weeks of heat acclimation. The firing was so synchronized and regular that Wojciech Ambroziak, a postdoctoral scholar in the lab at the time, described it as “soldiers marching in a line,” Siemens recalls. © 2024 Simons Foundation

Keyword: Obesity
Link ID: 29602 - Posted: 12.14.2024

Jon Hamilton Not all brain cells are found in the brain. For example, a team at Caltech has identified two distinct types of neurons in the abdomens of mice that appear to control different aspects of digestion. The finding, reported in the journal Nature, helps explain how clusters of neurons in the body play a key role in the gut-brain connection, a complex two-way communication system between the brain and digestive system. It also adds to the evidence that neurons in the body can take on specialized functions, "just like in the brain," says Yuki Oka, an author of the study. "The peripheral nervous system is smart," says Frank Duca of the University of Arizona, who was not involved in the study. "You have specific neurons within this system that are performing a wide variety of functions, either with the brain's help or sometimes even without the brain's input," he says. The study focused on a subset of the peripheral nervous system called the sympathetic nervous system, which becomes active when the brain detects danger. "Your adrenaline goes up and your glucose level in the blood is really high because you need to fight or flight," Oka says. At the same time, the sympathetic nervous system dials back functions that are less urgent, like digestion and moving food through the gut. © 2024 npr

Keyword: Obesity
Link ID: 29601 - Posted: 12.14.2024

By Max Kozlov A popular weight-loss regimen stunts hair growth, data collected from mice and humans suggest1. The study’s findings show that intermittent fasting, which involves short bouts of food deprivation, triggers a stress response that can inhibit or even kill hair-follicle stem cells, which give rise to hair. The results, published in today in Cell, suggest that although short-term fasting can provide health benefits, such as increased lifespan in mice, not all tissue and cell types benefit. “I was shocked to hear these results,” says Ömer Yilmaz, a stem-cell biologist at the Massachusetts Institute of Technology in Cambridge who was not involved in the study. “We’ve come to expect that fasting is going to be beneficial for most, if not all cell types and good for stem cells. This is the inverse of what we expected, and the finding seems to hold true in humans.” Deliberate deprivation During the past decade, intermittent fasting has become one of the most popular dieting regimens; by one count, about 12% of adults in the United States practised it in 2023. One of the most common forms is time-restricted eating, which involves eating only within a limited time frame each day. Stem cells seem to be particularly vulnerable to changes in diet. For example, Yilmaz and his colleagues reported2 in August that stem cells in the guts of mice showed a burst of activity during post-fast feasting. This activity helped to repair damage in the animals’ intestines. To learn whether dieting affects hair regrowth, which can be affected by stress, Bing Zhang, a regenerative biologist at Westlake University in Zhejiang, China, and his colleagues shaved mice and subjected them to one of two intermittent-fasting regimens: time-restricted eating and alternate-day fasting, in which animals fasted for 24 hours and then ate their normal diet for the following 24 hours. By the end of the three-month study, the dieting mice had not regrown as much hair as control animals that ate a similar number of calories, the authors found. © 2024 Springer Nature Limited

Keyword: Obesity
Link ID: 29600 - Posted: 12.14.2024

By Jason Bittel Have you ever felt like there was a pit in your stomach? What about a flutter in your heart? It turns out that the anatomical connections we make with certain emotions and feelings — what researchers call embodied emotions — may be more universal than you’d think. In fact, people have been making very similar statements about their bodies for about 3,000 years. In a new study published in iScience, researchers catalogued words for body parts and emotions used by people who lived in Mesopotamia between 934 and 612 BCE, in what is now a region that includes Egypt, Iraq, and Türkiye. Then, they compared those ancient ideas etched on clay tablets and other artifacts to commonly used modern-day links between emotions and body parts, using bodily maps to visualize the similarities and differences. “We see certain body areas that are still used in similar contexts in modern times,” says Juha Lahnakoski, lead author of the study and a cognitive neuroscientist at Germany’s LVR Clinic Düsseldorf, in an email. “For example, the heart was often mentioned together with positive emotions such as love, pride, and happiness, as we might still say ‘my heart swelled’ with joy or pride.” © Society for Science & the Public 2000–2024.

Keyword: Emotions
Link ID: 29599 - Posted: 12.14.2024

By Alissa Wilkinson There’s a moment in “Theater of Thought” (in theaters) when Darío Gil, the director of research at IBM, is explaining quantum computing to Werner Herzog, the movie’s director. Standing before a whiteboard, Gil draws some points on spheres to illustrate how qubits work, then proceeds to define the Schrödinger equation. As he talks and writes, the audio grows quieter, and Herzog’s distinctive resonant German accent takes over. “I admit that I literally understand nothing of this, and I assume most of you don’t either,” he intones in voice-over. “But I found it fascinating that this mathematical formula explains the law that draws the subatomic world.” It’s a funny moment, a playful way to keep us from glazing over when presented with partial differential equations. Herzog may be a world-renowned filmmaker, but he’s hardly a scientist, and that makes him the perfect director for “Theater of Thought,” a documentary about, as he puts it, the “mysteries of our brain.” Emphasis on mysteries. Herzog interviews a dizzying array of scientists, researchers, and even a Nobel Prize winner or two. He asks them about everything: how the brain works, what consciousness means, what the tiniest organisms in the world are, whether parrots understand human speech, whether rogue governments can control thoughts, whether we’re living in an elaborate simulation, how telepathy and psychedelics work, and, at several points, what thinking even is. Near the end of the film he notes that not one of the scientists could explain what a thought is, or what consciousness is, but “they were all keenly alive to the ethical questions in neuroscience.” In other words, they’re immersed in both the mystery and what their field of study implies about the future of humanity. There’s a boring way to make this movie, with talking-head interviews that are arranged to form a coherent argument. Herzog goes another direction, starting off by narrating why he’s making it, then talking about his interviewees as we are introduced to them in their labs or in their favorite outdoor settings. (He also visits Philippe Petit, the Twin Towers tightrope walker, as he practices in his Catskills backyard.) Herzog’s constant verbal presence brings us into his own head space — his own brain, if you will — and gives us the sense that we’re following his patterns of thought. © 2024 The New York Times Company

Keyword: Consciousness
Link ID: 29598 - Posted: 12.14.2024

By Miryam Naddaf Researchers have identified 13 proteins in the blood that predict how quickly or slowly a person’s brain ages compared with the rest of their body. Their study1, published in Nature Aging on 9 December, used a machine-learning model to estimate ‘brain ages’ from scans of more than 10,000 people. The authors then analysed thousands of scans alongside blood samples and found eight proteins that were associated with fast brain ageing, and five linked to slower brain ageing. “Previous studies mainly focused on the association between the proteins and the chronological age, that means the real age of the individual,” says study co-author Wei-Shi Liu, a neurologist at Fudan University in Shanghai, China. However, studying biomarkers linked to a person’s brain age could help scientists to identify molecules to target in future treatments for age-related brain diseases. “These proteins are all promising therapeutic targets for brain disorders, but it may take a long time to validate them,” says Liu. Using machine learning to analyse brain-imaging data from 10,949 people, Liu and his colleagues created a model to calculate a person’s brain age, on the basis of features such as the brain’s volume, surface area and distribution of white matter. They wanted to identify proteins that are associated with a large brain age gap — the difference between brain age and chronological age. To do this, the researchers analysed levels of 2,922 proteins in blood samples from 4,696 people, more than half of whom were female, and compared them with the same people’s brain ages derived from the scans. They identified 13 proteins that seemed to be connected with large brain age gaps, some of which are known to be involved in movement, cognition and mental health.

Keyword: Development of the Brain
Link ID: 29597 - Posted: 12.11.2024

By Grace Huckins Genes on the X and Y chromosomes—and especially those on the Y—appear to be associated with autism likelihood, according to a study focused on people who have missing or extra sex chromosomes. The findings add to the ongoing debate about whether autism’s sex bias reflects a male vulnerability, a female protective effect or other factors. “The Y chromosome is often left out of genetic discovery studies. We really have not interrogated it in [autism] studies very much,” says Matthew Oetjens, assistant professor of human genetics at Geisinger Medical Center’s Autism and Developmental Medicine Institute, who led the new work. There is a clear sex difference in autism prevalence: Men are about four times as likely as women to have a diagnosis. But uncovering the reasons for that discrepancy has proved challenging and contentious. Multiple biological factors may play a role, in addition to social factors—such as the difficult-to-measure gulfs between how boys and girls are taught to behave. Add on the possibility of diagnostic bias and the question starts to look less like a scientific problem and more like a politically toxic Gordian knot. But there are some threads that researchers can pull to disentangle these effects, as the new study illustrates. People with sex chromosome aneuploidies—or unusual combinations of sex chromosomes, such as XXY in those with Klinefelter syndrome or a single X in Turner syndrome—provide a unique opportunity to examine how adding or taking away chromosomes can affect biology and behavior. Previous studies noted high rates of autism in people with sex chromosome aneuploidies, but those analyses were subject to ascertainment bias; perhaps those people found out about their aneuploidies only after seeking support for their neurodevelopmental conditions. © 2024 Simons Foundation

Keyword: Autism; Sexual Behavior
Link ID: 29596 - Posted: 12.11.2024