By Holly Barker Prairie voles do not need oxytocin receptors to bond with a mate or care for their pups, but the receptors are indispensable for forming robust friendships, according to a study published today in Current Biology. Female voles that lack the receptors struggle to make friends with other females, and when they do, they are not motivated to spend time with friends over strangers and quickly lose track of their friends in a group, the study found. The findings suggest that oxytocin is required for nurturing specific relationships, rather than for general sociability, says principal investigator Annaliese Beery, associate professor of integrative biology and neuroscience at the University of California, Berkeley. That concept—known as selectivity—is a “really important component of human friendships,” she says. Until now, prairie voles have typically been used to probe the neural basis of love: The animals are unusual among rodents for selecting a single partner to nest and raise pups with. Compared with non-monogamous vole species, prairie voles have a high density of oxytocin receptors in multiple brain regions, including the nucleus accumbens. Drugs that block the receptors there impair mate attachment in prairie voles, whereas brain infusions of oxytocin fast track the animal’s choice of a lifelong partner. Oxytocin appears to be especially important in the initial stages of bond formation, according to studies of transgenic prairie voles. Voles genetically engineered to carry loss-of-function mutations in both copies of the oxytocin receptor gene are less likely to bond with a littermate they have been housed with for less than a week, according to work reported in a 2024 preprint. © 2025 Simons Foundation

Keyword: Hormones & Behavior; Evolution
Link ID: 29883 - Posted: 08.09.2025

By K. R. Callaway Ever bite into something so bitter that you had to spit it out? An ages-old genetic mutation helps you and other animals perceive bitterness and thus avoid toxins associated with it. But while most creatures instinctively spit first and ask questions later, molecular biologists have been trying to get a taste of what bitterness can tell us about sensory evolution and human physiology. A new study, published in the Journal of Agricultural and Food Chemistry, is the first analysis of how taste receptors respond to a mushroom’s bitter compounds—which include some of the most potently bitter flavors currently known to science. The bitter bracket mushroom is nontoxic but considered inedible because of its taste. Researchers extracted its bitter compounds, finding two familiar ones—and three that were previously unknown. Instead of tasting these substances themselves, the scientists introduced them to an “artificial tongue” that they made by inserting human taste receptors into fast-growing embryonic kidney cells. One of the newfound bitter substances activated the taste receptors even at the lowest concentration measured, 63.3 micrograms per liter. That’s like sensing three quarters of a cup of sugar in an Olympic-sized swimming pool. Humans have about 25 kinds of bitter taste receptors lining our mouths and throats, but these same receptors also grow throughout the body—in the lungs, digestive tract and even brain. Despite their ubiquity, they have been only partially explored. Four of our bitter receptors have no known natural activator. Finding activating compounds could illuminate the interactions that might have shaped those taste receptors’ evolution, says study lead author Maik Behrens, a molecular biologist at the Leibniz Institute for Food Systems Biology. © 2025 SCIENTIFIC AMERICAN,

Keyword: Chemical Senses (Smell & Taste)
Link ID: 29882 - Posted: 08.09.2025

By Annika Inampudi Once placed in sodas as a mood enhancer and eventually made into a drug for bipolar disorder, lithium is probably best known for powering the batteries in our electronics. But a new study suggests yet another potential use for this versatile metal as a treatment for Alzheimer’s disease. In a paper published today in Nature, researchers report reduced lithium levels in the brains of people with Alzheimer’s and mild cognitive impairment. They also found that a form of lithium improved memory when fed to mice with Alzheimer’s-like symptoms. The paper is a “thorough and pioneering exploration” of lithium’s role in the brain during cognitive decline, says Ashley Bush, a psychiatrist at the Florey Institute of Neuroscience and Mental Health who was not involved in the study. The work offers a new route forward for a field still eager to find new treatments despite the recent approval of antiamyloid drugs, he says. Found in extremely low concentrations in rocks and seawater, lithium enters the human body through foods such as cereals, cabbage, and tomatoes, or through drinking water that naturally flows through lithium-rich rocks. For reasons that remain unknown, lithium seems to stabilize mood, and the compound lithium carbonate has been used for decades to treat mania in bipolar disorder. Some previous studies have hinted that the metal might also have neuroprotective effects, leading researchers to propose it as a treatment for neurodegenerative conditions. But these findings come mostly from observational studies and haven’t proved lithium can change the course of Alzheimer’s. Small clinical trials in dementia patients have produced mixed results. © 2025 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 29881 - Posted: 08.09.2025

By Shoshana Walter In 2005, J. was a young pharmacist, in the middle of a divorce, when he decided he needed a change. He was outgoing, a former rugby player, and he had begun to feel out of place among his quiet co-workers. “Does a pharmacist ever come over to you and chitchat?” he says. “They’re very mousy and very introverted.” For his new job, J. — who asked to be referred to by his first initial to protect his privacy — had in mind something a little more glamorous: pharmaceutical sales. He found a contract position at Reckitt Benckiser Pharmaceuticals, a U.S. subsidiary of a household-goods company based in Britain that was best known for Lysol and French’s mustard. The company had recently introduced Suboxone, a groundbreaking new medication in the United States that treats opioid addiction. Much like nicotine gum, Suboxone worked as a substitute, binding to the same receptors in the brain as illicit opioids, taking away withdrawal symptoms, quelling cravings and making it hard to continue misusing drugs. At other companies — like Purdue Pharma, the maker of OxyContin — sales reps regularly trawled doctors’ offices and used company credit cards to treat physicians to expensive meals and lavish trips. At Reckitt, sales reps were told they had a different mandate. “You weren’t a credit card on legs,” says Chris Hassan, who oversaw Reckitt’s sales force at the time. Reps held the title “clinical liaisons,” and their job was not only to sell Suboxone but also to convince doctors that addiction was a disease, not a moral failing, and that it could be treated with medication instead of prison sentences. Reckitt hired people of all backgrounds — counselors and behavioral-health clinicians as well as traditional salespeople, including ones they recruited from Purdue Pharma. Those who had sold OxyContin, Hassan notes, seemed especially motivated to sell the solution to the problem they had helped cause. “The people that had mirrors in their home and had to look at themselves, they didn’t like what they saw,” he says. “Purdue was a great source of hires for us.” Almost right away, however, it became clear that most doctors were not lining up to care for addicted patients. Some were the same physicians who were driving the opioid crisis by overprescribing painkillers. Others felt ill equipped to treat substance users or dismissed such patients as untrustworthy. An addicted patient was “a liar or crook,” says George Agapios, an Indiana doctor who initially resisted offering treatment. He describes many physicians’ feelings in that era as: “The people associated with it were not exactly the cream of the crop — so let’s not waste our time.” Several doctors turned Reckitt reps away from their offices. © 2025 The New York Times Company

Keyword: Drug Abuse
Link ID: 29880 - Posted: 08.09.2025

By Tina Hesman Saey A snail may hold the key to restoring vision for people with some eye diseases. Golden apple snails (Pomacea canaliculata) are freshwater snails from South America. Alice Accorsi became familiar with the species as a graduate student in Italy. “You could literally buy them in a pet store as snails that clean the bottom of the fish tanks,” she recalls. Turns out, the snails are among the most invasive species in the world. And that got Accorsi thinking: Why are they so resilient and able to thrive in new environments? She began studying the snails’ immune systems and has now found they are not the only parts of the animals able to bounce back from adversity. These snails can completely regrow a functional eye within months of having one amputated, Accorsi and colleagues report August 6 in Nature Communications. Side-by-side images of snail eyes. On the left is a normal, intact snail eye. On the right is an eye that has regrown two months after it was surgically removed. The eyes look similar. They are both round with a black spot in the middle. A snail’s eye was surgically removed, but it grew a new one. Two months after amputation the new eye (right) looks much like the uninjured one (left).Alice Accorsi Scientists have known for centuries that some snails can regrow their heads, and research has revealed other animals can regenerate bodies, tails or limbs. But this finding is exciting because apple snails have camera-like eyes similar to those of humans. Understanding how the snails re-create or repair their eyes might lead to therapies to heal people’s eye injuries or reverse diseases such as macular degeneration. Accorsi, now a developmental biologist at the University of California, Davis, used the molecular scissors called CRISPR/Cas9 to genetically disable certain key genes involved in eye development and established lineages of snails carrying those mutations. © Society for Science & the Public 2000–2025.

Keyword: Vision; Regeneration
Link ID: 29879 - Posted: 08.06.2025

By Andrew Iwaniuk, Georg Striedter Sleep is the most obvious behavior that, in most animals, follows a circadian rhythm. But have you ever seen a bird asleep? Maybe you have, though they usually wake up before you get close enough to see whether they have their eyes closed. Moreover, just because an animal is still and closed its eyes, does that really mean it is sleeping? Maybe it is just resting. Conversely, might some birds sleep with one or both eyes open? Indeed, it is difficult to tell whether an animal is sleeping just by observing it. To overcome this problem, researchers may prod the animal to see whether it is less responsive at certain times of day. A more definitive method for demonstrating sleep in vertebrates is to record an animal’s brain waves (its electroencephalogram, or EEG), because these waves change significantly as an individual falls asleep and then progresses through several stages of sleep. In birds, the use of EEG recordings is essential because they can sleep with one or both eyes open, presumably so they can stay alert to threats. Ostriches, for example, tend to sleep while sitting on the ground, holding their head up high, and keeping both eyes open. They certainly look alert during this time, but EEG waves reveal that they are actually asleep Types and patterns of sleep An EEG measures the activity of many neurons simultaneously. In mammals, it is usually recorded from multiple electrodes placed over the neocortex; in birds, the electrodes are typically placed on top of the hyperpallium (aka the Wulst; see Chapter 1). In addition to performing an EEG, sleep researchers typically record the animal’s eye movements and an electromyogram (EMG), which is a measure of muscle activity, often characterized as muscle “tone.” These kinds of studies have revealed that, in mammals, the transition from the waking state to sleep is marked by a shift from EEG waves that are low in amplitude (i.e., small) and high in frequency (>20 Hz) to waves that are much larger but lower in frequency (1–4 Hz). Because the latter state is characterized by powerful low-frequency EEG waves (aka slow-wave activity), it is commonly called slow-wave sleep (SWS). The mechanisms that cause SWS are complicated and involve a variety of sleep-promoting processes. However, the large amplitude of these slow waves reflects that, during SWS, numerous neurons fire in rhythm with one another so that their electrical potentials sum when they are recorded through the EEG electrodes. © 2025 Simons Foundation

Keyword: Sleep; Evolution
Link ID: 29878 - Posted: 08.06.2025

By Kamal Nahas High-intensity yoga for less than 30 minutes, twice a week, may be the best workout routine for catching high-quality shut-eye, a new study shows. But before people jump on the yoga trend, researchers say more experiments are needed to confirm the study’s findings. While exercise in general is known to improve sleep, a meta-analysis published July 11 in Sleep and Biological Rhythms presents a broad comparison of exercise routines and their influence on sleep quality. By indirectly comparing 30 trials from about a dozen countries, researchers at Harbin Sport University in China ranked how well different exercise methods influence sleep. Yoga won out, followed by walking, resistance training and aerobic exercise. While sleep disorders can be treated with cognitive behavioral therapy or sleeping pills, these interventions don’t work for everyone. “Medications are helpful in the short-term, but some of them have negative effects on the elderly,” says Saurabh Thosar, a sleep researcher at the Oregon Institute of Occupational Health Sciences in Portland. Exercise offers an alternative, but it’s tough to tell which routine is best, making it unclear how best to prescribe it. Trials that investigate this question tend to include one or two types of exercise differing in factors such as how hard, how often or how long they were performed for. Given the global prevalence of sleep problems such as insomnia, which recent estimates say affects about 16 percent of people worldwide, there is a pressing need to find the best exercise to prescribe for a good night’s snooze. © Society for Science & the Public 2000–2025.

Keyword: Sleep
Link ID: 29877 - Posted: 08.06.2025

By Bridget Alex More than 10 million years ago, ancestral apes in Africa rummaged through leaf litter for tasty morsels: fallen, fermenting fruit. Tapping this resource may have given some apes a nutritional boost, an advantage that could have paved the way for the evolution of our own alcohol tolerance. A study out today in BioScience adds support to this so-called “drunken monkey” hypothesis by examining just how often living apes indulge in fallen—presumably boozy—fruits. The research also gives this behavior a much-needed name: “scrumping.” The work provides “a fresh and useful perspective on the importance of fallen fruit,” says Amanda Melin, a biological anthropologist at the University of Calgary who was not involved with the research. She adds that scrumping “is an efficient and evocative way to describe this behavior” that she will use in the future. The form of alcohol we imbibe, ethanol, occurs naturally when yeast grows in fruits, saps, or nectars. Many animals, from elephants to songbirds, can get buzzed off these wild taps. Meanwhile, most human societies have invented ways to ferment food and drink. Biomolecular traces on artifacts show that by at least 8000 years ago, people in the Caucasus region were brewing alcoholic beverages from grapes, while people in China were sipping on boozy drinks made from many ingredients, including millet, rice, ginger, and yam. These beverages’ arrival coincides roughly with the start of farming. In fact, some scholars think cereals may have been domesticated for beer rather than bread. The idea that our species’ ability to consume alcohol arose in our distant primate ancestors was formulated by evolutionary biologist Robert Dudley 25 years ago as he was studying monkeys—hence the name of the hypothesis—rather than the chimps and other apes analyzed in the new study. Rank, fermenting fruit is easy to sniff out, the idea goes, so being able to eat it would have given ancient apes an additional resource that other animals avoided.

Keyword: Drug Abuse; Evolution
Link ID: 29876 - Posted: 08.06.2025

Mariana Lenharo In late 2005, five months after a car accident, a 23-year-old woman lay unresponsive in a hospital bed. She had a severe brain injury and showed no sign of awareness. But when researchers scanning her brain asked her to imagine playing tennis, something striking happened: brain areas linked to movement lit up on her scan1. The experiment, conceived by neuroscientist Adrian Owen and his colleagues, suggested that the woman understood the instructions and decided to cooperate — despite appearing to be unresponsive. Owen, now at Western University in London, Canada, and his colleagues had introduced a new way to test for consciousness. Whereas some previous tests relied on observing general brain activity, this strategy zeroed in on activity directly linked to a researcher’s verbal command. The strategy has since been applied to hundreds of unresponsive people, revealing that many maintain an inner life and are aware of the world around them, at least to some extent. A 2024 study found that one in four people who were physically unresponsive had brain activity that suggested they could understand and follow commands to imagine specific activities, such as playing tennis or walking through a familiar space2. The tests rely on advanced neuroimaging techniques, so are mostly limited to research settings because of their high costs and the needed expertise. But since 2018, medical guidelines have started to recommend using these tests in clinical practice3. Since these methods emerged, scientists have been developing ways to probe layers of consciousness that are even more hidden. The stakes are high. Tens of thousands of people worldwide are currently in a persistent unresponsive state. Assessing their consciousness can guide important treatment decisions, such as whether to keep them on life support. Studies also suggest that hospitalized, unresponsive people with hidden signs of awareness are more likely to recover than are those without such signs (see, for example, ref. 4). © 2025 Springer Nature Limited

Keyword: Consciousness
Link ID: 29875 - Posted: 08.02.2025

By Tim Bayne One of the key scientific questions about consciousness concerns its distribution. We know that adult humans have the capacity for consciousness, but what about human neonates, bees or artificial intelligence (AI) systems? Who else—other than ourselves—belongs in the “consciousness club,” and how might we figure this out? It is tempting to assume, as many do, that we need a theory of consciousness to answer the distribution question. In the words of neuroscientists Giulio Tononi and Christof Koch, “we need not only more data but also a theory of consciousness—one that says what experience is and what type of physical systems can have it.” This is what philosopher Jonathan Birch has labeled the “theory-heavy” approach to the distribution problem. But there are serious issues with the theory-heavy approach. One is that we don’t have a consensus theory of consciousness. In a highly selective review that Anil Seth and I published in 2022, we listed no fewer than 22 neurobiological theories of consciousness. This overabundance of theories could reasonably be ignored if most agreed on fundamental questions in the field, such as which systems have the capacity for consciousness or the question of when consciousness first emerges in human development, but they don’t. A further problem with the theory-heavy approach is that in order to speak to the distribution problem, a theory cannot be restricted to consciousness as it occurs in adult humans, but must also apply to human infants, nonhuman animals, synthetic biological systems and AI. But because theories are largely based on data drawn from the study of adult humans, there will inevitably be a gap between the evidence base of a general theory and its scope. Why should we think that a theory developed in response to adult humans applies to different kinds of systems? © 2025 Simons Foundation

Keyword: Consciousness
Link ID: 29874 - Posted: 08.02.2025

By Roni Caryn Rabin The Food and Drug Administration on Wednesday approved a medical device that offers new hope to patients incapacitated by rheumatoid arthritis, a chronic condition that afflicts 1.5 million Americans and is often resistant to treatment. The condition is usually managed with medications. The device represents a radical departure from standard care, tapping the power of the brain and nervous system to tamp down the uncontrolled inflammation that leads to the debilitating autoimmune disease. The SetPoint System is an inch-long device that is surgically implanted into the neck, where it sits in a pod wrapped around the vagus nerve, which some scientists believe is the longest nerve in the body. The device electrically stimulates the nerve for one minute each day. The stimulation can turn off crippling inflammation and “reset” the immune system, research has shown. Most drugs used to treat rheumatoid arthritis suppress the immune system, leaving patients vulnerable to serious infections. On a recent episode of the American College of Rheumatology podcast, the SetPoint implant was described as representing a “true paradigm shift” in treatment of the disease, which until now has relied almost entirely on an evolving set of pharmaceutical interventions, from gold salts to powerful agents called biologics. The F.D.A. designated the implant as a breakthrough last year in order to expedite its development and approval. It represents an early test of the promise of so-called bioelectronic medicine to modulate inflammation, which plays a key role in diseases including diabetes, heart disease and cancer. Clinical trials are already underway testing vagus nerve stimulation to manage inflammatory bowel disease in children, lupus and other conditions. Trials for patients with multiple sclerosis and Crohn’s disease are also planned. In a yearlong randomized controlled trial of 242 patients that included a sham-treatment arm, over half of the participants using the SetPoint implant alone achieved remission or saw their disease recede. Measures of joint pain and swelling fell by 60 percent and 63 percent, respectively. © 2025 The New York Times Company

Keyword: Pain & Touch; Neuroimmunology
Link ID: 29873 - Posted: 08.02.2025

By Claire L. Evans In 1983, the octogenarian geneticist Barbara McClintock stood at the lectern of the Karolinska Institute in Stockholm. She was famously publicity averse — nearly a hermit — but it’s customary for people to speak when they’re awarded a Nobel Prize, so she delivered a halting account of the experiments that had led to her discovery, in the early 1950s, of how DNA sequences can relocate across the genome. Near the end of the speech, blinking through wire-framed glasses, she changed the subject, asking: “What does a cell know of itself?” McClintock had a reputation for eccentricity. Still, her question seemed more likely to come from a philosopher than a plant geneticist. She went on to describe lab experiments in which she had seen plant cells respond in a “thoughtful manner.” Faced with unexpected stress, they seemed to adjust in ways that were “beyond our present ability to fathom.” What does a cell know of itself? It would be the work of future biologists, she said, to find out. Forty years later, McClintock’s question hasn’t lost its potency. Some of those future biologists are now hard at work unpacking what “knowing” might mean for a single cell, as they hunt for signs of basic cognitive phenomena — like the ability to remember and learn — in unicellular creatures and nonneural human cells alike. Science has long taken the view that a multicellular nervous system is a prerequisite for such abilities, but new research is revealing that single cells, too, keep a record of their experiences for what appear to be adaptive purposes. In a provocative study published in Nature Communications late last year, the neuroscientist Nikolay Kukushkin and his mentor Thomas J. Carew at New York University showed that human kidney cells growing in a dish can “remember” patterns of chemical signals (opens a new tab) when they’re presented at regularly spaced intervals — a memory phenomenon common to all animals, but unseen outside the nervous system until now. Kukushkin is part of a small but enthusiastic cohort of researchers studying “aneural,” or brainless, forms of memory. What does a cell know of itself? So far, their research suggests that the answer to McClintock’s question might be: much more than you think. © 2025 Simons Foundation

Keyword: Learning & Memory
Link ID: 29872 - Posted: 08.02.2025

Emily Kwong A grayscale ballerina who appears to be moving. A human who can fit in a doll box. A black-and-white prism which appear to change shape when viewed from three different directions. Those are the top winners of the 2024 Best Illusion of the Year Contest, open to illusion makers around the world. The contest was co-created by neuroscientist and science writer Susana Martinez-Conde. After 20 years, Martinez-Conde is still amazed that novel illusions keep coming in — submitted by artists, magicians, vision scientists and illusion makers all over the world. "Illusions are fundamental to the way that we perceive the world — the way that, frankly, we exist as human beings. Illusions are a feature and not a bug," she told All illusions are perceptual experiences that do not match physical reality. Aristotle was one of the first to document an illusion in nature, the so-called "waterfall illusion," or motion aftereffect. When someone watches a moving stimulus, such as a river, a nearby stationary object, like a rock, may also appear to move. Other famous illusions include "Rotating Snakes," which Martinez-Conde has studied as part of her research into peripheral drift. As a scientist, Martinez-Conde sees as illusions as an opportunity to study how the human brain constructs perceptions of the world. "We can analyze the neurons and the brain circuits that support neural activity that matches perception, and those could be part of the neural basis of consciousness." Voting for the 2025 Best Illusion of the Year will take place next year. The online contest is run by the non-profit Neural Correlate Society. © 2025 npr

Keyword: Vision
Link ID: 29871 - Posted: 08.02.2025

By Pam Belluck A combination of healthy activities including exercise, nutritious diet, computer brain games and socializing can improve cognitive performance in people at risk for dementia, according to a large new study. The study, conducted in five locations across the United States over two years, is the biggest randomized trial to examine whether healthy behaviors protect brain health. “It confirms that paying attention to things like physical activity and vascular risk factors and diet are all really important ways to maintain brain health,” said Dr. Kristine Yaffe, an expert in cognitive aging at the University of California, San Francisco, who was not involved in the study. The results were presented on Monday at the Alzheimer’s Association International Conference in Toronto and published in the journal JAMA. The study involved 2,111 people, ages 60 to 79, from diverse racial and ethnic backgrounds. None were cognitively impaired. All had sedentary lifestyles, suboptimal diets and two other dementia risk factors, such as a family history of cognitive decline and high blood pressure. Half of the participants followed a structured program. They were prescribed a healthy diet, socially engaging activities and a weekly regimen of eight exercise sessions and three sessions of computerized cognitive training. They attended 38 meetings with facilitators and fellow participants. The other participants followed a self-guided program. They were given educational materials and resources, and were regularly encouraged to engage in healthy behaviors. They attended six team meetings during the study. © 2025 The New York Times Company

Keyword: Alzheimers
Link ID: 29870 - Posted: 08.02.2025

By Siddhant Pusdekar The food we eat, the air we breathe, and our daily activities all shape how our minds work. Yet most brain research focuses on a narrow slice of humanity: people in high-income countries in the Northern Hemisphere. That leaves a vast gap in our understanding of how neural activity varies across cultures, environments, and lifestyles. A team of researchers from Tanzania and India has taken a step toward closing that gap. In a study published this week in eNeuro, they describe a strategy for collecting data from the brains of diverse groups—from hunter-gatherers to urban dwellers—using electroencephalography (EEG). The technology relies on portable headsets, widely used in clinical settings, that record the brain’s electrical activity through electrodes placed on the scalp. The researchers trained trusted community members as “surveyors,” who visited participants where they live and work to gather EEG data and conduct surveys about their lifestyles and experiences. The initial effort, which involved nearly 8000 volunteers across Tanzania and India, shows that this kind of data collection in low- and middle-income countries is feasible and affordable, the researchers say. The work cost them $50 for each person studied, a fraction of equivalent, large-scale studies conducted in research labs. A: I think mental health is one of the defining health issues in India. When we survey 18- to 24-year-olds, 50% tell us that almost every other day of the month they don’t feel like going to work or college. India is a young country and is increasingly relying on its youth to grow its economy. If they can’t function in their daily activities, you can’t expect them to be productive and contribute to the economy.

Keyword: Brain imaging
Link ID: 29869 - Posted: 07.26.2025

By Diana Kwon A new sensor makes it possible for the first time to simultaneously track dopamine and up to two additional molecules in the brains of living animals. The sensor, dubbed HaloDA1.0, uses a novel dopamine-tagging system that emits light at the far-red end of the color spectrum, according to the team behind the work. “There’s a real need to monitor multiple relevant molecules, as they’re doing here,” says Nicolas Tritsch, assistant professor of neuroscience at McGill University, who was not involved in the study. Because dopamine is involved in a range of key brain functions, when studying its effects on a cell it’s important to consider other neuromodulators that are released at the same time, as well as the signaling cascades these molecules may trigger, Tritsch says. Most dopamine-tracking strategies genetically encode a naturally occurring fluorescent protein into dopamine receptors; when dopamine attaches to the modified receptors, the fluorescent protein changes shape and emits light. But naturally occurring fluorescent proteins have a limited color palette, which has made it difficult to develop sensors that can go beyond two-color imaging, says study investigator Yulong Li, professor of life sciences at Peking University. Instead of genetically encoding a fluorescent protein, HaloDA1.0 attaches a synthetic molecule called HaloTag to dopamine receptors. This tag binds tightly to previously developed artificial dyes that change shape and fluoresce in the far-red spectrum when dopamine binds to its receptors. Because the dyes fluoresce at the far end of the red spectrum, it leaves room for other sensors to glow at different wavelengths. © 2025 Simons Foundation

Keyword: Brain imaging
Link ID: 29868 - Posted: 07.26.2025

Maria Godoy Back in the 1800s, obesity was almost nonexistent in the United States. Over the last century, it's become common here and in other industrialized nations, though it remains rare among people who live more traditional lifestyles, such as the Hadza hunter-gatherers of Tanzania. So what's changed? One common explanation is that as societies have developed, they've also become more sedentary, and people have gotten less active. The assumption is that as a result, we burn fewer calories each day, contributing to an energy imbalance that leads to weight gain over time, says Herman Pontzer, a professor of evolutionary biology and global health at Duke University who studies how human metabolism has evolved. Sponsor Message But in a major new study published in the journal PNAS, Pontzer and an international team of collaborators found that's not the case. They compared the daily total calorie burn for people from 34 different countries and cultures around the world. The people involved ran the spectrum from hunter-gatherers and farming populations with low obesity rates, to people in more sedentary jobs in places like Europe and the U.S., where obesity is widespread. "Surprisingly, what we find is that actually, the total calories burned per day is really similar across these populations, even though the lifestyle and the activity levels are really different," says Pontzer. And that finding offers strong evidence that diet — not a lack of physical activity — is the major driver of weight gain and obesity in our modern world. © 2025 npr

Keyword: Obesity
Link ID: 29867 - Posted: 07.26.2025

By Sofia Caetano Avritzer The original paleo diet might have included fewer succulent steaks and more juicy maggots. Neandertals are often depicted at the top of the food chain for their time, consuming as much meat as lions or hyenas. But maggots growing on rotting meat might have been the real signature dish of the Neandertal diet, researchers report July 25 in Science Advances. The idea that Neandertals were extreme carnivores comes partly from the high levels of a specific type of nitrogen called N-15 in their bones. Nitrogen has two stable forms. N-14 is lighter and a lot more common in nature, while N-15 is heavier and much rarer. When an animal eats a plant with both types of nitrogen, it will keep more N-15 than N-14 in its body after digestion. If that animal gets eaten, its predator will have an even higher proportion of N-15. That makes this molecule more prominent in animals that eat a lot of meat, says Melanie Beasley, a biological anthropologist at Purdue University in West Lafayette, Ind. The proportion of N-15 to N-14 found in Neandertal bones is similar to that found in animals like hyenas, which eat almost exclusively meat, Beasley says. But humans can’t consume as much meat as specialized carnivores, says Karen Hardy, a prehistoric archeologist at the University of Glasgow in Scotland. Without a balanced diet, the human body transforms protein into energy instead of using it to develop muscle, hormones and more. This creates toxic waste products that can cause nausea, diarrhea and even death. So, if Neandertals probably couldn’t eat as much meat as lions or hyenas, where does all the N-15 come from? Rotting meat. © Society for Science & the Public 2000–2025.

Keyword: Evolution; Obesity
Link ID: 29866 - Posted: 07.26.2025

By Michael S. Rosenwald Sarah Morlok Cotton, the last surviving member of a set of identical quadruplets who charmed Depression-era America with song-and-dance performances, and then took part in a landmark psychological study after being diagnosed with schizophrenia, died on July 7 in Belleville, Mich. She was 95. Her death, at an adult foster home, was confirmed by her son David Cotton. The Morlok Quads, as they came to be known, were a medical marvel and attracted crowds of people to Edward W. Sparrow Hospital in Lansing, Mich., shortly after they were born there on May 19, 1930. Newspapers held naming contests, and the winning entry suggested names that derived from the first letters of the hospital: Edna, Wilma, Sarah and Helen. The quadruplets’ middle names were simply initials denoting their birth order. (Sarah, the third born, was C.) Donations poured in almost immediately. The city of Lansing provided the family with a rent-free home. The Massachusetts Carriage Company sent a custom-made baby carriage with four seats. Businessmen opened bank accounts for each child. “Lansing’s Morlok quadruplets,” The Associated Press wrote, “are the most famous group of babies on the American continent.” The Morloks charged visitors 25 cents to visit their home and see the babies. Carl Morlok, who ran for constable of Lansing in 1931, used photos of his daughters on his campaign ads with the slogan, “We will appreciate your support.” He won in a landslide. Amid the commotion, Sadie Morlok tried to provide her daughters with a sense of normalcy. “Our mother used to dress us in pretty little identical crocheted sweaters and bonnets in spring and summer, or snow pant outfits in winter,” Mrs. Cotton wrote in her autobiography, “The Morlok Quadruplets: The Alphabet Sisters” (2015). “Then, she would carefully seat two of us facing the other two in the carriage and go for a nice stroll around the block to give us sunshine and a breath.” © 2025 The New York Times Company

Keyword: Schizophrenia; Genes & Behavior
Link ID: 29865 - Posted: 07.26.2025

Katie Kavanagh How does your brain wake up from sleep? A study of more than 1,000 arousals from slumber has revealed precisely how the brain bestirs itself during the transition to alertness1 — a finding that might help to manage sleep inertia, the grogginess that many people feel when hitting the snooze button. Recordings of people as they woke from the dream-laden phase of sleep showed that the first brain regions to rouse are those associated with executive function and decision-making, located at the front of the head. A wave of wakefulness then spreads to the back, ending with an area associated with vision. The findings could change how we think of waking up, says Rachel Rowe, a neuroscientist at the University of Colorado Boulder, who was not involved with the work. The results emphasize that “falling asleep and waking up aren’t simply reverse processes, but really waking up is this ordered wave of activation that moves from the front to the back of the brain”, whereas falling asleep seems to be less linear and more gradual. The study was published today in Current Biology1. The wide-awake brain shows a characteristic pattern of electrical activity, recorded by sensors on the scalp — it looks like a jagged line made up of small, tightly packed peaks and valleys. Although the pattern looks similar during rapid eye movement (REM) sleep, when vivid dreams occur, this stage features a lack of skeletal-muscle movement. The peaks are taller during most stages of non-REM sleep, which ranges from light to very deep slumber. Scientists already knew that the ‘awakened’ signature occurs at different times in different brain regions, but common imaging techniques did not allow these patterns to be explored on a precise timescale. © 2025 Springer Nature Limited

Keyword: Sleep; Attention
Link ID: 29864 - Posted: 07.19.2025