By Laura Sanders Ancient ear-wiggling muscles kick on when people strain to hear. That auricular activity, described January 30 in Frontiers in Neuroscience, probably doesn’t do much, if anything. But these small muscles are at least present, and more active than anyone knew. You’ve probably seen a cat or dog swing their ears toward a sound, like satellite dishes orienting to a signal. We can’t move our relatively rigid human ears this dramatically. And yet, humans still possess ear-moving muscles, as those of us who can wiggle our ears on demand know. Neuroscientist Andreas Schröer and colleagues asked 20 people with normal hearing to listen to a recorded voice while distracting podcasts played in the background. All the while, electrodes around the ears recorded muscle activity. An ear muscle called the superior auricular muscle, which sits just above the ear and lifts it up, fired up when the listening conditions were difficult, the researchers found. Millions of years ago, these muscles may have helped human ancestors collect sounds. Today, it’s doubtful that this tiny wisp of muscle activity helps a person hear better, though scientists haven’t tested that. “It does its best, but it probably doesn’t work,” says Schröer, of Saarland University in Saarbrücken, Germany. These vestigial muscles may not help us hear, but their activity could provide a measurement of a person’s hearing efforts. That information may be useful to hearing aid technology, telling the device to change its behavior when a person is struggling, for instance. © Society for Science & the Public 2000–2025.

Keyword: Hearing; Evolution
Link ID: 29665 - Posted: 02.12.2025

By Felicity Nelson Mice immediately bolt for shelter when they see the looming shadow of a bird, just as humans jump when they see a spider. But these instinctive reactions, which are controlled by the brainstem, can be suppressed if animals learn that a scary stimulus is harmless. In Science today, neuroscientists reveal the precise regions of the brain that suppress fear responses in mice1 — a finding that might help scientists to develop strategies for treating post-traumatic stress disorder and anxiety in people. The study showed that two parts of the brain work together to learn to suppress fear. But, surprisingly, only one of these regions is involved in later recalling the learnt behaviour. “This is the first evidence of that mechanism,” says neuroscientist Pascal Carrive at the University of New South Wales in Sydney, Australia. In the study, an expanding dark circle was used to imitate a swooping bird, and caused naive mice to run to a shelter. To teach the mice that this looming stimulus was not dangerous, a barrier was added to prevent the animals from hiding. “I like their behavioural model,” says Christina Perry, a behavioural neuroscientist at Macquarie University in Sydney. “It’s very simple,” she adds. The mice “don’t get eaten, so they learn that this fake predator is not, in fact, a threat”. As the mice were learning to be bolder, the researchers switched specific types of neurons on or off using optogenetics — a well-established technique that allows neurons to be controlled with light. When researchers silenced the parts of the cerebral cortex that analyse visual stimuli (called the posterolateral higher visual areas), the mice did not learn to suppress fear and continued to try to escape from the fake bird — suggesting that this area of the brain is necessary for learning to suppress this fear reaction. © 2025 Springer Nature Limited

Keyword: Emotions; Stress
Link ID: 29664 - Posted: 02.08.2025

By Laura Sanders So many of us struggle to fall asleep and stay there through the night. About a third of U.S. adults aren’t sleeping enough. Teenagers’ sleep is even worse; 8 in 10 teens are sleep deprived. Our collective exhaustion isn’t good for us. Lack of sleep can come with a range of health problems. Our immune systems, hormones, hearts — maybe all the body’s major systems — are influenced by sleep. In the brain, our memory, creativity and ability to learn are, too. But for something that’s so entwined with our health, the actual jobs of sleep are still, in many ways, a mystery. Scientists have tons of ideas: Perhaps sleep is for rifling through memories, picking out the important ones. Or maybe it’s a quiet, still time for growing bones in children. Or maybe it’s a time to let the brain loose on whatever problem vexed you that day. (One delightfully myopic theory posits that sleep, especially the rapid eye movement stage, is for squeezing fluid around the eye to keep it lubricated.) Figuring out why we sleep has puzzled scientists for as long as the question has existed. It’s like following hundreds of disappearing breadcrumbs on paths through a forest of trees that keep shifting spots, only to realize you’re standing alone in only your underwear. Oh, and you forgot to study for the test. Given this hazy scientific landscape, it’s no surprise that efforts to help the sleep-deprived catch some z’s might fall short or have unintended consequences. That’s clear from a new study of the sleep medicine zolpidem. Zolpidem, sold as Ambien, messes with yet another possible job of sleep – housekeeping. © Society for Science & the Public 2000–2025

Keyword: Sleep
Link ID: 29663 - Posted: 02.08.2025

By Emily Anthes The English language is full of wonderful words, from “anemone” and “aurora” to “zenith” and “zodiac.” But these are special occasion words, sprinkled sparingly into writing and conversation. The words in heaviest rotation are short and mundane. And they follow a remarkable statistical rule, which is universal across human languages: The most common word, which in English is “the,” is used about twice as frequently as the second most common word (“of,” in English), three times as frequently as the third most common word (“and”), continuing in that pattern. Now, an international, interdisciplinary team of scientists has found that the intricate songs of humpback whales, which can spread rapidly from one population to another, follow the same rule, which is known as Zipf’s law. The scientists are careful to note that whale song is not equivalent to human language. But the findings, they argue, suggest that forms of vocal communication that are complex and culturally transmitted may have shared structural properties. “We expect them to evolve to be easy to learn,” said Simon Kirby, an expert on language evolution at the University of Edinburgh and an author of the new study. The results were published on Thursday in the journal Science. “We think of language as this culturally evolving system that has to essentially be passed on by its hosts, which are humans,” Dr. Kirby added. “What’s so gratifying for me is to see that same logic seems to also potentially apply to whale song.” Zipf’s law, which was named for the linguist George Kingsley Zipf, holds that in any given language the frequency of a word is inversely proportional to its rank. There is still considerable debate over why this pattern exists and how meaningful it is. But some research suggests that this kind of skewed word distribution can make language easier to learn. © 2025 The New York Times Company

Keyword: Language; Evolution
Link ID: 29662 - Posted: 02.08.2025

By Avery Schuyler Nunn Migratory songbirds may talk to one another more than we thought as they wing through the night. Each fall, hundreds of millions of birds from dozens of species co-migrate, some of them making dangerous journeys across continents. Come spring, they return home. Scientists have long believed that these songbirds rely on instinct and experience alone to make the trek. But new research from a team of ornithologists at the University of Illinois suggests they may help one another out—even across species—through their nocturnal calls. “They broadcast vocal pings into the sky, potentially sharing information about who they are and what lies ahead,” says ornithologist Benjamin Van Doren of the University of Illinois, Urbana-Champaign and a co-author of the study, published in Current Biology. Using ground-based microphones across 26 sites in eastern North America, Van Doren and his team recorded over 18,300 hours of nocturnal flight calls from 27 different species of birds—brief, high-pitched vocalizations that some warblers, thrushes, and sparrows emit while flying. To process the enormous dataset of calls, they used machine-learning tools, including a customized version of Merlin, the Cornell Lab of Ornithology’s bird-call identification app. The analysis revealed that birds of different species were flying in close proximity and calling to one another in repeated patterns that suggested a kind of code. Flight proximity was closest between migrating songbirds species that made similar calls in pitch and rhythm, traveled at similar speeds, and had similar wing shapes. © 2025 NautilusNext Inc.,

Keyword: Language; Evolution
Link ID: 29661 - Posted: 02.08.2025

By Matt Richtel Cursing is coursing through society. Words once too blue to publicly utter have become increasingly commonplace. “Language is just part of the whole shift to a more casual lifestyle,” said Timothy Jay, a professor emeritus of psychology at the Massachusetts College of Liberal Arts in North Adams, Mass. Dr. Jay has spent a career studying the use of profanity, from what motivates it to the ways in which it satisfies, signals meaning and offends. Although officially retired, he has continued to edit studies on profanity and he recently offered an expert opinion in an ongoing legal dispute in Michigan over whether the phrase “Let’s go Brandon” (a euphemism used to denigrate former President Joseph R. Biden Jr.) should be reasonably interpreted as “profane.” (It should not, Dr. Jay opined.) Dr. Jay posits that the increasingly casual nature of the spoken word derives in part from the way people communicate on social media. One study, published in 2014 by other researchers in the field, found that curse words on Twitter, now known as X, appeared in 7.7 percent of posts, with profanity representing about 1 in every 10 words on the platform. That compared to a swearing rate of 0.5 to 0.7 percent in spoken language, the study found. If that data troubles you, Dr. Jay has some thoughts on how to dial back the profanity. F*@%-free February, anyone? Tis interview has been condensed and edited for clarity, and scrubbed of some of the vernacular that Dr. Jay conceded he regularly uses on the golf course. © 2025 The New York Times Company

Keyword: Emotions; Language
Link ID: 29660 - Posted: 02.08.2025

By Andrew Jacobs and Rachel Nuwer After more than three decades of planning and a $250 million investment, Lykos Therapeutics’ application for the first psychedelic drug to reach federal regulators was expected to be a shoo-in. Lykos, the corporate arm of a nonprofit dedicated to winning mainstream acceptance of psychedelics, had submitted data to the Food and Drug Administration showing that its groundbreaking treatment for post-traumatic stress disorder — MDMA plus talk therapy — was significantly more effective than existing treatments. At a pivotal public hearing last summer, two dozen scientists, doctors and trauma survivors told an F.D.A. advisory panel how MDMA-assisted therapy had brought marked relief from a mental health condition associated with high rates of suicide, especially among veterans. Then came skeptics with disturbing accusations: that Lykos was “a therapy cult,” that practitioners in its clinical trials had engaged in widespread abuse of participants and that the company had concealed a litany of adverse events. “The most significant harms in Lykos’s clinical trials were not caused by MDMA, but by the people who were entrusted to supervise its administration,” Neşe Devenot, one of the speakers opposed to Lykos’s treatment and a writing instructor at Johns Hopkins University, told the committee. Dr. Devenot and six others presented themselves as experts in the field of psychedelics, but none had expertise in medicine or therapy. Nor had the speakers disclosed their connection to Psymposia, a leftist advocacy group whose members oppose the commercialization of psychedelics and had been campaigning against Lykos and its nonprofit parent, the Multidisciplinary Association for Psychedelic Studies, or MAPS. The critics did not provide evidence to back their claims of systematic wrongdoing, but when the votes were counted that day, the panel overwhelmingly rejected Lykos’s application. Before voting, panelists cited a number of concerns, among them MDMA’s potential effects on the heart and liver, and whether trial results were influenced by the fact that most study participants correctly guessed they had received the drug and not a placebo. © 2025 The New York Times Company

Keyword: Drug Abuse; Depression
Link ID: 29659 - Posted: 02.05.2025

Nell Greenfieldboyce People are constantly looking at the behavior of others and coming up with ideas about what might be going on in their heads. Now, a new study of bonobos adds to evidence that they might do the same thing. Specifically, some bonobos were more likely to point to the location of a treat when they knew that a human companion was not aware of where it had been hidden, according to a study which appears in the Proceedings of the National Academy of Sciences. The findings add to a long-running debate about whether humans have a unique ability to imagine and understand the mental states of others. Some researchers say this kind of "theory of mind" may be practiced more widely in the animal kingdom, and potentially watching it in action was quite the experience. "It's quite surreal. I mean, I've worked with primates for quite some years now and you never get used to it," says Luke Townrow, a PhD student at Johns Hopkins University. "We found evidence that they are tailoring their communication based on what I know." Hmmm, where is the grape? To see what bonobos might know about what humans around them know, Townrow worked with Chris Krupenye of Johns Hopkins University to devise a simple experiment. "It's always a challenge for us, that animals don't speak, so we can't just ask them what they're thinking. We have to come up with creative, experimental designs that allow them to express their knowledge," says Krupenye. © 2025 npr

Keyword: Attention; Consciousness
Link ID: 29658 - Posted: 02.05.2025

By Laura Hercher edited by Gary Stix It is impossible, of course, to identify the precise moment we first suspected the changes in my mother were something other than normal aging. In my own imperfect memory, what rises up is the first morning of a weeklong trip to Rome, when my mother woke up at 2 A.M., got dressed and went down for breakfast. A hotel employee found her wandering from room to room, looking for toast and coffee. She was jet-lagged, my brother and I told each other uneasily. It could happen to anyone. But weren’t there cues? Didn’t she notice the darkened lobby, the stillness, the clock? If we had known then, would it have helped? To date, no U.S. Food and Drug Administration–­approved therapy exists for asymptomatic people at risk of Alzheimer’s disease (AD). My mother was not a smoker, drank in moderation, read books, took classes, and spent that week in Italy soaking up everything the tour guide told her about Caravaggio and Bernini like she was prepping for a quiz. Five years passed after that trip before my mother received a diagnosis of dementia. Today, a simple blood test can detect changes in the brain that predict AD up to 15 years before the first symptoms emerge. For researchers, tools for early detection give a peek at the full spectrum of AD, pinpointing early seeds of pathology deep inside the brain. Cognitive decline—what we typically think of as the disease itself—is merely the illness’s denouement. “Dementia is a result. Dementia is a symptom,” explains Clifford R. Jack, Jr., a neuroradiologist at the Mayo Clinic in Rochester, Minn., and chair of the Alzheimer’s Association (AA) working group responsible for recent, controversial guidelines for the diagnosis of AD based on underlying biology, not clinical presentation. Scientific American is part of Springer Nature,

Keyword: Alzheimers
Link ID: 29657 - Posted: 02.05.2025

Damian Carrington Environment editor The exponential rise in microplastic pollution over the past 50 years may be reflected in increasing contamination in human brains, according to a new study. It found a rising trend in micro- and nanoplastics in brain tissue from dozens of postmortems carried out between 1997 and 2024. The researchers also found the tiny particles in liver and kidney samples. The human body is widely contaminated by microplastics. They have also been found in blood, semen, breast milk, placentas and bone marrow. The impact on human health is largely unknown, but they have been linked to strokes and heart attacks. The scientists also found that the concentration of microplastics was about six times higher in brain samples from people who had dementia. However, the damage dementia causes in the brain would be expected to increase concentrations, the researchers said, meaning no causal link should be assumed. “Given the exponentially rising environmental presence of micro- and nanoplastics, this data compels a much larger effort to understand whether they have a role in neurological disorders or other human health effects,” said the researchers, who were led by Prof Matthew Campen at the University of New Mexico in the US. Microplastics are broken down from plastic waste and have polluted the entire planet, from the summit of Mount Everest to the deepest oceans. People consume the tiny particles via food, water and by breathing them in. A study published on Thursday found tiny plastic pollution to be significantly higher in placentas from premature births. Another recent analysis found that microplastics can block blood vessels in the brains of mice, causing neurological damage, but noted that human capillaries are much larger. © 2025 Guardian News & Media Limited

Keyword: Neurotoxins
Link ID: 29656 - Posted: 02.05.2025

By Laura Sanders Brain implants for depression: It sounds like science fiction but it’s real. The Deep End, a new podcast from Science News, will give you a glimpse of what it’s like to live with electrodes in your brain. It might change how you think about mental health, the brain and what makes you you. Transcript Laura Sanders: Inside your brain, there are billions of nerve cells that form trillions of connections. These connections make your thoughts, movements, emotions, and memories. Your first kiss, your favorite song, your dreams. Our brains make us who we are. But sometimes they can betray us. Support Science Today. Thank you for being a subscriber to Science News! Interested in more ways to support STEM? Consider making a gift to our nonprofit publisher, the Society for Science, an organization dedicated to expanding scientific literacy and ensuring that every young person can strive to become an engineer or scientist. Donate Now This is a story about four people whose brains turned against them, plunging their lives into the darkness of severe depression. This is also a story about an experiment designed to pull them back out. Amanda: My initial response was a little bit of skepticism, like, “OK, we’re gonna put a box in you, we’re gonna hook it up to some wires, we’re gonna shove them down in your brain and then electrocute you, and it’s gonna make you feel great.” Like, this doesn’t seem like a, like a safe thing to be doing. Sanders: This experiment sounds like science fiction, but it’s real. This is the Deep End, a new podcast from Science News. I’m Laura Sanders. On this podcast, you’ll hear what led people to sign up for this unconventional experiment and what it was like for them. © Society for Science & the Public 2000–202

Keyword: Depression
Link ID: 29655 - Posted: 02.05.2025

By Bethany Brookshire Self-awareness may be beyond primates in the wild. Chimps, organutans and other species faced with a mirror react to a dot on their face in the lab, a widely used measure of self-awareness. But while baboons in Namibia exposed to mirrors find the reflective glass fascinating, they don’t respond to dots placed on their faces, researchers report in the January Proceedings of the Royal Society B: Biological Sciences. The result could indicate that lab responses to mirrors are a result of training — and that self-awareness might exist on a spectrum. Support Science Today. Thank you for being a subscriber to Science News! Interested in more ways to support STEM? Consider making a gift to our nonprofit publisher, the Society for Science, an organization dedicated to expanding scientific literacy and ensuring that every young person can strive to become an engineer or scientist. Donate Now “Psychological self-awareness is this idea that you as an individual can become an object of your own attention,” says Alecia Carter, an evolutionary anthropologist at University College London. It’s a hard concept to measure in other species, in part, she notes, because “it’s also difficult to imagine not having that kind of self-awareness.” One measure of self-awareness is the mark test. An animal sits in front of a mirror, and a mark is placed somewhere they normally cannot see, such as on the face. If the animal recognizes themselves in the mirror, and the mark as out of place, the animal will respond to the mark. Chimps, orangutans and bonobos have “passed” the mark test in the lab, while primates that are not great apes, such as rhesus macaques, have mastered it only after training. Other species, such as Asian elephants, dolphins and even a fish called the cleaner wrasse, have also responded to the mark test. © Society for Science & the Public 2000–2025.

Keyword: Chemical Senses (Smell & Taste); Evolution
Link ID: 29654 - Posted: 02.01.2025

By Gina Kolata The Food and Drug Administration approved a new medication Thursday to treat pain from an injury or surgery. It is expensive, with a list price of $15.50 per pill. But unlike opioid pain medicines, it cannot become addictive. That is because the drug, suzetrigine, made by Vertex Pharmaceuticals and to be sold as Journavx, works only on nerves outside the brain, blocking pain signals. It cannot get into the brain. Researchers say they expect it to be the first of a new generation of more powerful nonaddictive drugs to relieve pain. To test the drug, Vertex, which is based in Boston, conducted two large clinical trials, each with approximately 1,000 patients who had pain from surgery. They were randomly assigned to get a placebo; to get the opioid sold as Vicodin, a widely used combination pain medicine of acetaminophen (Tylenol) and hydrocodone; or to get suzetrigine. In one trial, patients had an abdominoplasty, or tummy tuck. In the other, they had a bunionectomy. Side effects of suzetrigine reported by patients were similar to the ones reported by those taking the placebo. The company also submitted data from a 250-person study that assessed the drug’s safety and tolerability in patients with pain from surgery, trauma or accidents. Suzetrigine eased pain as much as the combination opioid. Both were better than the placebo at relieving pain. Suzetrigine’s price, though, is much higher than that of acetaminophen plus hydrocodone. Patients are expected to take two pills a day, for a total cost of $31 a day. The older drug, said Dr. John D. Loeser, an emeritus pain expert at the University of Washington, is “dirt cheap” at pennies per pill. But suzetrigine does not have opioids’ unpleasant side effects like nausea and drowsiness, and it is nonaddictive. © 2025 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 29653 - Posted: 02.01.2025

By Catherine Offord In scientists’ search to understand the causes of autism, a spotlight has fallen on maternal health during pregnancy. Based partly on association studies, researchers have proposed that conditions including obesity and depression during pregnancy could lead to autism in a child by affecting fetal neurodevelopment. But a study of more than 1 million Danish children and their families, published today in Nature Medicine, pushes back against this view. Researchers analyzed more than 200 health conditions that occurred in these children’s mothers before or during pregnancy. They conclude that many of the supposed links to a child’s autism diagnosis may not be causal, and instead reflect inherited genetic variants or environmental factors shared within families. “It’s a very comprehensive and well-done study,” says Håkan Karlsson, a neuroscientist at the Karolinska Institute who was not involved in the work. It suggests “conditions [pregnant people] suffered from during pregnancy are probably not the cause of autism in their kid.” The findings dovetail with a growing view in the field that shared genetics could explain a lot of the apparent connections between maternal health and autism, adds Drexel University epidemiologist Brian Lee. However, he and others caution the study doesn’t rule out that some conditions during pregnancy could have a causative role, nor does it identify factors that do influence the likelihood of autism. Previous research has linked conditions such as maternal obesity, psychiatric disorders, and pregnancy or birth complications to an increased likelihood of autism diagnoses in children. Such findings can lead some pregnant people to feel that “if they get this or that condition, their [child’s] chance of autism may increase,” says Magdalena Janecka, an epidemiologist at New York University’s Grossman School of Medicine and a co-author on the new paper. © 2025 American Association for the Advancement of Science.

Keyword: Autism
Link ID: 29652 - Posted: 02.01.2025

By Marija Kundakovic The role of sex and gender in the brain is a popular but controversial research topic. Neuroscience has a reputation for being male-centric and focused on studying male brains, although researchers have recently embraced the idea that it is critical to study female brains as well. Generally speaking, human female and male brains are morphologically similar, but that does not suggest they don’t differ in their activity and function, or in their underlying molecular and cellular mechanisms. In fact, sex and gender bias in neuropsychiatric conditions is the rule rather than the exception. Men are three to five times as likely as women to have autism or attention-deficit/hyperactivity disorder, for example, and women are twice as likely as men to have anxiety or depression disorders. Understanding the biological factors and mechanisms that underlie gender- and sex-related bias in brain function and psychiatric conditions is essential to improve our fundamental knowledge of the brain and to open a path to develop novel, sex-informed treatments. But simply including females in research studies is insufficient to resolve the role of sex and gender in neuroscience. “Sex” and “gender” are both complex and evolving concepts, extending beyond a simple binary. In practice, people are assigned female or male at birth based on external genitalia, although up to 2 percent do not belong to either category because of differences in sex development. Though gender has traditionally been co-assigned with sex—females/women and males/men—the binary nature of sex does not suffice to account for today’s expanding gender landscape. Gender exists on a spectrum, including nonbinary, gender-fluid and agender people. In transgender people, gender identity differs from gender or sex assigned at birth. Some researchers would say that this complexity cannot (and perhaps should not) be tackled by science, and that we should stick to scientifically discernible female-male comparisons, particularly in animal research. But science should not exist in a vacuum; when detached from society, it does not serve its purpose. Indeed, in the case of gender, biology can be falsely used to fuel discriminatory laws and practices against gender-diverse and gender-non-conforming people, supposedly based on a scientific understanding of “biological sex.” © 2025 Simons Foundation

Keyword: Sexual Behavior
Link ID: 29651 - Posted: 02.01.2025

By Jackson Ryan Fruit fly larvae can sense the texture of rotting fruit.Credit: Scott Bauer/USDA/SPL For maggots, the experience of eating a succulent meal isn’t just about how their food tastes, but also how it feels. Researchers used genetic tools to reveal that certain neurons in the brain control food choice and can sense both taste and texture1 . The conventional view of taste sensing holds that specific neurons carry single signals to the brain, says study co-author Simon Sprecher, a neurobiologist at the University of Fribourg in Switzerland. For instance, sweet taste neurons carry sweet signals and bitter taste neurons carry bitter signals. But those assumptions have been challenged over the past two decades by studies in fruit flies and mice that suggest neurons might have the capacity to respond to both chemical signals, such as bitter or sweet, as well as mechanical signals, such as texture. In the current study, published in PLoS Biology on 30 January, Sprecher and his colleagues set out to see whether individual neurons in taste organs have this ‘multimodal’ capacity. They fed fruit-fly larvae — maggots — different preparations of agarose, a sugary gel. The maggots showed a propensity for a ‘Goldilocks’ preparation, one that was neither too hard nor too soft. The preferred hardness for larvae is “similar to [that] of decaying fruit”, says Sprecher. The researchers then used genetic engineering tools to disable a subset of taste-sensing neurons in the larval taste-sensing organs. Disabling the neurons prevented the maggots from tasting the sweetness of the agarose, as expected, but it also changed which preparations they ate — the maggots no longer preferred Goldilocks preparations, suggesting that they had also lost their ability to feel their food. By studying individual neurons, the researchers determined that C6 neurons can both taste sugar and sense mechanical simulation. © 2025 Springer Nature Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 29650 - Posted: 02.01.2025

Nicola Davis Science correspondent Wiggling your ears might be more of a pub party piece than a survival skill, but humans still try to prick up their ears when listening hard, researchers have found. Ear movement is crucial in many animals, not least in helping them focus their attention on particular noises and work out which direction they are coming from. But while the human ear is far more static, traces of our ancestors’ ear-orienting system remain in what has been called a “neural fossil”. “It is believed that our ancestors lost their ability to move their ears about 25m years ago. Why, exactly, is difficult to say,” said Andreas Schröer, the lead author of the research from Saarland University in Germany. “However, we have been able to demonstrate that the neural circuits still seem to be present in some state, [that is] our brain retained some of the structures to move the ears, even though they apparently are not useful any more.” The team previously found the movement of these muscles in humans is related to the direction of the sounds they are paying attention to. Now, they have found that some of these muscles become activated when humans listen hard to a sound. Writing in the journal Frontiers in Neuroscience, the team reported how they asked 20 adults without hearing problems to listen to an audiobook played through a speaker at the same time as a podcast was played from the same location. The team created three different scenarios: in the “easiest” scenario the podcast was quieter than the audiobook, with a large difference in pitch between the voices. In the “hardest” scenario, two podcasts were played which, taken together, were louder than the audiobook, with one of the podcasts spoken at a similar pitch to the audiobook. © 2025 Guardian News & Media Limited

Keyword: Hearing; Evolution
Link ID: 29649 - Posted: 02.01.2025

By Laura Sanders Scratching an itch can bring a contradictory wave of pleasure and misery. A mouse study on scratching, reported in the Jan. 31 Science, fleshes out this head-scratching paradox and could point out ways to better curb pernicious itch in people. First, the bad news: Scratching itchy ears led to a round of inflammation. Itch-provoking substances, such as the oil in poison ivy, activate mast cells, immune sentries that release itch signals and kick off inflammation. But so does scratching, the new study suggests. “The act of scratching is actually triggering the inflammation by synergizing with mast cells to make them more effective,” says study coauthor Daniel Kaplan, a dermatologist and immunologist at the University of Pittsburgh. Mice that couldn’t scratch their itchy ears, thanks to tiny cones of shame, had less inflammation than mice that scratched. The same was true for mice that didn’t sense the itch, the researchers report. Kaplan relates the results to a mosquito bite. “Most of the time, it’ll go away in five, 10 minutes,” he says. “But if you start scratching it, now, you get a really big, inflamed, itchy lesion on your skin that can stick around for several days. It’s a lot worse. And I think this could be a mechanism that explains why.” Now onto the good news: Scratching lessened the amount of potentially harmful bacteria (Staphylococcus aureus) on mice’s skin, perhaps through the heightened immune reaction it prompts. “That was a clear demonstration that scratching can have a benefit in the context of an acute infection,” Kaplan says. But too much scratching can rip the skin and usher in more bacteria, he cautions. “In that sense, scratching, through a different mechanism, also makes things even worse.” © Society for Science & the Public 2000–2025.

Keyword: Pain & Touch
Link ID: 29648 - Posted: 02.01.2025

By Katie J.M. BakerMegan TwoheyDanielle Ivory and Jeremy Singer-Vine At Stiiizy, the best-selling cannabis brand in America, the goal is explicit: producing powerful and cheap marijuana. Inside its Los Angeles headquarters, crews dust joints with concentrated THC, the intoxicating component of cannabis. They package pocket-size vape cartridges that promise “the highest potency possible.” On its website, the company declares that “it has never been easier (or quicker) to get silly high for an affordable price.” Dispensaries operating under the brand of another leading company, Cookies, have promoted “powerful medical benefits,” including “cancer fighting” qualities. A cannabis-infused chocolate bar was, until recently, described as containing properties “beneficial to those suffering” from glaucoma, bacterial infections and Huntington’s disease, a devastating genetic illness. More than a decade after states began legalizing recreational marijuana, businesses are enticing customers with unproven health claims, while largely escaping rigorous oversight. A New York Times review of 20 of the largest brands found that most were selling products with such claims, potentially violating federal and state regulations. And as companies compete, potency has gone up — with some products advertised as having as much as 99 percent THC — and prices have gone down. “What we’re seeing is really a race to the bottom,” said Matt Zehner, a senior analyst at Brightfield Group, which tracks the legal cannabis industry. Some executives said their companies are trying to navigate complex rules while satisfying their customers. Stiiizy’s co-founder and chief executive, James Kim, said in an interview that many are heavy users in search of a good deal, something he had sought as a broke “pothead” in his early 20s. “This is why I believe we’re very successful,” he said. But in a $32 billion industry that has been volatile — only about a quarter of businesses turned a profit last year, one survey found — companies say they also face pressure to do whatever they can to survive. © 2025 The New York Times Company

Keyword: Drug Abuse
Link ID: 29647 - Posted: 01.29.2025

By Katharine Gammon Today more than 55 million people around the world have Alzheimer’s disease and other dementias, which ravage the minds of those who suffer from them and have devastating impacts on their family members. In spite of decades of research, the precise origins of these diseases continue to elude scientists, though numerous factors have been found to be associated with higher risk, including genetics and various lifestyle and environmental factors. Nautilus Members enjoy an ad-free experience. Log in or Join now . The quest has recently taken a turn to a newer model for studying the brain: brain organoids. These three-dimensional clumps of neuronal tissue derived from human stem cells have been used to study everything from epilepsy to the origins of consciousness. And now, researchers in Massachusetts are slamming them with miniature metal pistons to test out whether they can lend credence to a controversial hypothesis: that concussions might reactivate a common virus in the brain, increasing dementia risk. A decade of research suggests traumatic brain injury, whether from accidents or high-contact sports, is a standout risk factor for Alzheimer’s and other forms of neurodegenerative decline. Some estimates suggest that up to 10 percent of cases could be attributed to at least one prior head injury, but why is not fully understood. Separately, a growing body of research proposes that viral infection, including a common virus known as herpes simplex one, can also increase susceptibility to these diseases. But all three things—head trauma, viral infection, and dementia—have not been directly connected in experimental research, until now. One of the challenges in getting to the roots of dementia is that humans lead complex, messy lives. In the soup of risk factors—from high blood pressure to loneliness to genetic inheritance—it can be hard to filter out the most impactful forces that have contributed to the onset of any one dementia case. There are no ethical ways to test these questions on humans, of course, while using lab animals presents its own ethical and cost challenges. Animals are never a perfect match for humans anyway, and dementia-related findings in animals have so far not translated well to human patients. © 2025 NautilusNext Inc.,

Keyword: Alzheimers; Brain Injury/Concussion
Link ID: 29646 - Posted: 01.29.2025