By Dana G. Smith When it comes to aging, we tend to assume that cognition gets worse as we get older. Our thoughts may slow down or become confused, or we may start to forget things, like the name of our high school English teacher or what we meant to buy at the grocery store. But that’s not the case for everyone. For a little over a decade, scientists have been studying a subset of people they call “super-agers.” These individuals are age 80 and up, but they have the memory ability of a person 20 to 30 years younger. Most research on aging and memory focuses on the other side of the equation — people who develop dementia in their later years. But, “if we’re constantly talking about what’s going wrong in aging, it’s not capturing the full spectrum of what’s happening in the older adult population,” said Emily Rogalski, a professor of neurology at the University of Chicago, who published one of the first studies on super-agers in 2012. A paper published Monday in the Journal of Neuroscience helps shed light on what’s so special about the brains of super-agers. The biggest takeaway, in combination with a companion study that came out last year on the same group of individuals, is that their brains have less atrophy than their peers’ do. The research was conducted on 119 octogenarians from Spain: 64 super-agers and 55 older adults with normal memory abilities for their age. The participants completed multiple tests assessing their memory, motor and verbal skills; underwent brain scans and blood draws; and answered questions about their lifestyle and behaviors. The scientists found that the super-agers had more volume in areas of the brain important for memory, most notably the hippocampus and entorhinal cortex. They also had better preserved connectivity between regions in the front of the brain that are involved in cognition. Both the super-agers and the control group showed minimal signs of Alzheimer’s disease in their brains. © 2024 The New York Times Company

Keyword: Learning & Memory; Development of the Brain
Link ID: 29280 - Posted: 04.30.2024

By Tim Vernimmen Most amphibians aren’t exactly doting parents — they just find a partner and release as many eggs or sperm as possible, in hopes that viable larvae will hatch from at least some fertilized eggs, and at least some of those larvae will survive to adulthood. Yet in as many as one in five amphibian species, one or both parents stick around to care for their offspring, using a staggering variety of strategies. The most well-known amphibian parents are the brightly colored poison frogs, a group of around 200 species that will repeatedly be leaping into view in this article. Yet their parenting skills may not be as exceptional as once thought, says biologist Jennifer Stynoski of the University of Costa Rica, who decided to study this group when she spotted them on a field trip as a student years ago. “I think they’ve just received a lot of attention because they’re so beautiful. They’re very cute to study.” So — what makes an exemplary amphibian parent? Much remains to be discovered, but some common principles have emerged. Stay away from the water Unlike reptiles and the birds that evolved from them, the ancestors of today’s amphibians never developed eggs with tough, watertight shells. This means their eggs need water to survive, as do the gilled larvae that usually come wriggling out. Yet the ponds in which many amphibians deposit their eggs are full of other animals, many eager to supplement their diet by slurping up a mouthful of eggs. “This must be one reason why so many species have evolved ways to lay their eggs away from the water,” says behavioral ecologist Eva Ringler of the University of Bern in Switzerland. © 2024 Annual Reviews

Keyword: Sexual Behavior; Evolution
Link ID: 29279 - Posted: 04.30.2024

By Kristen French Combat in nature is often a matter of tooth and claw, fang and talon. But some creatures have devised devious and dramatic ways to weaponize their bodily fluids, expelling them in powerful streams for the purposes of attack or self-defense. Researcher Elio Challita became fascinated by fluid ejections in nature when he began studying an insect called the sharpshooter, which pees one droplet at a time using a method called superpropulsion. These insects consume 300 times their own body weight per day in xylem sap, a watery solution of minerals and other nutrients found in the roots, stems, and leaves of plants. To efficiently expel the resulting waste, they use a kind of internal catapult that helps overcome the surface tension in the droplets. Challita and a team of researchers from the Bhamla Lab at Georgia Tech decided to survey the biomechanics and fluid dynamics that govern fluid ejections across the animal kingdom to see what commonalities they could find. Among others, they identified a number of creatures that use bodily fluids as powerful weapons in the fight for survival. These fluid ejections defy gravity and rebel against traditional notions of predator-prey tactics. The team’s review, “Fluid Ejections in Nature,” is forthcoming in the Annual Review of Chemical and Biological Engineering. 1. Ringnecked Spitting Cobra Cobras of the Naja genus defend against threats by spitting venom with extreme precision toward the eyes of an enemy, up to 6.5 feet away. These snakes release the venom through hollow microscopic fangs and can adjust the distribution of their spit with rapid movements. Spitting cobras have a venom discharge orifice that is more circular in shape than non-spitting species, which gives the venom more forward force. Contraction in the venom gland also helps. A 90-degree bend near the lip of the orifice gives the snake more precise control over venom flow. Naja pallida cobras can spit venom at average speeds of 1.27 milliliters per second. © 2024 NautilusNext Inc.,

Keyword: Neurotoxins; Evolution
Link ID: 29278 - Posted: 04.30.2024

Jon Hamilton Scientists have found a way to restore brain cells impaired by a rare and life-threatening genetic disorder called Timothy syndrome. A type of drug known as an antisense oligonucleotide allowed clusters of human neurons to develop normally even though they carried the mutation responsible for Timothy syndrome, a team reports in the journal Nature. The approach may help researchers develop treatments for other genetic conditions, including some that cause schizophrenia, epilepsy, ADHD, and autism spectrum disorder. "It's immensely exciting because we now have the tools," says Dr. Sergiu Pasca, a professor of psychiatry and behavioral sciences at Stanford University and the study's senior author. "It's the beginning of a new era for many of these diseases that we first thought were untreatable," says Dr. Huda Zoghbi, a professor at Baylor College of Medicine who was not involved in the research. But most of these conditions involve multiple genes, not just one — and scientists don't yet know enough about these multiple gene disorders to effectively treat them with antisense oligonucleotides, Zoghbi says. Timothy Syndrome has been diagnosed in fewer than 100 people worldwide. Children born with it often have heart problems, autism, epilepsy, developmental delay, and intellectual disability. But because Timothy syndrome is caused by a mutation in a single gene, it offers scientists a way to study changes that affect brain development. "Rare syndromes that are very clearly defined genetically are sort of like windows, or Rosetta Stones, into understanding other, more common conditions," Pasca says. © 2024 npr

Keyword: Autism; Genes & Behavior
Link ID: 29277 - Posted: 04.30.2024

By Claire Cameron On Aug. 19, 2021, a humpback whale named Twain whupped back. Specifically, Twain made a series of humpback whale calls known as “whups” in response to playback recordings of whups from a boat of researchers off the coast of Alaska. The whale and the playback exchanged calls 36 times. On the boat was naturalist Fred Sharpe of the Alaska Whale Foundation, who has been studying humpbacks for over two decades, and animal behavior researcher Brenda McCowan, a professor at the University of California, Davis. The exchange was groundbreaking, Sharpe says, because it brought two linguistic beings—humans and humpback whales—together. “You start getting the sense that there’s this mutual sense of being heard.” In their 2023 published results, McGowan, Sharpe, and their coauthors are careful not to characterize their exchange with Twain as a conversation. They write, “Twain was actively engaged in a type of vocal coordination” with the playback recordings. To the paper’s authors, the interspecies exchange could be a model for perhaps something even more remarkable: an exchange with an extraterrestrial intelligence. Sharpe and McGowan are members of Whale SETI, a team of scientists at the SETI Institute, which has been scanning the skies for decades, listening for signals that may be indicative of extraterrestrial life. The Whale SETI team seeks to show that animal communication, and particularly, complex animal vocalizations like those of humpback whales, can provide scientists with a model to help detect and decipher a message from an extraterrestrial intelligence. And, while they’ve been trying to communicate with whales for years, this latest reported encounter was the first time the whales talked back. It all might sound far-fetched. But then again, Laurance Doyle, an astrophysicist who founded the Whale SETI team and has been part of the SETI Institute since 1987, is accustomed to being doubted by the mainstream science community. © 2024 NautilusNext Inc.,

Keyword: Animal Communication; Language
Link ID: 29276 - Posted: 04.30.2024

By Christina Caron Antidepressants are among the most prescribed medications in the United States. This is, in part, because the number of people diagnosed with depression and anxiety has been on the rise, and prescriptions jumped sharply among some age groups during the pandemic. Despite the prevalence of these medications, some patients have “significant misconceptions” about how the drugs work, said Dr. Andrew J. Gerber, a psychiatrist and the president and medical director of Silver Hill Hospital in New Canaan, Conn. About 80 percent of antidepressants are prescribed by primary care doctors who have not had extensive training in managing mental illness. Dr. Paul Nestadt, an associate professor of psychiatry at the Johns Hopkins School of Medicine, said patients tell him, “‘You know, Doc, I’ve tried everything.’” But often, he said, “they never got to a good dose, or they were only on it for a week or two.” Here are some answers to frequently asked questions about antidepressants. How do antidepressants work? There are many types of antidepressants, and they all work a bit differently. In general, they initiate a change in the way brain cells — and different regions of the brain — communicate with one another, said Dr. Gerard Sanacora, a professor of psychiatry at the Yale School of Medicine. Clinical trials have shown that antidepressants are generally more effective with moderate, severe and chronic depression than with mild depression. Even then, it’s a modest effect when compared with placebo. © 2024 The New York Times Company

Keyword: Depression
Link ID: 29275 - Posted: 04.30.2024

By Laura Sanders What does it feel like to be a rat? We will never know, but some very unusual mice may now have an inkling. In a series of new experiments, bits of rat brain grew inside the brains of mice. Donor stem cells from rats formed elaborate — and functional — neural structures in mice’s brains, despite being from a completely different species, researchers report in two papers published April 25 in Cell. The findings are “remarkable,” says Afsaneh Gaillard, a neuroscientist at INSERM and the University of Poitiers in France. “The ability to generate specific neuronal cells that can successfully integrate into the brain may provide a solution for treating a variety of brain diseases associated with neuronal loss.” These chimeric mice are helping to reveal just how flexible brain development can be (SN: 3/29/23). And while no one is suggesting that human brains could be grown in another animal, the results may help clarify biological details relevant to interspecies organ transplants, the researchers say. The success of these rat-mouse hybrids depended on timing: The rat and mouse cells had to grow into brains together from a very young stage. Stem cells from rats that had the potential to mature into several different cell types were injected into mouse embryos. From there, these rat cells developed alongside mice cells in the growing brain, though researchers couldn’t control exactly where the rat cells ended up. In one set of experiments, researchers first cleared the way for these rat cells to develop in the young mouse brains. Stem cell biologist Jun Wu and colleagues used a form of the genetic tool CRISPR to inactivate a mouse gene that instructs their brain cells to build a forebrain, a large region involved in learning, remembering and sensing the world. This left the mice without forebrains — normally, a lethal problem. © Society for Science & the Public 2000–2024.

Keyword: Development of the Brain; Neurogenesis
Link ID: 29274 - Posted: 04.26.2024

Sofia Quaglia Noise pollution from traffic stunts growth in baby birds, even while inside the egg, research has found. Unhatched birds and hatchlings that are exposed to noise from city traffic experience long-term negative effects on their health, growth and reproduction, the study found. “Sound has a much stronger and more direct impact on bird development than we knew before,” said Dr Mylene Mariette, a bird communication expert at Deakin University in Australia and a co-author of the study, published in the journal Science. “It would be wise to work more to reduce noise pollution.” A growing body of research has suggested that noise pollution causes stress to birds and makes communication harder for them. But whether birds are already distressed at a young age because they are affected by noise, or by how noise disrupts their environment and parental care, was still unclear. Mariette’s team routinely exposed zebra finch eggs for five days to either silence, soothing playbacks of zebra finch songs, or recordings of city traffic noises such as revving motors and cars driving past. They did the same with newborn chicks for about four hours a night for up to 13 nights, without exposing the birds’ parents to the sounds. They noticed that the bird eggs were almost 20% less likely to hatch if exposed to traffic noise. The chicks that did hatch were more than 10% smaller and almost 15% lighter than the other hatchlings. When the team ran analyses on their red blood cells and their telomeres – a piece of DNA that shortens with stress and age – they were more eroded and shorter than their counterparts’. The effects continued even after the chicks were no longer exposed to noise pollution, and carried over into their reproductive age four years later. The birds disturbed by noise during the early stages of their lives produced fewer than half as many offspring as their counterparts. © 2024 Guardian News & Media Limited

Keyword: Hearing; Development of the Brain
Link ID: 29273 - Posted: 04.26.2024

By Carl Zimmer Earlier this month, millions of Americans looked up at the sky to witness a total eclipse. Now, another cyclical marvel has arrived, this time at our feet. Trillions of noisy, red-eyed insects called cicadas are emerging from the earth after more than a decade of feeding on tree roots. The United States is home to 15 cicada broods, and in most years at least one of them emerges. This spring, Brood XIX, known as the Great Southern Brood, and Brood XIII, or the Northern Illinois Brood, are emerging simultaneously. Cicada watchers have spotted the first insects coming out of the ground, reporting their sightings to apps such as iNaturalist and Cicada Safari. The Great Southern Brood, which emerges across the South and the Midwest every 13 years, has been seen at sites scattered from North Carolina to Georgia. The Northern Illinois Brood, which appears every 17 years in the Midwest, is expected to appear in the next month, as temperatures there warm. How cicadas manage to rise en masse after spending so long underground remains largely a mystery. “There’s surprisingly little information about cicadas that you’d like to know,” said Raymond Goldstein, a physicist at the University of Cambridge. Once a brood climbs out of the ground, the cicadas crawl up trees to mate, and the females lay eggs in tree branches. After hatching, the young insects drop to earth and burrow into the soil. Then, each cicada spends the next 13 or 17 years underground before emerging to mate and repeat the cycle. That means that trillions of insects have to track the passage of time in the soil. It’s possible that they detect annual changes in tree roots. But how can cicadas add up those changes to divine when 13 or 17 years have passed? Scientists cannot say. © 2024 The New York Times Company

Keyword: Biological Rhythms
Link ID: 29272 - Posted: 04.26.2024

By Sara Reardon Researchers have hailed organoids — 3D clusters of cells that mimic aspects of human organs — as a potential way to test drugs and even eliminate some forms of animal experimentation. Now, in two studies published on 24 April in Nature1,2, biologists have developed gut and brain organoids that could improve understanding of colon cancer and help to develop treatments for a rare neurological disorder. “In the last ten years, people spent a lot of time to develop and understand how to make organoids,” says Shuibing Chen, a chemical biologist at Weill Cornell Medical College in New York City. “But this is the time now to think more about how to use” the models. Organoids — particularly those made from human stem cells — sometimes reveal things that animal models can’t, says Sergiu Pașca, a neuroscientist at Stanford University in California and a co-author of one of the studies1. Pașca’s group studies Timothy syndrome: a genetic disorder involving autism, neurological problems and heart conditions that affects only a few dozen people in the world. Timothy syndrome is caused by a single mutation in a gene called CACNA1C, which encodes a channel through which calcium ions enter cells including neurons. Pașca says that there are no good animal models for Timothy syndrome because the underlying mutation doesn’t always cause the same symptoms in rodents. “It became very clear to us we’d need to find a way of testing in vivo,” he says. © 2024 Springer Nature Limited

Keyword: Development of the Brain
Link ID: 29271 - Posted: 04.26.2024

By Shaena Montanari The sympathetic nervous system may have originated in jawless fish—not tens of millions of years later as previously thought, according to a study published today in Nature. Anatomical work dating back to the 19th century suggested that the sympathetic nervous system was present only in jawed vertebrates. Yet the sea lamprey, the new findings reveal, sports clusters of sympathetic neurons along its trunk and expresses several genes involved in the “fight-or-flight” system, the response that kicks into gear when an animal perceives a threat. “Whenever new research causes troves of textbooks to need corrections, that’s always surprising,” says Tyler Square, assistant professor of molecular genetics at the University of Florida, who was not involved in the study. The team behind the new work decided to re-examine conventional wisdom after a postdoctoral researcher in the lab produced microscopy images of lamprey embryos stained for neurons in the animals’ gut. The stain highlighted some “small sort of concentrations of cells” that looked a lot like sympathetic neurons, recalls lead investigator Marianne Bronner, professor of biology at the California Institute of Technology. “I said, ‘Oh, those shouldn’t be there.’ So then we decided to delve deeper into it.” The unexpected neurons express several key genes—specifically ASCL1, PHOX2 and HAND—involved in the sympathoadrenal system, the team discovered using a suite of techniques, including immunohistochemistry, in situ hybridization chain reaction and RNA sequencing. These are “all transcription factors that are known to be important in sympathetic neuron differentiation in mammals,” Bronner says. © 2024 Simons Foundation

Keyword: Stress; Evolution
Link ID: 29270 - Posted: 04.26.2024

By Lilly Tozer How the brain processes visual information — and its perception of time — is heavily influenced by what we’re looking at, a study has found. In the experiment, participants perceived the amount of time they had spent looking at an image differently depending on how large, cluttered or memorable the contents of the picture were. They were also more likely to remember images that they thought they had viewed for longer. The findings, published on 22 April in Nature Human Behaviour1, could offer fresh insights into how people experience and keep track of time. “For over 50 years, we’ve known that objectively longer-presented things on a screen are better remembered,” says study co-author Martin Wiener, a cognitive neuroscientist at George Mason University in Fairfax, Virginia. “This is showing for the first time, a subjectively experienced longer interval is also better remembered.” Research has shown that humans’ perception of time is intrinsically linked to our senses. “Because we do not have a sensory organ dedicated to encoding time, all sensory organs are in fact conveying temporal information” says Virginie van Wassenhove, a cognitive neuroscientist at the University of Paris–Saclay in Essonne, France. Previous studies found that basic features of an image, such as its colours and contrast, can alter people’s perceptions of time spent viewing the image. In the latest study, researchers set out to investigate whether higher-level semantic features, such as memorability, can have the same effect. © 2024 Springer Nature Limited

Keyword: Attention; Vision
Link ID: 29269 - Posted: 04.24.2024

By Bill Wasik and Monica Murphy What makes a desert tortoise happy? Before you answer, we should be more specific: We’re talking about a Sonoran desert tortoise, one of a few species of drab, stocky tortoises native to North America’s most arid landscapes. Adapted to the rocky crevices that striate the hills from western Arizona to northern Mexico, this long-lived reptile impassively plods its range, browsing wildflowers, scrub grasses and cactus paddles during the hours when it’s not sheltering from the brutal heat or bitter cold. Sonoran desert tortoises evolved to thrive in an environment so different from what humans find comfortable that we can rarely hope to encounter one during our necessarily short forays — under brimmed hats and layers of sunblock, carrying liters of water and guided by GPS — into their native habitat. This past November, in a large, carpeted banquet room on the University of Wisconsin’s River Falls campus, hundreds of undergraduate, graduate and veterinary students silently considered the lived experience of a Sonoran desert tortoise. Perhaps nine in 10 of the participants were women, reflecting the current demographics of students drawn to veterinary medicine and other animal-related fields. From 23 universities in the United States and Canada, and one in the Netherlands, they had traveled here to compete in an unusual test of empathy with a wide range of creatures: the Animal Welfare Assessment Contest. That morning in the banquet room, the academics and experts who organize the contest (under the sponsorship of the American Veterinary Medical Association, the nation’s primary professional society for vets) laid out three different fictional scenarios, each one involving a binary choice: Which animals are better off? One scenario involved groups of laying hens in two different facilities, a family farm versus a more corporate affair. Another involved bison being raised for meat, some in a smaller, more managed operation and others ranging more widely with less hands-on human contact. © 2024 The New York Times Company

Keyword: Animal Rights; Emotions
Link ID: 29268 - Posted: 04.24.2024

By Angie Voyles Askham The ability of amphibians to metamorphosize and, in some cases, regenerate limbs and even brain tissue raises puzzling yet fundamental questions about how a nervous system wires itself up. For example, if a frog’s legs don’t exist when its brain begins to develop—those limbs later replace its tadpole tail—how are the neural connections maintained such that, once the legs take shape, a frog can move them? “How many connections are there between the spinal cord and the brain? How do they change over metamorphosis?” asks Lora Sweeney, assistant professor at the Institute of Science and Technology Austria. To find out, Sweeney and her colleagues decided to screen a panel of adeno-associated viruses (AAVs) in two species of frog and a newt. These viruses are commonly used to genetically manipulate brain cells in rodents and monkeys, but they have not been proven useful in amphibian experiments. With the right techniques, most common AAVs can deliver genes to amphibian cells through a process called transduction, according to Sweeney’s unpublished results, though the most effective viruses vary by species. These amphibian-friendly AAVs can be used to trace neuronal connections and track groups of neurons born at the same time, the new work shows. And a subset of these same AAVs can also transduce cells in axolotls, newts’ fuzzy-gilled Mexican cousins, according to another preprint from an independent team. Both preprints were posted on bioRxiv in February. “It’s a big game-changer,” says Helen Willsey, assistant professor of psychiatry at the University of California, San Francisco, who was not involved in either study but works with amphibian models. “It opens up a lot of doors for new experiments.” Other researchers had previously tried to get AAVs to transduce cells in frogs and fish, with little success. © 2024 Simons Foundation

Keyword: Brain imaging; Evolution
Link ID: 29267 - Posted: 04.24.2024

By John Horgan Philosopher Daniel Dennett died a few days ago, on April 19. When he argued that we overrate consciousness, he demonstrated, paradoxically, how conscious he was, and he made his audience more conscious. Dennett’s death feels like the end of an era, the era of ultramaterialist, ultra-Darwinian, swaggering, know-it-all scientism. Who’s left, Richard Dawkins? Dennett wasn’t as smart as he thought he was, I liked to say, because no one is. He lacked the self-doubt gene, but he forced me to doubt myself. He made me rethink what I think, and what more can you ask of a philosopher? I first encountered Dennett’s in-your-face brilliance in 1981 when I read The Mind’s I, a collection of essays he co-edited. And his name popped up at a consciousness shindig I attended earlier this month. To honor Dennett, I’m posting a revision of my 2017 critique of his claim that consciousness is an “illusion.” I’m also coining a phrase, “the Dennett paradox,”which is explained below. Of all the odd notions to emerge from debates over consciousness, the oddest is that it doesn’t exist, at least not in the way we think it does. It is an illusion, like “Santa Claus” or “American democracy.” René Descartes said consciousness is the one undeniable fact of our existence, and I find it hard to disagree. I’m conscious right now, as I type this sentence, and you are presumably conscious as you read it (although I can’t be absolutely sure). The idea that consciousness isn’t real has always struck me as absurd, but smart people espouse it. One of the smartest is philosopher Daniel Dennett, who has been questioning consciousness for decades, notably in his 1991 bestseller Consciousness Explained. © 2024 SCIENTIFIC AMERICAN,

Keyword: Consciousness
Link ID: 29266 - Posted: 04.24.2024

By Diana Kwon Overall, people in U.S. live longer than they did a hundred years ago. The growing number of people reaching old age has meant an increased proportion are at risk of developing dementia or Alzheimer’s disease, illnesses that typically strike later in life. However, researchers have found that, in the U.S. and elsewhere, dementia risk may actually be decreasing, at least in a subset of the population. A new study provides a potential explanation for this trend: Human brains may be getting larger—and thus more resilient to degeneration—over time. Several large population studies in countries including the U.S. and Great Britain have found that, in recent decades, the number of new cases, or incidence, of dementia has declined. Among these is the Framingham Heart Study, which has been collecting data from individuals living in Framingham, Massachusetts since 1948. Now accommodating a third generation of participants, the study includes data from more than 15,000 people. In 2016, Sudha Seshadri, a neurologist at UT Health San Antonio and her colleagues published findings revealing that while the prevalence—the total number of people with dementia—had increased, the incidence had declined since the late 1970s. “That was a piece of hopeful news,” Seshadri says. “It suggested that over 30 years, the average age at which somebody became symptomatic had gone up.” These findings left the team wondering: What was the cause of this reduced dementia risk? While the cardiovascular health of the Framingham residents and their descendants—which can influence the chances of developing dementia—had also improved over the decades, this alone could not fully explain the decline. On top of that, the effect only appeared in people who had obtained a high school diploma, which, according to Seshadri, pointed to the possibility that greater resilience against dementia may result from changes that occur in early life. © 2024 SCIENTIFIC AMERICAN,

Keyword: Development of the Brain; Learning & Memory
Link ID: 29265 - Posted: 04.20.2024

By Dan Falk In 2022, researchers at the Bee Sensory and Behavioral Ecology Lab at Queen Mary University of London observed bumblebees doing something remarkable: The diminutive, fuzzy creatures were engaging in activity that could only be described as play. Given small wooden balls, the bees pushed them around and rotated them. The behavior had no obvious connection to mating or survival, nor was it rewarded by the scientists. It was, apparently, just for fun. The study on playful bees is part of a body of research that a group of prominent scholars of animal minds cited today, buttressing a new declaration that extends scientific support for consciousness to a wider suite of animals than has been formally acknowledged before. For decades, there’s been a broad agreement among scientists that animals similar to us — the great apes, for example — have conscious experience, even if their consciousness differs from our own. In recent years, however, researchers have begun to acknowledge that consciousness may also be widespread among animals that are very different from us, including invertebrates with completely different and far simpler nervous systems. The new declaration, signed by biologists and philosophers, formally embraces that view. It reads, in part: “The empirical evidence indicates at least a realistic possibility of conscious experience in all vertebrates (including all reptiles, amphibians and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans and insects).” Inspired by recent research findings that describe complex cognitive behaviors in these and other animals, the document represents a new consensus and suggests that researchers may have overestimated the degree of neural complexity required for consciousness. © 2024the Simons Foundation.

Keyword: Consciousness; Evolution
Link ID: 29264 - Posted: 04.20.2024

By Gillian Dohrn No one wants to eat when they have an upset stomach. To pinpoint exactly where in the brain this distaste for eating originates, scientists studied nauseated mice. The work, published in Cell Reports on 27 March1, describes a previously uncharacterized cluster of brain cells that fire when a mouse is made to feel nauseous, but don’t fire when the mouse is simply full. This suggests that responses to satiety and nausea are governed by separate brain circuits. “With artificial activation of this neuron, the mouse just doesn’t eat, even if it is super hungry,” says Wenyu Ding at the Max Planck Institute for Biological Intelligence in Martinsried, Germany, who led the study. Ding and colleagues suspected that this group of neurons was involved in processing negative experiences, such as feeling queasy, so they injected the mice with a chemical that induces nausea and then scanned the animals’ brains. This confirmed that the neurons are active when mice feel nauseous. Using a light-based technique called optogenetics, the team artificially activated the neurons of mice that had been deprived of food in the hours before the experiment. When the neurons were ‘off’, the mice ate. When the researchers turned them on, the mice walked away mid-chow. These brain cells could influence how fast you eat — and when you stop Researchers also blocked the activity of these neurons in nauseated mice that were hungry and found that the mice overcame their nausea to eat. © 2024 Springer Nature Limited

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 29263 - Posted: 04.20.2024

By Ingrid Wickelgren Ishmail Abdus-Saboor has been fascinated by the variety of the natural world since he was a boy growing up in Philadelphia. The nature walks he took under the tutelage of his third grade teacher, Mr. Moore, entranced him. “We got to interact and engage with wildlife and see animals in their native environment,” he recalled. Abdus-Saboor also brought a menagerie of creatures — cats, dogs, lizards, snakes and turtles — into his three-story home, and saved up his allowance to buy a magazine that taught him about turtles. When adults asked him what he wanted to be when he grew up, “I said I wanted to become a scientist,” he said. “I always raised eyebrows.” Abdus-Saboor did not stray from that goal. Today, he is an associate professor of biological sciences at the Mortimer B. Zuckerman Mind Brain Behavior Institute at Columbia University, where he studies how the brain determines whether a touch to the skin is painful or pleasurable. “Although this question is fundamental to the human experience, it remains puzzling to explain with satisfying molecular detail,” he said. Because the skin is our largest sensory organ and a major conduit to our environment, it may hold clues for treating conditions from chronic pain to depression. To find those clues, Abdus-Saboor probes the nervous system at every juncture along the skin-to-brain axis. He does not focus on skin alone or home in on only the brain as many others do. “We merge these two worlds,” he said. That approach, he added, requires mastering two sets of techniques, reading two sets of literature and attending two sets of scientific meetings. “It gives us a unique leg up,” he said. It has led to a landmark paper published last year in Cell that laid out the entire neural circuit for pleasurable touch. © 2024 Simons Foundation.

Keyword: Pain & Touch; Emotions
Link ID: 29262 - Posted: 04.20.2024

By Saima S. Iqbal Before becoming a researcher, Aimee Grant worked as a caregiver for six years in Cornwall, England, supporting autistic adults in group homes. But only more than a decade later, after befriending an autistic colleague at a sociology conference, did she realize she was autistic herself. The stereotypical view of autism as a brain impairment more commonly found in men made it difficult for Grant to make sense of her internal world. From an early age, she struggled to pick up on important social cues and found the sounds and scents in her environment distractingly painful. But like many children in her generation, she says, she grew accustomed to either dismissing or disguising her discomfort. It was by listening to some of the stories of her female peers that Grant saw that the label could fit. Receiving a diagnosis in 2019 prompted her to “reframe [my] entire life,” she says. She began working with her mind rather than against it. She no longer felt the same pressure to seem as nonautistic as possible with friends and family members, and she began to make use of accommodations at work, such as a light filter for her computer monitor. Today, as a public health researcher at Swansea University in Wales, Grant aims to uncover the lived experience of autistic people. Many scientists and clinicians see autism as a developmental disorder that hinders a person’s ability to understand and communicate with others. Grant believes that their work often obscures the heterogeneity of autism. And because many studies view autism as a disease, they overlook the reality that autistic people can feel more disabled by widespread misunderstanding and a lack of accommodations than by autistic traits themselves. © Society for Science & the Public 2000–2024.

Keyword: Autism
Link ID: 29261 - Posted: 04.20.2024