Most Recent Links
Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.
By Laura Dattaro When John Tuthill was a postdoctoral researcher at Harvard Medical School, he worked just down the hall from Wei-Chung Allen Lee, who was developing new technology to image and map cell connections in the central nervous system. Lee wanted to use his technique in the fruit fly Drosophila, but he knew that other groups were already making such images of the fly brain. So Tuthill, who was studying touch stimuli in Drosophila, suggested Lee pivot to map the fly’s ventral nerve cord (VNC) instead. A decade later, Tuthill, Lee and colleagues have published a map of the connections among motor neurons in a female fly’s VNC, which is analogous to the spinal cord in mammals. The diagram, published on 26 June in Nature, details roughly 45 million synapses that connect nearly 15,000 neurons, and is the second such connectome to be released. A different team, at Howard Hughes Medical Institute’s Janelia Research Campus, published a male fly’s VNC connectome to eLife’s preprint server in June 2023. (The team posted an updated, reviewed preprint on 23 May 2024.) “The connectome is only useful if you can connect it to the muscles,” says Tuthill, associate professor of neuroscience at the University of Washington. “The output of the connectome is the activity of motor neurons.” With connectomes from both a male and a female fly, researchers are starting to look for differences not only between individuals, but between the sexes. An initial comparison of the two connectomes, posted to bioRxiv on 28 June by members of both teams, including Tuthill and Lee, identified circuits that appear to control sex-specific behaviors, including male courtship songs and the female extension of an organ used to deposit eggs. © 2024 Simons Foundation
Keyword: Brain imaging
Link ID: 29407 - Posted: 07.27.2024
By Vivian La Great Basin was burning the midnight oil on a chilly fall evening in 2016 when he made his move. Slinking out of the shadows in Laramie, Wyoming, the raccoon approached what looked like a metal filing cabinet lying on its side. He could smell a mix of dog kibble and sardines within, but 12 latched narrow doors blocked his entry. Making matters worse, a fellow raccoon had beaten him there. So Great Basin jumped on top of the cabinet and began to fiddle with the latches upside down. He quickly opened one of the doors, securing the treats and filling his belly. Humans have long regarded raccoons—renowned for their ability to jimmy their way into locked garbage cans and enter seemingly impassable attics—with a mixture of awe and scorn. But outside of the lab, researchers have little scientific sense of how clever these “trash pandas” really are. A study published today in the Proceedings of the Royal Society B: Biological Sciences may change that. The work was led by Lauren Stanton, a cognitive ecologist at the University of California, Berkeley who has studied raccoons for 10 years. She says she’s drawn by their quirky personalities and quick ability to adapt to environments such as urban areas. “I think it’s fascinating to think about how raccoons perceive the world.” Despite their reputation for cleverness, Stanton says raccoons generally are understudied because they can be “a menace in the lab,” gnawing on cages and biting scientists. Research on wild raccoons is even more scarce. © 2024 American Association for the Advancement of Science.
Keyword: Learning & Memory; Evolution
Link ID: 29406 - Posted: 07.27.2024
By Bianca Nogrady The ability to remember and recognize a musical theme does not seem to be affected by age, unlike many other forms of memory. “You’ll hear anecdotes all the time of how people with severe Alzheimer’s can’t speak, can’t recognize people, but will sing the songs of their childhood or play the piano,” says Sarah Sauvé, a feminist music scientist now at the University of Lincoln in the United Kingdom. Past research has shown that many aspects of memory are affected by ageing, such as recall tasks that require real-time processing, whereas recognition tasks that rely on well-known information and automatic processes are not. The effect of age on the ability to recall music has also been investigated, but Sauvé was interested in exploring this effect in a real-world setting such as a concert. In her study1, published today in PLoS ONE, she tested how well a group of roughly 90 healthy adults, ranging in age from 18 to 86 years, were able to recognize familiar and unfamiliar musical themes at a live concert. Participants were recruited at a performance of the Newfoundland Symphony Orchestra in St John’s, Canada. Another 31 people watched a recording of the concert in a laboratory. The study focused on three pieces of music played at the concert: Eine kleine Nachtmusik by Mozart, which the researchers assumed most participants were familiar with, and two specially commissioned experimental pieces. One of these was tonal and easy to listen to; the other was more atonal and didn’t conform to the typical melodic norms of Western classical music. A short melodic phrase from each of the three pieces was played three times at the beginning of that piece, and participants then logged whenever they recognized that theme in the piece. © 2024 Springer Nature Limited
Keyword: Learning & Memory; Alzheimers
Link ID: 29405 - Posted: 07.27.2024
By Christina Caron The 6-year-old boy sitting across from Douglas Tynan, a child and adolescent clinical psychologist based in Delaware, clearly did not have attention deficit hyperactivity disorder. Dr. Tynan was sure of that. But the boy’s first-grade teacher disagreed. He could be inattentive in class, but at home his behavior wasn’t out of the ordinary for a child his age. A voracious reader, he told Dr. Tynan that he liked to bring his own books to school because the ones in class were too easy. What his teacher had not considered was that the child was most likely academically gifted, as his mother had been as a child, Dr. Tynan said. (Studies have shown that Black children, like the boy in his office, are less likely to be identified for gifted programs.) Further testing revealed that Dr. Tynan was correct. The child wasn’t inattentive in school because of A.D.H.D. It was because he was bored. A.D.H.D. is a neurodevelopmental disorder that begins in childhood and typically involves inattention, disorganization, hyperactivity and impulsivity that cause trouble in two or more settings, like at home and at school. But those symptoms — for children and adults alike — can overlap with a multitude of other traits and disorders. In fact, difficulty concentrating is one of the most common symptoms listed in the American Psychiatric Association’s diagnostic manual, and it’s associated with 17 diagnoses, according to a study published in April. Patients need a careful evaluation to avoid either being misdiagnosed with A.D.H.D. or having a missed A.D.H.D. diagnosis. Here’s a look at some common problems that can mimic A.D.H.D. Mental health conditions like anxiety, depression or oppositional defiant disorder can show up as A.D.H.D.-like symptoms. © 2024 The New York Times Company
Keyword: ADHD; Development of the Brain
Link ID: 29404 - Posted: 07.27.2024
By Cathleen O’Grady Human conversations are rapid-fire affairs, with mere milliseconds passing between one person’s utterance and their partner’s response. This speedy turn taking is universal across cultures—but now it turns out that chimpanzees do it, too. By analyzing thousands of gestures from chimpanzees in five different communities in East Africa, researchers found that the animals take turns while communicating, and do so as quickly as we do. The speedy gestural conversations are also seen across chimp communities, just like in humans, the authors report today in Current Biology. The finding is “very exciting” says Maël Leroux, an evolutionary biologist at the University of Rennes who was not involved with the work. “Language is the hallmark of our species … and a central feature of language is our ability to take turns.” Finding a similar behavior in our closest living relative, he says, suggests we may have inherited this ability from our shared common ancestor. When chimps gesture—such as reaching out an arm in a begging gesture—they are most often making a request, says Gal Badihi, an animal communication researcher at the University of St Andrews. This can include things such as “groom me,” “give me,” or “travel with me.” Most of the time, the chimp’s partner does the requested behavior. But sometimes, the second chimp will respond with its own gestures instead—for instance, one chimp requesting grooming, and the other indicating where they would like to be groomed, essentially saying “groom me first.” To figure out whether these interactions resemble human turn taking, Badihi and colleagues combed through hundreds of hours of footage from a massive database of chimpanzee gestural interactions recorded by multiple researchers across decades of fieldwork in East Africa. The scientists studied the footage, describing the precise movements each chimp made when gesturing, the response of other chimps, the duration of the gestures, and other details. © 2024 American Association for the Advancement of Science.
Keyword: Language; Evolution
Link ID: 29403 - Posted: 07.23.2024
By Gina Kolata People with obesity now have a choice between two powerful drugs to help them lose weight. One is semaglutide, sold by Novo Nordisk as Wegovy for obesity treatment and as Ozempic for diabetes. The second, tirzepatide, is sold by Eli Lilly as Zepbound for obesity and as Mounjaro for diabetes. Many with neither obesity or diabetes take the drugs to get thinner. A recent study suggested that people lost more weight taking Mounjaro than they did taking Ozempic, and it may leave you wondering: Which should I take? And if I’m already taking one of them, should I switch? The answers, obesity medicine experts say, are not so simple. Here are some factors that can help sort out hype from realistic hope. Is one weight loss drug really better than the other? For now, it’s hard to say. All of the information available comes from “highly flawed studies,” said Dr. Diana Thiara, medical director of the weight loss clinic at the University of California, San Francisco. That includes the recent study comparing Mounjaro and Ozempic. Using electronic health records, the researchers reported that those taking Mounjaro lost an average of 15.3 percent of their weight after a year. Those taking Ozempic lost an average of 8.3 percent. While that sounds impressive, Dr. Susan Z. Yanovski, co-director of the Office of Obesity Research at the National Institute of Diabetes and Digestive and Kidney Diseases, said, “I wouldn’t make any decisions on my medical care based solely on a study like this.” There’s an inherent difficulty in using electronic health records, she noted, because it is not known why the patients were taking the drugs — the study was underway before Zepbound was approved for treating obesity. The investigators looked at prescriptions for Ozempic and Mounjaro, which were approved to treat diabetes. Yet many in the study did not have diabetes. © 2024 The New York Times Company
Keyword: Obesity
Link ID: 29402 - Posted: 07.23.2024
Oscar Allan The sluggish start to the day, the struggle to concentrate on everyday tasks and the lethargy that comes with just a few hours sleep, these are the symptoms that will be familiar to anyone who suffers with insomnia. But according to research, not all sleepless nights are the same. Brain scans have revealed evidence for distinct forms of insomnia, each with an associated pattern of neural wiring. And while the clinical distinction may mean little to those whose days are blighted by sleep deprivation, the discovery does raise the prospect of tailored interventions for people with different kinds of insomnia, which could lead to better treatments. Researchers at the Netherlands Institute for Neuroscience in Amsterdam analysed MRI scans from more than 200 insomniacs and dozens of sound sleepers and spotted structural changes that distinguished sleepers from the sleepless and five separate forms of insomnia. “If these subtypes differ in their biological mechanism, then patients in each subtype might benefit from different focused treatments,” said Tom Bresser, a neuroscientist and first author on the study. Insomnia is broadly defined as poor sleep, generally due to difficulties falling or staying asleep, which negatively affects daytime functioning. About a third of adults in western countries have sleep problems at least once a week, with up to 10% qualifying for a formal insomnia diagnosis. Chronic insomnia is diagnosed if someone suffers sleep problems on at least three nights a week for three months or more. The condition is nearly twice as common in women than men. © 2024 Guardian News & Media Limited
Keyword: Sleep
Link ID: 29401 - Posted: 07.23.2024
By Dana G. Smith Getting too little sleep later in life is associated with an increased risk for Alzheimer’s disease. But paradoxically, so is getting too much sleep. While scientists are confident that a connection between sleep and dementia exists, the nature of that connection is complicated. It could be that poor sleep triggers changes in the brain that cause dementia. Or people’s sleep might be disrupted because of an underlying health issue that also affects brain health. And changes in sleep patterns can be an early sign of dementia itself. Here’s how experts think about these various connections and how to gauge your risk based on your own sleep habits. Too Little Sleep Sleep acts like a nightly shower for the brain, washing away the cellular waste that accumulates during the day. During this process, the fluid that surrounds brain cells flushes out molecular garbage and transfers it into the bloodstream, where it’s then filtered by the liver and kidneys and expelled from the body. That trash includes the protein amyloid, which is thought to play a key role in Alzheimer’s disease. Everyone’s brain produces amyloid during the day, but problems can arise when the protein accumulates into sticky clumps, called plaques. The longer someone is awake, the more amyloid builds up and the less time the brain has to remove it. Scientists don’t know whether regularly getting too little sleep — typically considered six hours or less a night — is enough to trigger the accumulation of amyloid on its own. But research has found that among adults aged 65 to 85 who already have plaques in their brains, the less sleep they got, the more amyloid was present and the worse their cognition. “Is lack of sleep sufficient to cause dementia? Probably not by itself alone,” said Dr. Sudha Seshadri, the founding director of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at the University of Texas Health Science Center at San Antonio. “But it seems to definitely be a risk factor for increasing the risk of dementia, and perhaps also the speed of decline.” © 2024 The New York Times Company
Keyword: Sleep; Alzheimers
Link ID: 29400 - Posted: 07.23.2024
By Brandon Keim 1 How We Think About Animals Has a Long, Complicated History Back when I first started writing about scientific research on animal minds, I had internalized a straightforward historical narrative: The western intellectual tradition held animals to be unintelligent, but thanks to recent advances in the science, we were learning otherwise. The actual history is so much more complicated. The denial of animal intelligence does have deep roots, of course. You can trace a direct line from Aristotle, who considered animals capable of feeling only pain and hunger, to medieval Christian theologians fixated on their supposed lack of rationality, to Enlightenment intellectuals who likened the cries of beaten dogs to the squeaking of springs. But along the way, a great many thinkers, from early Greek philosopher Plutarch on through to Voltaire, pushed back. They saw animals as intelligent and therefore deserving of ethical regard, too. Those have always been the stakes of this debate: If animals are mindless then we owe them nothing. Through that lens it’s no surprise that societies founded on exploitation—of other human beings, of animals, of the whole natural world—would yield knowledge systems that formally regarded animals as dumb. The Plutarchs and Voltaires of the world were cast to the side. The scientific pendulum did swing briefly in the other direction, thanks in no small part to the popularity of Charles Darwin. He saw humans as related to other animals not only in body but in mind, and recognized rich forms of consciousness even in earthworms. But the backlash to that way of thinking was fierce, culminating in a principle articulated in the 1890s and later enshrined as Morgan’s Canon: An animal’s behavior should not be interpreted as evidence of a higher psychological faculty until all other explanations could be ruled out. Stupidity by default. © 2024 NautilusNext Inc.,
Keyword: Evolution; Attention
Link ID: 29399 - Posted: 07.23.2024
By Andrew Jacobs July 17, 2024 If you had to come up with a groovy visualization of the human brain on psychedelic drugs, it might look something like this. The image, as it happens, comes from dozens of brain scans produced by researchers at Washington University School of Medicine in St. Louis who gave psilocybin, the compound in “magic mushrooms,” to participants in a study before sending them into a functional M.R.I. scanner. The kaleidoscopic whirl of colors they recorded is essentially a heat map of brain changes, with the red, orange and yellow hues reflecting a significant departure from normal activity patterns. The blues and greens reflect normal brain activity that occurs in the so-called functional networks, the neural communication pathways that connect different regions of the brain. The scans, published Wednesday in the journal Nature, offer a rare glimpse into the wild neural storm associated with mind-altering drugs. Researchers say they could provide a potential road map for understanding how psychedelic compounds like psilocybin, LSD and MDMA can lead to lasting relief from depression, anxiety and other mental health disorders. “Psilocybin, in contrast to any other drug we’ve tested, has this massive effect on the whole brain that was pretty unexpected,” said Dr. Nico Dosenbach, a professor of neurology at Washington University and a senior author of the study. “It was quite shocking when we saw the effect size.” The study included seven healthy adults who were given either a single dose of psilocybin or a placebo in the form of methylphenidate, the generic version of the amphetamine Ritalin. Each participant underwent a total of 18 brain scans, taken before, during and after the initial dosing. © 2024 The New York Times Company
Keyword: Drug Abuse; Depression
Link ID: 29398 - Posted: 07.18.2024
By Jack Goulder Late last summer, in the waiting room of a children’s mental health clinic, I found Daniel, a softly spoken 16-year-old boy, flanked by his parents. He had been referred to the clinic for an assessment for attention deficit hyperactivity disorder (ADHD). As we took our seats on the plastic sofas in the consulting room, I asked him to tell me about the difficulties he was having. Tentatively, his gaze not leaving the floor, he started talking about school, about how he was finding it impossible to focus and would daydream for hours at a time. His exam results were beginning to show it too, his parents explained, and ADHD seemed to run in the family. They wanted to know more about any medication that could help. I had just begun a six-month placement working as a junior doctor in the clinic’s ADHD team. Doctors often take a temporary post before they formally apply to train in a speciality. Since medical school I had always imagined I would become a psychiatrist, but I wanted to be sure I was making the right choice. Armed with a textbook and the memory of some distant lectures, I began my assessment, running through the questions listed in the diagnostic manual. Are you easily distracted? Do you often lose things? Do people say you talk excessively? He answered yes to many of them. Are you accident-prone? He and his parents exchanged a knowing laugh. With Daniel exhibiting so many of the symptoms, I told them, this sounded like ADHD. I felt a sense of relief fill the room. Later that afternoon, I took Daniel’s case to a meeting where the day’s new referrals were discussed. Half a dozen senior doctors, nurses, psychologists and psychotherapists sat around the table and listened as each case was presented, trying to piece together the story being told and decide what to do next. When it was my turn, I launched into my findings, laying out what Daniel had told me and what I had gleaned from his parents about his childhood. © 2024 Guardian News & Media Limited
By Elissa Welle One question long plagued memory researcher André Fenton: How can memories last for years when a protein essential to maintaining them, called memory protein kinase Mzeta (PKMzeta), lasts for just days? The answer, Fenton now says, may lie in PKMzeta’s interaction with another protein, called postsynaptic kidney and brain expressed adaptor protein (KIBRA). Complexes of the two molecules maintain memories in mice for at least one month, according to a new study co-led by Fenton, professor of neural science at New York University. The bond between the two proteins “protects each of them,” Fenton says, from normal degradation in the cell. KIBRA preferentially gloms onto potentiated synapses, the study shows. And it may help PKMzeta stick there, too, where the kinase acts as a “molecular switch” to help memories persist, Fenton says. “As Theseus’ Ship was sustained for generations by continually replacing worn planks with new timbers, long-term memory can be maintained by continual exchange of potentiating molecules at activated synapses,” Fenton and his colleagues write in their paper, which was published last month in Science Advances. Before this study, the PKMzeta mystery had two “missing puzzle pieces,” says Justin O’Hare, assistant professor of pharmacology at the University of Colorado Denver, who was not involved in the study. One was how PKMzeta identifies potentiated synapses, part of the cellular mechanism underlying memory formation. The second was how memories persist despite the short lifetime of each PKMzeta molecule. This study “essentially proposes KIBRA as a solution to both of those—and the experiments themselves are pretty convincing and thorough. They do everything multiple ways.” PKMzeta has been widely studied, but its role in memory has been shrouded in controversy for more than a decade, Fenton says. Although early work suggested that PKMzeta is necessary for memory formation, later studies found that they still form in mice missing the gene for PKMzeta. © 2024 Simons Foundation
Keyword: Learning & Memory
Link ID: 29396 - Posted: 07.18.2024
By Ellen Barry In recent decades, mental health providers began screening for “adverse childhood experiences” — generally defined as abuse, neglect, violence, family dissolution and poverty — as risk factors for later disorders. But what if other things are just as damaging? Researchers who conducted a large study of adults in Denmark, published on Wednesday in the journal JAMA Psychiatry, found something they had not expected: Adults who moved frequently in childhood have significantly more risk of suffering from depression than their counterparts who stayed put in a community. In fact, the risk of moving frequently in childhood was significantly greater than the risk of living in a poor neighborhood, said Clive Sabel, a professor at the University of Plymouth and the paper’s lead author. “Even if you came from the most income-deprived communities, not moving — being a ‘stayer’ — was protective for your health,” said Dr. Sabel, a geographer who studies the effect of environment on disease. “I’ll flip it around by saying, even if you come from a rich neighborhood, but you moved more than once, that your chances of depression were higher than if you hadn’t moved and come from the poorest quantile neighborhoods,” he added. The study, a collaboration by Aarhus University, the University of Manchester and the University of Plymouth, included all Danes born between 1982 and 2003, more than a million people. Of those, 35,098, or around 2.3 percent, received diagnoses of depression from a psychiatric hospital. Are you concerned for your teen? If you worry that your teen might be experiencing depression or suicidal thoughts, there are a few things you can do to help. Dr. Christine Moutier, the chief medical officer of the American Foundation for Suicide © 2024 The New York Times Company
Keyword: Depression; Stress
Link ID: 29395 - Posted: 07.18.2024
By Freda Kreier Dogs’ ability to feel your pain could be innate. It is the result of centuries of co-evolution with humans, suggests a community-science study that compared the responses of dogs and pet pigs to the sound of humans crying and humming. The results were published on 2 July in Animal Behaviour1. Humans pay attention to how the animals in their lives are feeling, and it seems that this attentiveness is reciprocal. Researchers have found that horses will stop and listen longer to human growls than to laughter2. Pigs respond more strongly to sounds made by people than wild boars do3. But studies testing whether the animals are just reacting to weird human sounds, or are capable of true emotional contagion — the ability to interpret and reflect people’s emotional states — are thin on the ground. Most animals can accurately echo the feelings of only other members of their species. But studies have shown that dogs (Canis familiaris) can mirror the emotions of the people around them4,5. One question is whether this emotional contagion is rooted in ‘universal vocal signals of emotion ’ that can be understood by all domesticated animals, or is specific to companion animals such as dogs. To test this, researchers compared the stress response of dogs and pet pigs (Sus scrofa domesticus) to human sounds. Pet sounds Like dogs, pet pigs are social animals that are from a young age raised around people. But unlike dogs, pigs have been kept as livestock for most of their history with humans. So, if emotional contagion can be learnt through just proximity to people, pet pigs should respond in similar ways to dogs. The team recruited dog or pig owners around the world to film themselves in a room with their pets while playing recorded sounds of crying or humming. Researchers then tallied the number of stress behaviours — such as whining and yawning for dogs, and rapid ear flicks for pigs — exhibited during the experiment. © 2024 Springer Nature Limited
Keyword: Emotions; Evolution
Link ID: 29394 - Posted: 07.18.2024
By Phie Jacobs Is there really such a thing as a “male” or “female” brain? Sex certainly seems to affect a person’s risk of developing various psychiatric and other brain-related conditions—but scientists aren’t entirely sure why. Attention-deficit/hyperactivity disorder for example, is more commonly diagnosed in individuals who were assigned male at birth (AMAB), whereas those assigned female at birth (AFAB) are more likely to exhibit symptoms of anxiety. It’s unclear, however, whether these differences are actually driven by sex, or have more to do with how people are perceived and treated based on their sex or gender. Now, new research suggests sex and gender are associated with distinct brain networks. Published today in Science Advances, the findings draw on brain imaging data from nearly 5000 children to reveal that gender and sex aren’t just distinct from one another in society—they also play unique roles in biology. In science, the term “biological sex” encompasses a variety of genetic, hormonal, and anatomical characteristics. People are typically assigned “male” or “female” as their sex at birth, although the medical establishment in recent years has begun to acknowledge that sex doesn’t always fall neatly into binary categories. Indeed, about 0.05% of children born in the United States are assigned intersex at birth. Gender, by contrast, has more to do with a person’s attitudes, feelings, and behavior—and may not always align with the sex they were assigned at birth. These nuances often go unrecognized in neuroscience, says Sheila Shanmugan, a reproductive psychiatrist at the University of Pennsylvania who wasn’t involved in the new study. Sex and gender-based differences in the brain “have historically been understudied,” she explains, “and terms describing each are often conflated.” © 2024 American Association for the Advancement of Science.
Keyword: Sexual Behavior; Brain imaging
Link ID: 29393 - Posted: 07.13.2024
By Erin Garcia de Jesús In spring 2022, a handful of red foxes in Wisconsin were behaving oddly. Veterinary pathologist Betsy Elsmo learned that a local wildlife rehabilitation center was caring for foxes with neurological symptoms like seizures, tremors, uncoordinated movements and lethargy. But tests for common pathogens like canine distemper virus and rabies that typically cause the symptoms came back negative. Then a red fox kit tested positive for influenza A. This group of viruses includes seasonal flus that cause respiratory disease in people and many other strains that commonly circulate among animals such as waterfowl and other birds. “I was surprised,” says Elsmo, of the University of Wisconsin–Madison. “And to be honest, at first I kind of wrote it off.” That is, until a veterinary technician at the rehab center sent Elsmo a study describing cases of avian influenza in red foxes in the Netherlands. Examinations of the Wisconsin kit’s tissues under the microscope revealed lesions in the brain, lung and heart that matched what had been seen in the Netherlands animals. “And I thought, I think it is [bird flu],” she recalls. Additional testing confirmed the diagnosis in the kit and the other foxes, Elsmo and colleagues reported in the December 2023 Emerging Infectious Diseases. The animals had contracted a lethal strain of H5N1 avian influenza that emerged in late 2020 in Europe and has since spread around the world. At the time infections were discovered in the Wisconsin red foxes, bird flu was expanding its incursion into North America. Since H5N1 arrived on North American shores in December 2021, it has infected animals as wide-ranging as polar bears, skunks, sea lions, bottlenosed dolphins and cows (SN: 7/8/24). And one unwelcome revelation of the ongoing outbreak is the virus’s propensity to invade the brains of myriad mammals. © Society for Science & the Public 2000–2024.
Keyword: Stress
Link ID: 29392 - Posted: 07.13.2024
By Lara Lewington, It's long been known that our lifestyles can help to keep us healthier for longer. Now scientists are asking whether new technology can also help slow down the ageing process of our brains by keeping track of what happens to them as we get older. One sunny morning, 76-year-old Dutch-born Marijke and her husband Tom welcomed me in for breakfast at their home in Loma Linda, an hour east of Los Angeles. Oatmeal, chai seeds, berries, but no processed sugary cereal or coffee were served - a breakfast as pure as Loma Linda’s mission. Loma Linda has been identified as one of the world’s so-called Blue Zones, places where people have lengthier-than-average lifespans. In this case, it is the city’s Seventh-Day Adventist Church community who are living longer. They generally don’t drink alcohol or caffeine, stick to a vegetarian or even vegan diet and consider it a duty of their religion to look after their bodies as best they can. This is their “health message”, as they call it, and it has put them on the map - the city has been the subject of decades of research into why its residents live better for longer. Dr Gary Fraser from the University of Loma Linda told me members of the Seventh-Day Adventist community there can expect not only a longer lifespan, but an increased “healthspan” - that is, time spent in good health - of four to five years extra for women and seven years extra for men. Marijke and Tom had moved to the city later in life, but both were now firmly embedded in the community. Copyright 2024 BBC.
Keyword: Development of the Brain; Learning & Memory
Link ID: 29391 - Posted: 07.13.2024
By Mitch Leslie Millions of people have taken glucagon-like peptide-1 (GLP-1) agonist drugs such as Ozempic to lose weight, despite the fact that the drugs can cause severe nausea and vomiting. But a new mouse study shows distinct groups of neurons in the brain diminish appetite and trigger nausea, a finding that could lead to less stomach-turning treatments that activate one set of cells and not the other. “It’s a very solid paper,” says neuroscientist Chuchu Zhang of the University of California, Los Angeles, who wasn’t connected to the study. “It shows us something new” about the activity of GLP-1 agonists. Scientists haven’t pinned down exactly how GLP-1 agonist drugs work, and previous studies have produced conflicting results on where they exert their effects. Some research suggests the drugs curb appetite by targeting the hypothalamus, a control center for physiological functions such as thirst and hunger that is located in the center of the brain. Other findings point to the rear portion of the brain, known as the hindbrain, and still others implicate the vagus nerve, which carries messages to and from organs such as the stomach and heart. All of these locations contain cells bearing GLP-1 receptors, to which the drugs bind. Another key question is whether the drugs cause weight loss primarily because people feel full or because they feel nauseated—a side effect suffered by more than half of individuals who take the drugs. “Do we need the nausea and aversion [to food] to see the appetite suppression and weight loss?” asks neuroscientist Amber Alhadeff of the Monell Chemical Senses Center. To answer that question, she and her colleagues first tried to pinpoint where GLP-1 agonists act. Using a genetically modified virus containing genes for either of two cell-killing molecules, they selectively eliminated cells bearing GLP-1 receptors in the hypothalamus, the hindbrain, or the vagus nerve. Only destroying the hindbrain cells prevented weight loss when mice received a GLP-1 agonist, suggesting this region curtails appetite. In a follow-up experiment, the researchers stimulated cells in the hindbrain and found that even slender mice lost weight. © 2024 American Association for the Advancement of Science.
Keyword: Obesity
Link ID: 29390 - Posted: 07.11.2024
Anna Bawden The idea that night owls who don’t go to bed until the early hours struggle to get anything done during the day may have to be revised. It turns out that staying up late could be good for our brain power as research suggests that people who identify as night owls could be sharper than those who go to bed early. Researchers led by academics at Imperial College London studied data from the UK Biobank study on more than 26,000 people who had completed intelligence, reasoning, reaction time and memory tests. They then examined how participants’ sleep duration, quality, and chronotype (which determines what time of day we feel most alert and productive) affected brain performance. They found that those who stay up late and those classed as “intermediate” had “superior cognitive function”, while morning larks had the lowest scores. Going to bed late is strongly associated with creative types. Artists, authors and musicians known to be night owls include Henri de Toulouse-Lautrec, James Joyce, Kanye West and Lady Gaga. But while politicians such as Margaret Thatcher, Winston Churchill and Barack Obama famously seemed to thrive on little sleep, the study found that sleep duration is important for brain function, with those getting between seven and nine hours of shut-eye each night performing best in cognitive tests. © 2024 Guardian News & Media Limited
Keyword: Biological Rhythms; Learning & Memory
Link ID: 29389 - Posted: 07.11.2024
By Miryam Naddaf About one-third of people who suffer from migraines experience a phenomenon known as aura before the headache.Credit: Tunatura/Getty For one billion people worldwide, the symptoms can be debilitating: throbbing head pain, nausea, blurred vision and fatigue that can last for days. But how brain activity triggers these severest of headaches — migraines — has long puzzled scientists. A study1 in mice, published in Science on 4 July, now offers clues about the neurological events that spark migraines. It suggests that a brief brain ‘blackout’ — when neuronal activity shuts down — temporarily changes the content of the cerebrospinal fluid, the clear liquid that surrounds the brain and spinal cord. This altered fluid, researchers suggest, travels through a previously unknown gap in anatomy to nerves in the skull where it activates pain and inflammatory receptors, causing headaches. “This work is a shift in how we think the headaches originate,” says Gregory Dussor, a neuroscientist at the University of Texas at Dallas in Richardson. “A headache might just be a general warning sign for lots of things happening inside the brain that aren’t normal.” “Migraine is actually protective in that way. The pain is protective because it’s telling the person to rest and recover and sleep,” says study co-author Maiken Nedergaard, a neuroscientist at the University of Copenhagen. The brain itself has no pain receptors; the sensation of headaches comes from areas outside the brain that are in the peripheral nervous system. But how the brain, which is not directly linked to the peripheral nervous system, triggers nerves to cause headaches is poorly understood, making them difficult to treat. © 2024 Springer Nature Limited
Keyword: Pain & Touch
Link ID: 29388 - Posted: 07.11.2024