Chapter 13. Memory and Learning
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By Sara Reardon Elephants love showering to cool off, and most do so by sucking water into their trunks and spitting it over their bodies. But an elderly pachyderm named Mary has perfected the technique by using a hose as a showerhead, much in the way humans do. The behavior is a remarkable example of sophisticated tool use in the animal kingdom. But the story doesn’t end there. Mary’s long, luxurious baths have drawn so much attention that an envious elephant at the Berlin Zoo has figured out how to shut the water off on her supersoaking rival—a type of sabotage rarely seen among animals. Both behaviors, reported today in Current Biology, further cement elephants as complex thinkers, says Lucy Bates, a behavioral ecologist at the University of Portsmouth not involved in the study. The work, she says, “suggests problem solving or even ‘insight.’” Many elephants enjoy playing with hoses, probably because they remind them of trunks, says Michael Brecht, a computational neuroscientist at Humboldt University of Berlin. But Mary takes the activity to another level. Using her trunk, the 54-year-old Asian elephant (Elephas maximus)—a senior citizen, given the average captive life span of her species of 48 years—holds a hose over her head and waves it back and forth. She also changes her grip on the hose to spray different parts of her body and swings it like a lasso to throw water over her back. Brecht’s graduate student, Lena Kaufmann, noticed Mary’s hose use while studying other types of behavior in the zoo’s elephants; the zookeepers told her Mary did this frequently. So Kaufman and her colleagues started to record the showering on video over the course of a year, testing how Mary reacted to changes in the setup.
Keyword: Learning & Memory; Evolution
Link ID: 29547 - Posted: 11.09.2024
By Heidi Ledford To unlock the secrets of human ageing, researchers might do better to look to the pet napping on their couch than to a laboratory mouse. As cats age, their brains show signs of atrophy and cognitive decline that more closely resemble the deterioration seen in ageing humans than do the changes in the brains of ageing mice, according to findings presented last month at the Lake Conference on Comparative and Evolutionary Neurobiology near Seattle, Washington. The results are part of a large project, called Translating Time, that compares brain development across more than 150 mammal species, and is now expanding to include data on aging. The hope is that the data will aid researchers trying to crack the causes of age-related diseases, particularly conditions that affect the brain, such as Alzheimer’s disease. “To address challenges in human medicine, we need to draw from a wide range of model systems,” says Christine Charvet, a comparative neuroscientist at Auburn University College of Veterinary Medicine in Alabama, who presented the work. “Cats, lemurs, mice are all useful. We shouldn’t focus all our efforts on one.” The Translating Time project started in the 1990s as a tool for developmental biologists1. Project scientists compiled data on how long it takes for the brain to reach a range of developmental milestones in a variety of mammals and used these data to graph the relative development of two species over time. This can help researchers to link observations of animal development to the corresponding human age. Over the years, however, as Charvet presented these data at conferences, researchers kept asking her to extend the database to include not only early development, but also how the brain changes as animals age. © 2024 Springer Nature Limited
Keyword: Development of the Brain
Link ID: 29545 - Posted: 11.06.2024
By Thomas Fuller Over and over, the crows attacked Lisa Joyce as she ran screaming down a Vancouver street. They dive bombed, landing on her head and taking off again eight times by Ms. Joyce’s count. With hundreds of people gathered outdoors to watch fireworks that July evening, Ms. Joyce wondered why she had been singled out. “I’m not a fraidy-cat, I’m not generally nervous of wildlife,” said Ms. Joyce, whose crow encounters grew so frequent this past summer that she changed her commute to work to avoid the birds. “But it was so relentless,” she said, “and quite terrifying.” Ms. Joyce is far from alone in fearing the wrath of the crow. CrowTrax, a website started eight years ago by Jim O’Leary, a Vancouver resident, has since received more than 8,000 reports of crow attacks in the leafy city, where crows are relatively abundant. And such encounters stretch well beyond the Pacific Northwest. A Los Angeles resident, Neil Dave, described crows attacking his house, slamming their beaks against his glass door to the point where he was afraid it would shatter. Jim Ru, an artist in Brunswick, Maine, said crows destroyed the wiper blades of dozens of cars in the parking lot of his senior living apartment complex. Nothing seemed to dissuade them. Renowned for their intelligence, crows can mimic human speech, use tools and gather for what seem to be funeral rites when a member of their murder, as groups of crows are known, dies or is killed. They can identify and remember faces, even among large crowds. They also tenaciously hold grudges. When a murder of crows singles out a person as dangerous, its wrath can be alarming, and can be passed along beyond an individual crow’s life span of up to a dozen or so years, creating multigenerational grudges. © 2024 The New York Times Company
Keyword: Intelligence; Learning & Memory
Link ID: 29534 - Posted: 10.30.2024
By RJ Mackenzie Microglia were once thought to have one job—as the brain’s resident garbage collectors. If neurons became damaged or diseased, microglia would spring into action, engulfing dead or infected cells and pumping up the local immune response. Between clean-up operations, scientists believed, they rested in a deep sleep. In 2005, though, researchers got their first direct look at what microglia were doing in the brain, and they promptly tore up this cellular CV. The grainy live-cell imaging footage, published in Science, showed that the supposedly “resting” microglia were actually marauding around in the neocortex of adult mice, firing out processes and furtively feeling out the surrounding parenchyma. “This, for me, was a game changer,” says Rosa Paolicelli, associate professor of biomedical sciences at the University of Lausanne, who was about to embark on a Ph.D. at the time. “People started to think about the physiological role of microglia. What do they do in the intact, healthy brain?” The work kick-started two decades of research that has changed how the field classifies microglia, and led to new tools to help scientists define and scrutinize the cells’ functions in detail. Many studies have focused on “critical windows”—at the beginning and end of an animal’s life, Paolicelli says. During these time frames, microglia take on many side jobs: as sculptors of the developing brain, cultivators of new neural connections and fighters of neurodegeneration, for example. Along with this rise in profile from garbage collector to cellular polymath has come controversy. “There are some players that are trying to bring forward some ideas that are a bit too simplistic or restrictive. And I feel it’s very dangerous not to stay open-minded regarding the implications of the findings, not to stay open-minded regarding the limitations of all these models,” says Marie-Ève Tremblay, professor of medical sciences at the University of Victoria, who studies microglial function in health and disease. © 2024 Simons Foundation
Keyword: Glia; Learning & Memory
Link ID: 29533 - Posted: 10.30.2024
Emily Anthes In the summer of 2018, off the coast of British Columbia, an orca named Tahlequah gave birth. When the calf died after just half an hour, Tahlequah refused to let go. For more than two weeks, she carried her calf’s body around, often balancing it on her nose as she swam. The story went viral, which came as no surprise to Susana Monsó, a philosopher of animal minds at the National Distance Education University in Madrid. Despite the vast chasm that seems to separate humans and killer whales, this orca mother was behaving in a way that was profoundly relatable. “This idea of a mother clinging on to the corpse of her baby for 17 days seems like something we can understand, something we can relate to, for those of us who have experienced loss,” Dr. Monsó said. Of course, projecting our own human experiences onto other species can be a tricky business, and scientists often warn about the mistakes we can make when we engage in this sort of anthropomorphism. But we can also be misled by our tendency to assume that many cognitive and emotional traits are unique to humans, Dr. Monsó said. And in her new book, “Playing Possum,” she argues that a variety of animal species have at least a rudimentary concept of death. Dr. Monsó spoke with The New York Times about her work. This conversation has been condensed and edited for clarity. How did you get interested in this aspect of animal minds? I’ve always been interested in those capacities that are understood to be uniquely human, such as morality or rationality. Death was a natural topic to pick up. There had been a growing number of reports of animals reacting in different ways to corpses. This seemed to be the birth of a new discipline, which is called comparative thanatology: the study of animals’ relationship with death. © 2024 The New York Times Company
Keyword: Intelligence; Animal Communication
Link ID: 29530 - Posted: 10.30.2024
By Jennifer Couzin-Frankel Two esteemed hospitals in the midwestern United States are a 5-hour drive apart, but when it comes to how they’re prescribing new drugs for Alzheimer’s disease, they might as well be on different planets. “I’ve been worrying about these therapies for a long time,” says Alberto Espay, a neurologist at the University of Cincinnati Medical Center, where, to his knowledge, not a single patient has gotten the monoclonal antibody lecanemab or its more recently approved cousin donanemab. Both therapies clear the brain of the protein beta amyloid, which is widely thought to fuel the disease’s symptoms. In June, Espay wrote to his Alzheimer’s patients urging them to steer clear. “The risks are high,” his letter said, citing brain swelling and bleeding. “True benefits are minuscule.” But travel a few states west, to Washington University in St. Louis (WUSTL), and the vibe is completely different. “Any patient I see with mild Alzheimer’s disease, I’m at least asking myself, ‘Should we recommend this?’” says Joy Snider, a neurologist at the university, where 230 people have received lecanemab. (Donanemab isn’t widely available yet.) “We don’t want to overplay these drugs,” Snider says. “It’s a small effect, but it’s compelling.” The contrasting views underscore deep divisions and uncertainty. The treatments are the first that have been shown to change the course of a shattering and ultimately deadly disease. But their effectiveness is under debate and they can cause sometimes severe brain swelling and bleeding. Clinicians at centers offering the drugs meet regularly to discuss patient side effects, consider whether people with other health conditions can safely get the treatments, and experiment with lower doses or extra monitoring for higher risk patients. As Alzheimer’s experts converge in Madrid this week for the Clinical Trials on Alzheimer’s Disease (CTAD) conference, the antibodies’ real-world rollout is causing a stir.
Keyword: Alzheimers
Link ID: 29529 - Posted: 10.30.2024
By Walt Bogdanich and Carson Kessler By 2021, nearly 2,000 volunteers had answered the call to test an experimental Alzheimer’s drug known as BAN2401. For the drugmaker Eisai, the trial was a shot at a windfall — potentially billions of dollars — for defanging a disease that had confounded researchers for more than a century. To assess the drug’s effectiveness and safety, Eisai sought to include people whose genetic profiles made them especially prone to develop Alzheimer’s. But these same people were also more vulnerable to brain bleeding or swelling if they received the drug. To identify these high-risk volunteers, Eisai told everyone that they would be given a genetic test. But the results, the company added, would remain secret. In all, 274 volunteers joined the trial without Eisai telling them they were at an especially high risk for brain injuries, documents obtained by The New York Times show. One of them was Genevieve Lane, a 79-year-old resident of the Villages in Florida who died in September 2022 after three doses of the drug, her brain riddled with 51 microhemorrhages. An autopsy determined that the drug’s side effects had contributed to her death. Her final hours were spent thrashing so violently that nurses had to tie her down. Another high-risk trial volunteer died, and more than 100 others suffered brain bleeding or swelling. While most of those injuries were mild and asymptomatic, some were serious and life-threatening. “This is a medication that has some significant side effects, and we need to be aware of them,” said Dr. Matthew Schrag, the Vanderbilt University neurologist who assisted with Ms. Lane’s autopsy. This past July, the agency approved a second, similar drug, Kisunla. In a clinical trial, its maker, Eli Lilly, also chose not to tell 289 volunteers that their genetic profiles made them vulnerable to brain injuries, The Times found. Dozens experienced what Lilly classified as “severe” brain bleeding. © 2024 The New York Times Company
Keyword: Alzheimers
Link ID: 29528 - Posted: 10.26.2024
By Katarina Zimmer Adriana Weisleder knows well the benefits of being bilingual: being able to communicate with one’s community, cultivating connection with one’s heritage culture, contributing to the richness and diversity of society, and opening up professional opportunities. Research also suggests some cognitive benefits of bilingualism — such as improved multitasking — although those are more debated, says Weisleder, a developmental psychologist and language scientist of Costa Rican heritage who directs the Child Language Lab at Northwestern University near Chicago. Nearly 22 percent of Americans speak a language other than English at home; many of them are English and Spanish speakers from immigrant families. Yet many children from immigrant families in the United States struggle to develop or maintain proficiency in two languages. Some may lose their heritage language in favor of English; others may fall behind in schools where their progress is evaluated only in English. In a 2020 article in the Annual Review of Developmental Psychology, Weisleder and educational psychologist Meredith Rowe explain how a person’s environment — at a family, community and societal level — affects language acquisition. In the US, for instance, language development in children from immigrant families is influenced by parental misconceptions about raising children bilingually, a general scarcity of support for bilinguals in schools, and anti-immigrant sentiment in society more broadly. In her research, Weisleder leads in-depth studies of bilingual toddlers in different social contexts to better understand how they comprehend and learn multiple languages. She hopes her insights will help to dispel misconceptions and fears around bilingualism and improve support for children learning multiple languages.
Keyword: Language; Development of the Brain
Link ID: 29526 - Posted: 10.26.2024
By Mariana Lenharo Feeding a baby born by caesarean section milk containing a tiny bit of their mother’s poo introduces beneficial microbes to their gut, according to a clinical trial. The approach might one day help to prevent diseases during childhood and later in life. The study — which reported early results last week during IDWeek, a meeting of infectious-disease specialists and epidemiologists in Los Angeles, California — is the first randomized controlled trial to test the ‘poo milkshake’ concept. The preliminary findings confirm researchers’ hypothesis that a small faecal-matter transplant is enough to have a positive effect on the infant’s microbiome, says Otto Helve, director of the public-health department at the Finnish Institute for Health and Welfare in Helsinki, Finland, and the study’s primary investigator. Inherited microbes Some studies show that babies born by c-section, rather than vaginal birth, have a higher risk of asthma, inflammation of the digestive system and other diseases associated with a dysfunctional immune system1. Scientists think that these differences arise because babies born by c-section aren’t exposed to and rapidly colonized by the microbes in their mothers’ vaginas and guts. Studies have even shown that c-section babies are more vulnerable to pathogens in hospitals than are babies born by vaginal birth2. Experiments have attempted to compensate for that by swabbing babies born by c-section with microbes from their mother’s vagina or giving them these microbes orally, a practice known as ‘vaginal seeding’. But this technique has had limited success, because vaginal microbes, scientists have learnt, cannot effectively colonize infants’ guts, says Yan Shao, a microbiome scientist at the Wellcome Sanger Institute in Hinxton, UK. © 2024 Springer Nature Limited
Keyword: Obesity; Development of the Brain
Link ID: 29525 - Posted: 10.26.2024
By Laurie McGinley When Dennis Carr learned he had early Alzheimer’s disease, he immediately thought of his older brother who had died of the illness in 2023. “There was not much anyone could do,” Carr said of his brother’s long decline. “You could see him diminishing.” Today, Carr is trying a new treatment called Leqembi that has been shown to modestly slow the disease for people in the initial stages of Alzheimer’s. Carr knows it is not a cure but he wants to buy time — to be with his family, to work and to give scientists a chance to find more solutions. “I’m hoping this is the first steppingstone to something better,” said Carr, 74, an electrical contractor in Montgomery County, Pa. Carr’s experience offers a glimpse of the shifting landscape of Alzheimer’s, a memory-robbing disease that affects more than 6 million Americans and is the seventh leading cause of death in the United States. Two new treatments, including Carr’s, target toxic clumps of a protein called amyloid beta in the brain and are the first to slow progression of the illness. Blood tests could revolutionize the way the illness is diagnosed. Lifestyle factors such as diet and exercise are showing promise in helping reduce the risk of cognitive decline. “Progress against Alzheimer’s has been unprecedented,” said Howard Fillit, co-founder and chief science officer of the Alzheimer’s Drug Discovery Foundation, a nonprofit that funds the development of drugs and diagnostics. “But we have a long way to go.” The new FDA-approved Alzheimer’s treatment Leqembi is prepared at Abington Neurological Associates in Abington, Pa., on Nov. 7. (Hannah Yoon for The Washington Post) Doctors used to refer to Alzheimer’s as “diagnose and adios” because they had little to offer patients, said Adam Boxer, a neurologist at the University of California at San Francisco. “But now we see light at the end of the tunnel,” he said. “We might be able to have a big impact.”
Keyword: Alzheimers
Link ID: 29510 - Posted: 10.09.2024
By Sara Reardon Researchers have mapped nearly 140,000 neurons in the fruit-fly brain. This version shows the 50 largest. Credit: Tyler Sloan and Amy Sterling for FlyWire, Princeton University (ref. 1) A fruit fly might not be the smartest organism, but scientists can still learn a lot from its brain. Researchers are hoping to do that now that they have a new map — the most complete for any organism so far — of the brain of a single fruit fly (Drosophila melanogaster). The wiring diagram, or ‘connectome’, includes nearly 140,000 neurons and captures more than 54.5 million synapses, which are the connections between nerve cells. “This is a huge deal,” says Clay Reid, a neurobiologist at the Allen Institute for Brain Science in Seattle, Washington, who was not involved in the project but has worked with one of the team members who was. “It’s something that the world has been anxiously waiting for, for a long time.” The map1 is described in a package of nine papers about the data published in Nature today. Its creators are part of a consortium known as FlyWire, co-led by neuroscientists Mala Murthy and Sebastian Seung at Princeton University in New Jersey. Seung and Murthy say that they’ve been developing the FlyWire map for more than four years, using electron microscopy images of slices of the fly’s brain. The researchers and their colleagues stitched the data together to form a full map of the brain with the help of artificial-intelligence (AI) tools. But these tools aren’t perfect, and the wiring diagram needed to be checked for errors. The scientists spent a great deal of time manually proofreading the data — so much time that they invited volunteers to help. In all, the consortium members and the volunteers made more than three million manual edits, according to co-author Gregory Jefferis, a neuroscientist at the University of Cambridge, UK. (He notes that much of this work took place in 2020, when fly researchers were at loose ends and working from home during the COVID-19 pandemic.) © 2024 Springer Nature Limited
Keyword: Brain imaging; Development of the Brain
Link ID: 29508 - Posted: 10.05.2024
By Calli McMurray Daniel Heinz clicked through each folder in the file drive, searching for the answers that had evaded him and his lab mates for years. Heinz, a graduate student in Brenda Bloodgood’s lab at the University of California, San Diego (UCSD), was working on a Ph.D. project, part of which built on the work of a postdoctoral researcher who had left the lab and started his own a few years prior. The former postdoc studied how various types of electrical activity in the mouse hippocampus induce a gene called NPAS4 in different ways. One of his discoveries was that, in some situations, NPAS4 was induced in the far-reaching dendrites of neurons. The postdoc’s work resulted in a paper in Cell, landed him more than $1.4 million in grants and an assistant professor position at the University of Utah, and spawned several follow-up projects in the lab. In other words, it was a slam dunk. But no one else in the lab—including Heinz—could replicate the NPAS4 data. Other lab members always had a technical explanation for why the replication experiments failed, so for years the problem was passed from one trainee to another. Which explains why, on this day in early April 2023, Heinz was poking around the postdoc’s raw data. What he eventually found would lead to a retraction, a resignation and a reckoning, but in the moment, Heinz says, he was not thinking about any of those possibilities. In fact, he had told no one he was doing this. He just wanted to figure out why his experiments weren’t working. To visualize the location of NPAS4, the lab used immunohistochemistry, which tags a gene product with a tailored fluorescent antibody. Any part of the cell that expresses the gene should glow. In his replication attempts, Heinz says he struggled to see any expression, and when he saw indications of it, the signal was faint and noisy. So he wanted to compare his own images to the postdoc’s raw results rather than the processed images included in the 2019 Cell paper. © 2024 Simons Foundation
Keyword: Learning & Memory
Link ID: 29504 - Posted: 10.05.2024
By Miryam Naddaf Neurons in the hippocampus help to pick out patterns in the flood of information pouring through the brain.Credit: Arthur Chien/Science Photo Library The human brain is constantly picking up patterns in everyday experiences — and can do so without conscious thought, finds a study1 of neuronal activity in people who had electrodes implanted in their brain tissue for medical reasons. The study shows that neurons in key brain regions combine information on what occurs and when, allowing the brain to pick out the patterns in events as they unfold over time. That helps the brain to predict coming events, the authors say. The work was published today in Nature. “The brain does a lot of things that we are not consciously aware of,” says Edvard Moser, a neuroscientist at the Norwegian University of Science and Technology in Trondheim. “This is no exception.” To make sense of the world around us, the brain must process an onslaught of information on what happens, where it happens and when it happens. The study’s authors wanted to explore how the brain organizes this information over time — a crucial step in learning and memory. The team studied 17 people who had epilepsy and had electrodes implanted in their brains in preparation for surgical treatment. These electrodes allowed the authors to directly capture the activity of individual neurons in multiple brain regions. Among those regions were the hippocampus and entorhinal cortex, which are involved in memory and navigation. These areas contain time and place cells that act as the body’s internal clock and GPS system, encoding time and locations. “All the external world coming into our brain has to be filtered through that system,” says study co-author Itzhak Fried, a neurosurgeon and neuroscientist at the University of California, Los Angeles. © 2024 Springer Nature Limited
Keyword: Attention; Learning & Memory
Link ID: 29497 - Posted: 09.28.2024
By Amber Dance Billions of cells die in your body every day. Some go out with a bang, others with a whimper. They can die by accident if they’re injured or infected. Alternatively, should they outlive their natural lifespan or start to fail, they can carefully arrange for a desirable demise, with their remains neatly tidied away. Originally, scientists thought those were the only two ways an animal cell could die, by accident or by that neat-and-tidy version. But over the past couple of decades, researchers have racked up many more novel cellular death scenarios, some specific to certain cell types or situations. Understanding this panoply of death modes could help scientists save good cells and kill bad ones, leading to treatments for infections, autoimmune diseases and cancer. “There’s lots and lots of different flavors here,” says Michael Overholtzer, a cell biologist at Memorial Sloan Kettering Cancer Center in New York. He estimates that there are now more than 20 different names to describe cell death varieties. The identification of new forms of cell death has sped up in recent years. Lots of bad things can happen to cells: They get injured or burned, poisoned or starved of oxygen, infected by microbes or otherwise diseased. When a cell dies by accident, it’s called necrosis. There are several necrosis types, none of them pretty: In the case of gangrene, when cells are starved for blood, cells rot away. In other instances, dying cells liquefy, sometimes turning into yellow goop. Lung cells damaged by tuberculosis turn smushy and white — the technical name for this type, “caseous” necrosis, literally means “cheese-like.” Any form of death other than necrosis is considered “programmed,” meaning it’s carried out intentionally by the cell because it’s damaged or has outlived its usefulness.
Keyword: Development of the Brain; Apoptosis
Link ID: 29495 - Posted: 09.28.2024
Ian Sample Science editor Where does our personal politics come from? Does it trace back to our childhood, the views that surround us, the circumstances we are raised in? Is it all about nurture – or does nature have a say through the subtle levers of DNA? And where, in all of this, is the brain? Scientists have delved seriously into the roots of political belief for the past 50 years, prompted by the rise of sociobiology, the study of the biological basis of behaviour, and enabled by modern tools such as brain scanners and genome sequencers. The field is making headway, but teasing out the biology of behaviour is never straightforward. Take a study published last week. Researchers in Greece and the Netherlands examined MRI scans from nearly 1,000 Dutch people who had answered questionnaires on their personal politics. The work was a replication study, designed to see whether the results from a small 2011 study, bizarrely commissioned by the actor Colin Firth, stood up. Firth’s study, conducted at UCL, reported structural differences between conservative and liberal brains. Conservatives, on average, had a larger amygdala, a region linked to threat perception. Liberals, on average, had a larger anterior cingulate cortex, a region involved in decision-making. In the latest study of Dutch people, the researchers found no sign of a larger anterior cingulate cortex in liberals. They did, however, find evidence for a very slightly larger amygdala in conservatives. The MailOnline declared evidence that conservatives were more “compassionate”, but later changed their headline noting that the study said nothing about compassion. © 2024 Guardian News & Media Limited
Keyword: Emotions; Attention
Link ID: 29493 - Posted: 09.25.2024
Jon Hamilton For 22 years, Jason Mazzola’s life was defined by Fragile X, a genetic condition that often causes autism and intellectual disability. Jason, who is 24 now, needed constant supervision. He had disabling anxiety, and struggled to answer even simple questions. All that began to change when he started taking an experimental drug called zatolmilast in May of 2023. “It helps me focus a lot, helps me get more confident, more educated,” Jason says. His mother, Lizzie Mazzola, credits zatolmilast with transforming her son. “I have a different child in my house,” she says. “He gets himself to work, he walks downtown, gets his haircut, gets lunch. He wouldn't have done any of that before.” Other parents of children with Fragile X are also reporting big changes with zatolmilast. Those anecdotes are supported by data. A 2021 study of 30 adult male participants with Fragile X found that taking zatolmilast for 12 weeks improved performance on a range of memory and language measures. Now, two larger studies are underway that will determine whether zatolmilast becomes the first drug approved by the Food and Drug Administration to treat Fragile X. Mazzola realized early on that Jason was falling behind. “He could hardly talk by three,” she says. “At four he started to put some words together, but really wasn’t talking in sentences.” Genetic tests revealed the cause: Fragile X. The inherited condition affects the X chromosome, making one segment appear fragile or broken. This anomaly blocks production of a protein that’s important to brain development. © 2024 npr
Keyword: Development of the Brain; Genes & Behavior
Link ID: 29492 - Posted: 09.25.2024
Natasha May Young people with severe depression experience disruptions in the way regions of their brain communicate with each other which are distinct from those observed in adults, a study has found. The research published on Tuesday in Nature Mental Health could be used to identify potential targets for brain stimulation therapies, extending their existing application from adults to youth. The study analysed the brain scans of 810 young people aged 12-25, of which 440 had major depressive disorder (MDD) and 370 were healthy comparison individuals. The study led by the University of Melbourne found that in those with MDD, some densely connected regions of the brain (known as hubs) showed stronger connectivity and others showed weaker connectivity compared with youth without depression. Young woman running at sunset on Australian beach Nutrition and exercise as good as therapy for mild and moderate depression, study says Prof Andrew Zalesky, the supervising researcher, said they found the connectivity was particularly strong in the part of the brain associated with someone’s internalised thoughts and rumination. “We see that in youth with depression, the default mode is more strongly connected, it’s more activated, which suggests that there is a greater focus on self-thought and self-reflection,” Zalesky said. The study, whose first author was third-year PhD student at the University of Melbourne, Nga (Connie) Yan Tse, also found the extent of these differences could reliably predict how severe a person’s depressive symptoms were. © 2024 Guardian News & Media Limited
Keyword: Depression; Brain imaging
Link ID: 29491 - Posted: 09.25.2024
Jon Hamilton Scientists have created a virtual brain network that can predict the behavior of individual neurons in a living brain. The model is based on a fruit fly’s visual system, and it offers scientists a way to quickly test ideas on a computer before investing weeks or months in experiments involving actual flies or other lab animals. “Now we can start with a guess for how the fly brain might work before anyone has to make an experimental measurement,” says Srini Turaga, a group leader at the Janelia Research Campus, a part of the Howard Hughes Medical Institute (HHMI). The approach, described in the journal Nature, also suggests that power-hungry artificial intelligence systems like ChatGPT might consume much less energy if they used some of the computational strategies found in a living brain. A fruit fly brain is “small and energy efficient,” says Jakob Macke, a professor at the University of Tübingen and an author of the study. “It’s able to do so many computations. It’s able to fly, it’s able to walk, it’s able to detect predators, it’s able to mate, it’s able to survive—using just 100,000 neurons.” In contrast, AI systems typically require computers with tens of billions of transistors. Worldwide, these systems consume as much power as a small country. “When we think about AI right now, the leading charge is to make these systems more power efficient,” says Ben Crowley, a computational neuroscientist at Cold Spring Harbor Laboratory who was not involved in the study. Borrowing strategies from the fruit fly brain might be one way to make that happen, he says. © 2024 npr
Keyword: Brain imaging; Evolution
Link ID: 29484 - Posted: 09.18.2024
By Julian Nowogrodzki Millions of adults around the world take potent drugs such as Wegovy to shed pounds. Should kids do the same? That question is growing more urgent in the face of mounting evidence that children and adolescents, as well as adults, slim down if they take the latest generation of obesity drugs. Clinical trials1,2 have shown that many adolescents with obesity lose substantial amounts of weight on these drugs, which work by mimicking a natural hormone called glucagon-like peptide 1 (GLP-1). The GLP-1 mimics semaglutide, commonly sold as Ozempic and Wegovy, and liraglutide, marketed as Saxenda and Victoza, are approved in the United States and Europe to treat obesity in children as young as 12. Now a trial has produced some of the first data on anti-obesity drugs in even younger children: those aged 6 to 11. The study3 reports that children who were treated with liraglutide showed a decrease in their body mass index (BMI), a measure of obesity. The results were published on 10 September in The New England Journal of Medicine. Nature asked specialists in obesity about the costs and benefits of giving the GLP-1 mimics to youngsters who are still growing and developing. Why test powerful weight-loss drugs on kids? Most kids with obesity become teens with obesity and then adults with obesity. Many young children with severe obesity have “already developed significant health issues”, says physician Sarah Ro, who directs the University of North Carolina Physicians Network Weight Management Program and has served as a consultant to Novo Nordisk, the manufacturer of semaglutide. Her clinic in Hillsborough treats children with severe obesity who have health issues such as high blood pressure, type 2 diabetes or an advanced form of liver disease linked to excess weight. © 2024 Springer Nature Limited
Keyword: Obesity; Development of the Brain
Link ID: 29482 - Posted: 09.18.2024
By Max Kozlov A low-cost diabetes drug slows ageing in male monkeys and is particularly effective at delaying the effects of ageing on the brain, finds a small study that tracked the animals for more than three years1. The results raise the possibility that the widely used medication, metformin, could one day be used to postpone ageing in humans. Monkeys that received metformin daily showed slower age-associated brain decline than did those not given the drug. Furthermore, their neuronal activity resembled that of monkeys about six years younger (equivalent to around 18 human years) and the animals had enhanced cognition and preserved liver function. This study, published in Cell on 12 September, helps to suggest that, although dying is inevitable, “ageing, the way we know it, is not”, says Nir Barzilai, a geroscientist at the Albert Einstein College of Medicine in New York City, who was not involved in the study. Metformin has been used for more than 60 years to lower blood-sugar levels in people with type 2 diabetes — and is the second most-prescribed medication in the United States. The drug has long been known to have effects beyond treating diabetes, leading researchers to study it against conditions such as cancer, cardiovascular disease and ageing. Data from worms, rodents, flies and people who have taken the drug for diabetes suggest the drug might have anti-ageing effects. But its effectiveness against ageing had not been tested directly in primates, and it is unclear whether its potential anti-ageing effects are achieved by lowering blood sugar or through a separate mechanism. This led Guanghui Liu, a biologist who studies ageing at the Chinese Academy of Sciences in Beijing, and his colleagues to test the drug on 12 elderly male cynomolgus macaques (Macaca fasciucularis); another 16 elderly monkeys and 18 young or middle-aged animals served as a control group. Every day, treated monkeys received the standard dose of metformin that is used to control diabetes in humans. The animals took the drug for 40 months, which is equivalent to about 13 years for humans. © 2024 Springer Nature Limited
Keyword: Development of the Brain; Obesity
Link ID: 29481 - Posted: 09.14.2024