By Gina Kolata A national survey released on Friday by KFF, a nonprofit organization focused on health policy, has found that Americans long for safe and effective drugs for weight loss. But the more they learn about new drugs like Wegovy that are transforming obesity treatment, the more their enthusiasm fades. The survey found that 59 percent of people who were trying to lose weight said they were interested in taking a safe and effective drug. But only 23 percent remained interested when asked if they would take such a drug if it had to be injected. And just 16 percent were still interested if their insurance would not pay for the drug. The list price of the drugs is about $1,300 a month. When they heard they would regain their lost weight it they stopped taking the drug, interest declined to 14 percent. “People always want that magic pill,” said Ashley Kirzinger, director of survey methodology at KFF. “There is no magic.” The survey was conducted in July online and by telephone with a representative sample of 1,327 U.S. adults. That’s the median weight loss experienced by people who take Wegovy, a drug from Novo Nordisk. The new drugs are the first truly effective obesity medicines. They act by stemming people’s appetites and cravings for food. Many patients started by taking Ozempic, a diabetes drug also by Novo Nordisk that led to weight loss as a side effect. But many more patients are asking for Wegovy, which is approved for obesity. Mounjaro, made by Eli Lilly and approved for treating diabetes, is expected to be approved soon for obesity. People taking it lose a median of 20 percent of their body weight. Obesity is a chronic disease that can result in diabetes and other conditions like high blood pressure, heart disease, sleep apnea and joint problems. But it was so difficult to treat obesity that many doctors and patients had all but given up. © 2023 The New York Times Company

Keyword: Obesity
Link ID: 28865 - Posted: 08.05.2023

By Simon Makin Rats are extremely playful creatures. They love playing chase, and they literally jump for joy when tickled. Central to this playfulness, a new study finds, are cells in a specific region of rats’ brains. Neurons in the periaqueductal gray, or PAG, are active in rats during different kinds of play, scientists report July 28 in Neuron. And blocking the activity of those neurons makes the rodents much less playful. The results give insight into a poorly understood behavior, particularly in terms of how play is controlled in the brain. “There are prejudices that it’s childish and not important, but play is an underrated behavior,” says Michael Brecht, a neuroscientist at Humboldt University in Berlin. Scientists think play helps animals develop resilience. Some even relate it to optimal functioning. “When you’re playing, you’re being your most creative, thoughtful, interactive self,” says Jeffrey Burgdorf, a neuroscientist at Northwestern University in Evanston, Ill., who was not involved in the new study. This is the opposite of depressive states, and Burgdorf’s own research aims to turn understanding the neuroscience of play into new therapies for mood disorders. For the new study, Brecht and colleagues got rats used to lab life and being tickled and played with in a game of chase-the-hand. When rats play, they squeal with glee at a frequency of 50 kilohertz, which humans can’t hear. The researchers recorded these ultrasonic giggles as a way of measuring when the rats were having fun. To explore how a specific brain region in rats might relate to their well-documented play behavior, researchers tickled rats on their bellies and backs and played chase-the-hand. Rats also played together, chasing and play-fighting. Ultrasonic giggles, processed to make them audible to humans, coordinate social play and show that the rats are having fun. © Society for Science & the Public 2000–2023.

Keyword: Emotions; Evolution
Link ID: 28864 - Posted: 08.02.2023

By Claudia López Lloreda When someone loses a hand or leg, they don’t just lose the ability to grab objects or walk—they lose the ability to touch and sense their surroundings. Prosthetics can restore some motor control, but they typically can’t restore sensation. Now, a preliminary studyposted to the preprint server bioRxiv this month—shows that by mimicking the activity of nerves, a device implanted in the remaining part of the leg helps amputees “feel” as they walk, allowing them to move faster and with greater confidence. “It's a really elegant study,” says Jacob George, neuroengineer at the University of Utah who was not involved with the research. Because the experiments go from a computational model to an animal model and then, finally humans, he says, “This work is really impactful, because it's one of the first studies that's done in a holistic way.” Patients with prosthetics often have a hard time adapting. One big issue is that they can’t accurately control the device because they can’t feel the pressure that they’re exerting on an object. Hand and arm amputees, for example, are more prone to drop or break things. As a result, some amputees refuse to use such prosthetics. In the past few years, researchers have been working on prosthetic limbs that provide more natural sensory feedback both to help control the device better and give them back a sense of agency over their robotic limb. In a critical study in 2019, George and his team showed that so-called biomimetic feedback, sensory information that aims to resemble the natural signals that occur with touch, allowed a patient who’d lost his hand to more precisely grip fragile objects such as eggs and grapes. But such studies have been limited to single patients. They’ve also left many questions unanswered about how exactly this feedback helps with motor control and improves the use of the prosthetic. So in the new work, researchers used a computer model that re-creates how nerves in the foot respond to different inputs, such as feeling pressure. The goal was to create natural patterns of neural activity that might occur when sensing something with the foot or walking. © 2023 American Association for the Advancement of Science.

Keyword: Pain & Touch; Robotics
Link ID: 28863 - Posted: 08.02.2023

McKenzie Prillaman It’s rare to find a product so successful that its makers stop advertising it. But that’s what happened to the weight-loss drug Wegovy in May. In the United States, where prescription drugs can be advertised, developer Novo Nordisk pulled its television adverts because it couldn’t keep up with demand. The injectable medication, called semaglutide, works by imitating a hormone that curbs appetite and was approved as an obesity treatment by the US Food and Drug Administration (FDA) in 2021. In a study, participants who took semaglutide for over a year lost more than twice as much body weight on average — almost 16% — as did people taking an older weight-loss drug that mimics the same hormone1. Semaglutide’s approval for treatment of weight loss came four years after the drug was approved for type 2 diabetes under the trade name Ozempic, also made by Novo Nordisk, based in Bagsværd, Denmark. Demand for Ozempic has skyrocketed as physicians prescribe it for weight loss outside its approved use. Now, even more-potent medications for obesity are on the way. The drug tirzepatide, which is FDA-approved for type 2 diabetes under the name Mounjaro and made by Eli Lilly in Indianapolis, Indiana, imitates two hunger-related hormones. And the company’s drug retatrutide, which mimics three hormones, showed promising results for weight loss in its mid-stage clinical trial, announced at a conference in June. Neither of these newcomers has been approved for obesity. But treating the condition is more urgent than ever. Obesity rates have tripled in the past 50 years, and carrying significant extra weight often brings a heightened risk of other health complications, including type 2 diabetes, heart disease and some cancers. It can also impede quality of life in other ways, such as limiting a person’s range of movement or resulting in feelings of shame because of weight stigma. With this wave of drugs comes a fresh set of questions for researchers. “We are currently in such a dynamic phase of these transformative developments,” says physician-scientist Matthias Tschöp, chief executive of Helmholtz Munich, a research centre in Germany. “We’re still overwhelmed with curiosity.” © 2023 Springer Nature Limited

Keyword: Obesity
Link ID: 28862 - Posted: 08.02.2023

by Brendan Borrell The New York State Psychiatric Institute in New York City is undergoing an audit and a change in leadership following a suicide that occurred during one of its clinical trials. Autism researcher Jeremy Veenstra-VanderWeele has abruptly taken the helm as the interim executive director of the institute and chair of the Columbia University psychiatry department, replacing Helen Blair Simpson, Spectrum has learned. The New York State Psychiatric Institute is part of the New York State Office of Mental Health, but it shares buildings and staff with Columbia University and the university’s hospital. The Office of Mental Health is currently conducting an audit of the institute, according to Carla Cantor, the institute’s director of communications. The audit and turnover in leadership comes after the halting of a series of clinical trials conducted by Columbia psychiatrist Bret Rutherford, which tested whether the drug levodopa — typically used to treat Parkinson’s disease — could improve mood and mobility in adults with depression. During a double-blind study that began in 2019, a participant in the placebo group died by suicide. That study was suspended prior to completion, according to an update posted on ClinicalTrials.gov in 2022. Two published reports based on Rutherford’s pilot studies have since been retracted, as Spectrum has previously reported. The National Institute of Mental Health has terminated Rutherford’s trials and did not renew funding of his research grant or K24 Midcareer Award. Former members of Rutherford’s laboratory describe it as a high-pressure environment that often put publications ahead of study participants. “Research is important, but not more so than the lives of those who participate in it,” says Kaleigh O’Boyle, who served as clinical research coordinator there from 2018 to 2020. © 2023 Simons Foundation

Keyword: Depression; Parkinsons
Link ID: 28861 - Posted: 08.02.2023

By Yasemin Saplakoglu On warm summer nights, green lacewings flutter around bright lanterns in backyards and at campsites. The insects, with their veil-like wings, are easily distracted from their natural preoccupation with sipping on flower nectar, avoiding predatory bats and reproducing. Small clutches of the eggs they lay hang from long stalks on the underside of leaves and sway like fairy lights in the wind. The dangling ensembles of eggs are beautiful but also practical: They keep the hatching larvae from immediately eating their unhatched siblings. With sickle-like jaws that pierce their prey and suck them dry, lacewing larvae are “vicious,” said James Truman, a professor emeritus of development, cell and molecular biology at the University of Washington. “It’s like ‘Beauty and the Beast’ in one animal.” This Jekyll-and-Hyde dichotomy is made possible by metamorphosis, the phenomenon best known for transforming caterpillars into butterflies. In its most extreme version, complete metamorphosis, the juvenile and adult forms look and act like totally different species. Metamorphosis is not an exception in the animal kingdom; it’s almost a rule. More than 80% of the known animal species today, mainly insects, amphibians and marine invertebrates, undergo some form of metamorphosis or have complex, multistage life cycles. The process of metamorphosis presents many mysteries, but some of the most deeply puzzling ones center on the nervous system. At the center of this phenomenon is the brain, which must code for not one but multiple different identities. After all, the life of a flying, mate-seeking insect is very different from the life of a hungry caterpillar. For the past half-century, researchers have probed the question of how a network of neurons that encodes one identity — that of a hungry caterpillar or a murderous lacewing larva — shifts to encode an adult identity that encompasses a completely different set of behaviors and needs. Truman and his team have now learned how much metamorphosis reshuffles parts of the brain. In a recent study published in the journal eLife, they traced dozens of neurons in the brains of fruit flies going through metamorphosis. They found that, unlike the tormented protagonist of Franz Kafka’s short story “The Metamorphosis,” who awakes one day as a monstrous insect, adult insects likely can’t remember much of their larval life. Although many of the larval neurons in the study endured, the part of the insect brain that Truman’s group examined was dramatically rewired. That overhaul of neural connections mirrored a similarly dramatic shift in the behavior of the insects as they changed from crawling, hungry larvae to flying, mate-seeking adults. All Rights Reserved © 2023

Keyword: Learning & Memory
Link ID: 28860 - Posted: 07.27.2023

Liam Drew Scientific advances are rapidly making science-fiction concepts such as mind-reading a reality — and raising thorny questions for ethicists, who are considering how to regulate brain-reading techniques to protect human rights such as privacy. On 13 July, neuroscientists, ethicists and government ministers discussed the topic at a Paris meeting organized by UNESCO, the United Nations scientific and cultural agency. Delegates plotted the next steps in governing such ‘neurotechnologies’ — techniques and devices that directly interact with the brain to monitor or change its activity. The technologies often use electrical or imaging techniques, and run the gamut from medically approved devices, such as brain implants for treating Parkinson’s disease, to commercial products such as wearables used in virtual reality (VR) to gather brain data or to allow users to control software. How to regulate neurotechnology “is not a technological discussion — it’s a societal one, it’s a legal one”, Gabriela Ramos, UNESCO’s assistant director-general for social and human sciences, told the meeting. Advances in neurotechnology include a neuroimaging technique that can decode the contents of people’s thoughts, and implanted brain–computer interfaces (BCIs) that can convert people’s thoughts of handwriting into text1. The field is growing fast — UNESCO’s latest report on neurotechnology, released at the meeting, showed that, worldwide, the number of neurotechnology-related patents filed annually doubled between 2015 and 2020. Investment rose 22-fold between 2010 and 2020, the report says, and neurotechnology is now a US$33-billion industry. One area in need of regulation is the potential for neurotechnologies to be used for profiling individuals and the Orwellian idea of manipulating people’s thoughts and behaviour. Mass-market brain-monitoring devices would be a powerful addition to a digital world in which corporate and political actors already use personal data for political or commercial gain, says Nita Farahany, an ethicist at Duke University in Durham, North Carolina, who attended the meeting. © 2023 Springer Nature Limited

Keyword: Brain imaging
Link ID: 28859 - Posted: 07.27.2023

By Tanvi Dutta Gupta The Arctic Ocean is a noisy place. Creatures of the deep have learned to live with the cacophony of creaking ice sheets and breaking icebergs, but humanmade sources of noise from ships and oil and gas infrastructure are altering that natural submarine soundscape. Now, a research team has found that even subtle underwater noise pollution can cause narwhals to make shallower dives and cut their hunts short. The research, published today in Science Advances, uncovers “some really great information on a species we know very little about,” says Ari Friedlaender, an ocean ecologist at the University of California, Santa Cruz, not involved in the study. Knowing how the whales react to these noises could help conservationists “act proactively” to protect the animals in their Arctic home where warming waters already threaten their lifestyles. Narwhals—with their long, unicornlike horns extending from their faces—live in one of the most extreme environments in the world, explains Outi Tervo, an ecologist at the Greenland Institute of Natural Resources and the study’s first author. Each narwhal returns in summer to the same small fjord where it was born in order to feed on fish, squid, and shrimp. As humans increasingly encroach on Arctic waters, though, scientists, conservationists, and Inuit communities have worried about how development and ship traffic will affect the whales. Many of Greenland’s Inuit communities rely on the narwhals as a culturally important food source. When Greenland’s government started to auction new permits for offshore oil exploration in 2011, Tervo and colleagues decided to examine whether the noise pollution associated with such development affected narwhals. For instance, boats exploring the sea floor tow instruments called airguns, which blast air a few meters below the vessels to sonically suss out the presence of cavities that may contain oil and gas. Those pulses can be the “loudest sound put in the ocean by humans,” says study co-author Susanna Blackwell, a biologist with Greeneridge Sciences.

Keyword: Animal Communication; Hearing
Link ID: 28858 - Posted: 07.27.2023

by Giorgia Guglielmi Mice with a mutation that boosts the activity of the autism-linked protein UBE3A show an array of behaviors reminiscent of the condition, a new study finds. The behaviors differ depending on whether the animals inherit the mutation from their mother or their father, the work also reveals. The results add to mounting evidence that hyperactive UBE3A leads to autism. Duplications of the chromosomal region that includes UBE3A have been associated with autism, whereas deletions and mutations that destroy the gene’s function are known to cause Angelman syndrome, which is characterized by developmental delay, seizures, lack of speech, a cheerful demeanor and, often, autism. “UBE3A is on a lot of clinicians’ radar because it is well known to be causative for Angelman syndrome when mutated or deleted,” says lead investigator Mark Zylka, professor of cell biology and physiology at the University of North Carolina at Chapel Hill. “What our study shows is that just because you have a mutation in UBE3A, it doesn’t mean that it’s going to be Angelman syndrome.” In the cell, UBE3A is involved in the degradation of proteins, and “gain-of-function” mutations — which send the UBE3A protein into overdrive — result in enhanced degradation of its targets, including UBE3A itself. Studying the effects of these mutations could provide insight into how they affect brain development and suggest targets for therapies, says study investigator Jason Yi, assistant professor of neuroscience at Washington University in St. Louis, Missouri. Gain-of-function mutations in UBE3A can disrupt early brain development and may contribute to neurodevelopmental conditions that are distinct from Angelman syndrome, Yi and Zylka have shown in previous studies. One of the mutations they analyzed had been found in an autistic child, so the team used CRISPR to create mice with this mutation. © 2023 Simons Foundation

Keyword: Autism
Link ID: 28857 - Posted: 07.27.2023

Lilly Tozer A study that followed thousands of people over 25 years has identified proteins linked to the development of dementia if their levels are unbalanced during middle age. The findings, published in Science Translational Medicine on 19 July1, could contribute to the development of new diagnostic tests, or even treatments, for dementia-causing diseases. Most of the proteins have functions unrelated to the brain. “We’re seeing so much involvement of the peripheral biology decades before the typical onset of dementia,” says study author Keenan Walker, a neuroscientist at the US National Institute on Aging in Bethesda, Maryland. Equipped with blood samples from more than 10,000 participants, Walker and his colleagues questioned whether they could find predictors of dementia years before its onset by looking at a person’s proteome — the collection of all the proteins expressed throughout the body. They searched for any signs of dysregulation — when proteins are at levels much higher or lower than normal. The samples were collected as part of an ongoing study that began in 1987. Participants returned for examination six times over three decades, and during this time, around 1 in 5 of them developed dementia. The researchers found 32 proteins that, if dysregulated in people aged 45 to 60, were strongly associated with an elevated chance of developing dementia in later life. It is unclear how exactly these proteins might be involved in the disease, but the link is “highly unlikely to be due to just chance alone”, says Walker © 2023 Springer Nature Limited

Keyword: Alzheimers
Link ID: 28856 - Posted: 07.22.2023

By Robert Kolker Barb was the youngest in her large Irish Catholic family — a surprise baby, the ninth child, born 10 years after the eighth. Living in the suburbs of Pittsburgh, her family followed the football schedule: high school games on Friday night, college games on Saturday, the Steelers on Sunday. Dad was an engineer, mom was a homemaker and Barb was the family mascot, blond and adorable, watching her brothers and sisters finish school and go on to their careers. Barb was the only child left at home in the 1980s to witness the seams of her parents’ marriage come apart. Her father all but left, and her mother turned inward, sitting quietly in front of the television, always smoking, often with a cocktail. Something had overtaken her, though it wasn’t clear what. Barb observed it all with a measure of detachment; her parents had been older than most, and her sisters and brothers supplied more than enough parental energy to make up the difference. And so in 1990, when Barb was 14 and her mother learned she had breast cancer and died within months at the age of 62, Barb was shattered and bewildered but also protected. Her siblings had already stepped in, three of them living back home. Together they arrived at a shared understanding of the tragedy. Their mother could have lived longer if she had cut back on her drinking sooner or gone to see a doctor or hadn’t smoked. Six years later, Barb was 20 and in college when someone else in the family needed help. Her sister Christy was the second-born, 24 years older than Barb and the star of the family in many ways. She had traveled extensively as a pharmaceutical-company executive while raising two children with her husband in a nice house in a New Jersey suburb. But where once Christy was capable and professionally ambitious and socially conscious, now, at 44, she was alone, her clothes unkempt and ripped, her hair unwashed, her marriage over. Again, the family came together: Susan, the third-born, volunteered to take care of Christy full time, and Jenny, the eighth, searched for a specialist (the family members asked to be identified by their first names to protect their privacy). Depression was the first suspected diagnosis, then schizophrenia, though neither seemed quite right. Christy wasn’t sad or delusional; she wasn’t even upset. It was more as if she were reverting to a childlike state, losing her knack for self-regulation. Her personality was diluting — on its way out, with seemingly nothing to replace it. © 2023 The New York Times Company

Keyword: Alzheimers; Genes & Behavior
Link ID: 28855 - Posted: 07.22.2023

Geneva Abdul The so-called “brain fog” symptom associated with long Covid is comparable to ageing 10 years, researchers have suggested. In a study by King’s College London, researchers investigated the impact of Covid-19 on memory and found cognitive impairment highest in individuals who had tested positive and had more than three months of symptoms. The study, published on Friday in a clinical journal published by The Lancet, also found the symptoms in affected individuals stretched to almost two years since initial infection. “The fact remains that two years on from their first infection, some people don’t feel fully recovered and their lives continue to be impacted by the long-term effects of the coronavirus,” said Claire Steves, a professor of ageing and health at King’s College. “We need more work to understand why this is the case and what can be done to help.” An estimated two million people living in the UK were experiencing self-reported long Covid – symptoms continuing for more than four weeks since infection – as of January 2023, according to the 2023 government census. Commonly reported symptoms included fatigue, difficulty concentrating, shortness of breath and muscle aches. The study included more than 5,100 participants from the Covid Symptom Study Biobank, recruited through a smartphone app. Through 12 cognitive tests measuring speed and accuracy, researchers examined working memory, attention, reasoning and motor controls between two periods of 2021 and 2022. © 2023 Guardian News & Media Limited or

Keyword: Learning & Memory; Attention
Link ID: 28854 - Posted: 07.22.2023

Max Kozlov Dead in California but alive in New Jersey: that was the status of 13-year-old Jahi McMath after physicians in Oakland, California, declared her brain dead in 2013, after complications from a tonsillectomy. Unhappy with the care that their daughter received and unwilling to remove life support, McMath’s family moved with her to New Jersey, where the law allowed them to lodge a religious objection to the declaration of brain death and keep McMath connected to life-support systems for another four and a half years. Prompted by such legal discrepancies and a growing number of lawsuits around the United States, a group of neurologists, physicians, lawyers and bioethicists is attempting to harmonize state laws surrounding the determination of death. They say that imprecise language in existing laws — as well as research done since the laws were passed — threatens to undermine public confidence in how death is defined worldwide. “It doesn’t really make a lot of sense,” says Ariane Lewis, a neurocritical care clinician at NYU Langone Health in New York City. “Death is something that should be a set, finite thing. It shouldn’t be something that’s left up to interpretation.” Since 2021, a committee in the Uniform Law Commission (ULC), a non-profit organization in Chicago, Illinois, that drafts model legislation for states to adopt, has been revising its recommendation for the legal determination of death. The drafting committee hopes to clarify the definition of brain death, determine whether consent is required to test for it, specify how to handle family objections and provide guidance on how to incorporate future changes to medical standards. The broader membership of the ULC will offer feedback on the first draft of the revised law at a meeting on 26 July. After members vote on it, the text could be ready for state legislatures to consider by the middle of next year. But as the ULC revision process has progressed, clinicians who were once eager to address these issues have become increasingly worried. © 2023 Springer Nature Limited

Keyword: Consciousness
Link ID: 28853 - Posted: 07.22.2023

By Pam Belluck Treating Alzheimer’s patients as early as possible — when symptoms and brain pathology are mildest — provides a better chance of slowing cognitive decline, a large study of an experimental Alzheimer’s drug presented Monday suggests. The study of 1,736 patients reported that the drug, donanemab, made by Eli Lilly, can modestly slow the progression of memory and thinking problems in early stages of Alzheimer’s, and that the slowing was greatest for early-stage patients when they had less of a protein that creates tangles in the brain. For people at that earlier stage, donanemab appeared to slow decline in memory and thinking by about four and a half to seven and a half months over an 18-month period compared with those taking a placebo, according to the study, published in the journal JAMA. Among people with less of the protein, called tau, slowing was most pronounced in those younger than 75 and those who did not yet have Alzheimer’s but had a pre-Alzheimer’s condition called mild cognitive impairment, according to data presented Monday at the Alzheimer’s Association International Conference in Amsterdam. “The earlier you can get in there, the more you can impact it before they’ve already declined and they’re on this fast slope,” Dr. Daniel Skovronsky, Eli Lilly’s chief medical and scientific officer, said in an interview. “No matter how you cut the data — earlier, younger, milder, less pathology — every time, it just looks like early diagnosis and early intervention are the key to managing this disease,” he added. The findings and the recent approval of another drug that modestly slows decline in the early stages of Alzheimer’s, Leqembi, signal a potentially promising turn in the long, rocky path toward finding effective medications for Alzheimer’s, a brutal disease that plagues more than six million Americans. Donanemab is currently being considered for approval by the Food and Drug Administration. © 2023 The New York Times Company

Keyword: Alzheimers
Link ID: 28852 - Posted: 07.19.2023

Nicola Davis Science correspondent Taking part in activities such as chess, writing a journal, or educational classes in older age may help to reduce the risk of dementia, a study has suggested. According to the World Health Organization, more than 55 million people have the disease worldwide, most of them older people. However experts have long emphasised that dementia is not an inevitable part of ageing, with being active, eating well and avoiding smoking among the lifestyle choices that can reduce risk. Now researchers have revealed fresh evidence that challenging the brain could also be beneficial. Writing in the journal Jama Network Open, researchers in the US and Australia report how they used data from the Australian Aspree Longitudinal Study of Older Persons covering the period from 1 March 2010 to 30 November 2020. Participants in the study were over the age of 70, did not have a major cognitive impairment or cardiovascular disease when recruited between 2010 and 2014, and were assessed for dementia through regular study visits. In the first year, participants were asked about their social networks. They were also questioned on whether they undertook certain leisure activities or trips out to venues such as galleries or restaurants, and how frequently: never, rarely, sometimes, often or always. The team analysed data from 10,318 participants, taking into account factors such as age, sex, smoking status, education, socioeconomic status, and whether participants had other diseases such as diabetes. The results reveal that for activities such as writing letters or journals, taking educational classes or using a computer, increasing the frequency of participation by one category, for example from “sometimes” to “often”, was associated with an 11% drop in the risk of developing dementia over a 10-year period. Similarly, increased frequency of activities such as card games, chess or puzzle-solving was associated with a 9% reduction in dementia risk. © 2023 Guardian News & Media Limited

Keyword: Alzheimers; Learning & Memory
Link ID: 28851 - Posted: 07.19.2023

by Holly Barker By bloating brain samples and imaging them with a powerful microscope, researchers can reconstruct neurons across the entire mouse brain, according to a new preprint. The technique could help scientists uncover the neural circuits responsible for complex behaviors, as well as the pathways that are altered in neurological conditions. Tracking axons can help scientists understand how individual neurons and brain areas communicate over long distances. But tracing their path through the brain is tricky, says study investigator Adam Glaser, senior scientist at the Allen Institute for Neural Dynamics in Seattle, Washington. Axons, which are capable of spanning the entire brain, can be less than a micrometer in diameter, so mapping their route requires detailed imaging, he says. One existing approach involves a microscope that slices off an ultra-thin section of the brain and then scans it, repeating the process about 20,000 times to capture the entire mouse brain. Scientists then blend the images together to form a 3D reconstruction of neuronal pathways. But the process takes several days and is therefore more prone to complications — bubbles forming on the lens, say — than faster techniques, Glaser says. And slicing can distort the edges of the image, making it “challenging or impossible” to stitch them back together, says Paul Tillberg, principal scientist at the Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Virginia, who was not involved in the study. “This is particularly an issue when reconstructing brain-wide axonal projections, where a single point of confusion can misalign an entire axonal arbor to the wrong neuron,” he says. © 2023 Simons Foundation

Keyword: Brain imaging
Link ID: 28850 - Posted: 07.19.2023

By Alejandra Manjarrez Rafael Jiménez Medina learned how to hunt elusive Iberian moles in the fields of southern Spain in the 1980s, when he was a young PhD student in genetics at the University of Granada. A local hunter of the moles (Talpa occidentalis) taught him how to capture these solitary, aggressive and territorial animals. The moles dig subterranean galleries and labyrinths in the meadows of the Iberian Peninsula, especially those with soft soils rich in earthworms, their favorite food. Such activity can benefit the soil — by aerating or mixing it — but the moles’ presence and constant movement in cultivated land raise the ire of farmers, who pay hunters to get rid of them. Jiménez Medina had a different motivation for hunting these subterranean mammals. His doctoral project was to visualize and analyze their chromosomes, which meant collecting, preparing and examining samples from the testes of males. His lab analyses led to a curious finding: Some of the moles he had identified as males were in fact genetically females — that is, their sex chromosomes were XX (female) and not XY (male). The confusion, we now know, stems from the unusual composition of the reproductive organs of female moles. In contrast to most female mammals, which have only ovaries, female Iberian moles also have testicular tissue. This tissue anatomically resembles male testicles but differs in that it produces testosterone but no sperm. The female mole’s organs are composed of both an ovarian and a testicular portion and are known as ovotestes. In addition, female moles have a clitoris covered with a foreskin and with an elongated appearance that resembles a penis; they urinate through this structure. Another unique anatomical feature is that during these females’ juvenile stage, the vaginal orifice remains closed. © 2023 Annual Reviews

Keyword: Sexual Behavior; Evolution
Link ID: 28849 - Posted: 07.19.2023

By David Ovalle The evolving overdose crisis in the United States is making another lethal turn, federal disease trackers reported Wednesday: Increasingly, people dying from opioids are also using stimulants such as cocaine and methamphetamine. An analysis by the Centers for Disease Control and Prevention shows that between 2011 and 2021, the age-adjusted rate of overdose deaths involving opioids and cocaine nearly quintupled, far outpacing the rate of deaths involving only cocaine. In 2021 alone, nearly 80 percent of the 24,486 cocaine overdose deaths recorded in the United States also involved an opioid. Experts say it represents the latest wave of the nation’s drug epidemic. For many users injecting or smoking fentanyl for some time, “adding a stimulant makes the drug feel like it did in the beginning,” said Daniel Ciccarone, a professor of addiction medicine at the University of California at San Francisco who has been studying the simultaneous use of stimulants and opioids. The federal analysis adds clarity to the staggering number of drug poisonings, largely driven by fentanyl, which can be up to 50 times more powerful than heroin. The CDC estimates that in 2022, more than 110,000 people succumbed to overdoses, edging past the previous year but representing a plateau from earlier spikes. Preliminary CDC data also suggest a slight increase in deaths in 2022 involving opioids taken with cocaine and psychostimulants such as meth. “These aren’t mutually exclusive categories. Someone can die of more than one drug,” said CDC researcher Merianne Rose Spencer, who led the analysis. The international cocaine market has thrived despite shutdowns associated with the coronavirus pandemic, according to the U.N.’s Global Report on Cocaine 2023, with record production in Latin America, new trafficking hubs in Africa and increased seizures.

Keyword: Drug Abuse
Link ID: 28848 - Posted: 07.19.2023

Lilly Tozer Injecting ageing monkeys with a ‘longevity factor’ protein can improve their cognitive function, a study reveals. The findings, published on 3 July in Nature Aging1, could lead to new treatments for neurodegenerative diseases. It is the first time that restoring levels of klotho — a naturally occurring protein that declines in our bodies with age — has been shown to improve cognition in a primate. Previous research on mice had shown that injections of klotho can extend the animals’ lives and increases synaptic plasticity2 — the capacity to control communication between neurons, at junctions called synapses. “Given the close genetic and physiological parallels between primates and humans, this could suggest potential applications for treating human cognitive disorders,” says Marc Busche, a neurologist at the UK Dementia Research Institute group at University College London. The protein is named after the Greek goddess Clotho, one of the Fates, who spins the thread of life. The study involved testing the cognitive abilities of old rhesus macaques (Macaca mulatta), aged around 22 years on average, before and after a single injection of klotho. To do this, researchers used a behavioural experiment to test for spatial memory: the monkeys had to remember the location of an edible treat, placed in one of several wells by the investigator, after it was hidden from them. Study co-author Dena Dubal, a physician-researcher at the University of California, San Francisco, compares the test to recalling where you left your car in a car park, or remembering a sequence of numbers a couple of minutes after hearing it. Such tasks become harder with age. The monkeys performed significantly better in these tests after receiving klotho — before the injections they identified the correct wells around 45% of the time, compared with around 60% of the time after injection. The improvement was sustained for at least two weeks. Unlike in previous studies involving mice, relatively low doses of klotho were effective. This adds an element of complexity to the findings, which suggests a more nuanced mode of actions than was previously thought, Busche says. © 2023 Springer Nature Limited

Keyword: Learning & Memory; Development of the Brain
Link ID: 28847 - Posted: 07.06.2023

Jon Hamilton Dr. Josef Parvizi remembers meeting a man with epilepsy whose seizures were causing some very unusual symptoms. "He came to my clinic and said, 'My sense of self is changing,'" says Parvizi, a professor of neurology at Stanford University. The man told Parvizi that he felt "like an observer to conversations that are happening in my mind" and that "I just feel like I'm floating in space." Parvizi and a team of researchers would eventually trace the man's symptoms to a "sausage-looking piece of brain" called the anterior precuneus. This area, nestled between the brain's two hemispheres, appears critical to a person's sense of inhabiting their own body, or bodily self, the team recently reported in the journal Neuron. The finding could help researchers develop forms of anesthesia that use electrical stimulation instead of drugs. It could also help explain the antidepressant effects of mind-altering drugs like ketamine. It took Parvizi's team years of research to discover the importance of this obscure bit of brain tissue. In 2019, when the man first came to Stanford's Comprehensive Epilepsy Program, Parvizi thought his symptoms were caused by seizures in the posteromedial cortex, an area toward the back of the brain. This area includes a brain network involved in the narrative self, a sort of internal autobiography that helps us define who we are. Parvizi's team figured that the same network must be responsible for the bodily self too. "Everybody thought, 'Well, maybe all kinds of selves are being decoded by the same system,'" he says. © 2023 npr

Keyword: Attention; Consciousness
Link ID: 28846 - Posted: 07.06.2023