By Miryam Naddaf Researchers have identified 13 proteins in the blood that predict how quickly or slowly a person’s brain ages compared with the rest of their body. Their study1, published in Nature Aging on 9 December, used a machine-learning model to estimate ‘brain ages’ from scans of more than 10,000 people. The authors then analysed thousands of scans alongside blood samples and found eight proteins that were associated with fast brain ageing, and five linked to slower brain ageing. “Previous studies mainly focused on the association between the proteins and the chronological age, that means the real age of the individual,” says study co-author Wei-Shi Liu, a neurologist at Fudan University in Shanghai, China. However, studying biomarkers linked to a person’s brain age could help scientists to identify molecules to target in future treatments for age-related brain diseases. “These proteins are all promising therapeutic targets for brain disorders, but it may take a long time to validate them,” says Liu. Using machine learning to analyse brain-imaging data from 10,949 people, Liu and his colleagues created a model to calculate a person’s brain age, on the basis of features such as the brain’s volume, surface area and distribution of white matter. They wanted to identify proteins that are associated with a large brain age gap — the difference between brain age and chronological age. To do this, the researchers analysed levels of 2,922 proteins in blood samples from 4,696 people, more than half of whom were female, and compared them with the same people’s brain ages derived from the scans. They identified 13 proteins that seemed to be connected with large brain age gaps, some of which are known to be involved in movement, cognition and mental health.

Keyword: Development of the Brain
Link ID: 29597 - Posted: 12.11.2024

By Grace Huckins Genes on the X and Y chromosomes—and especially those on the Y—appear to be associated with autism likelihood, according to a study focused on people who have missing or extra sex chromosomes. The findings add to the ongoing debate about whether autism’s sex bias reflects a male vulnerability, a female protective effect or other factors. “The Y chromosome is often left out of genetic discovery studies. We really have not interrogated it in [autism] studies very much,” says Matthew Oetjens, assistant professor of human genetics at Geisinger Medical Center’s Autism and Developmental Medicine Institute, who led the new work. There is a clear sex difference in autism prevalence: Men are about four times as likely as women to have a diagnosis. But uncovering the reasons for that discrepancy has proved challenging and contentious. Multiple biological factors may play a role, in addition to social factors—such as the difficult-to-measure gulfs between how boys and girls are taught to behave. Add on the possibility of diagnostic bias and the question starts to look less like a scientific problem and more like a politically toxic Gordian knot. But there are some threads that researchers can pull to disentangle these effects, as the new study illustrates. People with sex chromosome aneuploidies—or unusual combinations of sex chromosomes, such as XXY in those with Klinefelter syndrome or a single X in Turner syndrome—provide a unique opportunity to examine how adding or taking away chromosomes can affect biology and behavior. Previous studies noted high rates of autism in people with sex chromosome aneuploidies, but those analyses were subject to ascertainment bias; perhaps those people found out about their aneuploidies only after seeking support for their neurodevelopmental conditions. © 2024 Simons Foundation

Keyword: Autism; Sexual Behavior
Link ID: 29596 - Posted: 12.11.2024

By Steven Strogatz Death might seem like a pure loss, the disappearance of what makes a living thing distinct from everything else on our planet. But zoom in closer, to the cellular level, and it takes on a different, more nuanced meaning. There is a challenge in simply defining what makes an individual cell alive or dead. Scientists today are working to understand the various ways and reasons that cells disappear, and what these processes mean to biological systems. In this episode, cellular biologist Shai Shaham talks to Steven Strogatz about the different forms of cell death, their roles in evolution and disease, and why the right kinds and patterns of cell death are essential to our development and well-being. STEVE STROGATZ: In the second that it took you to hit play on this episode, a million cells in your body died. Some were programmed to expire in natural, regulated processes, such as apoptosis. Some terminated their own lives after infection, to stop viral invaders from spreading. Others suffered physical damage and went through necrosis, their membranes splitting open and their contents spilling out. We know there are nearly a dozen different ways for our cells to kick the bucket. And learning how to control these processes can make all the difference in the world to a sick patient. In this episode, we ask cellular biologist Shai Shaham (opens a new tab), how can the death of a cell help other cells around it? And how do these insights help us understand life itself? Shai is a professor at The Rockefeller University (opens a new tab), where he studies programmed cell death during animal development and the complex role that glial cells play in the nervous system. There was an example near and dear to my heart, since we work on C. elegans, which is a nematode worm. And there was a recent description of a nematode that was extracted from permafrost in Siberia where it froze about 40,000 years ago and was revived back in the lab. And so you ask yourself, was that whole organism alive or dead for 40,000 years? © 2024 Simons Foundation

Keyword: Apoptosis; Development of the Brain
Link ID: 29591 - Posted: 12.07.2024

Aswathy Ammothumkandy, Charles Liu, Michael A. Bonaguidi Your brain can still make new neurons when you’re an adult. But how does the rare birth of these new neurons contribute to cognitive function? Neurons are the cells that govern brain function, and you are born with most of the neurons you will ever have during your lifetime. While the brain undergoes most of its development during early life, specific regions of the brain continue to generate new neurons throughout adulthood, although at a much lower rate. Whether this process of neurogenesis actually happens in adults and what function it serves in the brain is still a subject of debate among scientists. Past research has shown that people with epilepsy or Alzheimer’s disease and other dementias develop fewer neurons as adults than people without these conditions. However, whether the absence of new neurons contributes to the cognitive challenges patients with these neurological disorders face is unknown. We are part of a team of stem cell researchers, neuroscientists, neurologists, neurosurgeons and neuropsychologists. Our newly published research reveals that the new neurons that form in adults’ brains are linked to how you learn from listening to other people. Researchers know that new neurons contribute to memory and learning in mice. But in humans, the technical challenges of identifying and analyzing new neurons in adult brains, combined with their rarity, had led scientists to doubt their significance to brain function. To uncover the relationship between neurogenesis in adults and cognitive function, we studied patients with drug-resistant epilepsy. These patients underwent cognitive assessments prior to and donated brain tissue during surgical procedures to treat their seizures. To see whether how many new neurons a patient had was associated with specific cognitive functions, we looked under the microscope for markers of neurogenesis. © 2010–2024, The Conversation US, Inc.

Keyword: Neurogenesis; Learning & Memory
Link ID: 29590 - Posted: 12.07.2024

Amy Fleming Nine years ago, Nikki Schultek, an active and healthy woman in her early 30s, experienced a sudden cascade of debilitating and agonising symptoms – including cognitive and breathing problems and heart arrhythmia – and was investigated for multiple sclerosis. But three brain scans and numerous X-rays later, there was still no diagnosis or treatment plan. “It was like living in a nightmare, imagining not watching my children – three and five years old – grow up,” says Schultek. Now, speaking on a video call from North Carolina, she is as bright as a button and shows no signs of degenerative brain disease. It turned out she had multiple chronic infections, including Borrelia burgdorferi bacteria, which causes Lyme disease and which had stealthily reached her brain. Antibiotics restored her health, but B burgdorferi is hard to eradicate once in the brain. She may need maintenance treatment to keep the disease at bay. Schultek is not the only person whose neurological disorder turned out to be caused by microbes in the brain. A recent paper she jointly lead-authored, published in Alzheimer’s and Dementia, compiled a long list of case reports where infectious disease was discovered to be the primary cause of dementia, meaning that, in many cases, the dementia was reversible. A few of the patients died, but most survived and saw significant improvements in cognitive function, including a man in his 70s who had been diagnosed with Alzheimer’s disease after his swift cognitive decline saw him unable to drive or, eventually, leave the house alone. A sample of his cerebrospinal fluid was taken and revealed a fungal infection caused by Cryptococcus neoformans. Within two years of taking antifungal medication, he was driving again and back at work as a gardener. Richard Lathe, a professor of infectious medicine at the University of Edinburgh and another lead author of the paper, says these patients “were by accident found to be suffering from various fungal, bacterial or viral infections, and when they treated the patient with antifungals, antivirals or antibiotics, the dementia went away”. He, among others, has been investigating the possibility that, like the gut, the brain hosts a community of microbes – an area of largely scientifically uncharted waters, but with huge life-saving potential. © 2024 Guardian News & Media Limited

Keyword: Alzheimers; Obesity
Link ID: 29587 - Posted: 12.04.2024

By Teddy Rosenbluth Cassava Sciences, a small biotechnology company based in Austin, Texas, announced it would stop the advanced clinical trial for an experimental Alzheimer’s drug, ending a long-contested bid for regulatory approval. The company announced on Monday that the drug, simufilam, did not significantly reduce cognitive decline in people with mild to moderate Alzheimer’s disease in the trial, which enrolled more than 1,900 patients. “The results are disappointing for patients and their families who are living with this disease and physicians who have been looking for novel treatment options,” the company’s chief executive, Richard J. Barry, said in a statement. These results were unsurprising to many dementia researchers, who had questioned why the trial had been allowed to proceed in the first place, since much of the drug’s underlying science had been called into question. Studies that once seemed to support the drug have been retracted from scientific journals. A consultant researcher who helped conduct some of the drug’s foundational studies was charged with fraud by a federal grand jury for allegedly falsifying data to obtain research grants. In September, the company settled with the Securities and Exchange Commission over allegations that Cassava had made misleading statements about the results of earlier clinical trial data. However, the company neither admitted nor denied wrongdoing. © 2024 The New York Times Company

Keyword: Alzheimers
Link ID: 29577 - Posted: 11.27.2024

By Miryam Naddaf Humans have evolved disproportionately large brains compared with our primate relatives — but this neurological upgrade came at a cost. Scientists exploring the trade-off have discovered unique genetic features that show how human brain cells handle the stress of keeping a big brain working. The work could inspire new lines of research to understand conditions such as Parkinson’s disease and schizophrenia. The study, which was posted to the bioRxiv preprint server on 15 November1, focuses on neurons that produce the neurotransmitter dopamine, which is crucial for movement, learning and emotional processing. By comparing thousands of laboratory-grown dopamine neurons from humans, chimpanzees, macaques and orangutans, researchers found that human dopamine neurons express more genes that boost the activity of damage-reducing antioxidants than do those of the other primates. The findings, which are yet to be peer-reviewed, are a step towards “understanding human brain evolution and all the potentially negative and positive things that come with it”, says Andre Sousa, a neuroscientist at the University of Wisconsin–Madison. “It's interesting and important to really try to understand what's specific about the human brain, with the potential of developing new therapies or even avoiding disease altogether in the future.” Just as walking upright has led to knee and back problems, and changes in jaw structure and diet resulted in dental issues, the rapid expansion of the human brain over evolutionary time has created challenges for its cells, says study co-author Alex Pollen, a neuroscientist at the University of California, San Francisco. “We hypothesized that the same process may be occurring, and these dopamine neurons may represent vulnerable joints.” © 2024 Springer Nature Limited

Keyword: Development of the Brain; Stress
Link ID: 29565 - Posted: 11.20.2024

Ari Daniel The birds of today descended from the dinosaurs of yore. Researchers have known relatively little, however, about how the bird's brain took shape over tens of millions of years. "Birds are one of the most intelligent groups of living vertebrate animals," says Daniel Field, a vertebrate biologist at the University of Cambridge. "They really rival mammals in terms of their relative brain size and the complexity of their behaviors, social interactions, breeding displays." Now, a newly discovered fossil provides the most complete glimpse to date of the brains of the ancestral birds that once flew above the dinosaurs. The species was named Navaornis hestiae, and it's described in the journal Nature. Piecing together how bird brains evolved has been a challenge. First, most of the fossil evidence dates back to tens of millions of years before the end of the Cretaceous period when dinosaurs went extinct and birds diversified. In addition, the fossils of feathered dinosaurs that have turned up often have a key problem. "They're beautiful, but they're all like roadkill," says Luis Chiappe, a paleontologist and curator at the Natural History Museum of Los Angeles County. "They're all flattened and there are aspects that you're never going to be able to recover from those fossils." The shape and three-dimensional structure of the brain are among those missing aspects. But in 2016, Brazilian paleontologist William Nava discovered a remarkably well-preserved fossil in São Paulo state. It came from a prehistoric bird that fills in a crucial gap in understanding of how modern bird brains evolved. © 2024 npr

Keyword: Evolution; Development of the Brain
Link ID: 29561 - Posted: 11.16.2024

By Elena Renken Small may be mightier than we think when it comes to brains. This is what neuroscientist Marcella Noorman is learning from her neuroscientific research into tiny animals like fruit flies, whose brains hold around 140,000 neurons each, compared to the roughly 86 billion in the human brain. Nautilus Members enjoy an ad-free experience. Log in or Join now . In work published earlier this month in Nature Neuroscience, Noorman and colleagues showed that a small network of cells in the fruit fly brain was capable of completing a highly complex task with impressive accuracy: maintaining a consistent sense of direction. Smaller networks were thought to be capable of only discrete internal mental representations, not continuous ones. These networks can “perform more complex computations than we previously thought,” says Noorman, an associate at the Howard Hughes Medical Institute. The scientists monitored the brains of fruit flies as they walked on tiny rotating foam balls in the dark, and recorded the activity of a network of cells responsible for keeping track of head direction. This kind of brain network is called a ring attractor network, and it is present in both insects and in humans. Ring attractor networks maintain variables like orientation or angular velocity—the rate at which an object rotates—over time as we navigate, integrating new information from the senses and making sure we don’t lose track of the original signal, even when there are no updates. You know which way you’re facing even if you close your eyes and stand still, for example. After finding that this small circuit in fruit fly brains—which contains only about 50 neurons in the core of the network—could accurately represent head direction, Noorman and her colleagues built models to identify the minimum size of a network that could still theoretically perform this task. Smaller networks, they found, required more precise signaling between neurons. But hundreds or thousands of cells weren’t necessary for this basic task. As few as four cells could form a ring attractor, they found. © 2024 NautilusNext Inc.,

Keyword: Development of the Brain; Vision
Link ID: 29560 - Posted: 11.16.2024

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 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

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 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