By Miryam Naddaf Researchers have developed a four-dimensional model of spinal-cord injury in mice, which shows how nearly half a million cells in the spinal cord respond over time to injuries of varying severity. The model, known as a cell atlas, could help researchers to resolve outstanding questions and develop new treatments for people with spinal-cord injury (SCI). “If you know what every single cell on the spinal cord is doing in response to injury, you could use that knowledge to develop tailor-made and mechanism-based therapies,” says Mark Anderson, a neurobiologist at the Swiss Federal Institute of Technology in Geneva, Switzerland, who worked on the atlas. “Things don’t need to be a shot in the dark.” Anderson and his colleagues used machine-learning algorithms to build the atlas by mapping data from RNA sequencing and other cell-biology techniques. They described the work in a Nature paper published today1 and have made the entire atlas available through an online platform. The atlas is a valuable resource for testing hypotheses about SCI, says Binhai Zheng, who studies spinal-cord regeneration at the University of California, San Diego. “There are a lot of hidden treasures.” The researchers examined sections of the spinal cord, sampled from 52 injured and uninjured mice at 1, 4, 7, 14, 30 and 60 days after injury. Their analysis involved 18 experimental SCI conditions, including different types of injury and levels of severity. They used RNA-sequencing tools to explore how 482,825 cells responded to injury over time. © 2024 Springer Nature Limited

Keyword: Brain imaging; Brain Injury/Concussion
Link ID: 29368 - Posted: 06.26.2024

Hannah Devlin Science correspondent A UK teenager with severe epilepsy has become the first person in the world to be fitted with a brain implant aimed at bringing seizures under control. Oran Knowlson’s neurostimulator sits under the skull and sends electrical signals deep into the brain, reducing his daytime seizures by 80%. His mother, Justine, said that her son had been happier, chattier and had a much better quality of life since receiving the device. “The future looks hopeful, which I wouldn’t have dreamed of saying six months ago,” she said. Martin Tisdall, a consultant paediatric neurosurgeon who led the surgical team at Great Ormond Street hospital (Gosh) in London, said: “For Oran and his family, epilepsy completely changed their lives and so to see him riding a horse and getting his independence back is absolutely astounding. We couldn’t be happier to be part of their journey.” Oran, who is 13 and lives in Somerset, had the surgery in October as part of a trial at Gosh in partnership with University College London, King’s College hospital and the University of Oxford. Oran has Lennox-Gastaut syndrome, external, a treatment-resistant form of epilepsy which he developed at the age of three. Between then and having the device fitted, he hasn’t had a single day without a seizure and sometimes suffered hundreds in a day. He often lost consciousness and would stop breathing, needing resuscitation. This means Oran needed round-the-clock care, as seizures could happen at any time of day, and he was at a significantly increased risk of sudden unexpected death in epilepsy (Sudep). © 2024 Guardian News & Media Limited

Keyword: Epilepsy; Robotics
Link ID: 29367 - Posted: 06.24.2024

Jon Hamilton A flexible film bristling with tiny sensors could make surgery safer for patients with a brain tumor or severe epilepsy. The experimental film, which looks like Saran wrap, rests on the brain’s surface and detects the electrical activity of nerve cells below. It’s designed to help surgeons remove diseased tissue while preserving important functions like language and memory. “This will enable us to do a better job,” says Dr. Ahmed Raslan, a neurosurgeon at Oregon Health and Science University who helped develop the film. The technology is similar in concept to sensor grids already used in brain surgery. But the resolution is 100 times higher, says Shadi Dayeh, an engineer at the University of California, San Diego, who is leading the development effort. In addition to aiding surgery, the film should offer researchers a much clearer view of the neural activity responsible for functions including movement, speech, sensation, and even thought. “We have these complex circuits in our brains,” says John Ngai, who directs the BRAIN Initiative at the National Institutes of Health, which has funded much of the film’s development. “This will give us a better understanding of how they work.” Mapping an ailing brain The film is intended to improve a process called functional brain mapping, which is often used when a person needs surgery to remove a brain tumor or tissue causing severe epileptic seizures. © 2024 npr

Keyword: Brain imaging; Epilepsy
Link ID: 29357 - Posted: 06.13.2024

Hannah Devlin Science correspondent A 10-minute brain scan could detect dementia several years before people develop noticeable symptoms, a study suggests. Scientists used a scan of “resting” brain activity to identify whether people would go on to develop dementia, with an estimated 80% accuracy up to nine years before people received a diagnosis. If the findings were confirmed in a larger cohort, the scan could become a routine procedure in memory clinics, scientists said. “We’ve known for a long time that the function of the brain starts to change many years before you get dementia symptoms,” said Prof Charles Marshall, who led the work at Queen Mary University of London. “This could help us to be more precise at identifying those changes using an MRI scan that you could do on any NHS scanner.” The research comes as a new generation of Alzheimer’s drugs are on the horizon. The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) is assessing lecanemab, made by Eisai and Biogen, and donanemab, made by Eli Lilly, and both drugs are widely expected to be licensed this year. “Predicting who is going to get dementia in the future will be vital for developing treatments that can prevent the irreversible loss of brain cells that causes the symptoms of dementia,” Marshall said. The researchers used functional MRI (fMRI) scans from 1,100 UK Biobank volunteers to detect changes in the brain’s “default mode network” (DMN). The scan measures correlations in brain activity between different regions while the volunteer lies still, not doing any particular task. The network, which reflects how effectively different regions are communicating with each other, is known to be particularly vulnerable to Alzheimer’s disease. © 2024 Guardian News & Media Limited

Keyword: Alzheimers; Brain imaging
Link ID: 29349 - Posted: 06.08.2024

By Gemma Conroy Researchers have developed biodegradable, wireless sensors that can monitor changes in the brain following a head injury or cancer treatment, without invasive surgery. In rats and pigs, the soft sensors performed just as well as conventional wired sensors for up to a month after being injected under the skull. The gel-based sensors measure key health markers, including temperature, pH and pressure. “It is quite likely this technology will be useful for people in medical settings,” says study co-author Yueying Yang, a biomedical engineer at Huazhong University of Science and Technology (HUST) in Wuhan, China. The findings were published today in Nature1. “It’s a very comprehensive study,” says Christopher Reiche, who develops implantable microdevices at the University of Utah in Salt Lake City. For years, scientists have been developing brain sensors that can be implanted inside the skull. But many of these devices rely on wires to transmit data to clinicians. The wires are difficult to insert and remove, and create openings in the skin for viruses and bacteria to enter the body. Wireless sensors offer a solution to this problem, but are thwarted by their limited communication range and relatively large size. Developing sensors that can access and monitor the brain is “extremely difficult”, says Omid Kavehei, a biomedical engineer who specializes in neurotechnology at the University of Sydney in Australia. To overcome these challenges, Yang and her colleagues created a set of 2-millimetre cube-shaped sensors out of hydrogel, a soft, flexible material that’s often used in tissue regeneration and drug delivery. The gel sensors change shape under different temperatures, pressures and pH conditions, and respond to vibrations caused by variations in blood flow in the brain. When the sensors are implanted under the skull and scanned with an ultrasound probe — a tool that is already used to image the human brain in clinics — these changes are detectable in the form of ultrasonic waves that pass through the skull. The tiny gel-cubes completely dissolve in saline solution after around four months, and begin to break down in the brain after five weeks. © 2024 Springer Nature Limited

Keyword: Brain Injury/Concussion; Brain imaging
Link ID: 29346 - Posted: 06.06.2024

By Rebecca Horne The drawings and photographs of Santiago Ramón y Cajal are familiar to any neuroscientist—and probably anyone even remotely interested in the field. Most people who take a cursory look at his iconic images might assume that he created them using only direct observation. But that’s not the case, according to a paper published in March 2024 by Dawn Hunter, visual artist and associate professor of art at the University of South Carolina, and her colleagues. For instance, the Golgi-stained tissue Ramón y Cajal drew contained neurons that were cut in half—so he painstakingly reconstructed the cells by drawing from elements in multiple slides. And he also fleshed out his illustrations using educated guesses and classical drawing principles, such as contrast and occlusion. In this way, Ramón y Cajal’s art training was essential to his research, Hunter says. She came across Ramón y Cajal’s drawings while creating illustrations for a neuroscience textbook. “The first time I saw his work, out of pure inspiration, I decided to draw it,” she says. “It was in those moments of drawing that I realized his process was more profound and conceptually layered than merely retracing pencil lines with ink. Examining Ramón y Cajal’s work through the act of drawing is a more active experience than viewing his work as a gallery visitor or in a textbook.” In 2015, Hunter installed her drawings and paintings alongside original Ramón y Cajal works in an ongoing exhibition at the U.S. National Institutes of Health (NIH). That effort led to a Fulbright fellowship to Spain in 2017, providing her access to the Legado Cajal archives at the Instituto Cajal National Archives, which contain thousands of Ramón y Cajal artifacts. Hunter spoke to The Transmitter about her research in Spain and her realizations about how Ramón y Cajal worked as an artist and as a scientist. The Transmitter: What do you think your work contributes that is new? Dawn Hunter: It spells out the connection to [Ramón y Cajal’s] art training. There are some things that to me as a painter are obvious to zero in on that nobody’s really talked about. For example, Ramón y Cajal’s copying of the Renaissance painter Rafael’s entire portfolio. That in itself is a profound thing. © 2024 Simons Foundation

Keyword: Brain imaging
Link ID: 29338 - Posted: 06.04.2024

By Liqun Luo The brain is complex; in humans it consists of about 100 billion neurons, making on the order of 100 trillion connections. It is often compared with another complex system that has enormous problem-solving power: the digital computer. Both the brain and the computer contain a large number of elementary units—neurons and transistors, respectively—that are wired into complex circuits to process information conveyed by electrical signals. At a global level, the architectures of the brain and the computer resemble each other, consisting of largely separate circuits for input, output, central processing, and memory.1 Which has more problem-solving power—the brain or the computer? Given the rapid advances in computer technology in the past decades, you might think that the computer has the edge. Indeed, computers have been built and programmed to defeat human masters in complex games, such as chess in the 1990s and recently Go, as well as encyclopedic knowledge contests, such as the TV show Jeopardy! As of this writing, however, humans triumph over computers in numerous real-world tasks—ranging from identifying a bicycle or a particular pedestrian on a crowded city street to reaching for a cup of tea and moving it smoothly to one’s lips—let alone conceptualization and creativity. So why is the computer good at certain tasks whereas the brain is better at others? Comparing the computer and the brain has been instructive to both computer engineers and neuroscientists. This comparison started at the dawn of the modern computer era, in a small but profound book entitled The Computer and the Brain, by John von Neumann, a polymath who in the 1940s pioneered the design of a computer architecture that is still the basis of most modern computers today.2 Let’s look at some of these comparisons in numbers (Table 1). © 2024 NautilusNext Inc.,

Keyword: Stroke
Link ID: 29331 - Posted: 05.29.2024

By Elissa Welle A new study suggests that the brain clears less waste during sleep and under anesthesia than while in other states—directly contradicting prior results that suggest sleep initiates that process. The findings are stirring fresh debate on social media and elsewhere over the glymphatic system hypothesis, which contends that convective flow of cerebrospinal fluid clears the sleeping brain of toxins. The new work, published 13 May in Nature Neuroscience, proposes that fluid diffusion is responsible for moving waste throughout the brain. It uses a different method than the earlier studies—injecting tracers into mouse brain tissue instead of cerebrospinal fluid—which is likely a more reliable way to understand how the fluid moves through densely packed neurons, says Jason Rihel, professor of behavioral genetics at University College London, who was not involved in any of the studies on brain clearance. The findings have prompted some sleep researchers, including Rihel, to question the existence of a glymphatic system and whether brain clearance is tied to sleep-wake states, he says. But leading proponents of the sleep-induced clearance theory are pushing back against the study’s techniques. The new study is “misleading” and “extremely poorly done,” says Maiken Nedergaard, professor of neurology at the University of Rochester Medical Center, whose 2013 study on brain clearance led to the hypothesis of a glymphatic system. She says she plans to challenge the work in a proposed Matters Arising commentary for Nature Neuroscience. Inserting needles into the brain damages the tissue, and injecting fluid, as the team behind the new work did, increases intracranial pressure, says Jonathan Kipnis, professor of pathology and immunology at Washington University School of Medicine in St. Louis. Kipnis and his colleagues published a study in February in support of the glymphatic system hypothesis that suggests neural activity facilitates brain clearance. “You disturb the system when you inject into the brain,” Kipnis says, “and that’s why we were always injecting in the CSF.” © 2024 Simons Foundation

Keyword: Sleep
Link ID: 29327 - Posted: 05.25.2024

By Laura Sanders It’s a bit like seeing a world in a grain of sand. Except the view, in this case, is the exquisite detail inside a bit of human brain about half the size of a grain of rice. Held in that minuscule object is a complex collective of cells, blood vessels, intricate patterns and biological puzzles. Scientists had hints of these mysteries in earlier peeks at this bit of brain (SN: 6/29/21). But now, those details have been brought into new focus by mapping the full landscape of some 57,000 cells, 150 million synapses and their accompanying 23 centimeters of blood vessels, researchers report in the May 10 Science. The full results, the scientists hope, may lead to greater insights into how the human brain works. “We’re going in and looking at every individual connection attached to every cell — a very high level of detail,” says Viren Jain, a computational neuroscientist at Google Research in Mountain View, Calif. The big-picture goal of brain mapping efforts, he says, is “to understand how human brains work and what goes wrong in various kinds of brain diseases.” The newly mapped brain sample was removed during a woman’s surgery for epilepsy, so that doctors could reach a deeper part of the brain. The bit, donated with the woman’s consent, was from the temporal lobe of the cortex, the outer part of the brain involved in complex mental feats like thinking, remembering and perceiving. This digital drawing of a person's head shows the brain inside. An arrow points to the bottom left side of the brain. After being fixed in a preservative, the brain bit was sliced into almost impossibly thin wisps, and then each slice was imaged with a high-powered microscope. Once these views were collected, researchers used computers to digitally reconstruct the three-dimensional objects embedded in the piece of brain. © Society for Science & the Public 2000–2024

Keyword: Brain imaging; Development of the Brain
Link ID: 29324 - Posted: 05.25.2024

By Amanda Heidt For the first time, a brain implant has helped a bilingual person who is unable to articulate words to communicate in both of his languages. An artificial-intelligence (AI) system coupled to the brain implant decodes, in real time, what the individual is trying to say in either Spanish or English. The findings1, published on 20 May in Nature Biomedical Engineering, provide insights into how our brains process language, and could one day lead to long-lasting devices capable of restoring multilingual speech to people who can’t communicate verbally. “This new study is an important contribution for the emerging field of speech-restoration neuroprostheses,” says Sergey Stavisky, a neuroscientist at the University of California, Davis, who was not involved in the study. Even though the study included only one participant and more work remains to be done, “there’s every reason to think that this strategy will work with higher accuracy in the future when combined with other recent advances”, Stavisky says. The person at the heart of the study, who goes by the nickname Pancho, had a stroke at age 20 that paralysed much of his body. As a result, he can moan and grunt but cannot speak clearly. In his thirties, Pancho partnered with Edward Chang, a neurosurgeon at the University of California, San Francisco, to investigate the stroke’s lasting effects on his brain. In a groundbreaking study published in 20212, Chang’s team surgically implanted electrodes on Pancho’s cortex to record neural activity, which was translated into words on a screen. Pancho’s first sentence — ‘My family is outside’ — was interpreted in English. But Pancho is a native Spanish speaker who learnt English only after his stroke. It’s Spanish that still evokes in him feelings of familiarity and belonging. “What languages someone speaks are actually very linked to their identity,” Chang says. “And so our long-term goal has never been just about replacing words, but about restoring connection for people.” © 2024 Springer Nature Limited

Keyword: Language; Robotics
Link ID: 29321 - Posted: 05.23.2024

By Carissa Wong Researchers have mapped a tiny piece of the human brain in astonishing detail. The resulting cell atlas, which was described today in Science1 and is available online, reveals new patterns of connections between brain cells called neurons, as well as cells that wrap around themselves to form knots, and pairs of neurons that are almost mirror images of each other. The 3D map covers a volume of about one cubic millimetre, one-millionth of a whole brain, and contains roughly 57,000 cells and 150 million synapses — the connections between neurons. It incorporates a colossal 1.4 petabytes of data. “It’s a little bit humbling,” says Viren Jain, a neuroscientist at Google in Mountain View, California, and a co-author of the paper. “How are we ever going to really come to terms with all this complexity?” The brain fragment was taken from a 45-year-old woman when she underwent surgery to treat her epilepsy. It came from the cortex, a part of the brain involved in learning, problem-solving and processing sensory signals. The sample was immersed in preservatives and stained with heavy metals to make the cells easier to see. Neuroscientist Jeff Lichtman at Harvard University in Cambridge, Massachusetts, and his colleagues then cut the sample into around 5,000 slices — each just 34 nanometres thick — that could be imaged using electron microscopes. Jain’s team then built artificial-intelligence models that were able to stitch the microscope images together to reconstruct the whole sample in 3D. “I remember this moment, going into the map and looking at one individual synapse from this woman’s brain, and then zooming out into these other millions of pixels,” says Jain. “It felt sort of spiritual.” When examining the model in detail, the researchers discovered unconventional neurons, including some that made up to 50 connections with each other. “In general, you would find a couple of connections at most between two neurons,” says Jain. Elsewhere, the model showed neurons with tendrils that formed knots around themselves. “Nobody had seen anything like this before,” Jain adds. © 2024 Springer Nature Limited

Keyword: Brain imaging; Development of the Brain
Link ID: 29304 - Posted: 05.14.2024

By Miryam Naddaf Scientists have developed brain implants that can decode internal speech — identifying words that two people spoke in their minds without moving their lips or making a sound. Although the technology is at an early stage — it was shown to work with only a handful of words, and not phrases or sentences — it could have clinical applications in future. Similar brain–computer interface (BCI) devices, which translate signals in the brain into text, have reached speeds of 62–78 words per minute for some people. But these technologies were trained to interpret speech that is at least partly vocalized or mimed. The latest study — published in Nature Human Behaviour on 13 May1 — is the first to decode words spoken entirely internally, by recording signals from individual neurons in the brain in real time. “It's probably the most advanced study so far on decoding imagined speech,” says Silvia Marchesotti, a neuroengineer at the University of Geneva, Switzerland. “This technology would be particularly useful for people that have no means of movement any more,” says study co-author Sarah Wandelt, a neural engineer who was at the California Institute of Technology in Pasadena at the time the research was done. “For instance, we can think about a condition like locked-in syndrome.” The researchers implanted arrays of tiny electrodes in the brains of two people with spinal-cord injuries. They placed the devices in the supramarginal gyrus (SMG), a region of the brain that had not been previously explored in speech-decoding BCIs. © 2024 Springer Nature Limited

Keyword: Brain imaging; Language
Link ID: 29302 - Posted: 05.14.2024

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

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

By McKenzie Prillaman It was hailed as a potentially transformative technique for measuring brain activity in animals: direct imaging of neuronal activity (DIANA), held the promise of mapping neuronal activity so fast that neurons could be tracked as they fired. But nearly two years on from the 2022 Science paper1, no one outside the original research group and their collaborators have been able to reproduce the results. Now, two teams have published a record of their replication attempts — and failures. The studies, published on 27 March in Science Advances2,3, suggest that the original results were due to experimental error or data cherry-picking, not neuronal activity after all. But the lead researcher behind the original technique stands by the results. “I’m also very curious as to why other groups fail in reproducing DIANA,” says Jang-Yeon Park, a magnetic resonance imaging (MRI) physicist at Sungkyunkwan University in Suwon, South Korea. Science said in an e-mail to Nature that, although it’s important to report the negative results, the Science Advances studies “do not allow a definitive conclusion” to be drawn about the original work, “because there were methodological differences between the papers”. In conventional functional MRI (fMRI), researchers monitor changes in blood flow to different brain regions to estimate activity. But this response lags by at least one second behind the activity of neurons, which send messages in milliseconds. Park and his co-authors said that DIANA could measure neuronal activity directly, which is an “extraordinary claim”, says Ben Inglis, a physicist at the University of California, Berkeley. © 2024 Springer Nature Limited

Keyword: Brain imaging
Link ID: 29253 - Posted: 04.11.2024

By Claudia López Lloreda As animals carry out complex behaviors, multiple brain areas turn on and talk to one another. But neuroscientists have had limited means to measure that neuronal dialogue. Electrical recordings, for example, are typically constrained to one brain area at a time, or require that mice have their head fixed in a specific position. A new technology overcomes those restrictions. The device, called E-Scope, reported in a peer-reviewed preprint in eLife, effectively measures the activity of neurons in two different areas at the same time, even as rodents move freely. The headset captures images of calcium currents, made using a microscope, and recordings of neurons’ electrical activity through electrodes to show how the cerebellum communicates with other brain regions during social interaction in mice. “Everything [is] synchronized together that way,” says Peyman Golshani, assistant professor of neurology at the University of California, Los Angeles and a study investigator. This approach holds the potential to illuminate how coordination between brain areas in conditions marked by impaired social interaction, such as attention-deficit/hyperactivity disorder and autism, is disrupted, Golshani says. By combining technologies, researchers who use the E-Scope “don’t need separate electrophysiology and imaging hardware,” he adds. It’s also much more comfortable for the animals, according to Golshani. A single wire conveys all of the small headset’s data, so mice can move more freely than when wearing other devices. © 2024 Simons Foundation

Keyword: Brain imaging
Link ID: 29244 - Posted: 04.06.2024

By Nico Dosenbach, Scott Marek In 2022, we caused a stir when, together with Brenden Tervo-Clemmens and Damien Fair, we published an article in Nature titled “Reproducible brain-wide association studies require thousands of participants.” The study garnered a lot of attention—press coverage, including in Spectrum, as well as editorials and commentary in journals. In hindsight, the consternation we caused in calling for larger sample sizes makes sense; up to that point, most brain imaging studies of this type were based on samples with fewer than 100 participants, so our findings called for a major change. But it was an eye-opening experience that taught us how difficult it is to convey a nuanced scientific message and to guard against oversimplifications and misunderstandings, even among experts. Being scientific is hard for human brains, but as an adversarial collaboration on a massive scale, science is our only method for collectively separating how we want things to be from how they are. The paper emerged from an analysis of the Adolescent Brain Cognitive Development (ABCD) Study, a large longitudinal brain-imaging project. Starting with data from 2,000 children, Scott showed that an average brain connectivity map he made using half of the large sample replicated almost perfectly in the other half. But when he mapped the association between resting-state activity—a measure of the brain during rest—and intelligence in two matched sets of 1,000 children, he found large differences in the patterns. Even with a sample size of 2,000—large in the human brain imaging world—the brain-behavior maps showed poor reproducibility. For card-carrying statisticians, the result was not surprising. It reflected a pattern known as the winner’s curse, namely that large cross-sectional correlations can occur by chance in small samples. Paradoxically, the largest correlations will be “statistically significant” and therefore most likely to be published, even though they are the most likely to be wrong. © 2024 Simons Foundation

Keyword: Brain imaging
Link ID: 29215 - Posted: 03.26.2024

By Nora Bradford Early in her research, forensic anthropologist Alexandra Morton-Hayward came across a paper describing a 2,500-year-old brain preserved in a severed skull. The paper referenced another preserved brain. She found another. And another. By the time she’d reached 12, she noticed all of the papers described the brains as a unique phenomenon. She kept digging. Naturally preserved brains, it turns out, aren’t so rare after all, Morton-Hayward, of the University of Oxford, and colleagues report March 20 in Proceedings of the Royal Society B. The researchers have built an archive of 4,400 human brains preserved in the archaeological record, some dating back nearly 12,000 years. The archive includes brains from North Pole explorers, Inca sacrificial victims and Spanish Civil War soldiers. Because the brains have been described as exceptionally rare, little research has been done on them. “If they’re precious, one-of-a-kind materials, then you don’t want to analyze them or disturb them,” Morton-Hayward says. Less than 1 percent of the archive has been investigated. Matching where the brains were found with historical climate patterns hints at what might keep the brains from decaying. Over a third of the samples persisted because of dehydration; others were frozen or tanned. Depending on the conditions, the brains’ texture could be anywhere from dry and brittle to squishy and tofulike. © Society for Science & the Public 2000–2024.

Keyword: Brain imaging
Link ID: 29206 - Posted: 03.21.2024

By Claudia López Lloreda Loss of smell, headaches, memory problems: COVID-19 can bring about a troubling storm of neurological symptoms that make everyday tasks difficult. Now new research adds to the evidence that inflammation in the brain might underlie these symptoms. Not all data point in the same direction. Some new studies suggest that SARS-CoV-2, the virus that causes COVID-19, directly infects brain cells. Those findings bolster the hypothesis that direct infection contributes to COVID-19-related brain problems. But the idea that brain inflammation is key has gotten fresh support: one study, for example, has identified specific brain areas prone to inflammation in people with COVID-191. “The whole body of literature is starting to come together a little bit more now and give us some more concrete answers,” says Nicola Fletcher, a neurovirologist at University College Dublin. Immunological storm When researchers started looking for a culprit for the brain problems caused by COVID-19, inflammation quickly became a key suspect. That’s because inflammation — the flood of immune cells and chemicals that the body releases against intruders — has been linked to the cognitive symptoms caused by other viruses, such as HIV. SARS-CoV-2 stimulates a strong immune response throughout the body, but it was unclear whether brain cells themselves contributed to this response and, if so, how. Helena Radbruch, a neuropathologist at the Charité – Berlin University Medicine, and her colleagues looked at brain samples from people who’d died of COVID-19. They didn’t find any cells infected with SARS-CoV-2. But they did find these people had more immune activity in certain brain areas than did people who died from other causes. This unusual activity was noticeable in regions such as the olfactory bulb, which is involved in smell, and the brainstem, which controls some bodily functions, such as breathing. It was seen only in the brains of people who had died soon after catching the virus. © 2024 Springer Nature Limited

Keyword: Learning & Memory; Attention
Link ID: 29202 - Posted: 03.21.2024

By Clay Risen Mary Bartlett Bunge, who with her husband, Richard, studied how the body responds to spinal cord injuries and continued their work after his death in 1996, ultimately discovering a promising treatment to restore movement to millions of paralyzed patients, died on Feb. 17, at her home in Coral Gables, Fla. She was 92. The Miami Project to Cure Paralysis, a nonprofit research organization with which Dr. Bunge (pronounced BUN-ghee) was affiliated, announced the death. “She definitely was the top woman in neuroscience, not just in the United States but in the world,” Dr. Barth Green, a co-founder and dean at the Miami Project, said in a phone interview. Dr. Bunge’s focus for much of her career was on myelin, a mix of proteins and fatty acids that coats nerve fibers, protecting them and boosting the speed at which they conduct signals. Early in her career, she and her husband, whom she met as a graduate student at the University of Wisconsin in the 1950s, used new electron microscopes to describe the way that myelin developed around nerve fibers, and how, after because of injury or illness, it receded, in a process called demyelination. Treating spinal-cord injuries is one of the most frustrating corners of medical research. Thousands of people are left partially or fully paralyzed after automobile accidents, falls, sports injuries and gun violence each year. Unlike other parts of the body, the spinal cord is stubbornly difficult to rehabilitate. Through their research, the Bunges concluded that demyelination was one reason spinal-cord injuries have been so difficult for the body to repair — an insight that in turn opened doors to the possibility of reversing it through treatments. © 2024 The New York Times Company

Keyword: Glia; Regeneration
Link ID: 29175 - Posted: 03.05.2024

By Liam Drew The first person to receive a brain-monitoring device from neurotechnology company Neuralink can control a computer cursor with their mind, Elon Musk, the firm’s founder, revealed this week. But researchers say that this is not a major feat — and they are concerned about the secrecy around the device’s safety and performance. The company is “only sharing the bits that they want us to know about”, says Sameer Sheth, a neurosurgeon specializing in implanted neurotechnology at Baylor College of Medicine in Houston, Texas. “There’s a lot of concern in the community about that.” Threads for thoughts Musk announced on 29 January that Neuralink had implanted a brain–computer interface (BCI) into a human for the first time. Neuralink, which is headquartered in Fremont, California, is the third company to start long-term trials in humans. Some implanted BCIs sit on the brain’s surface and record the average firing of populations of neurons, but Neuralink’s device, and at least two others, penetrates the brain to record the activity of individual neurons. Neuralink’s BCI contains 1,024 electrodes — many more than previous systems — arranged on innovative pliable threads. The company has also produced a surgical robot for inserting its device. But it has not confirmed whether that system was used for the first human implant. Details about the first recipient are also scarce, although Neuralink’s volunteer recruitment brochure says that people with quadriplegia stemming from certain conditions “may qualify”.

Keyword: Robotics; Brain imaging
Link ID: 29163 - Posted: 02.25.2024