Chapter 2. Functional Neuroanatomy: The Cells and Structure of the Nervous System

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By Miryam Naddaf Moving a prosthetic arm. Controlling a speaking avatar. Typing at speed. These are all things that people with paralysis have learnt to do using brain–computer interfaces (BCIs) — implanted devices that are powered by thought alone. These devices capture neural activity using dozens to hundreds of electrodes embedded in the brain. A decoder system analyses the signals and translates them into commands. Although the main impetus behind the work is to help restore functions to people with paralysis, the technology also gives researchers a unique way to explore how the human brain is organized, and with greater resolution than most other methods. Scientists have used these opportunities to learn some basic lessons about the brain. Results are overturning assumptions about brain anatomy, for example, revealing that regions often have much fuzzier boundaries and job descriptions than was thought. Such studies are also helping researchers to work out how BCIs themselves affect the brain and, crucially, how to improve the devices. “BCIs in humans have given us a chance to record single-neuron activity for a lot of brain areas that nobody’s ever really been able to do in this way,” says Frank Willett, a neuroscientist at Stanford University in California who is working on a BCI for speech. The devices also allow measurements over much longer time spans than classical tools do, says Edward Chang, a neurosurgeon at the University of California, San Francisco. “BCIs are really pushing the limits, being able to record over not just days, weeks, but months, years at a time,” he says. “So you can study things like learning, you can study things like plasticity, you can learn tasks that require much, much more time to understand.” © 2024 Springer Nature Limited

Keyword: Brain imaging; Robotics
Link ID: 29159 - Posted: 02.22.2024

Nicola Davis Science correspondent From forgetfulness to difficulties concentrating, many people who have long Covid experience “brain fog”. Now researchers say the symptom could be down to the blood-brain barrier becoming leaky. The barrier controls which substances or materials enter and exit the brain. “It’s all about regulating a balance of material in blood compared to brain,” said Prof Matthew Campbell, co-author of the research at Trinity College Dublin. “If that is off balance then it can drive changes in neural function and if this happens in brain regions that allow for memory consolidation/storage then it can wreak havoc.” Writing in the journal Nature Neuroscience, Campbell and colleagues report how they analysed serum and plasma samples from 76 patients who were hospitalised with Covid in March or April 2020, as well 25 people before the pandemic. Among other findings, the team discovered that samples from the 14 Covid patients who self-reported brain fog contained higher levels of a protein called S100β than those from Covid patients without this symptom, or people who had not had Covid. caskets at a funeral home This protein is produced by cells within the brain, and is not normally found in the blood, suggesting these patients had a breakdown of the blood-brain barrier. The researchers then recruited 10 people who had recovered from Covid and 22 people with long Covid – 11 of whom reported having brain fog. None had, at that point, received a Covid vaccine, or been hospitalised for Covid. These participants underwent an MRI scan in which a dye was administered intravenously. The results reveal long Covid patients with brain fog did indeed show signs of a leaky blood-brain barrier, but not those without this symptom, or who had recovered. © 2024 Guardian News & Media Limited

Keyword: Neuroimmunology
Link ID: 29158 - Posted: 02.22.2024

Rob Stein Benjamin Franklin famously wrote: "In this world nothing can be said to be certain, except death and taxes." While that may still be true, there's a controversy simmering today about one of the ways doctors declare people to be dead. The debate is focused on the Uniform Determination of Death Act, a law that was adopted by most states in the 1980s. The law says that death can be declared if someone has experienced "irreversible cessation of all functions of the entire brain." But some parts of the brain can continue to function in people who have been declared brain dead, prompting calls to revise the statute. Many experts say the discrepancy needs to be resolved to protect patients and their families, maintain public trust and reconcile what some see as a troubling disconnect between the law and medical practice. The debate became so contentious, however, that the Uniform Law Commission, the group charged with rewriting model laws for states, paused its process last summer because participants couldn't reach a consensus. "I'm worried," says Thaddeus Pope, a bioethicist and lawyer at Mitchell Hamline School of Law in St. Paul, Minnesota. "There's a lot of conflict at the bedside over this at hospitals across the United States. Let's get in front of it and fix it before it becomes a crisis. It's such an important question that everyone needs to be on the same page." The second method, brain death, can be declared for people who have sustained catastrophic brain injury causing the permanent cessation of all brain function, such as from a massive traumatic brain injury or massive stroke, but whose hearts are still pumping through the use of ventilators or other artificial forms of life support. © 2024 npr

Keyword: Brain Injury/Concussion; Brain imaging
Link ID: 29147 - Posted: 02.13.2024

Nicholas J. Kelley In the middle of 2023, a study conducted by the HuthLab at the University of Texas sent shockwaves through the realms of neuroscience and technology. For the first time, the thoughts and impressions of people unable to communicate with the outside world were translated into continuous natural language, using a combination of artificial intelligence (AI) and brain imaging technology. This is the closest science has yet come to reading someone’s mind. While advances in neuroimaging over the past two decades have enabled non-responsive and minimally conscious patients to control a computer cursor with their brain, HuthLab’s research is a significant step closer towards accessing people’s actual thoughts. As Alexander Huth, the neuroscientist who co-led the research, told the New York Times: Combining AI and brain-scanning technology, the team created a non-invasive brain decoder capable of reconstructing continuous natural language among people otherwise unable to communicate with the outside world. The development of such technology – and the parallel development of brain-controlled motor prosthetics that enable paralysed patients to achieve some renewed mobility – holds tremendous prospects for people suffering from neurological diseases including locked-in syndrome and quadriplegia. In the longer term, this could lead to wider public applications such as fitbit-style health monitors for the brain and brain-controlled smartphones. On January 29, Elon Musk announced that his Neuralink tech startup had implanted a chip in a human brain for the first time. He had previously told followers that Neuralink’s first product, Telepathy, would one day allow people to control their phones or computers “just by thinking”. © 2010–2024, The Conversation US, Inc.

Keyword: Brain imaging
Link ID: 29136 - Posted: 02.08.2024

Jon Hamilton Scientists know that Black people are at a greater risk for health problems like heart disease, diabetes and Alzheimer's disease than white people. A growing body of research shows that racism in health care and in daily life contributes to these long-standing health disparities for Black communities. Now, some researchers are asking whether part of the explanation involves how racism, across individual interactions and systems, may physically alter the brain. "That could be behaviors like, let's say, a woman clutching her purse as a black man is walking next to her. Or they could be verbal, like someone saying, like... 'I didn't expect you to be so articulate,'" says Negar Fani, a clinical neuroscientist at Emory University who studies people experiencing Posttraumatic Stress Disorder, or PTSD. Recently, Fani has collaborated with Nate Harnett, an assistant professor of psychiatry at Harvard Medical School, to study how the brain responds to traumatic events and extreme stress, including the events and stress related to racism. So how does one go about measuring the impact of zoomed out, societal-scale issues on the individual? Harnett is the first to admit, it's not the simplest task. "It's very difficult for neuroimaging to look specifically at redlining," notes Harnett. But he can—indirectly. For example, Harnett has used inequities in neighborhood resources as a way of tracking or measuring structural racism. "We're able to look at these sort of proxy measures in these outcomes of structural racism and then correlate those with both brain and behavioral responses to stress or trauma and see how they tie with different psychiatric disorders like PTSD," Harnett says. In other research, Harnett and Fani have looked at correlations between racial discrimination and the response to threat in Black women who had experienced trauma. Fani says patients who experience PTSD tend to be more vigilant or show hyperarousal and be startled easily. Fani says their bodies are in a constant state of fight or flight—even when they're in a safe situation. But in patients who've also experienced racial discrimination, Fani says she sees the opposite effect: They show an increased activation in areas related to emotion regulation. In some ways, Fani says this activation can be adaptive. For example, people may experience microaggressions or discrimination at work and need to regulate their emotional response in order to get through the moment. But when people have to utilize this strategy over long periods of time, Fani and Harnett think it may contribute to the degradation they've seen in other areas in the brain. © 2024 npr

Keyword: Stress; Aggression
Link ID: 29114 - Posted: 01.27.2024

By Evelyn Lake Functional MRI (fMRI), though expensive, has many properties of an ideal clinical tool. It’s safe and noninvasive. It is widely available in some countries, and increasingly so on a global scale. Its “blood oxygen level dependent,” or BOLD, signal is altered in people with almost any neurological condition and is rich enough to contain information specific to each person, offering the potential for a personalized approach to medical care across a wide spectrum of neurological conditions. But despite enormous interest and investment in fMRI — and its wide use in basic neuroscience research — it still lacks broad clinical utility; it is mainly employed for surgical planning. For fMRI to inform a wider range of clinical decision-making, we need better ways of deciphering what underlying changes in the brain drive changes to the BOLD signal. If someone with Alzheimer’s disease has an increase in functional connectivity (a measure of synchrony between brain regions), for example, does this indicate that synapses are being lost? Or does it suggest that the brain is forming compensatory pathways to help the person avoid further cognitive decline? Or something else entirely? Depending on the answer, one can imagine different courses of treatment. Put simply, we cannot extract sufficient information from fMRI and patient outcomes alone to determine which scenarios are playing out and therefore what we should do when we observe changes in our fMRI readouts. To better understand what fMRI actually shows, we need to use complementary methodologies, such as the emerging optical imaging tool of wide-field fluorescence calcium imaging. Combining modalities presents significant technical challenges but offers the potential for deeper insights: observing the BOLD signal alongside other signals that report more directly on what is occurring in brain tissue. Using these more direct measurements instead of fMRI in clinical practice is not an option — they are unethical to use in people or invasive, requiring physical or optical access to the brain. © 2023 Simons Foundation.

Keyword: Brain imaging
Link ID: 29109 - Posted: 01.23.2024

By Mark Johnson In the first study of its kind in humans, researchers have discovered that it is safe to use sound waves fired into specific areas of the brain to open a protective barrier and clear the way for Alzheimer’s medications. The study, reported in the New England Journal of Medicine, involved just three patients, but it raises hope about the long-term potential of the treatment strategy known as focused ultrasound. “We want to be very cautious. This is the first three people in the world that have had this [treatment]. What we’ve learned from this, I think, can help us,” said Ali Rezai, lead author of the study and executive chair and director of the Rockefeller Neuroscience Institute at West Virginia University. Rezai stressed that the goal of the research is not to replace pharmaceutical treatments but to improve their benefits by helping more of the drug penetrate the brain. Nature has provided humans with a barrier made of tightly packed cells that blocks harmful toxins, such as viruses, bacteria and fungi, from reaching the brain. Known as the blood-brain barrier, this shield has for decades presented a major challenge to scientists trying to treat neurodegenerative diseases such as Alzheimer’s and Parkinson’s, which afflict at least 7 million Americans. The barrier is a locked door that stops about 98 percent of treatments from reaching the brain. With focused ultrasound, Rezai explained, “what we want to do is push individuals toward the milder stages of Alzheimer’s with less plaques to give them a fighting chance.” Two men and a woman suffering from mild loss of memory, learning, concentration and decision-making skills due to Alzheimer’s took part in the study. The patients, who ranged in age from 59 to 77, were given six monthly doses of the federally approved — if somewhat controversial — lab-made antibody aducanumab, sold under the brand name Aduhelm. The antibody, which is administered directly into a patient’s vein, reduces a sticky substance in the brain called amyloid beta, which clumps between neurons and disrupts their function.

Keyword: Alzheimers; Brain imaging
Link ID: 29085 - Posted: 01.09.2024

By Fletcher Reveley One afternoon in May 2020, Jerry Tang, a Ph.D. student in computer science at the University of Texas at Austin, sat staring at a cryptic string of words scrawled across his computer screen: “I am not finished yet to start my career at twenty without having gotten my license I never have to pull out and run back to my parents to take me home.” The sentence was jumbled and agrammatical. But to Tang, it represented a remarkable feat: A computer pulling a thought, however disjointed, from a person’s mind. For weeks, ever since the pandemic had shuttered his university and forced his lab work online, Tang had been at home tweaking a semantic decoder — a brain-computer interface, or BCI, that generates text from brain scans. Prior to the university’s closure, study participants had been providing data to train the decoder for months, listening to hours of storytelling podcasts while a functional magnetic resonance imaging (fMRI) machine logged their brain responses. Then, the participants had listened to a new story — one that had not been used to train the algorithm — and those fMRI scans were fed into the decoder, which used GPT1, a predecessor to the ubiquitous AI chatbot ChatGPT, to spit out a text prediction of what it thought the participant had heard. For this snippet, Tang compared it to the original story: “Although I’m twenty-three years old I don’t have my driver’s license yet and I just jumped out right when I needed to and she says well why don’t you come back to my house and I’ll give you a ride.” The decoder was not only capturing the gist of the original, but also producing exact matches of specific words — twenty, license. When Tang shared the results with his adviser, a UT Austin neuroscientist named Alexander Huth who had been working towards building such a decoder for nearly a decade, Huth was floored. “Holy shit,” Huth recalled saying. “This is actually working.”

Keyword: Brain imaging; Language
Link ID: 29073 - Posted: 01.03.2024

By Gary Stix This year was full of roiling debate and speculation about the prospect of machines with superhuman capabilities that might, sooner than expected, leave the human brain in the dust. A growing public awareness of ChatGPT and other so-called large language models (LLMs) dramatically expanded public awareness of artificial intelligence. In tandem, it raised the question of whether the human brain can keep up with the relentless pace of AI advances. The most benevolent answer posits that humans and machines need not be cutthroat competitors. Researchers found one example of potential cooperation by getting AI to probe the infinite complexity of the ancient game of Go—which, like chess, has seen a computer topple the highest-level human players. A study published in March showed how people might learn from machines with such superhuman skills. And understanding ChatGPT’s prodigious abilities offers some inkling as to why an equivalence between the deep neural networks that underlie the famed chatbot and the trillions of connections in the human brain is constantly invoked. Importantly, the machine learning incorporated into AI has not totally distracted mainstream neuroscience from avidly pursuing better insights into what has been called “the most complicated object in the known universe”: the brain. One of the grand challenges in science—understanding the nature of consciousness—received its due in June with the prominent showcasing of experiments that tested the validity of two competing theories, both of which purport to explain the underpinnings of the conscious self. The past 12 months provided lots of examples of impressive advances for you to store in your working memory. Now here’s a closer look at some of the standout mind and brain stories we covered in Scientific American in 2023. © 2023 SCIENTIFIC AMERICAN

Keyword: Brain imaging; Consciousness
Link ID: 29069 - Posted: 12.31.2023

By The Transmitter It has been a year of many firsts for the Transmitter team. Despite launching this site just over a month ago, though, we published dozens of news stories on a range of important topics in neuroscience research earlier in the year in Spectrum. Here, we bring you a short list of some of our favorites, which broke news about changes in research leadership, exposed issues in studies involving human participants, provided new insights into the brain’s neuropeptide signaling network and memory-encoding mechanisms, and gave glimpses into the lives neuroscientists lead outside of work. ‘Wireless’ connectomes detail signaling outside synapses Connectomes were once again all the rage this year. As some teams continued to map the complete circuitry of increasingly larger brains — including those of a larval and an adult fruit fly — other teams went back to basics, plugging some invisible gaps of the humble roundworm’s synaptic connectome. Those latter efforts detail how neurons communicate using short proteins called neuropeptides outside synapses, helping to address key criticisms of conventional wiring diagrams. Neural ‘barcodes’ help seed-stashing birds recall their hidden haul As we enter the throes of winter here in New York City, some of the resident non-migratory birds may begin to seek out the seeds they stashed earlier in the year to help them survive for the next few months. Their ability to relocate their caches may stem from memories stored in the hippocampus in the form of non-overlapping patterns of brain activity, or “barcodes,” new research suggests. These barcodes originate when a bird hides a seed and reappear only when the bird returns to that same seed — and may represent the basis for episodic memories of specific events in time. © 2023 Simons Foundation.

Keyword: Miscellaneous
Link ID: 29068 - Posted: 12.27.2023

Emily Baumgaertner This is not a work of art. It’s an image of microscopic blood flow in a rat’s brain, taken with one of many new tools that are yielding higher levels of detail in brain imaging. Here are seven more glorious images from neuroscience research → © 2023 The New York Times Company

Keyword: Brain imaging
Link ID: 29059 - Posted: 12.22.2023

By Yasemin Saplakoglu In the 16th century, the Belgian cartographer Abraham Ortelius created the world’s first modern atlas — a collection of maps that he called “The Theater of the World.” The maps, drawn by Ortelius and others, detailed what was at the time the best knowledge of the world’s continents, cities, mountains, rivers, lakes and oceans and helped usher in a new understanding of global geography. Similarly, the creation of cell atlases — maps of organs and bodies constructed cell by cell — is heralding a new era in our understanding of biology. Powerful sequencing and imaging technologies invented in the last decade are revealing with unprecedented detail the composition of human organs and tissues, from the pancreas and liver to the placenta, as well as those of other animals like the mouse and fruit fly. With these new tools, researchers can fingerprint individual cells based on which genes they are expressing. That information has revealed subtle and unsuspected distinctions among cells and has begun to illuminate how the diversity of cell types can be essential to the healthy functioning of organs. “We’re at this amazing point in time in science where we’re now able to understand the composition of these cell types,” said Steve Quake, a bioengineer and biophysicist at Stanford University who helped develop the technologies that make cell atlases possible. “It’s changed the way we understand how human biology works.” Two cell atlas efforts, part of the National Institutes of Health’s $250 million brain cell census, that just released their findings illustrate the excitement bubbling up in the field. Today in Nature, a coalition of laboratories published nine studies that collectively form a detailed atlas of the mouse brain — the most comprehensive mammalian brain atlas to date. It describes more than 5,300 types of cells found throughout the organ. How these cells are distributed and are related to one another suggests many intriguing ideas about the evolution of the mammalian brain. All Rights Reserved © 2023

Keyword: Development of the Brain; Brain imaging
Link ID: 29053 - Posted: 12.16.2023

By Simon Makin Our thoughts and feelings arise from networks of neurons, brain cells that send signals using chemicals called neurotransmitters. But neurons aren't alone. They're supported by other cells called glia (Greek for “glue”), which were once thought to hold nerve tissue together. Today glia are known to help regulate metabolism, protect neurons and clean up cellular waste—critical but unglamorous roles. Now, however, neuroscientists have discovered a type of “hybrid” glia that sends signals using glutamate, the brain's most common neurotransmitter. These findings, published in Nature, breach the rigid divide between signaling neurons and supportive glia. “I hope it's a boost for the field to move forward, to maybe begin studying why certain [brain] circuits have this input and others don't,” says study co-author Andrea Volterra, a neuroscientist at the University of Lausanne in Switzerland. Around 30 years ago researchers began reporting that star-shaped glia called astrocytes could communicate with neurons. The idea was controversial, and further research produced contradictory results. To resolve the debate, Volterra and his team analyzed existing data from mouse brains. These data were gathered using a technique called single-cell RNA sequencing, which lets researchers catalog individual cells' molecular profiles instead of averaging them in a bulk tissue sample. Of nine types of astrocytes they found in the hippocampus—a key memory region—one had the cellular machinery required to send glutamate signals. The small numbers of these cells, present only in certain regions, may explain why earlier research missed them. “It's quite convincing,” says neuroscientist Nicola Hamilton-Whitaker of King's College London, who was not involved in the study. “The reason some people may not have seen these specialized functions is they were studying different astrocytes.” © 2023 SCIENTIFIC AMERICAN,

Keyword: Glia
Link ID: 29025 - Posted: 11.26.2023

Liam Drew In a laboratory in San Francisco, California, a woman named Ann sits in front of a huge screen. On it is an avatar created to look like her. Thanks to a brain–computer interface (BCI), when Ann thinks of talking, the avatar speaks for her — and in her own voice, too. In 2005, a brainstem stroke left Ann almost completely paralysed and unable to speak. Last year, neurosurgeon Edward Chang, at the University of California, San Francisco, placed a grid of more than 250 electrodes on the surface of Ann’s brain, on top of the regions that once controlled her body, face and larynx. As Ann imagined speaking certain words, researchers recorded her neural activity. Then, using machine learning, they established the activity patterns corresponding to each word and to the facial movements Ann would, if she could, use to vocalize them. The system can convert speech to text at 78 words per minute: a huge improvement on previous BCI efforts and now approaching the 150 words per minute considered average for regular speech1. Compared with two years ago, Chang says, “it’s like night and day”. In an added feat, the team programmed the avatar to speak aloud in Ann’s voice, basing the output on a recording of a speech she made at her wedding. “It was extremely emotional for Ann because it was the first time that she really felt that she was speaking for almost 20 years,” says Chang. This work was one of several studies in 2023 that boosted excitement about implantable BCIs. Another study2 also translated neural activity into text at unprecedented speed. And in May, scientists reported that they had created a digital bridge between the brain and spinal cord of a man paralysed in a cycling accident3. A BCI decoded his intentions to move and directed a spinal implant to stimulate the nerves of his legs, allowing him to walk. © 2023 Springer Nature Limited

Keyword: Brain imaging; Language
Link ID: 28997 - Posted: 11.11.2023

by Giorgia Guglielmi / The ability to see inside the human brain has improved diagnostics and revealed how brain regions communicate, among other things. Yet questions remain about the replicability of neuroimaging studies that aim to connect structural or functional differences to complex traits or conditions, such as autism. Some neuroscientists call these studies ‘brain-wide association studies’ — a nod to the ‘genome-wide association studies,’ or GWAS, that link specific variants to particular traits. But unlike GWAS, which typically analyze hundreds of thousands of genomes at once, most published brain-wide association studies involve, on average, only about two dozen participants — far too few to yield reliable results, a March analysis suggests. Spectrum talked to Damien Fair, co-lead investigator on the study and director of the Masonic Institute for the Developing Brain at the University of Minnesota in Minneapolis, about solutions to the problem and reproducibility issues in neuroimaging studies in general. Spectrum: How have neuroimaging studies changed over time, and what are the consequences? Damien Fair: The realization that we could noninvasively peer inside the brain and look at how it’s reacting to certain types of stimuli blew open the doors on studies correlating imaging measurements with behaviors or phenotypes. But even though there was a shift in the type of question that was being asked, the study design stayed identical. That has caused a lot of the reproducibility issues we’re seeing today, because we didn’t change sample sizes. The opportunity is huge right now because we finally, as a community, are understanding how to use magnetic resonance imaging for highly reliable, highly reproducible, highly generalizable findings. S: Where did the reproducibility issues in neuroimaging studies begin? DF: The field got comfortable with a certain type of study that provided significant and exciting results, but without having the rigor to show how those findings reproduced. For brain-wide association studies, the importance of having large samples just wasn’t realized until more recently. It was the same problem in the early age of genome-wide association studies looking at common genetic variants and how they relate to complex traits. If you’re underpowered, highly significant results may not generalize to the population. © 2023 Simons Foundation

Keyword: Brain imaging
Link ID: 28980 - Posted: 11.01.2023

By Carl Zimmer An international team of scientists has mapped the human brain in much finer resolution than ever before. The brain atlas, a $375 million effort started in 2017, has identified more than 3,300 types of brain cells, an order of magnitude more than was previously reported. The researchers have only a dim notion of what the newly discovered cells do. The results were described in 21 papers published on Thursday in Science and several other journals. Ed Lein, a neuroscientist at the Allen Institute for Brain Science in Seattle who led five of the studies, said that the findings were made possible by new technologies that allowed the researchers to probe millions of human brain cells collected from biopsied tissue or cadavers. “It really shows what can be done now,” Dr. Lein said. “It opens up a whole new era of human neuroscience.” Still, Dr. Lein said that the atlas was just a first draft. He and his colleagues have only sampled a tiny fraction of the 170 billion cells estimated to make up the human brain, and future surveys will certainly uncover more cell types, he said. Biologists first noticed in the 1800s that the brain was made up of different kinds of cells. In the 1830s, the Czech scientist Jan Purkinje discovered that some brain cells had remarkably dense explosions of branches. Purkinje cells, as they are now known, are essential for fine-tuning our muscle movements. Later generations developed techniques to make other cell types visible under a microscope. In the retina, for instance, researchers found cylindrical “cone cells” that capture light. By the early 2000s, researchers had found more than 60 types of neurons in the retina alone. They were left to wonder just how many kinds of cells were lurking in the deeper recesses of the brain, which are far harder to study. © 2023 The New York Times Company

Keyword: Brain imaging; Development of the Brain
Link ID: 28963 - Posted: 10.14.2023

By Laura Sanders A new look at the human brain is beginning to reveal the inner lives of its cellular residents. The human brain holds a dizzying collection of diverse cells, and no two brains are the same, cellularly speaking. Those are the prevailing conclusions of an onslaught of 21 papers published online October 12 in Science, Science Advances and Science Translational Medicine. The results just start to scratch the surface of understanding the mysteries of the brain. Still, they provide the most intimate look yet at the cells that build the brain, and offer clues about how the brain enables thoughts, actions and memories. The collection of data may also guide researchers in their hunt for the causes of brain disorders such as schizophrenia, Alzheimer’s disease and depression. The new brain map is a result of a coordinated international research effort called the National Institutes of Health’s Brain Initiative Cell Census Network, or BICCN, which ramped up in 2017. Many of the studies in the collection are based on a powerful technology called single-cell genomics. The method reveals which genes are active inside of a single cell, information that provides clues about the cell’s identity and job. As part of the BICCN, researchers examined all sorts of brains. One project detailed the cells in small pieces of live brain tissue taken from 75 people undergoing surgery for tumors or epilepsy, an approach that’s been used on smaller scales before (SN: 8/7/19). Another looked at samples taken from the brains of 17 deceased children. Still another looked at brain tissue from seven people, seven chimpanzees, four gorillas, three rhesus macaques and three marmosets. © Society for Science & the Public 2000–2023.

Keyword: Development of the Brain; Brain imaging
Link ID: 28962 - Posted: 10.14.2023

by Maris Fessenden A new lightweight device with a wisplike tether can record neural activity while mice jump, run and explore their environment. The open-source recording system, which its creators call ONIX, overcomes several of the limitations of previous systems and enables the rodents to move more freely during recording. The behavior that ONIX allows brings to mind children running around in a playground, says Jakob Voigts, a researcher at the Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Virginia, who helped build and test the system. He and his colleagues describe their work in a preprint posted on bioRxiv earlier this month. To understand how the brain creates complex behaviors — such as those found in social interaction, sensory processing and cognition, which are commonly affected in autism — researchers observe brain signals as these behaviors unfold. Head-mounted devices enable researchers to eavesdrop on the electrical chatter between brain cells in mice, rats and primates. But as the smallest of these animal models, mice present some significant challenges. Current neural recording systems are bulky and heavy, making the animals carry up to a fifth of their body weight on their skulls. Predictably, this slows the mice down and tires them out. And most neural recording systems use a tether to relay signals from the mouse’s brain to a computer. But this tether twists and tangles as the mouse turns its head and body, exerting torque that the mouse can feel. Researchers must therefore periodically replace or untangle the tether. Longer tethers allow for more time to elapse between changeouts, but the interruptions still affect natural behavior. And battery-powered, wireless systems add too much weight. Altogether, these challenges inhibit natural behaviors and limit the amount of time that recording can take place, preventing scientists from studying, for example, the complete process of learning a new task. © 2023 Simons Foundation

Keyword: Brain imaging
Link ID: 28930 - Posted: 09.27.2023

By Gina Kolata Tucker Marr’s life changed forever last October. He was on his way to a wedding reception when he fell down a steep flight of metal stairs, banging the right side of his head so hard he went into a coma. He’d fractured his skull, and a large blood clot formed on the left side of his head. Surgeons had to remove a large chunk of his skull to relieve pressure on his brain and to remove the clot. “Getting a piece of my skull taken out was crazy to me,” Mr. Marr said. “I almost felt like I’d lost a piece of me.” But what seemed even crazier to him was the way that piece was restored. Mr. Marr, a 27-year-old analyst at Deloitte, became part of a new development in neurosurgery. Instead of remaining without a piece of skull or getting the old bone put back, a procedure that is expensive and has a high rate of infection, he got a prosthetic piece of skull made with a 3-D printer. But it is not the typical prosthesis used in such cases. His prosthesis, which is covered by his skin, is embedded with an acrylic window that would let doctors peer into his brain with ultrasound. A few medical centers are offering such acrylic windows to patients who had to have a piece of skull removed to treat conditions like a brain injury, a tumor, a brain bleed or hydrocephalus. “It’s very cool,” Dr. Michael Lev, director of emergency radiology at Massachusetts General Hospital, said. But, “it is still early days,” he added. Advocates of the technique say that if a patient with such a window has a headache or a seizure or needs a scan to see if a tumor is growing, a doctor can slide an ultrasound probe on the patient’s head and look at the brain in the office. © 2023 The New York Times Company

Keyword: Brain imaging; Brain Injury/Concussion
Link ID: 28914 - Posted: 09.16.2023

By Miryam Naddaf, It took 10 years, around 500 scientists and some €600 million, and now the Human Brain Project — one of the biggest research endeavours ever funded by the European Union — is coming to an end. Its audacious goal was to understand the human brain by modelling it in a computer. During its run, scientists under the umbrella of the Human Brain Project (HBP) have published thousands of papers and made significant strides in neuroscience, such as creating detailed 3D maps of at least 200 brain regions, developing brain implants to treat blindness and using supercomputers to model functions such as memory and consciousness and to advance treatments for various brain conditions. “When the project started, hardly anyone believed in the potential of big data and the possibility of using it, or supercomputers, to simulate the complicated functioning of the brain,” says Thomas Skordas, deputy director-general of the European Commission in Brussels. Advertisement Almost since it began, however, the HBP has drawn criticism. The project did not achieve its goal of simulating the whole human brain — an aim that many scientists regarded as far-fetched in the first place. It changed direction several times, and its scientific output became “fragmented and mosaic-like”, says HBP member Yves Frégnac, a cognitive scientist and director of research at the French national research agency CNRS in Paris. For him, the project has fallen short of providing a comprehensive or original understanding of the brain. “I don’t see the brain; I see bits of the brain,” says Frégnac. HBP directors hope to bring this understanding a step closer with a virtual platform — called EBRAINS — that was created as part of the project. EBRAINS is a suite of tools and imaging data that scientists around the world can use to run simulations and digital experiments. “Today, we have all the tools in hand to build a real digital brain twin,” says Viktor Jirsa, a neuroscientist at Aix-Marseille University in France and an HBP board member. But the funding for this offshoot is still uncertain. And at a time when huge, expensive brain projects are in high gear elsewhere, scientists in Europe are frustrated that their version is winding down. “We were probably one of the first ones to initiate this wave of interest in the brain,” says Jorge Mejias, a computational neuroscientist at the University of Amsterdam, who joined the HBP in 2019. Now, he says, “everybody’s rushing, we don’t have time to just take a nap”. Chequered past

Keyword: Brain imaging; Robotics
Link ID: 28884 - Posted: 08.26.2023