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Authors retract Science paper on controversial fMRI method

By Calli McMurray The authors behind a contentious 2022 Science paper that purported to measure neuronal activity using functional MRI (fMRI) retracted the work today. The retraction marks the end of the road for the method, called “direct imaging of neuronal activity,” or DIANA, says Noam Shemesh, principal investigator at the Champalimaud Centre for the Unknown, who was not involved in the now-retracted work. But many neuroimaging researchers still hope to one day use fMRI to capture neuronal activity. “MRI is such a rich modality. It has such rich physics, and not all of it has been exploited in the functional sense,” Shemesh says. DIANA collected fMRI data in a way that enabled the researchers to measure signal changes on the order of tens of milliseconds. The team, led by Jang-Yeon Park at Sungkyunkwan University, captured a signal peak in the somatosensory cortex of mice 25 milliseconds after shocking their whisker pads. Despite an initial flurry of excitement from the field, other labs could not replicate the results. As a result, the paper received an editorial expression of concern in August 2023 because “the methods described in the paper are inadequate to allow reproduction of the results and … the results may have been biased by subjective data selection,” the notice states. Following the editorial expression of concern, “we reanalyzed the data. Unfortunately, the additional results revealed unexpected MR signal characteristics and did not robustly support the original conclusions. We are therefore retracting the paper,” the retraction notice states. Science did not have any additional comment beyond what is outlined in the expression of concern and retraction notice. © 2025 Simons Foundation

Related chapters from BN: Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 29943 - Posted: 09.27.2025

Worms help untangle brain structure/function mystery

By Holly Barker When scientists produced the first map of all synaptic connections in the roundworm Caenorhabditis elegans in 1986, many hailed it as a blueprint for the flow of brain signals. As it turned out, though, models of neuronal activity based on this wiring diagram bore little resemblance to the functional maps of brain activity measured in living worms. This disconnect isn’t limited to worms. Mice, for instance, appear to have widespread silent synapses—wired connections that don’t send signals—and the actual responses of some cells in the fruit fly’s visual system do not match the responses the connectome predicts. A new preprint helps to explain why: Most network features, in C. elegans at least, are not conserved between the anatomical and functional connectomes. Yet the anatomical connectome can still forecast—albeit in a complex way—observed neuronal activity in the worms, according to a second preprint by the same team, because “most signaling is happening along the wires,” says Andrew Leifer, associate professor of physics and neuroscience at Princeton University and principal investigator on both preprints. The findings begin to address the long-standing challenge of reconciling structure and function, and show that “we weren’t entirely wrong” about the importance of synaptic connectivity, says Jihong Bai, professor of basic sciences at the Fred Hutchinson Cancer Center, who was not involved in the work. The debut of a color-coded map of cell types in the worm brain in 2021 split the neuroscience community. It made it possible to identify individual neurons in whole-brain recordings and compare annotated recordings with the connectome—an exercise that revealed no correlation between the two. © 2025 Simons Foundation

Longer fMRI brain scans boost reliability—but only to a point

By Claudia López Lloreda fMRI researchers have long faced a conundrum: Given finite resources and time to spend on scanning, is it better to scan lots of participants for a short time each, or a smaller number of people for a longer time? A new study quantifies this tradeoff for brain-wide association studies (BWAS), which aim to link brain differences to physical and cognitive traits. Using large-scale public fMRI datasets, the team found that their ability to accurately predict cognitive features from functional connectivity data increased with sample size and with scan length, up to 20 minutes. But accuracy began to plateau for longer scans, and beyond 30 minutes, the added length (and cost) provided diminishing returns. A half-hour seems to be the optimal scanning time, says Thomas Yeo, associate professor of electrical and computer engineering at the National University of Singapore and principal investigator of the study. Scan duration is “essentially providing a different knob for people to tune” to meet power requirements in their fMRI experiments, he says. Although the neuroimaging community already knew that scan time is important and five minutes is insufficient, “this is one of the first major studies in the past few years to really quantitatively map that out” for BWAS studies, says Brenden Tervo-Clemmens, assistant professor of psychiatry and behavioral sciences at the University of Minnesota, who was not involved with the study. Tervo-Clemmens and his colleagues had previously shown in a 2022 study the importance of sample size in BWAS, calculating that these analyses need thousands of participants to get meaningful associations. This new study adds another part of the equation, he says. Yeo’s team developed the Optimal Scan Time Calculator to help other neuroscientists design their own studies. “Democratizing these complex methodological issues into a usable package is really, really useful,” Tervo-Clemmens says. © 2025 Simons Foundation

Can portable headsets peer into the minds of hunter-gatherers and other understudied populations?

By Siddhant Pusdekar The food we eat, the air we breathe, and our daily activities all shape how our minds work. Yet most brain research focuses on a narrow slice of humanity: people in high-income countries in the Northern Hemisphere. That leaves a vast gap in our understanding of how neural activity varies across cultures, environments, and lifestyles. A team of researchers from Tanzania and India has taken a step toward closing that gap. In a study published this week in eNeuro, they describe a strategy for collecting data from the brains of diverse groups—from hunter-gatherers to urban dwellers—using electroencephalography (EEG). The technology relies on portable headsets, widely used in clinical settings, that record the brain’s electrical activity through electrodes placed on the scalp. The researchers trained trusted community members as “surveyors,” who visited participants where they live and work to gather EEG data and conduct surveys about their lifestyles and experiences. The initial effort, which involved nearly 8000 volunteers across Tanzania and India, shows that this kind of data collection in low- and middle-income countries is feasible and affordable, the researchers say. The work cost them $50 for each person studied, a fraction of equivalent, large-scale studies conducted in research labs. A: I think mental health is one of the defining health issues in India. When we survey 18- to 24-year-olds, 50% tell us that almost every other day of the month they don’t feel like going to work or college. India is a young country and is increasingly relying on its youth to grow its economy. If they can’t function in their daily activities, you can’t expect them to be productive and contribute to the economy.

New dopamine sensor powers three-color imaging in live animals

By Diana Kwon A new sensor makes it possible for the first time to simultaneously track dopamine and up to two additional molecules in the brains of living animals. The sensor, dubbed HaloDA1.0, uses a novel dopamine-tagging system that emits light at the far-red end of the color spectrum, according to the team behind the work. “There’s a real need to monitor multiple relevant molecules, as they’re doing here,” says Nicolas Tritsch, assistant professor of neuroscience at McGill University, who was not involved in the study. Because dopamine is involved in a range of key brain functions, when studying its effects on a cell it’s important to consider other neuromodulators that are released at the same time, as well as the signaling cascades these molecules may trigger, Tritsch says. Most dopamine-tracking strategies genetically encode a naturally occurring fluorescent protein into dopamine receptors; when dopamine attaches to the modified receptors, the fluorescent protein changes shape and emits light. But naturally occurring fluorescent proteins have a limited color palette, which has made it difficult to develop sensors that can go beyond two-color imaging, says study investigator Yulong Li, professor of life sciences at Peking University. Instead of genetically encoding a fluorescent protein, HaloDA1.0 attaches a synthetic molecule called HaloTag to dopamine receptors. This tag binds tightly to previously developed artificial dyes that change shape and fluoresce in the far-red spectrum when dopamine binds to its receptors. Because the dyes fluoresce at the far end of the red spectrum, it leaves room for other sensors to glow at different wavelengths. © 2025 Simons Foundation

Super-resolution microscopes showcase the inner lives of cells

By Katarina Zimmer Using a tiny, spherical glass lens sandwiched between two brass plates, the 17th century Dutch microscopist Antonie van Leeuwenhoek was the first to officially describe red blood cells and sperm cells in human tissues, and observe “animalcules” — bacteria and protists — in the water of a lake. Increasingly powerful light microscopes followed, revealing cell organelles like the nucleus and energy-producing mitochondria. But by 1873, scientists realized there was a limit to the level of detail. When light passes through a lens, the light gets spread out through diffraction. This means that two objects can’t be distinguished if they’re less than roughly 250 nanometers (250 billionths of a meter) apart — instead, they’ll appear as a blur. That put the inner workings of cell structures off limits. Electron microscopy, which uses electron beams instead of light, offers higher resolution. But the resulting black-and-white images make it hard tell proteins apart, and the method only works on dead cells. Now, however, optics engineers and physicists have developed sophisticated tricks to overcome the diffraction limit of light microscopes, opening up a new world of detail. These “super-resolution” light microscopy techniques can distinguish objects down to 100 nanometers and sometimes even less than 10 nanometers. Scientists attach tiny, colored fluorescent tags to individual proteins or bits of DNA, often in living cells where they can watch them in action. As a result, they are now filling in key knowledge gaps about how cells work and what goes wrong in neurological diseases and cancers, or during viral infections. “We can really see new biology — things that we were hoping to see but hadn’t seen before,” says molecular cell biologist Lothar Schermelleh, who directs an imaging center at the University of Oxford in the United Kingdom. Here’s some of what scientists are learning in this new age of light microscopy. Overcoming the diffraction limit

Giant map details nerves across a mouse’s body: see stunning pics

Mariana Lenharo A speedy imaging method can map the nerves running from a mouse’s brain and spinal cord to the rest of its body at micrometre-scale resolution, revealing details such as individual fibres travelling from a key nerve to distant organs1. Previous efforts have mapped the network of connections between nerve cells, known as the connectome, in the mouse brain. But tracing the complex paths of nerves through the rest of the body has been challenging. To do so, the creators of the new map used a custom-built microscope to scan exposed tissue, completing the process in just 40 hours. Nerves look blue in the reconstructed view of a genetically engineered mouse (left) whose neurons produce a fluorescent marker. In a separate animal (right), antibodies detail the sympathetic nerves (purple). Credit: M.-Y. Shi et al./Cell (CC-BY-4.0) The method, described today in Cell, is an important technical achievement, says Ann-Shyn Chiang, a neuroscientist at the National Tsing Hua University in Hsinchu, Taiwan, who was not involved with the research. “This work is a major step forward in expanding connectomics beyond the brain,” he says. To prepare a mouse’s body for the scan, researchers treat it with chemicals that make its tissues transparent by removing fat, calcium and other components that block light. This provides a clear view of the nerves, which have been labelled with fluorescent marker proteins. The see-through body is then placed into a device that combines a slicing tool and a microscope that takes 3D images. A piston gradually pushes the mouse towards the slicing blade, 400 micrometres at a time. After each slice, a microscope images the newly exposed surface of the mouse, capturing details up to 600 micrometres deep — roughly the thickness of six sheets of paper — below the surface. The body then advances for the next cut. The cycle repeats around 200 times without pause, to cover the entire body. The images are then combined. © 2025 Springer Nature Limited

Brain-reading devices raise ethical dilemmas — researchers propose protections

Kristel Tjandra For two decades, Ann Johnson has been unable to walk or talk after she experienced a stroke that impaired her balance and her breathing and swallowing abilities. But in 2022, Johnson was finally able to hear her voice through an avatar, thanks to a brain implant. The implant is an example of the neurotechnologies that have entered human trials during the past five years. These devices, developed by research teams and firms including entrepreneur Elon Musk’s Neuralink, can alter the nervous system’s activity to influence functions such as speech, touch and movement. Last month, they were the topic of a meeting in Paris, hosted by the United Nations scientific and cultural agency UNESCO, at which delegates finalized a set of ethical principles to govern neurotechnologies. The recommendations focus on protecting users from technology misuse that could infringe on their human rights, including their autonomy and freedom of thought. The delegates, who included scientists, ethicists and legal specialists, decided on nine principles. These include recommendations that technology developers disclose how neural information is collected and used, and that they ensure the long-term safety of a product on people’s mental states. “This document clarifies how to protect human rights, especially in relation to the nervous system,” says Pedro Maldonado, a neuroscientist at the University of Chile in Santiago who was one of 24 experts who drafted the recommendations in 2024. The principles are not legally binding, but nations and organizations can use them to develop their own policies. In November, UNESCO’s 194 member states will vote on whether to adopt the standards. The meeting considered a range of neurotechnology applications, including devices designed to be implanted into the body and non-invasive devices, which are being explored in medicine, entertainment and education. © 2025 Springer Nature Limited

Billy Joel Has Normal Pressure Hydrocephalus. What Is It?

By Maggie Astor Billy Joel has canceled his upcoming concerts because of a brain disorder affecting his hearing, vision and balance, the singer-songwriter announced on Friday. The condition, called normal pressure hydrocephalus, or N.P.H., is estimated to affect hundreds of thousands of older Americans. Here’s what to know about it. What is normal pressure hydrocephalus? N.P.H. occurs when excess cerebrospinal fluid accumulates in the brain, causing difficulty walking, trouble controlling one’s bladder and memory problems. Those symptoms together suggest the disorder. The bladder symptoms can include incontinence and waking up at night to urinate with increasing frequency, said Dr. Charles Matouk, a neurosurgeon at Yale University and director of the university’s Normal Pressure Hydrocephalus Program. A statement posted to Mr. Joel’s social media accounts on Friday said his condition had been “exacerbated by recent concert performances.” N.P.H. is rare, but risk increases with age. Dr. Matouk estimated that it might affect less than 1 percent of the population ages 65 to 80, but likely 5 percent or more of people over 80. Experts say the condition is likely underdiagnosed because its symptoms can easily be dismissed as normal effects of aging. Dr. Matouk urged people to see a doctor if they experienced trouble walking, controlling their bladder and remembering things. How is it diagnosed? When a patient shows up with gait, bladder and memory problems, the first test may be a CT scan or M.R.I. In patients with N.P.H., that imaging will show enlargement of the brain’s fluid-filled ventricles. But the conclusive test is a spinal tap: Because that procedure removes cerebrospinal fluid, patients with N.P.H. experience a temporary alleviation of symptoms, confirming the diagnosis, Dr. Matouk said. © 2025 The New York Times Company

Related chapters from BN: Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 15: Language and Lateralization
Link ID: 29801 - Posted: 05.24.2025

Connectomics 2.0: Simulating the brain

By Laura Dattaro In 2012, neuroscientists Sebastian Seung and J. Anthony Movshon squared off at a Columbia University event over the usefulness of connectomes—maps of every connection between every cell in the brain of a living organism. Such a map, Seung argued, could crack open the brain’s computations and provide insight into processes such as sensory perception and memory. But Movshon, professor of neural science and psychology at New York University, countered that the relationship between structure and function was not so straightforward—that even if you knew how all of a brain’s neurons connect to one another, you still wouldn’t understand how the organ turns electrical signals into cognition and behavior. The debate in the field continues, even though Seung and his colleagues in the FlyWire Consortium completed the first connectome of a female Drosophila melanogaster in 2023, and even though a slew of new computational models built from that and other connectomes hint that structure does, in fact, reveal something about function. “This is just the beginning, and that’s what’s exciting,” says Seung, professor of neuroscience at the Princeton Neuroscience Institute. “These papers are kicking off a beginning to an entirely new field, which is connectome-based brain simulation.” A simulated fruit fly optic lobe, detailed in a September 2024 Nature paper, for example, accurately predicts which neurons in living fruit flies respond to different visual stimuli. “All the work that’s been done in the past year or two feels like the beginning of something new,” says John Tuthill, associate professor of neuroscience at the University of Washington. Tuthill was not involved in the optic lobe study but used a similar approach to identify a circuit that seems to control walking in flies. Most published models so far have made predictions about simple functions that were already understood from recordings of neural activity, Tuthill adds. But “you can see how this will build up to something that is eventually very insightful.” © 2025 Simons Foundation

Noninvasive technologies can map and target human brain with unprecedented precision

By Bruce Rosen The past two decades—and particularly the past 10 years, with the tool-focused efforts of the BRAIN Initiative—have delivered remarkable advances in our ability to study and manipulate the brain, both in exquisite cellular detail and across increasing swaths of brain territory. These advances resulted from improvements in tools such as optical imaging, chemogenetics and multiprobe electrodes, to name a few. Powerful as these technologies are, though, their invasive nature makes them ill-suited for widespread adoption in human brain research. Fortunately, our fundamental understanding of the physics and engineering behind noninvasive modalities—based largely on recording, generating and manipulating electromagnetic and acoustic fields in the human brain—has also progressed over the past decade. These advances are on the threshold of providing much more detailed recordings of electromagnetic activity, not only across the human cortex but at depth. And these same principles can improve our ability to precisely and noninvasively stimulate the human brain. Though these tools have limitations compared with their invasive counterparts, their noninvasive nature make them suitable for wide-scale investigation of the links between human behavior and action, as well as for individually understanding and treating an array of brain disorders. The most common method to assess brain electrophysiology is the electroencephalogram (EEG), first developed in the 1920s and now routinely used for both basic neuroscience and the clinical diagnosis of conditions ranging from epilepsy to sleep disorders to traumatic brain injury. It’s widely used, given its simplicity and low cost, but it has drawbacks. Understanding exactly where the EEG signals arise from in the brain is often difficult, for example; electric current from the brain must pass through multiple tissue layers (including overlying brain itself) before it can be detected with electrodes on the scalp surface, blurring the spatial resolution. Advanced computational methods combined with imaging data from MRI can partially mitigate these issues, but the analysis is complex, and results are imperfect. Still, because EEG can be readily combined with behavioral assessments and other

An Advance in Brain Research That Was Once Considered Impossible

By Carl Zimmer The human brain is so complex that scientific brains have a hard time making sense of it. A piece of neural tissue the size of a grain of sand might be packed with hundreds of thousands of cells linked together by miles of wiring. In 1979, Francis Crick, the Nobel-prize-winning scientist, concluded that the anatomy and activity in just a cubic millimeter of brain matter would forever exceed our understanding. “It is no use asking for the impossible,” Dr. Crick wrote. Forty-six years later, a team of more than 100 scientists has achieved that impossible, by recording the cellular activity and mapping the structure in a cubic millimeter of a mouse’s brain — less than one percent of its full volume. In accomplishing this feat, they amassed 1.6 petabytes of data — the equivalent of 22 years of nonstop high-definition video. “This is a milestone,” said Davi Bock, a neuroscientist at the University of Vermont who was not involved in the study, which was published Wednesday in the journal Nature. Dr. Bock said that the advances that made it possible to chart a cubic millimeter of brain boded well for a new goal: mapping the wiring of the entire brain of a mouse. “It’s totally doable, and I think it’s worth doing,” he said. More than 130 years have passed since the Spanish neuroscientist Santiago Ramón y Cajal first spied individual neurons under a microscope, making out their peculiar branched shapes. Later generations of scientists worked out many of the details of how a neuron sends a spike of voltage down a long arm, called an axon. Each axon makes contact with tiny branches, or dendrites, of neighboring neurons. Some neurons excite their neighbors into firing voltage spikes of their own. Some quiet other neurons. Human thought somehow emerges from this mix of excitation and inhibition. But how that happens has remained a tremendous mystery, largely because scientists have been able to study only a few neurons at a time. In recent decades, technological advances have allowed scientists to start mapping brains in their entirety. In 1986, British researchers published the circuitry of a tiny worm, made up of 302 neurons. In subsequent years, researchers charted bigger brains, such as the 140,000 neurons in the brain of a fly. © 2025 The New York Times Company

To make a meaningful contribution to neuroscience, fMRI must break out of its silo

Avram Holmes. Human thought and behavior emerge through complex and reciprocal interactions that link microscale molecular and cellular processes with macroscale functional patterns. Functional MRI (fMRI), one of the most common methods for studying the human brain, detects these latter patterns through the “blood oxygen level dependent,” or BOLD, signal, a composite measure of both neural and vascular signals that reflects an indirect measure of brain activity. Despite an enormous investment by scientific funders and the research community in the use of fMRI, though, researchers still don’t fully understand the underlying mechanisms that drive individual or population-level differences measured via in-vivo brain imaging, which limits our ability to interpret those data. For fMRI to meaningfully contribute to progress in neuroscience, we need to develop research programs that link phenomena across levels, from genes and molecules to cells, circuits, networks and behavior. Without a concerted effort in this direction, fMRI will remain a methodological spandrel, a byproduct of technological development rather than a tool explicitly designed to reveal neural mechanisms, generating isolated datapoints that are left unintegrated with broader scientific theory or progress. Recently, the human functional neuroimaging community has turned a critical eye toward its own methods and findings. These debates have led to field-wide initiatives calling for larger and more diverse study samples, better phenotypic reliability and findings that generalize across populations. But researchers have put relatively little emphasis on contextualizing the resulting work across levels of analysis or on deciphering the biological mechanism that may underpin changes to the BOLD signal across groups and individual people or over the lifespan. Appeals to better integrate the different levels of neuroscience are not new. But despite persuasive arguments, fMRI researchers have largely remained scientifically siloed, isolated by a nearly ubiquitous focus on a single level of analysis and a rigid adherence to a select set of imaging methods. Our work is typically presented inside of field-specific echo chambers—departmental or group seminars, topic-specific journals and society meetings—where our methodological and analytic choices go unchallenged. What progress can we expect to make if we remain isolated from other fields of study? © 2025 Simons Foundation

The Mysterious Flow of Fluid in the Brain

By Veronique Greenwood Encased in the skull, perched atop the spine, the brain has a carefully managed existence. It receives only certain nutrients, filtered through the blood-brain barrier; an elaborate system of protective membranes surrounds it. That privileged space contains a mystery. For more than a century, scientists have wondered: If it’s so hard for anything to get into the brain, how does waste get out? The brain has one of the highest metabolisms of any organ in the body, and that process must yield by-products that need to be removed. In the rest of the body, blood vessels are shadowed by a system of lymphatic vessels. Molecules that have served their purpose in the blood move into these fluid-filled tubes and are swept away to the lymph nodes for processing. But blood vessels in the brain have no such outlet. Several hundred kilometers of them, all told, seem to thread their way through this dense, busily working tissue without a matching waste system. However, the brain’s blood vessels are surrounded by open, fluid-filled spaces. In recent decades, the cerebrospinal fluid, or CSF, in those spaces has drawn a great deal of interest. “Maybe the CSF can be a highway, in a way, for the flow or exchange of different things within the brain,” said Steven Proulx, who studies the CSF system at the University of Bern. A recent paper in Cell contains a new report about what is going on around the brain (opens a new tab) and in its hidden cavities. A team at the University of Rochester led by the neurologist Maiken Nedergaard (opens a new tab) asked whether the slow pumping of the brain’s blood vessels might be able to push the fluid around, among, and in some cases through cells, to potentially drive a system of drainage. In a mouse model, researchers injected a glowing dye into CSF, manipulated the blood vessel walls to trigger a pumping action, and saw the dye concentration increase in the brain soon after. They concluded that the movement of blood vessels might be enough to move CSF, and possibly the brain’s waste, over long distances. © 2025 Simons Foundation.

First map of human brain mitochondria is ‘groundbreaking’ achievement

Nora Bradford Scientists have created the first map of the crucial structures called mitochondria throughout the entire brain ― a feat that could help to unravel age-related brain disorders1. The results show that mitochondria, which generate the energy that powers cells, differ in type and density in different parts of the brain. For example, the evolutionarily oldest brain regions have a lower density of mitochondria than newer regions. The map, which the study’s authors call the MitoBrainMap, is “both technically impressive and conceptually groundbreaking”, says Valentin Riedl, a neurobiologist at Friedrich-Alexander University in Erlangen, Germany, who was not involved in the project. The brain’s mitochondria are not just bit-part players. “The biology of the brain, we know now, is deeply intertwined with the energetics of the brain,” says Martin Picard, a psychobiologist at Columbia University in New York City, and a co-author of the study. And the brain accounts for 20% of the human body’s energy usage2. Wielding a tool typically used for woodworking, the study’s authors divided a slice of frozen human brain ― from a 54-year-old donor who died of a heart attack ― into 703 tiny cubes. Each cube measured 3 × 3 × 3 millimetres, which is comparable to the size of the units that make up standard 3D images of the brain. “The most challenging part was having so many samples,” says Picard. The team used biochemical and molecular techniques to determine the density of mitochondria in each of the 703 samples. In some samples, the researchers also estimated the mitochondria’s efficiency at producing energy. To extend their findings beyond a single brain slab, the authors developed a model to predict the numbers and types of mitochondria across the entire brain. They fed it brain-imaging data and the brain-cube data. To check their model, they applied it to other samples of the frozen brain slice and found that it accurately predicted the samples’ mitochondrial make-up. © 2025 Springer Nature

New brain scan method could help people with drug-resistant epilepsy

Anna Bawden Health and social affairs correspondent Researchers have developed ultra-powerful scans that could enable surgery for previously treatment-resistant epilepsy. Globally, about 50 million people have epilepsy. In England, epileptic seizures are the sixth most common reason for hospital admission. About 360,000 people in the UK have focal epilepsy, which causes recurring seizures in a specific part of the brain. Many patients successfully treat their condition with medication but for more than 100,000 patients, their symptoms do not improve with drugs, leaving surgery as the only option. Finding brain lesions, a significant cause of epilepsy, can be tricky. Ultra-powerful MRI scanners are capable of identifying even tiny lesions in patients’ brains. These 7T MRI scanners produce much more detailed resolution on brain scans, enabling better detection of lesions. If surgeons can see the lesions on MRI scans, this can double the chances of the patient being free of seizures after surgery. But 7T scanners are also susceptible to “dark patches” known as signal dropouts. Now researchers in Cambridge and Paris have developed a new technique to overcome the problem. Scientists at the University of Cambridge’s Wolfson Brain Imaging Centre, and the Université Paris-Saclay, used eight transmitters around the brain, rather than the usual one, to “parallel transmit” MRI images, which significantly reduced the number of black spots. The first study to use this approach, doctors at Addenbrooke’s hospital, Cambridge, then trialled the technique with 31 drug-resistant epilepsy patients to see whether the parallel transmit 7T scanner was better than conventional 3T scanners at detecting brain lesions. The research, published in the journal Epilepsia, found that the parallel transmit 7T scanner identified previously unseen structural lesions in nine patients. © 2025 Guardian News & Media Limited

Vesuvius Turned One Victim’s Brain to Glass

Five years ago Italian researchers published a study on the eruption of Mount Vesuvius in A.D. 79. that detailed how one victim of the blast, a male presumed to be in his mid 20s, had been found nearby in the seaside settlement of Herculaneum. He was lying facedown and buried by ash on a wooden bed in the College of the Augustales, a public building dedicated to the worship of Emperor Augustus. Some scholars believe that the man was the center’s caretaker and was asleep at the time of the disaster. In 2018, one researcher discovered black, glossy shards embedded inside the caretaker’s skull. The paper, published in 2020, speculated that the heat of the explosion was so immense that it had fused the victim’s brain tissue into glass. Vesuvius Erupted, but When Exactly? March 2, 2025 Forensic analysis of the obsidian-like chips revealed proteins common in brain tissue and fatty acids found in human hair, while a chunk of charred wood unearthed near the skeleton indicated a thermal reading as high as 968 degrees Fahrenheit, roughly the dome temperature of a wood-fired Neapolitan pizza oven. It was the only known instance of soft tissue — much less any organic material — being naturally preserved as glass. On Thursday, a paper published in Nature verified that the fragments are indeed glassified brain. Using techniques such as electron microscopy, energy dispersive X-ray spectroscopy and differential scanning calorimetry, scientists examined the physical properties of samples taken from the glassy fragments and demonstrated how they were formed and preserved. “The unique finding implies unique processes,” said Guido Giordano, a volcanologist at the Roma Tre University and lead author of the new study. Foremost among those processes is vitrification, by which material is burned at a high heat until it liquefies. To harden into glass, the substance requires rapid cooling, solidifying at a temperature higher than its surroundings. This makes organic glass formation challenging, Dr. Giordano said, as vitrification entails very specific temperature conditions and the liquid form must cool fast enough to avoid being crystallized as it congeals. © 2025 The New York Times Company

Cell ‘fingerprints’ identify distinct cortical networks

By Holly Barker Hunched over a microscope more than a century ago, Santiago Ramón y Cajal discovered that distinct types of neurons favor different brain regions. Looking at tissue from a pigeon’s cerebellum, he drew Purkinje cells, their dendrites outspread and twisted like a ravaged oak. And drawing from another sample—the first cortical layer of a newborn rabbit’s brain—he traced the tentacled nerve cells that would later bear his name. But the brain’s cellular organization is even more ordered than Ramón y Cajal could have imagined, a new study suggests. Different functional networks—measured using functional MRI—involve distinct blends of cell types, identified from their transcriptional profiles. And a machine-learning tool trained on cell distributions in postmortem tissue can identify functional networks based on these cellular “fingerprints,” the researchers found. The findings could address the gulf between neuroimaging and cell-based research, says the study’s principal investigator, Avram Holmes, associate professor of psychiatry at Rutgers University. “In-vivo imaging studies are almost never linked back to the underlying biological cascades that give rise to the phenotypes,” he says. But the new approach “lets you jump between fields of study—that was very difficult to do in the past.” Using bulk gene-expression data from postmortem human brain tissue—obtained from the Allen Human Brain Atlas—Holmes and his colleagues classified 24 different types of cells. They then mapped the cells’ spatial distribution to two features of large-scale brain organization derived from a popular fMRI atlas: networks, and those networks’ position in the cortical gradient, which is based on location, style of information processing and connectivity pattern. Unimodal sensorimotor networks—those that perceive stimuli and act on them—anchor one end of the gradient, and the other end is occupied by transmodal systems, such as the default mode network, that integrate multiple information streams across the cortex. The remaining networks are parked between these two extremes. © 2025 Simons Foundation

This drawing is the oldest known sketch of an insect brain

By Tina Hesman Saey After nearly 350 years, a depiction of a bee’s brain is getting some buzz. A manuscript created in the mid-1670s contains the oldest known depiction of an insect’s brain, historian of science Andrea Strazzoni of the University of Turin in Italy reports January 29 in Royal Society Notes and Records. Handwritten by Dutch biologist and microscopist Johannes Swammerdam, the manuscript contains a detailed description and drawing of a honeybee drone’s brain. The illustration, based on his own dissections, was just one of Swammerdam’s firsts. In 1658, he was also the first to see and describe red blood cells. Since no one had previously reported dissecting a bee brain, Swammerdam based his descriptions on what was known about the brain anatomy of humans and other mammals. “He knew what to expect from or to imagine in his observations: in particular, the pineal gland and the cerebellum,” Strazzoni writes. Bees have neither of those parts but have brain structures that the 17th century scientist mistook for them. But Swammerdam deserves some slack, Strazzoni suggests. He was working with single-lens microscopes and developing new techniques for dissecting and observing insects’ internal organs. Even with those crude instruments, he was able to identify some nerves and describe how parts of the brain connected. © Society for Science & the Public 2000–2025.

Related chapters from BN: Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 29644 - Posted: 01.29.2025

Digitization of ‘breathtaking’ neuroanatomy slide collection offers untapped research gold mine

By Shaena Montanari For evolutionary neuroanatomists who compare diverse animal brains, access to a gold mine of 500,000 histological sections and whole mounts is now only a mouse-click away. The R. Glenn Northcutt Collection of Comparative Vertebrate Neuroanatomy and Embryology at Harvard University—which comprises 33,000 slides of tissue samples from more than 240 vertebrate genera—is one of the world’s largest and most diverse collections of its kind. Northcutt, a prolific comparative vertebrate neuroanatomist and emeritus professor of neurosciences at the University of California, San Diego, amassed the collection over the course of five decades. Since 2021, James Hanken, research professor of biology at Harvard University and curator at the Museum of Comparative Zoology, has led an effort to digitize it. The scanning process is still ongoing and may take another two years to complete, Hanken says, but more than 8,000 slides are already publicly available in two online data repositories: MCZBase and MorphoSource. A comprehensive inventory of the entire collection appears in a paper Hanken and his colleagues published last week in the Bulletin of the Museum of Comparative Zoology. It provides researchers with an in-depth guide for using the collection, Hanken says. Few other resources of this type are available online to researchers interested in evolutionary biology and brain anatomy, says Andrew Iwaniuk, professor of neuroscience at the University of Lethbridge. For example, neither the Welker Comparative Anatomy Collection nor the Starr Collection, both housed at the U.S. National Museum of Health and Medicine in Silver Spring, Maryland, are available online. To access slide collections such as these, scientists have had to travel to see them in person, which can be difficult for those outside the United States, Iwaniuk adds. © 2025 Simons Foundation

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