Links for Keyword: Brain imaging

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Michael Eisenstein In March, researchers in Japan mapped the cellular organization of the mouse brain in unprecedented detail. Systems biologist Hiroki Ueda at the RIKEN Center for Biosystems Dynamics Research in Osaka, Japan, and his team created an atlas of the mouse brain using a technique called CUBIC-X, in which they chemically labelled every cell in the brain, then rendered the organ crystal-clear while also expanding its size tenfold1. From there, they used sophisticated imaging techniques to compile a comprehensive 3D neuronal survey — of some 72 million cells in all, Ueda says. The resulting atlas reduces the brain to a compact database of cellular addresses, which the team used to explore changes in various brain regions during development. Moving forward, the atlas could drive deeper explorations of brain structures that control behaviours such as the sleep–wake cycle. CUBIC-X is just one component in a growing toolbox of such methods, which exploit readily available chemicals to provide researchers with a window not just into the brain, but into virtually every organ in the body. Some are tissue-clearing methods that make opaque tissues transparent, whereas others complement tissue clearing with a proportional size increase that exposes molecular details to conventional microscopy. The choice comes down to the scientific question. There are many ways to achieve similar ends, and users should investigate the strengths and limitations of different methods before deciding which to use. The hunger for tissue-clearing techniques originated with neuroscientists, who were frustrated by their limited ability to trace the snaking routes of axons and dendrites in the brain. © 2018 Springer Nature Publishing AG

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25755 - Posted: 12.06.2018

By R. Douglas Fields SAN DIEGO—In the textbook explanation for how information is encoded in the brain, neurons fire a rapid burst of electrical signals in response to inputs from the senses or other stimulation. The brain responds to a light turning on in a dark room with the short bursts of nerve impulses, called spikes. Each close grouping of spikes can be compared to a digital bit, the binary off-or-on code used by computers. Neuroscientists have long known, though, about other forms of electrical activity present in the brain. In particular, rhythmic voltage fluctuations in and around neurons—oscillations that occur at the same 60-cycle-per-second frequency as AC current in the U.S.—have caught the field’s attention. These gamma waves encode information by changing a signal’s amplitude, frequency or phase (relative position of one wave to another)—and the rhythmic voltage surges influence the timing of spikes. Heated debate has arisen in recent years as to whether these analog signals, akin to the ones used to broadcast AM or FM radio, may play a role in sorting, filtering and organizing the information flows required for cognitive processes. They may be instrumental in perceiving sensory inputs, focusing attention, making and recalling memories and coupling various cognitive processes into one coherent scene. It is thought that populations of neurons that oscillate at gamma frequencies may unite the neural activity in the same way the violin section of an orchestra is coupled together in time and rhythm with the percussion section to create symphonic music. When gamma waves oscillate in resonance, “you get very rich repertoires of behaviors,” says Wolf Singer, a neuroscientist at the Ernst Strüngmann Institute in Frankfurt, Germany, who researches gamma waves. Just as your car’s dashboard will vibrate in sync with the motor vibrating at a resonant frequency, so too can separate populations of neurons couple in resonance. © 2018 Scientific American

Related chapters from BN8e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25731 - Posted: 11.29.2018

By Sharon Begley, The brain surgeon began as he always does, making an incision in the scalp and gently spreading it apart to expose the skull. He then drilled a 3-inch circular opening through the bone, down to the thick, tough covering called the dura. He sliced through that, and there in the little porthole he’d made was the glistening, blood-flecked, pewter-colored brain, ready for him to approach the way spies do a foreign embassy: He bugged it. Dr. Ashesh Mehta, a neurosurgeon at the Feinstein Institute for Medical Research on Long Island, was operating on his epilepsy patient to determine the source of seizures. But the patient agreed to something more: to be part of an audacious experiment whose ultimate goal is to translate thoughts into speech. While he was in there, Mehta carefully placed a flat array of microelectrodes on the left side of the brain’s surface, over areas involved in both listening to and formulating speech. By eavesdropping on the electrical impulses that crackle through the gray matter when a person hears in the “mind’s ear” what words he intends to articulate (often so quickly it’s barely conscious), then transmitting those signals wirelessly to a computer that decodes them, the electrodes and the rest of the system hold the promise of being the first “brain-computer interface” to go beyond movement and sensation. If all goes well, it will conquer the field’s Everest: developing a brain-computer interface that could enable people with a spinal cord injury, locked-in syndrome, ALS, or other paralyzing condition to talk again. © 2018 Scientific America

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 25708 - Posted: 11.21.2018

Sara Reardon A new technique that makes dead mice transparent and hard like plastic is giving researchers an unprecedented view of how different types of cell interact in the body. The approach lets scientists pinpoint specific tissues within an animal while scanning its entire body. The approach, called vDISCO, has already revealed surprising structural connections between organs, including hints about the extent to which brain injuries affect the immune system and nerves in other parts of the body. That could lead to better treatments for traumatic brain injury or stroke. Methods that turn entire organs clear have become popular in the past few years, because they allow scientists to study delicate internal structures without disturbing them. But removing organs from an animal’s body for analysis can make it harder to see the full effect of an injury or disease. And if scientists use older methods to make an entire mouse transparent, it can be difficult to ensure that the fluorescent markers used to label cells reach the deepest parts of an organ. The vDISCO technique overcomes many of these problems. By making the dead mice rigid and see-through, it can preserve their bodies for years, down to the structure of individual cells, says Ali Ertürk, a neuroscientist at Ludwig Maximilian University of Munich in Germany, who led the team that developed vDISCO. He presented the work this week at a meeting of the Society for Neuroscience in San Diego, California. © 2018 Springer Nature Limited.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25676 - Posted: 11.13.2018

Surgeons have tested the use of a fluorescent marker that can help them remove dangerous brain tumour cells from patients more accurately. The research was carried out on people who had suspected glioblastoma, the disease that killed British politician Dame Tessa Jowell in May, and the most common form of brain cancer. Treatment usually involves surgery to remove as much of the cancer as possible, but it can be challenging for surgeons to identify all the cancer cells while avoiding healthy brain tissue. Researchers said using the fluorescent marker helped distinguish the most aggressive cancer cells from other brain tissue and they hope this will ultimately improve patient survival. They used a compound called 5-aminolevulinic acid or 5-ALA, which the patient drinks. The compound glows pink when a light is shone on it. Previous research shows that 5-ALA accumulates in fast-growing cancer cells so it can act as a fluorescent marker of high-grade cells. The study was carried out on 99 patients with suspected high-grade gliomas – a kind of tumour –who were treated at Royal Liverpool hospital, King’s college hospital in London and Addenbrooke’s hospital in Cambridge. They were aged between 23 and 77, with an average age of 59. During their operations, surgeons reported seeing fluorescence in 85 patients and 81 of these were subsequently confirmed by pathologists to have high-grade disease. One was found to have low-grade disease and three could not be assessed. © 2018 Guardian News and Media Limited

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25646 - Posted: 11.05.2018

Devika G. Bansal Tools that use light, drugs, or temperature to make neurons fire or rest on command have become a mainstay in neuroscience. Thermogenetics, which enables neurons to respond to temperature shifts, first took off with fruit flies about a decade ago, but is emerging as a new trick to manipulate the neural functioning of other model organisms. That’s due to some advantages it affords over optogenetics—the light-based technique that started it all. Genetic toolkits such as thermogenetics and optogenetics follow a basic recipe: scientists pick a receptor that responds to an external cue such as temperature or light, express the receptor in specific neurons as a switch that changes the cell’s voltage—triggering or inhibiting firing—and then use the cue to turn the neural switch on or off. Optogenetics revolutionized our understanding of how the brain’s wiring affects animal behavior. But it comes with drawbacks. For one, delivering light into the deepest regions of the brains of nontransparent animals is a challenge. In mice, this requires surgically inserting optical fibers into the brain, tethering the animal to the light source. Researchers working with adult fruit flies can cut a window through the head cuticle to access the brain. In both cases, the necessary experimental setups are invasive and often time and effort intensive. Additionally, the light intensity required for optogenetics tends to damage tissue. “You pump a lot of light through the optical fiber to activate neurons,” says Vsevolod Belousov, a biochemist at the Russian Academy of Sciences in Moscow who develops thermogenetic tools. “In general, this is not avoidable.” © 1986 - 2018 The Scientist

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 5: The Sensorimotor System
Link ID: 25636 - Posted: 11.02.2018

Ashley P. Taylor Two studies in mice published today (October 31) in Nature report the existence of several types of brain cells that had not been acknowledged before. These cell types are distinguished by their gene expression patterns, and within one cortical area, they perform distinct functions. For the gene expression study, led by the Allen Institute’s Hongkui Zeng, researchers performed single-cell RNA sequencing on more than 20,000 cells, most of which were neurons, in the visual cortex and the anterior lateral motor cortex of the mouse brain. Using this method, they identified 133 distinct cell types, both excitatory and inhibitory. They found that the various inhibitory neurons were present in both cortical areas but that the excitatory cell types kept to specific regions, as neuroscientists Aparna Bhaduri and Tomasz Nowakowski of the University of California, San Francisco, describe in an accompanying Nature commentary. “When we see not only cell types that people have identified before, but a number of new ones that are showing up in the data, it’s really exciting for us,” says Zeng in a press release. “It’s like we are able to put all the different pieces of the puzzle The other study, led by Karel Svoboda of the Janelia Research Campus of the Howard Hughes Medical Institute, examined the functions of two subtypes identified through the gene-expression study. These are excitatory cells called pyramidal tract neurons that reside within layer five of the anterior lateral motor cortex in mice. The researchers used optogenetics to activate either one neuronal subtype or the other in mice and at the same time monitored the activity of the two types of neurons during movement. They found that pyramidal tract neurons in the upper part of layer five seem to be involved in preparing for movement, whereas those in the lower part of layer five help execute it. © 1986 - 2018 The Scientist

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25634 - Posted: 11.02.2018

Jeffrey M. Perkel Randal Burns recalls that the brain-science community was “abuzz” in 2011. Burns, a computer scientist at Johns Hopkins University in Baltimore, Maryland, was focusing on astrophysics and fluid dynamics data management at the time. But he was intrigued when Joshua Vogelstein, a neuroscientist and colleague at Johns Hopkins, told him that the first large-scale neural-connectivity data sets had just been collected and asked for his help to present them online. “It was the first time that you had data of that quality, at that resolution and scale, where you had the sense that you could build a neural map of an interesting portion of the brain,” says Burns. Vogelstein worked with Burns to build a system that would make those data — 20 trillion voxels’ worth — available to the larger neuroscience community. The team has now generalized the software to support different classes of imaging data and describes the system this week (J. T. Vogelstein et al. Nature Meth. 15, 846-847; 2018). NeuroData is a free, cloud-based collection of web services that supports large-scale neuroimaging data, from electron microscopy to magnetic resonance imaging and fluorescence photomicrographs. Key to its functionality, Vogelstein says, is the spatial database bossDB, which allows researchers to retrieve images of any section of the brain, at any resolution, and in several standard formats. Users can then explore those data using a tool known as Neuroglancer. As they navigate the images, the URL changes to reflect their specific view, allowing them to share particular visualizations with their colleagues. “These links become a core part of the way in which we communicate and pass data back and forth to one another,” says Forrest Collman, a neuroscientist at the Allen Institute for Brain Science in Seattle, Washington, and a co-author of the paper. © 2018 Springer Nature Limited.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25631 - Posted: 11.01.2018

Anna Nowogrodzki On a cold morning in Minneapolis last December, a man walked into a research centre to venture where only pigs had gone before: into the strongest magnetic resonance imaging (MRI) machine built to scan the human body. First, he changed into a hospital gown, and researchers made sure he had no metal on his body: no piercings, rings, metal implants or pacemakers. Any metal could be ripped out by the immensely powerful, 10.5-tesla magnet — weighing almost 3 times more than a Boeing 737 aeroplane and a full 50% more powerful than the strongest magnets approved for clinical use. Days earlier, he had passed a check-up that included a baseline test of his sense of balance to make sure that any dizziness from exposure to the magnets could be assessed properly. In the MRI room at the University of Minnesota’s Center for Magnetic Resonance Research, he lay down inside a 4-metre-long tube, surrounded by 110 tonnes of magnet and 600 tonnes of iron shielding, for an hour’s worth of imaging of his hips, whose thin cartilage would test the limits of the machine’s resolution. The centre’s director, Kamil Ugurbil, had been waiting for years for this day. The magnet faced long delays because the liquid helium needed to fill it was in short supply. After the machine was finally delivered, on a below-freezing day in 2013, it took four years of animal testing and ramping up the field strength before Ugurbil and his colleagues were comfortable sending in the first human. Even then, they didn’t quite know what they’d see. But it was worth the wait: when the scan materialized on screen, the fine resolution revealed intricate details of the wafer-thin cartilage that protects the hip socket. “It was extremely exciting and very rewarding,” Ugurbil says. © 2018 Springer Nature Limited

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25625 - Posted: 10.31.2018

Wenyao Xu Your brain is an inexhaustible source of secure passwords – but you might not have to remember anything. Passwords and PINs with letters and numbers are relatively easily hacked, hard to remember and generally insecure. Biometrics are starting to take their place, with fingerprints, facial recognition and retina scanning becoming common even in routine logins for computers, smartphones and other common devices. They’re more secure because they’re harder to fake, but biometrics have a crucial vulnerability: A person only has one face, two retinas and 10 fingerprints. They represent passwords that can’t be reset if they’re compromised. Like usernames and passwords, biometric credentials are vulnerable to data breaches. In 2015, for instance, the database containing the fingerprints of 5.6 million U.S. federal employees was breached. Those people shouldn’t use their fingerprints to secure any devices, whether for personal use or at work. The next breach might steal photographs or retina scan data, rendering those biometrics useless for security. Our team has been working with collaborators at other institutions for years, and has invented a new type of biometric that is both uniquely tied to a single human being and can be reset if needed. When a person looks at a photograph or hears a piece of music, her brain responds in ways that researchers or medical professionals can measure with electrical sensors placed on her scalp. We have discovered that every person’s brain responds differently to an external stimulus, so even if two people look at the same photograph, readings of their brain activity will be different. © 2010–2018, The Conversation US, Inc.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25622 - Posted: 10.27.2018

By Diana Kwon Spanish neuroscientist Santiago Ramón y Cajal revolutionized the study of the brain when he observed neurons for the first time. His investigations, now more than 100 years old, revealed intricate details of nerve cells in many different animals, including humans—rootlike dendrites attached to bulbous cell bodies, from which extend long, slender axons. Cajal’s examinations also revealed dendrites (via which nerve cells receive signals from other neurons) were much longer in humans than in rodents and other animals, even other non-human primates. A new study, published this week in Cell, shows that in people these antennalike projections also have distinct electrical properties that may help explain how the brain processes arriving information. Scientists have been meticulously studying dendrites in the decades since Cajal’s initial observations. Still, “the only thing we really knew about human dendrites was their anatomy,” Massachusetts Institute of Technology neuroscientist Mark Harnett says. “There was a lot of potential for human dendrites to be doing something different because of their length, but there was no published work, as far as I know, on their actual electrical properties.” So Harnett and his colleagues set out to investigate whether the length of dendrites affected electrical signals transmitted through them. With the help of a neurologist, Sydney Cash of Massachusetts General Hospital, they were able to obtain brain tissue that had been removed from epilepsy patients undergoing routine surgery to help allay seizures—a procedure in which physicians routinely remove part of the temporal cortex to get to the hippocampus, a structure deep inside the brain where seizures typically originate. © 2018 Scientific American

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25594 - Posted: 10.20.2018

By Neuroskeptic A new review paper in The Neuroscientist highlights the problem of body movements for neuroscience, from blinks to fidgeting. Authors Patrick J Drew and colleagues of Penn State discuss how many types of movements are associated with widespread brain activation, which can contaminate brain activity recordings. This is true, they say, of both humans and experimental animals such as rodents, e.g. with their ‘whisking’ movements of the whiskers. A particular concern is that many movements occur (or change in frequency) over similar timescales to some measures of neural activity – especially resting state fMRI – which means that movement-related activity could be mistaken for more interesting neural signals. Here’s how the authors describe the relationship between one kind of movement, blinking, and brain activity: Blink-related modulations are visible in BOLD functional magnetic resonance imaging (fMRI) signals in the primary visual cortex, as well as higher brain regions, such as the frontal eye field (FEF), and regions associated with the default network and somatosensory areas… If the rate of blinking were constant, ongoing blinks would not be an issue, and they would simply be averaged out. However, spontaneous eye blink rate dynamically varies on slow time scales (~0.001 Hz to 0.1 Hz), and these variations can drive correlated activity in multiple brain regions.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25574 - Posted: 10.15.2018

By Simon Makin Neuroscientists know a lot about how individual neurons operate but remarkably little about how large numbers of them work together to produce thoughts, feelings and behavior. They need a wiring diagram for the brain—known as a connectome—to identify the circuits that underlie the organ’s functions. Now researchers at Cold Spring Harbor Laboratory and their colleagues have developed an innovative brain-mapping technique and used it to trace the connections emanating from nearly 600 neurons in a mouse brain’s main visual area in just three weeks. This technology could someday be used to help understand disorders thought to involve atypical brain wiring, such as autism or schizophrenia. The technique works by tagging cells with genetic “bar codes.” Researchers inject viruses into mice brains, where the viruses direct cells to produce random 30-letter RNA sequences (consisting of the nucleotide “letters” G, A, U and C). The cells also create a protein that binds to these RNA bar codes and drags them the length of each neuron’s output wire, or axon. The researchers later dissect the mice brains into target regions and sequence the cells in each area, enabling them to determine which tagged neurons are connected to which regions. The team found that neurons in a mouse’s primary visual cortex typically send outputs to multiple other visual areas. It also discovered that most cells fall into six distinct groups based on which regions—and how many of them—they connect to. This finding suggests there are subtypes of neurons in a mouse’s primary visual cortex that perform different functions. “Because we have so many neurons, we can do statistics and start understanding the patterns we see,” says Cold Spring Harbor’s Justus Kebschull, co-lead author of the study, which was published in April in Nature. © 2018 Scientific American

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 25527 - Posted: 10.04.2018

Giorgia Guglielmi Biophysicist Adam Cohen was strolling around San Francisco, California, in 2010, when a telephone call caught him by surprise. “We have a signal,” said the caller. Nearly 5,000 kilometres away, in Cambridge, Massachusetts, his collaborators had struck gold. After months of failed experiments, the researchers had found a fluorescent protein that allowed them to watch signals as they passed between neurons. But there was something weird going on. When Cohen got back to his lab at Harvard University, he learned that all the recordings of the experiment showed a strange progression. At first, neurons decorated with the protein flashed nicely as electric impulses whizzed through them. But then the cells turned into bright blobs. “Halfway through each recording, the signal would go all wild,” Cohen says. So he decided to join his team during an experiment. “When they started the recording, they would sit there holding their breath,” Cohen says. But as soon as they realized it was working, they would celebrate, “dancing and running around the room”. In their exuberance, they were letting the light from a desk lamp shine right onto the microscope. “We were actually recording our excitement,” says Daniel Hochbaum, then a graduate student in Cohen’s group. They toned down their celebrations, and a year later, the team published its study1 — one of the first to show that a fluorescent protein engineered into specific mammalian neurons could be used to track individual electric impulses in real time. © 2018 Springer Nature Limited

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25478 - Posted: 09.21.2018

By: Helene Benveniste, M.D., Ph.D. The brain, like other parts of the body, needs to maintain “homeostasis” (a constant state) to function, and that requires continuous removal of metabolic waste. For decades, the brain’s waste-removal system remained a mystery to scientists. A few years ago, a team of researchers—with the help of our author—finally found the answer. This discovery—dubbed the glymphatic system— will help us understand how toxic waste accumulates in devastating disorders such as Alzheimer’s disease and point to possible strategies to prevent it. In early February 2012, I received a note from Maiken Nedergaard, a renowned neuroscientist at the University of Rochester whom I knew from our time as medical students at the University of Copenhagen. She explained that her team had discovered important features of a new system that transports the fluid that surrounds the brain—a substance called cerebrospinal fluid (CSF). The discovery of how this fluid was transported in the brain, she believed, was the key to understanding how waste is cleared from the brain. Nedergaard’s work with the non-neuronal brain cells called “astroglia” had led her to suspect that these cells might play a role in CSF transport and brain cleansing. She was inspired by an older study' which showed that CSF could rapidly penetrate into channels along the brain vasculature, and astroglial cells structurally help create these channels. Now she needed help with visualizing the system in the whole brain to confirm her suspicions. Her team needed imaging scientists like myself who might be able to visualize the unique CSF flow patterns in a rodent brain and shed light on the new system. Because I had experience and expertise in imaging CSF in the small rodent brain and spinal cord, I was equipped to take on this new challenge. © 2018 The Dana Foundation.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25426 - Posted: 09.08.2018

Inga Vesper The executive director of the European Union’s ambitious — but contentious — Human Brain Project (HBP) has left his post after a disagreement with the institution that coordinates the initiative. The 10-year, €1-billion (US$1.1-billion) project aims to simulate the human brain using computers, and is a flagship science initiative of the EU. In a joint statement on 16 August, Chris Ebell and the HBP’s coordinating institution, the Swiss Federal Institute of Technology in Lausanne, said that they had decided to “separate by common agreement” following “differences of opinion on governance and on strategic orientations”. Ebell became director of the project in 2015, after the HBP disbanded its small executive committee in favour of a 22-member governing board. The HBP, which involves more than 100 partner institutions, had after its inception in 2013 been criticized by some neuroscientists for its scientific direction, its complicated structure and the lack of transparency surrounding its funding decisions. doi: 10.1038/d41586-018-06020-0 © 2018 Springer Nature Limited

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25360 - Posted: 08.22.2018

by Dr. Francis Collins Though our thoughts can wander one moment and race rapidly forward the next, the brain itself is often considered to be motionless inside the skull. But that’s actually not correct. When the heart beats, the pumping force reverberates throughout the body and gently pulsates the brain. What’s been tricky is capturing these pulsations with existing brain imaging technologies. Recently, NIH-funded researchers developed a video-based approach to magnetic resonance imaging (MRI) that can record these subtle movements [1]. Their method, called phase-based amplified MRI (aMRI), magnifies those tiny movements, making them more visible and quantifiable. The latest aMRI method, developed by a team including Itamar Terem at Stanford University, Palo Alto, CA, and Mehmet Kurt at Stevens Institute of Technology, Hoboken, NJ. It builds upon an earlier method developed by Samantha Holdsworth at New Zealand’s University of Auckland and Stanford’s Mahdi Salmani Rahimi [2]. In the video, a traditional series of brain scans captured using standard MRI (left) make the brain appear mostly motionless. But a second series of scans captured using the new technique (right) shows the brain pulsating with each and every heartbeat. As described in the journal Magnetic Resonance in Medicine, the team started by measuring the pulse of a healthy person. They synchronized the pulse with MRI images of the person’s brain, stitching the scans together to create a sequential video. Their new MRI approach then relies on a special algorithm developed by another group to magnify the subtle changes.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25311 - Posted: 08.10.2018

A handful of Alzheimer's patients signed up for a bold experiment: they let scientists beam sound waves into the brain to temporarily jiggle an opening in its protective shield. The so-called blood-brain barrier prevents germs and other damaging substances from leaching in through the bloodstream — but it can block drugs for Alzheimer's, brain tumours and other neurological diseases. Canadian researchers on Wednesday reported early hints that technology called focused ultrasound can safely poke holes in that barrier — holes that quickly sealed back up. It's a step toward one day using the non-invasive device to push brain treatments through. "It's been a major goal of neuroscience for decades, this idea of a safe and reversible and precise way of breaching the blood-brain barrier," said Dr. Nir Lipsman, a neurosurgeon at Toronto's Sunnybrook Health Sciences Centre who led the study. "It's exciting." The findings were presented at the Alzheimer's Association international conference in Chicago and published Wednesday in Nature Communications. This first-step research, conducted in just six people with mild to moderate Alzheimer's, didn't test potential therapies; its aim was to check whether patients' fragile blood vessels could withstand the breach without bleeding or other side-effects. ©2018 CBC/Radio-Canada

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 25249 - Posted: 07.26.2018

Laurel Hamers BRAINBOW Scientists have imaged the fruit fly brain in new detail. Colors highlight the paths of nerve cells that have been mapped so far. Cells with bodies close together share the same color, but not necessarily the same function. If the secret to getting the perfect photo is taking a lot of shots, then one lucky fruit fly is the subject of a masterpiece. Using high-speed electron microscopy, scientists took 21 million nanoscale-resolution images of the brain of Drosophila melanogaster to capture every one of the 100,000 nerve cells that it contains. It’s the first time the entire fruit fly brain has been imaged in this much detail, researchers report online July 19 in Cell. Experimental neurobiologists can now use the rich dataset as a roadmap to figure out which neurons talk to each other in the fly’s brain, says study coauthor Davi Bock, a neurobiologist at Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va. The rainbow image shown here captures the progress on that mapping so far. Despite the complex tangle of neural connections pictured, the mapping is far from complete, Bock says. Neurons with cell bodies close to each other are colored the same hue, to demonstrate how neurons born in the same place in the poppy seed–sized brain tend to send their spidery tendrils out in the same direction, too. |© Society for Science & the Public 2000 - 2018. All rights reserved.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 25231 - Posted: 07.20.2018

Catherine Offord Researchers at Caltech have designed a noninvasive method to control specific neural circuits in the mouse brain. The technique, published earlier this week (July 9) in Nature Biomedical Engineering, combines ultrasound waves with genetic engineering and the administration of designer compounds to selectively activate or inhibit neurons. Although currently only tested in mice, the approach could offer a novel way to administer therapy to regions of the human brain that are difficult to access using surgery. “By using sound waves and known genetic techniques, we can, for the first time, noninvasively control specific brain regions and cell types as well as the timing of when neurons are switched on or off,” study coauthor Mikhail Shapiro says in a statement. While several emerging methods in neuroscience allow researchers to manipulate brain circuits, most “require invasive techniques such as stereotaxic surgery, which can damage tissue and initiate a long-lasting immune response,” note neuroscientists Caroline Menard and Scott Russo of Quebec City’s Université Laval and the Icahn School of Medicine at Mount Sinai, respectively, in an accompanying News and Views article. “Also, conventional pharmacological approaches lack the spatial, temporal and cell-type specificity required to treat the brain, and can lead to deleterious side effects.” © 1986 - 2018 The Scientist.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 25218 - Posted: 07.17.2018