Links for Keyword: Brain imaging

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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

Paul Biegler explains. Mind-reading machines are now real, prising open yet another Pandora’s box for ethicists. As usual, there are promises of benefit and warnings of grave peril. The bright side was front and centre at the Society for Neuroscience annual meeting in Washington DC in November 2017. It was part of a research presentation led by Omid Sani from the University of Southern California. Sani and his colleagues studied six people with epilepsy who had electrodes inserted into their brains to measure detailed electrical patterns. It is a common technique to help neurosurgeons find where seizures start. The study asked patients, who can be alert during the procedure, to report their mood during scanning. That allowed the researchers to link the patients’ moods with their brainwave readings. Using sophisticated algorithms, the team claimed to predict patients’ feelings from their brainwaves alone. That could drive a big shift in the treatment of mental illness, say researchers. Deep brain stimulation (DBS), where electrodes implanted in the brain give circuits a regular zap, has been successful in Parkinson’s disease. It is also being trialled in depression; but the results, according to a 2017 report in Lancet Psychiatry, are patchy. Sani and colleagues suggest their discovery could bump up that success rate. A portable brain decoder may be available within a generation.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 1: An Introduction to Brain and Behavior
Link ID: 25136 - Posted: 06.25.2018

Maria Temming Getting robots to do what we want would be a lot easier if they could read our minds. That sci-fi dream might not be so far off. With a new robot control system, a human can stop a bot from making a mistake and get the machine back on track using brain waves and simple hand gestures. People who oversee robots in factories, homes or hospitals could use this setup, to be presented at the Robotics: Science and Systems conference on June 28, to ensure bots operate safely and efficiently. Electrodes worn on the head and forearm allow a person to control the robot. The head-worn electrodes detect electrical signals called error-related potentials — which people’s brains unconsciously generate when they see someone goof up — and send an alert to the robot. When the robot receives an error signal, it stops what it is doing. The person can then make hand gestures — detected by arm-worn electrodes that monitor electrical muscle signals — to show the bot what it should do instead. MIT roboticist Daniela Rus and colleagues tested the system with seven volunteers. Each user supervised a robot that moved a drill toward one of three possible targets, each marked by an LED bulb, on a mock airplane fuselage. Whenever the robot zeroed in on the wrong target, the user’s mental error-alert halted the bot. And when the user flicked his or her wrist left or right to redirect the robot, the machine moved toward the proper target. In more than 1,000 trials, the robot initially aimed for the correct target about 70 percent of the time, and with human intervention chose the right target more than 97 percent of the time. The team plans to build a system version that recognizes a wider variety of user movements. That way, “you can gesture how the robot should move, and your motion can be more fluidly interpreted,” says study coauthor Joseph DelPreto, also a roboticist at MIT. |© Society for Science & the Public 2000 - 2018

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 25111 - Posted: 06.20.2018

By Matt Warren Scientists regularly comb through 3D data, from medical images to maps of the moon, yet they are often stuck using flat computer screens that can’t fully represent 3D data sets. Now, researchers have developed a method of 3D printing that lets scientists produce stunning, high-definition 3D copies of their data. Conventional 3D-printing converts data into a computer model made up of tiny, connected triangles. But this process can create awkward images: The fine lines of the brain’s white matter, for example, show up as bulky tubes. Conventional printing also has problems creating objects where solid parts (or data points) are separated by empty space. The new process is far more direct. Instead of transforming into a computer model, the data set is sliced up into thousands of horizontal images, each consisting of hundreds of thousands of voxels, or 3D pixels. Each voxel is printed with droplets of colored resin hardened by ultraviolet light. Different colors can be combined to create new ones, and transparent resin is used to represent empty space. Each layer is printed, one on top of another, to gradually build up a 3D structure. So far, the researchers have used the voxel printing process to produce high-definition models of brain scans, topographical maps, and laser-scanned statues. And although it may take some time to get there, the team sees a day when anyone will be able to print off a copy of their data at the press of a button, from archaeologists reproducing important artifacts for conservation to doctors creating models of body parts to plan surgical procedures. Posted in: © 2018 American Association for the Advancement of Science.

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: 25050 - Posted: 06.02.2018

By Dennis Normile SHANGHAI, CHINA—The nascent China Brain Project took another step toward reality last week with the launch of the Shanghai Research Center for Brain Science and Brain-Inspired Intelligence. The new center and its Beijing counterpart, launched 2 months ago, are expected to become part of an ambitious national effort to bring China to the forefront of neuroscience. But details of that 15-year project—expected to rival similar U.S. and EU efforts in scale and ambition—are still being worked out, 2 years after the government made it a priority. Preparation for the national effort “was taking quite a long time,” says Zhang Xu, a neuroscientist and executive director of the new center here. So Beijing and Shanghai got started on their own plans, he says. China’s growing research prowess and an increasing societal interest in neuroscience—triggered in part by an aging population—as well as commercial opportunities and government support are all coming together to make this “a good time for China’s brain science efforts,” Zhang says. Government planners called for brain research to be a key science and technology project in the nation’s 13th Five-Year Plan, adopted in spring 2016. The effort would have three main pillars, according to a November 2016 Neuron paper from a group that included Poo Mu-ming, director of Shanghai’s Institute of Neuroscience (ION), part of the Chinese Academy of Sciences (CAS). It would focus on basic research on neural mechanisms underlying cognition, translational studies of neurological diseases with an emphasis on early diagnosis and intervention, and brain simulations to advance artificial intelligence and robotics. Support under the 5-year plan was just the start of a 15-year program, the group wrote. © 2018 American Association for the Advancement of Science.

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: 25013 - Posted: 05.23.2018

In 2007, I spent the summer before my junior year of college removing little bits of brain from rats, growing them in tiny plastic dishes, and poring over the neurons in each one. For three months, I spent three or four hours a day, five or six days a week, in a small room, peering through a microscope and snapping photos of the brain cells. The room was pitch black, save for the green glow emitted by the neurons. I was looking to see whether a certain growth factor could protect the neurons from degenerating the way they do in patients with Parkinson's disease. This kind of work, which is common in neuroscience research, requires time and a borderline pathological attention to detail. Which is precisely why my PI trained me, a lowly undergrad, to do it—just as, decades earlier, someone had trained him. Now, researchers think they can train machines to do that grunt work. In a study described in the latest issue of the journal Cell, scientists led by Gladstone Institutes and UC San Francisco neuroscientist Steven Finkbeiner collaborated with researchers at Google to train a machine learning algorithm to analyze neuronal cells in culture. The researchers used a method called deep learning, the machine learning technique driving advancements not just at Google, but Amazon, Facebook, Microsoft. You know, the usual suspects. It relies on pattern recognition: Feed the system enough training data—whether it's pictures of animals, moves from expert players of the board game Go, or photographs of cultured brain cells—and it can learn to identify cats, trounce the world's best board-game players, or suss out the morphological features of neurons.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 24862 - Posted: 04.13.2018

In a small room tucked away at the University of Toronto, Professor Dan Nemrodov is pulling thoughts right out of people's brains. He straps a hat with electrodes on someone's head and then shows them pictures of faces. By reading brain activity with an electroencephalography (EEG) machine, he's then able to reconstruct faces with almost perfect accuracy. Student participants wearing the cap look at a collection of faces for two hours. At the same time, the EEG software recognizes patterns relating to certain facial features found in the photos. Machine-learning algorithms are then used to recreate the images based on the EEG data, in some cases within 98-per-cent accuracy. Nemrodov and his colleague, Professor Adrian Nestor say this is a big thing. "Ultimately we are involved in a form of mind reading," he says. The technology has huge ramifications for medicine, law, government and business. But the ethical questions are just as huge. Here are some key questions: What can be the benefits of this research? If developed, it can help patients with serious neurological damage. People who are incapacitated to the point that they cannot express themselves or ask a question. According to clinical ethicist Prof. Kerry Bowman and his students at the University of Toronto, this technology can get inside someone's mind and provide a link of communication. It may give that person a chance to exercise their autonomy, especially in regard to informed consent to either continue treatment or stop. ©2018 CBC/Radio-Canada.

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: 24810 - Posted: 04.02.2018

By Liz Tormes When I first started working as a photo researcher for Scientific American MIND in 2013, a large part of my day was spent looking at brains. Lots of them. They appeared on my computer screen in various forms—from black-and-white CT scans featured in dense journals to sad-looking, grey brains sitting on the bottom of glass laboratory jars. At times they were boring, and often they could be downright disturbing. But every now and then I would come across a beautiful 3D image of strange, rainbow-colored pathways in various formations that looked like nothing I had ever seen before. I was sure it had been miscategorized somehow—no way was I looking at a brain! Through my work I have encountered countless images of multi-colored Brainbows, prismatic Diffusion Tensor Imaging (DTI), and even tiny and intricate neon mini-brains grown from actual stem cells in labs. Increasingly I have found myself dazzled, not just by the pictures themselves, but by the scientific and technological advances that have made this type of imaging possible in only the past few years. It was through my photo research that I happened upon the Netherlands Institute for Neuroscience’s (NIN) annual Art of Neuroscience contest. This exciting opportunity for neurologists, fine artists, videographers and illustrators, whose work is inspired by human and animal brains, was something I wanted to share with our readers. © 2018 Scientific American

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: 24803 - Posted: 03.31.2018

By Simon Makin Neuroscientists today 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. What is needed is a wiring diagram for the brain—known as a connectome—to identify the circuits that underlie brain functions. The challenge is dizzying: There are around 100 billion neurons in the human brain, which can each make thousands of connections, or synapses, making potentially hundreds of trillions of connections. So far, researchers have typically used microscopes to visualize neural connections, but this is laborious and expensive work. Now in a paper published March 28 in Nature, an innovative brain-mapping technique developed at Cold Spring Harbor Laboratory (CSHL) has been used to trace the connections emanating from hundreds of neurons in the main visual area of the mouse cortex, the brain’s outer layer. The technique, which exploits the advancing speed and plummeting cost of genetic sequencing, is more efficient than current methods, allowing the team to produce a more detailed picture than previously possible at unprecedented speed. Once the technology matures it could be used to provide clues to the nature of neuro-developmental disorders such as autism that are thought to involve differences in brain wiring. The team, led by Anthony Zador at CSHL and neuroscientist Thomas Mrsic-Flogel of the University of Basel in Switzerland, verified their method by comparing it with a previous gold-standard means of identifying connections among nerve cells—a technique called fluorescent single neuron tracing. This involves introducing into cells genes that produce proteins that fluoresce with a greenish glow, so they and their axons (neurons’ output wires) can be visualized with light microscopy. © 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: 24802 - Posted: 03.30.2018

Juliette Jowit The world’s first brain scanner that can be worn as people move around has been invented, by a team who hope the contraption can help children with neurological and mental disorders and reveal how the brain handles social situations. The new scalp caps – made on 3D printers – fit closely to the head, so can record the electromagnetic field produced by electrical currents between brain cells in much finer detail than previously. This design means the scanner can work in ways never possible before: subjects can move about, for example, and even play games with the equipment on, while medics can use it on groups such as babies, children and those with illnesses which cause them to move involuntarily. “This has the potential to revolutionise the brain imaging field, and transform the scientific and clinical questions that can be addressed with human brain imaging,” said Prof Gareth Barnes at University College London, one of three partners in the project. The other two are the University of Nottingham and the Wellcome Trust. The brain imaging technique known as magnetoencephalography, or MEG, has been helping scientists for decades, but in many cases has involved using huge contraptions that look like vintage hair salon driers. The scanners operated further from the head than the new devices, reducing the detail they recorded, and users had to remain incredibly still. © 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: 24780 - Posted: 03.22.2018

By Ruth Williams When optogenetics burst onto the scene a little over a decade ago, it added a powerful tool to neuroscientists’ arsenal. Instead of merely correlating recorded brain activity with behaviors, researchers could control the cell types of their choosing to produce specific outcomes. Light-sensitive ion channels (opsins) inserted into the cells allow neuronal activity to be controlled by the flick of a switch. Nevertheless, MIT’s Edward Boyden says more precision is needed. Previous approaches achieved temporal resolution in the tens of milliseconds, making them a somewhat blunt instrument for controlling neurons’ millisecond-fast firings. In addition, most optogenetics experiments have involved “activation or silencing of a whole set of neurons,” he says. “But the problem is the brain doesn’t work that way.” When a cell is performing a given function—initiating a muscle movement, recalling a memory—“neighboring neurons can be doing completely different things,” Boyden explains. “So there is a quest now to do single-cell optogenetics.” Illumination techniques such as two-photon excitation with computer-generated holography (a way to precisely sculpt light in 3D) allow light to be focused tightly enough to hit one cell. But even so, Boyden says, if the targeted cell body lies close to the axons or dendrites of neighboring opsin-expressing cells, those will be activated too. © 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: 24732 - Posted: 03.08.2018

By Diana Kwon When optogenetics debuted over a decade ago, it quickly became the method of choice for many neuroscientists. By using light to selectively control ion channels on neurons in living animal brains, researchers could see how manipulating specific neural circuits altered behavior in real time. Since then, scientists have used the technique to study brain circuity and function across a variety of species, from fruit flies to monkeys—the method is even being tested in a clinical trial to restore vision in patients with a rare genetic disorder. Today (February 8) in Science, researchers report successfully conducting optogenetics experiments using injected nanoparticles in mice, inching the field closer to a noninvasive method of stimulating the brain with light that could one day have therapeutic uses. “Optogenetics revolutionized how we all do experimental neuroscience in terms of exploring circuits,” says Thomas McHugh, a neuroscientist at the RIKEN Brain Science Institute in Japan. However, this technique currently requires a permanently implanted fiber—so over the last few years, researchers have started to develop ways to stimulate the brain in less invasive ways. A number of groups devised such techniques using magnetic fields, electric currents, and sound. McHugh and his colleagues decided to try another approach: They chose near-infrared light, which can more easily penetrate tissue than the blue-green light typically used for optogenetics. “What we saw as an advantage was a kind of chemistry-based approach in which we can harness the power of near-infrared light to penetrate tissue, but still use this existing toolbox that's been developed over the last decade of optogenetic channels that respond to visible light,” McHugh says. © 1986-2018 The Scientist

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: 24637 - Posted: 02.09.2018