Links for Keyword: Brain imaging

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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

By Giorgia Guglielmi ENIGMA, the world’s largest brain mapping project, was “born out of frustration,” says neuroscientist Paul Thompson of the University of Southern California in Los Angeles. In 2009, he and geneticist Nicholas Martin of the Queensland Institute of Medical Research in Brisbane, Australia, were chafing at the limits of brain imaging studies. The cost of MRI scans limited most efforts to a few dozen subjects—too few to draw robust connections about how brain structure is linked to genetic variations and disease. The answer, they realized over a meal at a Los Angeles shopping mall, was to pool images and genetic data from multiple studies across the world. After a slow start, the consortium has brought together nearly 900 researchers across 39 countries to analyze brain scans and genetic data on more than 30,000 people. In an accelerating series of publications, ENIGMA’s crowdsourcing approach is opening windows on how genes and structure relate in the normal brain—and in disease. This week, for example, an ENIGMA study published in the journal Brain compared scans from nearly 4000 people across Europe, the Americas, Asia, and Australia to pinpoint unexpected brain abnormalities associated with common epilepsies. ENIGMA is “an outstanding effort. We should all be doing more of this,” says Mohammed Milad, a neuroscientist at the University of Illinois in Chicago who is not a member of the consortium. ENIGMA’s founders crafted the consortium’s name—Enhancing NeuroImaging Genetics through Meta-Analysis—so that its acronym would honor U.K. mathematician Alan Turing’s code-breaking effort targeting Germany’s Enigma cipher machines during World War II. Like Turing’s project, ENIGMA aims to crack a mystery. Small brain-scanning studies of twins or close relatives done in the 2000s showed that differences in some cognitive and structural brain measures have a genetic basis. © 2018 American Association for the Advancement of Science.

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: 24560 - Posted: 01.24.2018

Harriet Dempsey-Jones Nobody really believes that the shape of our heads are a window into our personalities anymore. This idea, known as “phrenonolgy”, was developed by the German physician Franz Joseph Gall in 1796 and was hugely popular in the 19th century. Today it is often remembered for its dark history – being misused in its later days to back racist and sexist stereoptypes, and its links with Nazi “eugenics”. But despite the fact that it has fallen into disrepute, phrenology as a science has never really been subjected to rigorous, neuroscientific testing. That is, until now. Researchers at the University of Oxford have hacked their own brain scanning software to explore – for the first time – whether there truly is any correspondence between the bumps and contours of your head and aspects of your personality. The results have recently been published in an open science archive, but have also been submitted to the journal Cortex. But why did phrenologists think that bumps on your head might be so informative? Their enigmatic claims were based around a few general principles. Phrenologists believed the brain was comprised of separate “organs” responsible for different aspects of the mind, such as for self-esteem, cautiousness and benevolence. They also thought of the brain like a muscle – the more you used a particular organ the more it would grow in size (hypertrophy), and less used faculties would shrink. The skull would then mould to accommodate these peaks and troughs in the brain’s surface – providing an indirect reflection of the brain, and thus, the dominant features of an person’s character. © 2010–2018, The Conversation US, Inc.

Related chapters from BN8e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 24554 - Posted: 01.23.2018

By DENISE GRADY One blue surgical drape at a time, the patient disappeared, until all that showed was a triangle of her shaved scalp. “Ten seconds of quiet in the room, please,” said Dr. David J. Langer, the chairman of neurosurgery at Lenox Hill Hospital in Manhattan, part of Northwell Health. Silence fell, until he said, “O.K., I’ll take the scissors.” His patient, Anita Roy, 66, had impaired blood flow to the left side of her brain, and Dr. Langer was about to perform bypass surgery on slender, delicate arteries to restore the circulation and prevent a stroke. The operating room was dark, and everyone was wearing 3-D glasses. Lenox Hill is the first hospital in the United States to buy a device known as a videomicroscope, which turns neurosurgery into an immersive and sometimes dizzying expedition into the human brain. Enlarged on a 55-inch monitor, the stubble on Ms. Roy’s shaved scalp spiked up like rebar. The scissors and scalpel seemed big as hockey sticks, and popped out of the screen so vividly that observers felt an urge to duck. “This is like landing on the moon,” said a neurosurgeon who was visiting to watch and learn. The equipment produces magnified, high-resolution, three-dimensional digital images of surgical sites, and lets everyone in the room see exactly what the surgeon is seeing. The videomicroscope has a unique ability to capture “the brilliance and the beauty of the neurosurgical anatomy,” Dr. Langer said. He and other surgeons who have tested it predict it will change the way many brain and spine operations are performed and taught. “The first time I used it, I told students that this gives them an understanding of why I went into neurosurgery in the first place,” Dr. Langer said. © 2018 The New York Times Company

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: 24504 - Posted: 01.09.2018

Tina Hesman Saey In movies, exploring the body up close often involves shrinking to microscopic sizes and taking harrowing rides through the blood. Thanks to a new virtual model, you can journey through a three-dimensional brain. No shrink ray required. The Society for Neuroscience and other organizations have long sponsored the website BrainFacts.org, which has basic information about how the human brain functions. Recently, the site launched an interactive 3-D brain. A translucent, light pink brain initially rotates in the middle of the screen. With a click of a mouse or a tap of a finger on a mobile device, you can highlight and isolate different parts of the organ. A brief text box then pops up to provide a structure’s name and details about the structure’s function. For instance, the globus pallidus — dual almond-shaped structures deep in the brain — puts a brake on muscle contractions to keep movements smooth. Some blurbs tell how a structure got its name or how researchers figured out what it does. Scientists, for example, have learned a lot about brain function by studying people who have localized brain damage. But the precuneus, a region in the cerebral cortex along the brain’s midline, isn’t usually damaged by strokes or head injuries, so scientists weren’t sure what the region did. Modern brain-imaging techniques that track blood flow and cell activity indicate the precuneus is involved in imagination, self-consciousness and reflecting on memories. |© Society for Science & the Public 2000 - 2018

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: 24502 - Posted: 01.09.2018

by Emilie Reas Functional MRI (fMRI) is one of the most celebrated tools in neuroscience. Because of their unique ability to peer directly into the living brain while an organism thinks, feels and behaves, fMRI studies are often devoted disproportionate media attention, replete with flashy headlines and often grandiose claims. However, the technique has come under a fair amount of criticism from researchers questioning the validity of the statistical methods used to analyze fMRI data, and hence the reliability of fMRI findings. Can we trust those flashy headlines claiming that “scientists have discovered the area of the brain,” or are the masses of fMRI studies plagued by statistical shortcomings? To explore why these studies can be vulnerable to experimental failure, in their new PLOS One study coauthors Henk Cremers, Tor Wager and Tal Yarkoni investigated common statistical issues encountered in typical fMRI studies, and proposed how to avert them moving forward. The reliability of any experiment depends on adequate power to detect real effects and reject spurious ones, which can be influenced by various factors including the sample size (or number of “subjects” in fMRI), how strong the real effect is (“effect size”), whether comparisons are within or between subjects, and the statistical threshold used. To characterize common statistical culprits of fMRI studies, Cremers and colleagues first simulated typical fMRI scenarios before validating these simulations on a real dataset. One scenario simulated weak but diffusely distributed brain activity, and the other scenario simulated strong but localized brain activity (Figure 1). The simulation revealed that effect sizes are generally inflated for weak diffuse, compared to strong localized, activations, especially when the sample size is small. In contrast, effect sizes can actually be underestimated for strong localized scenarios when the sample size is large. Thus, more isn’t always better when it comes to fMRI; the optimal sample size likely depends on the specific brain-behavior relationship under investigation.

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: 24501 - Posted: 01.09.2018

By Sharon Begley Technologies to detect brain activity — fine, we’ll come right out and call it mind reading — as well as to change it are moving along so quickly that “a bit of a gold rush is happening, both on the academic side and the corporate side,” Michel Maharbiz of the University of California, Berkeley, told a recent conference at the Massachusetts Institute of Technology. Here are three fast-moving areas of neuroscience we’ll be watching in 2018: Neural dust/neurograins Whatever you call these electronics, they’re really, really tiny. We’re eagerly awaiting results from DARPA’s $65 million neural engineering program, which aims to develop a brain implant that can communicate digitally with the outside world. The first step is detecting neurons’ electrochemical signaling (DARPA, the Pentagon’s Defense Advanced Research Projects Agency, says 1 million neurons at a time would be nice). To do that, scientists at Brown University are developing salt-grain-sized “neurograins” containing an electrode to detect neural firing as well as to zap neurons to fire, all via a radio frequency antenna. Advertisement Maharbiz’s “neural dust” is already able to do the first part. The tiny wireless devices can detect what neurons are doing, he and his colleagues reported in a 2016 rat study. (The study’s lead scientist recently moved to Elon Musk’s startup Neuralink, one of a growing number of brain-tech companies.) Now Maharbiz and team are also working on making neural dust receive outside signals and cause neurons to fire in certain ways. Such “stimdust” would be “the smallest [nerve] stimulator ever built,” Maharbiz said. Eventually, scientists hope, they’ll know the neural code for, say, walking, letting them transmit the precise code needed to let a paralyzed patient walk. They’re also deciphering the neural code for understanding spoken language, which raises the specter of outside signals making people hear voices — raising ethical issues that, experts said, neurotech will generate in abundance. © 2017 Scientific American

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 5: The Sensorimotor System
Link ID: 24468 - Posted: 12.29.2017

by Bethany Brookshire An astonishing number of things that scientists know about brains and behavior are based on small groups of highly educated, mostly white people between the ages of 18 and 21. In other words, those conclusions are based on college students. College students make a convenient study population when you’re a researcher at a university. It makes for a biased sample, but one that’s still useful for some types of studies. It would be easy to think that for studies of, say, how the typical brain develops, a brain is just a brain, no matter who’s skull its resting in. A biased sample shouldn’t really matter, right? Wrong. Studies heavy in rich, well-educated brains may provide a picture of brain development that’s inaccurate for the American population at large, a recent study found. The results provide a strong argument for scientists to pay more attention to who, exactly, they’re studying in their brain imaging experiments. It’s “a solid piece of evidence showing that those of us in neuroimaging need to do a better job thinking about our sample, where it’s coming from and who we can generalize our findings to,” says Christopher Monk, who studies psychology and neuroscience at the University of Michigan in Ann Arbor. The new study is an example of what happens when epidemiology experiments — studies of patterns in health and disease — crash into studies of brain imaging. “In epidemiology we think about sample composition a lot,” notes Kaja LeWinn, an epidemiologist at the University of California in San Francisco. Who is in the study, where they live and what they do is crucial to finding out how disease patterns spread and what contributes to good health. But in conversations with her colleagues in psychiatry about brain imaging, LeWinn realized they weren’t thinking very much about whose brains they were looking at. Particularly when studying healthy populations, she says, there was an idea that “a brain is a brain is a brain.” |© Society for Science & the Public 2000 - 2017. All rights reserved.

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: 24432 - Posted: 12.16.2017

By Neuroskeptic Sometimes, scientific misconduct is so blatant as to be comical. I recently came across an example of this on Twitter. The following is an image from a paper published in the Journal of Materials Chemistry C: As pointed out on PubPeer, this image – which is supposed to be an electron microscope image of some carbon dot (CD) nanoparticles – is an obvious fake. The “dots” are identical, and have clearly been cut-and-pasted. Where one copy has been placed over the top of another, the overlap is quite visible. It would be charitable to even call this ‘scientific’ fraud. The Journal of Materials Chemistry editors said on Twitter that they are “urgently” looking into this paper; I’ve no doubt it will be retracted soon, although the fact that it was published at all raises questions about the peer-review standards of this journal. To me as a neuroscientist, cases like this from chemistry get me worried. In a field like materials chemistry, or any field in which results take the form of images or photographs (such as Western blots), low-effort fraud is easy to spot because the manipulation of an image can, at least in unsubtle cases, be easily proven from the image itself. But what of fields like psychology or neuroscience where data don’t take the form of images? Perhaps low-effort frauds occur in these fields as well, but it is much more difficult to detect them when the results are statistical rather than pictorial in nature.

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: 24383 - Posted: 12.01.2017

By Mary Beth Aberlin Like the entomologist in search of colorful butterflies, my attention has chased in the gardens of the grey matter cells with delicate and elegant shapes, the mysterious butterflies of the soul, whose beating of wings may one day reveal to us the secrets of the mind. —Santiago Ramón y Cajal, Recollections of My Life Based on this quote, I am pretty certain that Santiago Ramón y Cajal, a founding father of modern neuroscience, would approve of this month’s cover. The Spaniard had wanted to become an artist, but, goaded by his domineering father into the study of medicine, Ramón y Cajal concentrated on brain anatomy, using his artistic talent to render stunningly beautiful and detailed maps of neuron placement throughout the brain. Based on his meticulous anatomical studies of individual neurons, he proposed that nerve cells did not form a mesh—the going theory at the time—but were separated from each other by microscopic gaps now called synapses. Fast-forward from the early 20th century to the present day, when technical advances in imaging have revealed any number of the brain’s secrets. Ramón y Cajal would no doubt have marveled at the technicolor neuron maps revealed by the Brainbow labeling technique. (Compare Ramón y Cajal’s drawings of black-stained Purkinje neurons to a Brainbow micrograph of the type of neuron.) But the technical marvels have gotten even more revelatory. © 1986-2017 The Scientist

Related chapters from BN8e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 24348 - Posted: 11.24.2017

By Bahar Gholipour, The same techniques that generate images of smoke, clouds and fantastic beasts in movies can render neurons and brain structures in fine-grained detail. Two projects presented yesterday at the 2017 Society for Neuroscience annual meeting in Washington, D.C., gave attendees a sampling of what these powerful technologies can do. “These are the same rendering techniques that are used to make graphics for ‘Harry Potter’ movies,” says Tyler Ard, a neuroscientist in Arthur Toga’s lab at the University of Southern California in Los Angeles. Ard presented the results of applying these techniques to magnetic resonance imaging (MRI) scans. The methods can turn massive amounts of data into images, making them ideally suited to generate brain scans. Ard and his colleagues develop code that enables them to easily enter data into the software. They plan to make the code freely available to other researchers. The team is also combining the visualization software with virtual reality to enable scientists to explore the brain in three dimensions, and even perform virtual dissections of the brain. In one demo, the user can pick at a colored, segmented brain that can be pulled apart like pieces of Lego. “This can be useful when learning neuroanatomy,” Ard says. “The way that I learned it, we had to look at slices, and that’s real hard. This is a way that allows you to understand 3-D structure better.” The team plans to release the program, called Neuro Imaging in Virtual Reality, online next year. © 2017 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: 24340 - Posted: 11.20.2017

Summary A vast effort by a team of Janelia Research Campus scientists is rapidly increasing the number of fully-traced neurons in the mouse brain. Researchers everywhere can now browse and download the 3-D data. Inside the mouse brain, individual neurons zigzag across hemispheres, embroider branching patterns, and, researchers have now shown, often spool out spindly fibers nearly half a meter long. Scientists can see and explore these wandering neural traces in 3-D, in the most extensive map of mouse brain wiring yet attempted. The map – the result of an ongoing effort by an eclectic team of researchers at the Janelia Research Campus – reconstructs the entire shape and position of more than 300 of the roughly 70 million neurons in the mouse brain. Previous efforts to trace the path of individual neurons had topped out in the dozens. “Three hundred neurons is just the start,” says neuroscientist Jayaram Chandrashekar, who leads the Janelia project team, called MouseLight for its work illuminating the circuitry of the mouse brain. He and colleagues expect to trace hundreds more neurons in the coming months – and they’re sharing all the data with the neuroscience community. The team released their current dataset and an analysis tool, called the MouseLight NeuronBrowser, on October 27, 2017, and will report the work in November at the annual Society for Neuroscience meeting in Washington, D.C. They hope that the findings will help scientists ask, and begin to answer, questions about how neurons are organized, and how information flows through the brain. ©2017 Howard Hughes Medical Institute

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: 24319 - Posted: 11.11.2017

By: George Paxinos, Being an atlas maker, I have an image problem. I recently introduced myself to a lady at a Society for Neuroscience Meeting who had used the first edition of The Rat Brain in Stereotaxic Coordinates for her PhD thesis 35 years earlier. With surprise written on her face, she said, “George Paxinos, I thought you were dead.” On another occasion, I was giving a talk at Munich and one girl asked another, “Did you see Paxinos?” The other girl replied, “Yes, it is on my shelf.” The idea of constructing an atlas came to me while on a sabbatical at Cambridge. There, I used acetylcholinesterase (AChE) as a proxy (poor at that) for acetylcholine. Looking at the rat brain stained for AChE was like looking at a coloring book that was already colored. I was convinced immediately that I would be able to construct a better atlas of the rat brain than the then popular atlas of Konig and Klippel (1963). The Konig and Klippel atlas did not display the pons, medulla, cerebellum, olfactory bulbs, spinal cord, horizontal section or the point of bregma, the most frequently used reference point in stereotaxic surgery. Further it was based on 150g female rats, while most neuroscientists used 300g male rats. However, my greatest difficult with this atlas was that as an undergraduate in psychology at Berkeley, I was going to be instructed by my professor on stereotaxic surgery, but unfortunately the rat resisted going under the anesthetic. Trying to anesthetize the rat consumed the available time and my professor left, telling me to read the coordinates and implant the electrode in the hypothalamus. In my rush to implant the electrode without the rat getting out of the anesthetic, I failed to read the Introduction of the atlas, where it was stated clearly that the stereotaxic zero point of the atlas is not (repeat “not”) the stereotaxic zero point of the stereotaxic instrument, but 4.9mm above the true stereotaxic zero for convenience. So, in targeting the hypothalamus, I missed the brain by 4.9mm. I thought any psychologist would have been able to design a better atlas than that. The only problem I had in constructing the rat brain atlas was that I did not know anatomy. © 2017 Elsevier,

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: 24317 - Posted: 11.11.2017

Laura Sanders The human brain is teeming with diversity. By plucking out delicate, live tissue during neurosurgery and then studying the resident cells, researchers have revealed a partial cast of neural characters that give rise to our thoughts, dreams and memories. So far, researchers with the Allen Institute for Brain Science in Seattle have described the intricate shapes and electrical properties of about 100 nerve cells, or neurons, taken from the brains of 36 patients as they underwent surgery for conditions such as brain tumors or epilepsy. To reach the right spot, surgeons had to remove a small hunk of brain tissue, which is usually discarded as medical waste. In this case, the brain tissue was promptly packed up and sent — alive — to the researchers. Once there, the human tissue was kept on life support for several days as researchers analyzed the cells’ shape and function. Some neurons underwent detailed microscopy, which revealed intricate branching structures and a wide array of shapes. The cells also underwent tiny zaps of electricity, which allowed researchers to see how the neurons might have communicated with other nerve cells in the brain. The Allen Institute released the first publicly available database of these neurons on October 25. A neuron called a pyramidal cell, for instance, has a bushy branch of dendrites (orange in 3-D computer reconstruction, above) reaching up from its cell body (white circle). Those dendrites collect signals from other neural neighbors. Other dendrites (red) branch out below. The cell’s axon (blue) sends signals to other cells that spur them to action. |© Society for Science & the Public 2000 - 2017.

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: 24314 - Posted: 11.10.2017

By Amanda B. Keener On a fall day in 2015 at Sunnybrook hospital in Toronto, a dozen people huddled in a small room peering at a computer screen. They were watching brain scans of a woman named Bonny Hall, who lay inside an MRI machine just a few feet away. Earlier that day, Hall, who had been battling a brain tumor for eight years, had received a dose of the chemotherapy drug doxorubicin. She was then fitted with an oversized, bowl-shape helmet housing more than 1,000 transducers that delivered ultrasound pulses focused on nine precise points inside her brain. Just before each pulse, her doctors injected microscopic air bubbles into a vein in her hand. Their hope was that the microbubbles would travel to the capillaries of the brain and, when struck by the sound waves, oscillate. This would cause the blood vessels near Hall’s tumor to expand and contract, creating gaps that would allow the chemotherapy drug to escape from the bloodstream and seep into the neural tissue. Finally, she received an injection of a contrast medium, a rare-earth metal called gadolinium that lights up on MRI scans. Now, doctors, technicians, and reporters crowded around to glimpse a series of bright spots where the gadolinium had leaked into the targeted areas, confirming the first noninvasive opening of a human’s blood-brain barrier (BBB). “It was very exciting,” says radiology researcher Nathan McDannold, who directs the Therapeutic Ultrasound Lab at Brigham and Women’s Hospital in Boston and helped develop the technique that uses microbubbles and ultrasound to gently disturb blood vessels. Doctors typically depend on the circulatory system to carry a drug from the gut or an injection site to diseased areas of the body, but when it comes to the brain and central nervous system (CNS), the vasculature switches from delivery route to security system. The blood vessels of the CNS are unlike those throughout the rest of the body. © 1986-2017 The Scientist

Related chapters from BN8e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 24310 - Posted: 11.09.2017

Sara Reardon The 70 million neurons in the mouse brain look like a tangled mess, but researchers are beginning to unravel the individual threads that carry messages across the organ. A 3D brain map released on 27 October, called MouseLight, allows researchers to trace the paths of single neurons and could eventually reveal how the mind assembles information. The map contains 300 neurons and researchers plan to add another 700 in the next year. “A thousand is just beginning to scratch the surface,” says Nelson Spruston, a neuroscientist at the Howard Hughes Medical Institute (HHMI) Janelia Research Campus in Ashburn, Virginia. To create the maps, Spruston and HHMI neuroscientist Jayaram Chandrashekar injected mouse brains with viruses that infect only a few cells at a time, prompting them to produce fluorescent proteins1. The team made the organs transparent using a sugar-alcohol treatment to obtain an unobstructed view of the glowing neurons, and then scanned each brain with a high-resolution microscope. Computer programs created 3D models of the glowing neurons and their projections, called axons, which can be half a metre long and branch like a tree. MouseLight has already revealed new information, including the surprisingly extensive number of brain regions that a single axon can reach. For instance, four neurons associated with taste stretch into the region that controls movement and another area related to touch. Chandrashekar says the group is now working on identifying which genes each neuron expresses, which will help to pin down their function. © 2017 Macmillan Publishers 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: 24258 - Posted: 10.28.2017

Megan Molteni For patients with epilepsy, or cancerous brain lesions, sometimes the only way to forward is down. Down past the scalp and into the skull, down through healthy grey matter to get at a tumor or the overactive network causing seizures. At the end of the surgery, all that extra white and grey matter gets tossed in the trash or an incinerator. Well, not all of it. At least, not in Seattle. For the last few years, doctors at a number of hospitals in the Emerald City have been saving those little bits and blobs of brain, sticking them on ice, and rushing them off in a white van across town to the Allen Institute for Brain Science. Scientists there have been keeping the tissue on life support long enough to tease out how individual neurons look, act, and communicate. And today they’re sharing the first peek at these cells in a freely available public database. It provides a more intimate, intricate look into the circuitry of the human brain than ever before. And it’s just the beginning of a much larger effort to build a complete catalog of human brain cells. This first release includes electrical readings from a few hundred living neurons—all recently removed from 36 neurosurgery patients in Seattle area hospitals. For 100 of those cells, Allen Institute researchers built 3-D models of their branching structures, which they can use to simulate patterns of pulses and zaps. Scientists can see where in the brain neurons start and stop, and how current flows and spreads a signal throughout a neuronal network—signals that might move a muscle, or make a memory.

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: 24245 - Posted: 10.26.2017

By Roni Dengler One man’s neuron is another man’s knowledge. That’s the stance of the Allen Institute for Brain Science, which this week released the first open-access database of live human brain cells. It contains data on the electrical properties of about 300 cortical neurons taken from 36 patients and 3D reconstructions of 100 of those cells, plus gene expression data from 16,000 neurons from three other patients. Working with Seattle, Washington–area neurosurgeons, the Allen Institute acquired healthy cells from the cortex—the outermost layer of the brain that coordinates perception, memory, thoughts, and consciousness—from patients undergoing surgery for epilepsy or brain tumors. Normally considered medical waste, these tissues can now provide scientists with a unique resource for understanding the human brain. That’s because most studies on single human brain cells use dead rather than living tissue, and many others rely on cells from common laboratory animals, especially mice. The new data should help researchers pin down what makes human brains unique from other species—and what makes for a healthy versus diseased brain. © 2017 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: 24237 - Posted: 10.25.2017

Jon Hamilton Brain imaging studies have a diversity problem. That's what researchers concluded after they re-analyzed data from a large study that used MRI to measure brain development in children from 3 to 18. Like most brain imaging studies of children, this one included a disproportionate number of kids who have highly educated parents with relatively high household incomes, the team reported Thursday in the journal Nature Communications. For example, parents of study participants were three times more likely than typical U.S. parents to hold an advanced degree. And participants' family incomes were much more likely to exceed $100,000 a year. So the researchers decided to see whether the results would be different if the sample represented the U.S. population, says Kaja LeWinn, an assistant professor at the University of California, San Francisco School of Medicine. "We were able to weight that data so it looked more like the U.S." in terms of race, income, education and other variables, she says. And when the researchers did that, the picture of "normal" brain development changed dramatically. For instance, when the sample reflected the U.S. population, children's brains reached several development milestones much earlier. © 2017 npr

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: 24204 - Posted: 10.17.2017

By Emily Underwood If you’ve ever found yourself in an MRI machine, you know keeping still isn’t easy. For newborns, it’s nearly impossible. Now, a portable, ultrasonic brain probe about the size of a domino could do similar work, detecting seizures and other abnormal brain activity in real time, according to a new study. It could also monitor growing babies for brain damage that can lead to diseases like cerebral palsy. “This is a window of time we haven’t had access to, and techniques like this are really going to open that up,” says Moriah Thomason, a neuroscientist at Wayne State University in Detroit, Michigan, who wasn’t involved in the new study. Researchers have long been able to take still pictures of the newborn brain and study brain tissue after death. But brain function during the first few weeks of life, which is “utterly essential to future human health,” has always been something of a black box, Thomason says. Two techniques used in adults—functional magnetic resonance imaging (fMRI), which can measure blood flow; and electroencephalography (EEG), which measures electrical activity in the outer layers of the brain—have their drawbacks. FMRI doesn’t work well with squirmy tots, is expensive, and is too big to haul to a delicate baby’s bedside. EEG—which only requires attaching a few wires to someone’s head—can’t penetrate deeper brain structures or show where a seizure begins, critical information for doctors weighing treatment options, says Olivier Baud, a developmental neuroscientist at the Robert Debré University Hospital in Paris. © 2017 American Association for the Advancement of Science.

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: 24183 - Posted: 10.12.2017