Links for Keyword: Brain imaging

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Rebecca Goldin, Ph.D., Cindy S. Merrick With the news media telling us that neuroscience – and brain scans – can explain everything from a global pandemic of Justin Bieber fever to whether you are likely to stay with your spouse, we investigate what neuroscience can and can’t tell us about who we are and why we do the things we do. In the first part of an ongoing series, we look at functional magnetic resonance imaging, and whether it’s really the window on the mind that some in the media – and science – would have us believe. Gone are the days when the only people who believed in technologies that could read minds were distinguishable from the rest of us by their tin foil hats. With the advent of functional magnetic resonance imaging (fMRI), we are able to see, in near-video quality, the ebb and flow of a live mind at work. Or so it seems. Something, for certain, is at work, and there are lots of people willing to tell you they know exactly how to interpret what we can see. Certainly this new technology has already produced fascinating results: surgeons use it real-time to avoid critical regions while operating on brain tumors; physicians use it to look for changes in the brain activity of stroke victims as they experience physical rehabilitation; and fMRI data showing activity in the brains of patients thought to be in a vegetative state may be blurring the line that defines consciousness. Along with these advances, though, have appeared many somewhat less credible stories. The media reports claims ranging from fMRI’s ability to detect lies to its predicting future addictive behavior or determining whether or not you really love your spouse, or, maybe, your iPhone. Already, attempts have been made to use fMRI as admissible evidence of lie detection in court (so far, they have failed); and in another court case, fMRI results and a neuroscientist’s testimony were admitted in the sentencing hearing. The data were used as evidence that the defendant, a violent offender, was psychopathic.

Related chapters from BP7e: 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: 17047 - Posted: 07.17.2012

Neuron forest grows out of brain trauma experiment

Will Ferguson, reporter You can't visit this tropical jungle. It's a forest of neurons snaking through a pig's brain. The brain cells, enlarged and coloured here, are being investigated to give scientists a clearer view of the mechanics of brain matter when it is hit hard. Michel Destrade, an applied mathematician at the National University of Ireland, Galway, and colleagues obtained samples of pig brains from a local slaughterhouse to study the mechanics of brain matter undergoing rapid impacts. With the aim of improving the treatment of traumatic head injuries, they used the samples to create computer models of electrical signals inside the brain. But during the course of the experiment, Destrade's student Badar Rashid decided to find out what white and grey matter inside a brain look like. He started with an image of neuron bundles taken using scanning electron microscopy, and blew it up to 4,000 times its actual size. He then added colour to the black and white result according to his own aesthetic. The image appears in Physics Today (DOI:10.1063/PT.3.1651). © Copyright Reed Business Information Ltd.

Controversial science of brain imaging

By Mahir Ozdemir Hardly a week passes without some sensational news about brain scans unleashing yet another secret of our cognitive faculties. Very recently I stumbled upon the news that according to recent research neuroscientists can tell, depending on your brain responses, whether you and your significant one will still be together in a few years: “You might hide it from friends and family. But you can’t hide it from neuroscientists”. The technique at the bottom of the study, just like the majority of studies making a big splash, is functional magnetic resonance imaging, fMRI. Researchers have been struggling to unfold ‘what’s under the hood’ through the lens of Neuroscience and they have been finding all sorts of insights into human behavior. They have been looking at everything from how multitasking is harder for seniors to how people love talking about themselves. Neural basis of love and hatred, compassion and admiration have all been studied with fMRI, yielding colored blobs representing the corresponding love or hatred centers in our brains. First a brief background: The fMRI technique measures brain activity indirectly via changes in blood oxygen levels in different parts of the brain as subjects participate in various activities. While lying down with head immobilized in a small confined chamber of the notoriously noisy MR scanner, subjects are shown experimental stimuli. They wear earplugs to reduce at least some part of the noise while performing these cognitive tasks. © 2012 Scientific American

What’s a Voxel and What Can It Tell Us? A Primer on fMRI

By Daisy Yuhas At right is a picture of someone’s brain as seen through functional magnetic resonance imaging or fMRI. This particular subject is taxing his neurons with a working memory task—those sunny orange specks represent brain activity related to the task. fMRI images show the brain according to changes in blood oxygen level, a proxy for degree of mental activity. It’s a pretty amazing tool; it has validated a lot of assumptions about brain regions and helped us make comparisons between groups of people, shedding light on addiction, development and disease. Some scientists believe it can help us read minds (more on that later) or even predict the future. But fMRI doesn’t actually provide detail at the level of a cell. The 3-dimensionsal image it provides is built up in units called voxels. Each one represents a tidy cube of brain tissue—a 3-D image building block analogous to the 2-D pixel of computers screens, televisions or digital cameras. Each voxel can represent a million or so brain cells. Those orange blobs in the image above are actually clusters of voxels—perhaps tens or hundreds of them. fMRI is also too slow to capture all of the changes in the brain. Each scan requires a second or two, enough time for a neuron to fire more than a hundred times. That means it can’t provide a clear sense of precisely when things happen. Trying to explain whether activity in one spot causes activity in another is not possible through fMRI alone. Furthermore, you have to be careful with your conclusions. Just because voxels corresponding to one region ‘light up’ when your subject sees a terrifying tiger doesn’t mean that every time this region appears active, your subject is frightened. Many of the brain’s regions are quite complex and involved in multiple processes. © 2012 Scientific American

The Problem With Neuroscience Narratives

Neuroscientist and friend of the blog Bradley Voytek has a terrific piece about the relationship between popular science writing and neuroscience that’s well worth your time. In brief, he says, the primary problem are neuroscientists themselves. Or at least, some of the assumptions that neuroscientists make. The problem, he notes, is a problem that long term readers here are familiar with – the confusion of cause and effect, as well as an over-reductionist view of the brain. Namely, that imaging studies showing a portion of the brain “lighting up” when something happens means that that area of the brain is directly involved in the activity. Something that he analogizes to “like how when your arms swing faster when you run that means that your arms are ‘where running happens’.” Voytek also provides what I think is one of the best analogies I’ve read about the problem inherent in trying to isolate “which part of the brain does X”: Imagine asking “where is video located in my computer?” That doesn’t make any sense. Your monitor is required to see the video. Your graphics card is required to render the video. The software is required to generate the code for the video. But the “video” isn’t located anywhere in the computer. This is something that I think is exactly right. The best neuroscientists out there are, I think, very aware of this problem, but I think part of what’s going on here is the inherent limitations of our ability to experiment. Take fMRI’s, for example, which have provided an interesting look into what kinds of activity is going on in the brain while the person being imaged is doing or thinking something. It’s one of the best pieces of equipment available, but it’s very nature can be deceiving. Because it’s one of the few ways available to figure out what’s going on in the brain, it can be tempting to see what is measured by an fMRI image as definitive. 2012 Forbes.com LLC™

CT scans on children 'could triple brain cancer risk'

By Jane Dreaper Health correspondent, BBC News Multiple CT scans in childhood can triple the risk of developing brain cancer or leukaemia, a study suggests. The Newcastle University-led team examined the NHS medical records of almost 180,000 young patients. But writing in The Lancet the authors emphasised that the benefits of the scans usually outweighed the risks. They said the study underlined the fact the scans should only be used when necessary and that ways of cutting their radiation should be pursued. During a CT (computerised tomography) scan, an X-ray tube rotates around the patient's body to produce detailed images of internal organs and other parts of the body. In the first long-term study of its kind, the researchers looked at the records of patients aged under 21 who had CT scans at a range of British hospitals between 1985 and 2002. Because radiation-related cancer takes time to develop, they examined data on cancer cases and mortality up until 2009. The study estimated that the increased risk translated into one extra case of leukaemia and one extra brain tumour among 10,000 CT head scans of children aged under ten. BBC © 2012

Related chapters from BP7e: 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: 16883 - Posted: 06.07.2012

Speedy pH changes detected in brain for first time

by Linda Geddes SECOND by second changes in the brain's pH can be visualised for the first time. This ability may provide fresh insights into learning, memory and disease. Oxygen deprivation can alter the brain's pH, and even normal brain signals from acidic neurotransmitters or metabolic by-products such as lactic acid may lead to local changes in pH. Studies in mice have also uncovered pH-sensitive receptors in brain areas involved in emotion and memory - although their function is something of a mystery. "If these receptors are activated by pH change, it's possible that abnormalities in this system could lead to changes in learning, memory and mood," says Vincent Magnotta at the University of Iowa in Iowa City. A common way of studying the brain is with an MRI scanner, which detects differences in the spin of protons in tissues according to water content. Although brain pH can be measured using a form of MRI called MR spectroscopy, it only detects changes that occur over minutes - not fast enough to keep up with the rapid pace of the brain. T1ρ MRI analyses the interaction between spinning protons and other ions in a solution, which changes under different pHs. By tweaking the technique so that multiple measurements could be taken simultaneously, Magnotta and his colleagues have found that T1ρ MRI can detect changes in brain acidity happening over seconds. © Copyright Reed Business Information Ltd.

The Brain's Highways: Mapping the Last Frontier

By Partha Mitra Frontiers are in short supply. No explorer will again catch that first glimpse of the Pacific Ocean with “wild surmise,” take the first steps on the moon, or arrive first at the Challenger deep – the remotest corners of the earth are now tourist attractions. Even in science, great mysteries have fallen – life itself has gone from being the subject of metaphysical speculation about vital substances to the biophysical understanding of cellular processes. Uncharted territories, both physical and metaphorical, are hard to find. Yet there is one largely unmapped continent, perhaps the most intriguing of them all, because it is the instrument of discovery itself: the human brain. It is the presumptive seat of our thoughts, and feelings, and consciousness. Even the clinical criteria for death feature the brain prominently, so it arbitrates human life as well. One would think, that after a century of intensive research, its outlines would be well known to us: after all, colorful pictures of brain activity have been making regular appearances in the news media for some time. However, if one scratches the surface, our knowledge of how the human brain is put together remains limited: not in some esoteric, complicated manner, but in the straightforward sense that we have simply no means to visualize entire neurons in the brain (and the brain, being a collection of neurons, therefore remains a shut book in important ways). We can’t see them in their full glory, even with all our advanced technology. The problem is that compared to other cells visualized under a microscope, neurons are at the same time very small, and very big. While their soma (cell bodies) are like other cells, neurons can send out branches (axons) that travel very long distances, sometimes several feet, which don’t fit into the sections of tissue that we do histology on. © 2012 Scientific American,

Human brain prosciutto builds up 3D atlas

Sandrine Ceurstemont, editor, New Scientist TV Imagine being able to zoom into a human brain in extreme detail as you would navigate through Google Earth. This summer, a digital brain atlas being developed by neuroanatomist Jacopo Annese and his team from University of California, San Diego, will be available online, allowing people to interact with the brain's anatomy down to the level of the cell. The digital display is being created from slices of the brain of Henry Gustav Molaison, who lost his ability to form new long-term memories after a brain operation to treat epilepsy. By working with his brain, the team are building a 3D model in much higher resolution than is possible from MRI scans. To prepare a brain for dissection, it is first preserved in a process that takes months and then frozen. Next it is placed in a motorised tissue slicer specially built by Annese and his team to accommodate an organ as big as the brain (see video). A blade peels away layers about as thick as a human hair, which look like super-thin slices of prosciutto. They are collected with a paintbrush and placed in a salty solution. The sections are then laid out on glass slides so that they can be stained once dry. The purple dye used in the video stains genetic material in each cell, making fine anatomical structures visible. © Copyright Reed Business Information Ltd.

What was that dog thinking? Brain scan can now tell us

By Jeanna Bryner Managing editor Fido's expressive face, including those longing puppy-dog eyes, may lead owners to wonder what exactly is going on in that doggy's head. Scientists decided to find out, using brain scans to explore the minds of our canine friends. The researchers, who detailed their findings May 2 in the open-access journal PLoS ONE, were interested in understanding the human-dog relationship from the four-legged perspective. "When we saw those first (brain) images, it was unlike anything else," said lead researcher Gregory Berns in a video interview posted online. "Nobody, as far as I know, had ever captured images of a dog's brain that wasn't sedated. This was (a) fully awake, unrestrained dog, here we have a picture for the first time ever of her brain," added Berns, who is director of the Emory University Center for Neuropolicy. He added, "Now we can really begin to understand what dogs are thinking. We hope this opens a whole new door into canine cognition, social cognition of other species." Berns realized dogs could be trained to sit still in a brain-scanning machine after hearing that a U.S. Navy dog had been a member of the SEAL team that killed Osama bin Laden. "I realized that if dogs can be trained to jump out of helicopters and airplanes, we could certainly train them to go into an fMRI to see what they're thinking," Berns said. © 2012 msnbc.com

Myth, busted: You only use 10 percent of brain

By Brian Alexander Good news for all those who ever had a teacher or a parent say “If you would just apply yourself you could learn anything! You’re only using 10 percent of your brain!” All those people were wrong. If we did use only 10 percent of our brains we’d be close to dead, according to Eric Chudler, director of the Center for Sensorimotor Neural Engineering at the University of Washington, who maintains an entertaining brain science website for kids. “When recordings are made from brain EEGs, or PET scans, or any type of brain scan, there’s no part of the brain just sitting there unused,” he said. Larry Squire, a research neuroscientist with the Veterans Administration hospital in San Diego, and at the University of California San Diego, pointed out that “any place the brain is damaged there is a consequence.” Damaged brains may have been where this myth originated. During the first half of the last century, a pioneering neuroscientist named Karl Lashley experimented on rodents by excising portions of their brains to see what happened. When he put these rodents in mazes they’d been trained to navigate, he found that animals with missing bits of brain often successfully navigated the mazes. This wound up being transmuted into the idea humans must be wasting vast brain potential. With the rise of the human potential movement in the 1960s, some preached that all sorts of powers, including bending spoons and psychic abilities, were laying dormant in our heads and that all we had to do was get off our duffs and activate them. © 2012 msnbc.com

Related chapters from BP7e: 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: 16676 - Posted: 04.19.2012

Can a Brain Scan Tell You What Drugs to Take and Choices to Make?

by Carl Zimmer Ahmad Hariri stands in a dim room at the Duke University Medical Center, watching his experiment unfold. There are five computer monitors spread out before him. On one screen, a giant eye jerks its gaze from one corner to another. On a second, three female faces project terror, only to vanish as three more female faces, this time devoid of emotion, pop up instead. A giant window above the monitors looks into a darkened room illuminated only by the curve of light from the interior of a powerful functional magnetic resonance imaging (fMRI) scanner. A Duke undergraduate—we’ll call him Ross—is lying in the tube of the scanner. He’s looking into his own monitor, where he can observe pictures as the apparatus tracks his eye movements and the blood oxygen levels in his brain. Ross has just come to the end of an hour-long brain scanning session. One of Hariri’s graduate students, Yuliya Nikolova, speaks into a microphone. “Okay, we’re done,” she says. Ross emerges from the machine, pulls his sweater over his head, and signs off on his paperwork. As he’s about to leave, he notices the image on the far-left computer screen: It looks like someone has sliced his head open and imprinted a grid of green lines on his brain. The researchers will follow those lines to figure out which parts of Ross’s brain became most active as he looked at the intense pictures of the women. He looks at the brain image, then looks at Hariri with a smile. “So, am I sane?” Hariri laughs noncommitally. “Well, that I can’t tell you.” © 2012, Kalmbach Publishing Co.

Brain imaging: fMRI 2.0

Kerri Smith The blobs appeared 20 years ago. Two teams, one led by Seiji Ogawa at Bell Laboratories in Murray Hill, New Jersey, the other by Kenneth Kwong at Massachusetts General Hospital in Charlestown, slid a handful of volunteers into giant magnets. With their heads held still, the volunteers watched flashing lights or tensed their hands, while the research teams built the data flowing from the machines into grainy images showing parts of the brain illuminated as multicoloured blobs. The results showed that a technique called functional magnetic resonance imaging (fMRI) could use blood as a proxy for measuring the activity of neurons — without the injection of a signal-boosting compound1, 2. It was the first demonstration of fMRI as it is commonly used today, and came just months after the technique debuted — using a contrast agent — in humans3. Sensitive to the distinctive magnetic properties of blood that is rich in oxygen, the method shows oxygenated blood flowing to active brain regions. Unlike scanning techniques such as electroencephalography (EEG), which detects electrical activity at the skull's surface, fMRI produces measurements from deep inside the brain. It is also non-invasive, which makes it safer and more comfortable than positron emission tomography (PET), in which radioactive compounds are injected and traced as they flow around the body. fMRI has been applied to almost every aspect of brain science since. It has shown that the brain is highly compartmentalized, with specific regions responsible for tasks such as perceiving faces4 and weighing up moral responsibility5; that the resting brain is in fact humming with activity6; and that it may be possible to communicate with patients in a vegetative state by monitoring their brain activity7. In 2010, neuroscientists used fMRI in more than 1,500 published articles (see 'The rise of fMRI'). © 2012 Nature Publishing Group

Billionaire Paul Allen kicks off 'brain observatory' effort with $300 million

By Alan Boyle Software billionaire Paul Allen is pledging $300 million to establish a series of "brain observatories" at the Seattle research facility named after him, with the aim of mapping and manipulating the mouse brain. The project's leaders say the insights gained could be applied as well to higher forms of life, including humans. "We believe that this project has the potential to revolutionize our understanding of the mammalian brain," Christoph Koch, chief scientific officer for the Allen Institute for Brain Science, and Harvard neuroscientist R. Clay Reid said in the journal Nature. Details about the brain observatory project were laid out today at the Allen Institute in Seattle. In an advance interview, Koch cast the effort in terms usually reserved for the multibillion-dollar Hubble Space Telescope project or the $10 billion Large Hadron Collider. "We're focusing a huge amount of resources on trying to understand this piece of highly, highly complex math and science. The most organized piece of matter in the known universe is the cerebral cortex, the one that makes you and me think and smell and hear and talk. That's what we're trying to understand," Koch told me. "Just as people spend a huge amount of time and effort to build these different observatories to look at the origin of space and time, we're going to build these observatories, these very sophisticated instruments, all of them using common standards, all peering at the brain — primarily animal brains, but also the human brain." © 2012 msnbc.com

Neuroscience: Observatories of the mind

Christof Koch & R. Clay Reid Neuroscience is a splintered field. Some 10,000 laboratories worldwide are pursuing distinct questions about the brain across a panoply of spatio-temporal scales and in a dizzying variety of animal species, behaviours and developmental time-points. At any large neuroscience meeting, one is struck by the pace of discovery, with 50,000 or more practitioners heading away from each other in all directions, in a sort of scientific Big Bang. Although this independence is necessary, it has prevented neuroscience from entering a more mature phase, which would involve developing common standards and collaborative projects. Neurophysiologists are more likely to use each other's toothbrushes than each other's data and software; physiological results are hoarded and rarely made accessible online; molecular compounds and transgenic animals are shared only after publication. All of this has made comparisons across laboratories difficult and has slowed progress. At the Allen Institute for Brain Science in Seattle, Washington, we and our colleagues are initiating an experiment in the sociology of neuroscience — a huge endeavour that will involve several hundred scientists, engineers and technicians at the institute. Philanthropist Paul G. Allen, who founded the institute in 2003, has pledged US$300 million for the first four years of an ambitious ten-year plan that will accelerate progress in neuroscience, bringing his total commitment so far to $500 million. Our goal is to attract the best young scientists and build a series of 'brain observatories', with the aim of identifying, recording and intervening in the mouse cerebral cortex, the outermost layer of the brain. Unlike the telescopes that peer at remote events in space and time, our instruments will track the flow of information in complex, interbraided neural circuits within a layer of tissue one millimetre thick. © 2012 Nature Publishing Group,

The Connections May Be the Key

by Carl Zimmer If I didn’t know Sebastian Seung was a neuroscientist, I would have pegged him as a computer game designer. His onyx-black hair seems frozen in a windstorm. He wears black sneakers, jeans, and a frayed bomber jacket over an untucked shirt covered in fluorescent blobs. If someone had blindfolded me on Vassar Street in Cambridge, Massachusetts, led me into Building 46 on the campus of MIT, past the sign that says Department of Brain and Cognitive Science, taken me up in the elevator to the fifth floor and whisked off the blindfold in Seung’s lab, I still wouldn’t have guessed he had anything to do with brains. There are no specimens floating in jars on the shelves. There are no electrodes plugged into the heads of sea slugs. Instead, I see a dozen young men gazing at monitors, some pushing their computer mice, others drawing tethered pens across digital tablets to manipulate 3-D images, each packed with more megabytes than a feature film on a Blu-ray Disc. And there is Seung himself, gazing over the shoulder of postdoc Daniel Berger, whose monitor looks like a science fiction forest, with branches and trunks colored turquoise and cherry, floating unrooted in space. I almost find myself wondering when Seung’s next game will hit the stores. But appearances to the contrary, Seung is an expert on the web of neurons that make up the brain. And the images he’s creating are part of an ambitious attempt to understand how the connections between those brain cells give rise to the mind. “How do you put together dumb cells and get something smart?” he asks. © 2012, Kalmbach Publishing Co.

Neuroscience: Making connections

Jon Bardin A building that once housed a Second World War torpedo factory seems an unlikely location for a project aiming to map the human brain. But the Martinos Center for Biomedical Imaging — an outpost of the Massachusetts General Hospital in an industrialized stretch of Boston's riverfront — is home to an impressive collection of magnetic resonance imaging machines. In January, I slid into the newest of these, head first. The operator ran a few test sequences to see whether I experienced any side effects from the unusually rapid changes in this machine's magnetic field. And, when I didn't — no involuntary muscle twitches or illusory flashes of light in my peripheral vision — we began. The machine hummed, then started to vibrate. For 90 minutes, I held still as it scanned my brain. That scan would be one of the first carried out by the Human Connectome Project (HCP), a five-year, US$40-million initiative funded by the National Institutes of Health (NIH) in Bethesda, Maryland, to map the brain's long-distance communications network. The network, dubbed the 'connectome', is a web of nerve-fibre bundles that criss-cross the brain in their thousands and form the bulk of the brain's white matter. It relays signals between specialized regions devoted to functions such as sight, hearing, motion and memory, and ties them together into a system that perceives, decides and acts as a unified whole. The connectome is bewilderingly complex and poorly understood. The HCP proposes to resolve this by using new-generation magnetic resonance imaging (MRI) machines, like that used to scan my brain, to trace the connectomes of more than 1,000 individuals. The hope is that this survey will establish a baseline for what is normal, shed light on what the variations might mean for qualities such as intelligence or sociability, and possibly reveal what happens if the network goes awry. © 2012 Nature Publishing Group

A mania for dumbing down

It's not always clever to use brain science as an explanation for the most complex human problems. In the vast literature documenting the possible causes of the financial crises, from tepid governments to loose monetary policy to greedy bankers, there was the more lucid theme of a belief in the infallible nature of modern economic models, those mathematical pieces of wonder that tried to incorporate everything from the weather to political power-plays into the all-encompassing term that is risk. At the heart of this flawed world-view was the idea that economics had become a science much like physics and biochemistry - quantifiable, measurable and able to be modelled. In the wreckage thereafter, the reductionism inherent in such hubris was there for all to see. But the scientism that had inebriated the world of economics is part of a broader trend of viewing our very natures in a stripped back to the biological bones caricature. It is best epitomised by the ubiquity of musings about the brain from those attempting to bolster their authority, which includes everyone from leadership gurus to astrologers. The word is out that human consciousness - from the most elementary tingle of sensation to the most sophisticated sense of self - is identical with neural activity in the human brain and that this extraordinary metaphysical discovery is underpinned by the latest findings in neuroscience. The republic of letters is in thrall to the idea of neuroplasticity, imagining in wonder their brains modifying cells in parallel with their daily meanderings. © 2012 Fairfax Media

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 14: Attention and Consciousness
Link ID: 16527 - Posted: 03.17.2012

Brain 'X-ray' exposes broken connections after injury

Sandrine Ceurstemont, editor, New Scientist TV Just like an X-ray reveals fractured bones, a new imaging technique can now pinpoint broken connections in the brain resulting from injuries for the first time. Developed by Walter Schneider and a team from the University of Pittsburgh in Pennsylvania, the technology, called high definition fibre tracking (HDFT), allows doctors to visualise breaks in bundles of fibres, called fibre tracts, that connect different parts of the brain and control functions like language and limb movement. "Until now, there was no objective way of identifying how the injury damaged the patient's brain tissue, predicting how the patient would fare or planning rehabilitation to maximise the recovery," says neurosurgeon David Okonkwo, a member of the team. To generate the vivid brain images, computer algorithms process data captured from a sophisticated MRI scan. The pictures reveal forty major cables in the brain which can be dissected virtually to pinpoint a damaged area. The injured region can then be compared to the healthy side of the brain to quantify the proportion of severed fibres and thus the degree of connection that has been lost. This detail can help predict how a patient will recover from an injury. The technique is already being used to supplement conventional imaging, helping to plan the removal of tumours or vascular abnormalities in the brain. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Language and Our Divided Brain
Link ID: 16477 - Posted: 03.06.2012

First brain movie captures a mouse thinking

Andy Coghlan, reporter Ever wondered what's going on in the brain of a mouse? Now brain cells have been captured sending and receiving signals in high resolution for the first time, essentially showing its brain in action. To make the tiniest anatomical details of neurons visible, Katrin Willig and her team at the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany, gave mice an extra gene that generates a yellow glow. When their brains were viewed with a special microscope through a glass-sealed window in the skull, the signal junctions in neurons lit up. At these intersections, tiny spines sprout from longer branching fibers, called dendrites, and exchange signals by linking up with spines on neighbouring cells. The movie spans a 20 to 30 minute period, during which a live mouse was anaesthetised. The spines physically move and wobble at the top and base as they form and break connections with neighbouring spines. "There are always connections breaking and forming and it's the natural movement of the spine," says Willig. "It may be the mouse thinking". Brain cells have been imaged in live animals before, but the latest movie is the first to reveal parts of neurons in such fine detail - down to a resolution of 70 nanometers. © Copyright Reed Business Information Ltd.

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