Chapter 2. Cells and Structures: The Anatomy of the Nervous System
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By Kerry Grens Brain scans of 3,242 volunteers aged four to 63 years old revealed that those diagnosed with attention deficit hyperactivity disorder (ADHD)—roughly half of the group—had smaller tissue volumes in five brain regions. Because the differences were largest between children, the researchers concluded that ADHD likely involves a delay in brain maturation. The study, published in The Lancet Psychiatry on February 15, is the largest of its kind to date, and the authors hope it will change public perception of the disorder. “I think most scientists in the field already know that the brains of people with ADHD show differences, but I now hope to have shown convincing evidence … that will reach the general public and show that it has [a basis in the brain] just like other psychiatric disorders,” geneticist and coauthor Martine Hoogman of Radboud University in the Netherlands told The Washington Post. “We know that ADHD deals with stigma, but we also know that increasing knowledge will reduce stigma.” Most pronounced among the brain differences between those with and without ADHD was the amygdala, important for emotional processing. “The amygdala is heavily connected to other brain regions. It is a kind of hub for numerous kinds of signaling around salience and significance of events,” Joel Nigg, a psychiatry professor at Oregon Health & Science University School of Medicine who was not part of the study, told CNN. “The bigger story here is that alterations in amygdala have not been widely accepted as part of ADHD, so seeing that effect emerge here is quite interesting.” © 1986-2017 The Scientist
Daqing Li and Ying Li In 1969 Geoffrey Raisman, who has died aged 77, introduced the term “plasticity” to describe the ability of damaged nerve tissue to form new synaptic connections. He discovered that damaged nerves in the central nervous system (CNS) could be repaired and developed the theory that white matter (nerve fibres and supporting cells) is like a pathway – when it is disrupted by injury, such as spinal cord injury, growth of the regenerating fibres is blocked. In 1985 he described how olfactory ensheathing cells (OECs) “open doors” for newly formed nerve fibres in the nose to enter the CNS. Believing that reconstruction of the damaged pathway is essential to repair of the injured CNS and using the unique door-opening capability of OECs, in 1997, together with colleagues, Geoffrey showed that transplantation of OECs into the damaged spinal cord in experimental models repairs the damaged pathway and results in the regeneration of severed nerve fibres and the restoration of lost functions. The study led to a joint clinical trial with Pawel Tabakow and his team at Wroclaw Medical University, Poland. In 2014 the first patient with a complete severance of the thoracic spinal cord received transplantation of his own OECs. The operation enabled the patient, Darek Fidyka, to gain significant neurological recovery of sensation and voluntary movement. He can now get out of his wheelchair and ride a tricycle. The wider application of OECs has also been investigated. In 2012, with his team at University College London, collaborating with the UCL Institute of Ophthalmology and Southwest hospital, at the Third Military Medical University in Chongqing, China, Geoffrey described the protective effect of OECs in an experimental glaucoma model. The discovery has led to a plan to translate this research to clinical application which, it is hoped, will help many sufferers regain sight.
By Jennifer Couzin-Frankel At least two dozen junior and senior researchers are stuck in scientific limbo after being barred from publishing data collected over a 25-year period at a National Institutes of Health (NIH) lab. The unusual ban follows the firing last summer of veteran neurologist Allen Braun by the National Institute on Deafness and Other Communication Disorders (NIDCD) for what many scientists have told Science are relatively minor, if widespread, violations of his lab’s experimental protocol. Most of the violations, which were unearthed after Braun himself reported a problem, involve the prescreening or vetting of volunteers for brain imaging scans and other experiments on language processing. The fallout from the case was recently chronicled on a blog by one of Braun’s former postdocs, and it highlights a not-uncommon problem across science: the career harm to innocent junior investigators following lab misconduct or accidental violations on the part of senior scientists. But this case, say those familiar with it, is extreme. “We’re truly collateral damage,” says Nan Bernstein Ratner of the University of Maryland in College Park, who researches stuttering. She spent 5 years collaborating with Braun. Now, two of her graduate students have had to shift their master’s theses topics, and an undergraduate she mentored cannot publish a planned paper. “The process has been—you can use this term—surreal.” © 2017 American Association for the Advancement of Science
By Esther Landhuis For much of her life Anne Dalton battled depression. She seldom spoke with people. She stayed home a lot. The days dragged on with a sense of “why bother?” for the 61-year-old from New Jersey who used to work at a Wall Street investment firm. After trying more than a dozen combinations of antidepressant drugs to no avail, things got so bad two years ago that Dalton went in for electroconvulsive therapy—in which “basically they shock your brain,” as she puts it. Like Dalton, most of the estimated 16 million U.S. adults who have reported a major depressive episode in the past year find little relief even after several months on antidepressants—a problem that some researchers say may stem from the way mental illness is diagnosed. Objective lab tests can physically confirm heart disease or cancer, but psychiatric conditions are classified somewhat vaguely as clusters of reported symptoms. Doctors consider people clinically depressed if they say they have low mood and meet at least four additional criteria from an overall list of nine. Yet depression can manifest differently from person to person: One might be putting on pounds and sleeping much of the time whereas another might be losing weight, feeling anxious and finding it difficult to sit still, says Conor Liston, a neuroscientist and psychiatrist at Weill Cornell Medical College. “The fact that we lump people together like this has been a big obstacle in understanding the neurobiology of depression,” Liston explains. © 2017 Scientific American,
JoAnna Klein Some microscopes today are so powerful that they can create a picture of the gap between brain cells, which is thousands of times smaller than the width of a human hair. They can even reveal the tiny sacs carrying even tinier nuggets of information to cross over that gap to form memories. And in colorful snapshots made possible by a giant magnet, we can see the activity of 100 billion brain cells talking. Decades before these technologies existed, a man hunched over a microscope in Spain at the turn of the 20th century was making prescient hypotheses about how the brain works. At the time, William James was still developing psychology as a science and Sir Charles Scott Sherrington was defining our integrated nervous system. Meet Santiago Ramón y Cajal, an artist, photographer, doctor, bodybuilder, scientist, chess player and publisher. He was also the father of modern neuroscience. “He’s one of these guys who was really every bit as influential as Pasteur and Darwin in the 19th century,” said Larry Swanson, a neurobiologist at the University of Southern California who contributed a biographical section to the new book “The Beautiful Brain: The Drawings of Santiago Ramón y Cajal.” “He’s harder to explain to the general public, which is probably why he’s not as famous.” Last month, the Weisman Art Museum in Minneapolis opened a traveling exhibit that is the first dedicated solely to Ramón y Cajal’s work. It will make stops in Minneapolis; Vancouver, British Columbia; New York; Cambridge, Mass.; and Chapel Hill, N.C., through April 2019. Ramón y Cajal started out with an interest in the visual arts and photography — he even invented a method for making color photos. But his father pushed him into medical school. Without his artistic background, his work might not have had as much impact, Dr. Swanson said. © 2017 The New York Times Company
Keyword: Brain imaging
Link ID: 23251 - Posted: 02.18.2017
By Kelly Clancy More than two hundred years ago, a French weaver named Joseph Jacquard invented a mechanism that greatly simplified textile production. His design replaced the lowly draw boy—the young apprentice who meticulously chose which threads to feed into the loom to create a particular pattern—with a series of paper punch cards, which had holes dictating the lay of each stitch. The device was so successful that it was repurposed in the first interfaces between humans and computers; for much of the twentieth century, programmers laid out their code like weavers, using a lattice of punched holes. The cards themselves were fussy and fragile. Ethereal information was at the mercy of its paper substrate, coded in a language only experts could understand. But successive computer interfaces became more natural, more flexible. Immutable program instructions were softened to “If x, then y. When a, try b.” Now, long after Jacquard’s invention, we simply ask Amazon’s Echo to start a pot of coffee, or Apple’s Siri to find the closest car wash. In order to make our interactions with machines more natural, we’ve learned to model them after ourselves. Early in the history of artificial intelligence, researchers came up against what is referred to as Moravec’s paradox: tasks that seem laborious to us (arithmetic, for example) are easy for a computer, whereas those that seem easy to us (like picking out a friend’s voice in a noisy bar) have been the hardest for A.I. to master. It is not profoundly challenging to design a computer that can beat a human at a rule-based game like chess; a logical machine does logic well. But engineers have yet to build a robot that can hopscotch. The Austrian roboticist Hans Moravec theorized that this might have something to do with evolution. Since higher reasoning has only recently evolved—perhaps within the last hundred thousand years—it hasn’t had time to become optimized in humans the way that locomotion or vision has. The things we do best are largely unconscious, coded in circuits so ancient that their calculations don’t percolate up to our experience. But because logic was the first form of biological reasoning that we could perceive, our thinking machines were, by necessity, logic-based. © 2017 Condé Nast.
Hannah Devlin A transportable brain-scanning helmet that could be used for rapid brain injury assessments of stroke victims and those felled on the sports pitch or battlefield is being tested by US scientists. The wearable device, known as the PET helmet, is a miniaturised version of the hospital positron emission tomography (PET) scanner, a doughnut-shaped machine which occupies the volume of a small room. Julie Brefczynski-Lewis, the neuroscientist leading the project at West Virginia University, said that the new helmet could dramatically speed up diagnosis and make the difference between a positive outcome and devastating brain damage or death for some patients. “You could roll it right to their bedside and put it on their head,” she said ahead of a presentation at the American Association for the Advancement of Science’s (AAAS) annual meeting in Boston. “Time is brain for stroke.” Despite being only the size of a motorbike helmet, the new device produces remarkably detailed images that could be used to identify regions of trauma to the brain in the ambulance on the way to hospital or at a person’s bedside. The device is currently being tested on healthy volunteers, but could be used clinically within two years, the team predicted.
By Pallab Ghosh Scientists are appealing for more people to donate their brains for research after they die. They say they are lacking the brains of people with disorders such as depression and post-traumatic stress disorder. In part, this shortage results from a lack of awareness that such conditions are due to changes in brain wiring. The researchers' aim is to develop new treatments for mental and neurological disorders. The human brain is as beautiful as it is complex. Its wiring changes and grows as we do. The organ is a physical embodiment of our behaviour and who we are. In recent years, researchers have made links between the shape of the brain and mental and neurological disorders. Most of their specimens are from people with mental or neurological disorders. Samples are requested by scientists to find new treatments for Parkinson's, Alzheimer's and a whole host of psychiatric disorders. But there is a problem. Scientists at McLean Hospital and at brain banks across the world do not have enough specimens for the research community. According Dr Kerry Ressler, who is the chief scientific officer at McLean hospital, new treatments for many mental and neurological diseases are within the grasp of the research community. However, he says it is the lack of brain tissue that is holding back their development. © 2017 BBC.
Keyword: Brain imaging
Link ID: 23241 - Posted: 02.17.2017
By KENNETH CHANG Sir Peter Mansfield, who shared a Nobel Prize for discoveries that underpinned the invention of magnetic resonance imaging, the method of peering inside the human body that revolutionized medicine, died on Wednesday. He was 83. The University of Nottingham in England, where Dr. Mansfield had been a professor of physics, announced his death but not did say where he died. He lived in England. Magnetic resonance imaging, or M.R.I., has enabled doctors to diagnose and examine injuries to ligaments, bones and organs without cutting open the body or risking the radiation dangers of X-rays. “It’s hugely important,” said Charles P. Slichter, an emeritus physics professor at the University of Illinois at Urbana-Champaign. “It’s such an all-pervasive technique.” Dr. Mansfield worked in his laboratory as a postdoctoral researcher in the 1960s. Dr. Mansfield was awarded the Nobel Prize in Physiology or Medicine in 2003, along with Paul C. Lauterbur, a professor at the University of Illinois at Urbana-Champaign. The two had worked independent of each other in studying magnetic resonance imaging. Their research proceeded from an understanding that the nuclei of most atoms act as tiny magnets that line up when placed in a magnetic field. If the field is set at a specific strength, the atoms can absorb and emit radio waves. Scientists initially used the technique, called nuclear magnetic resonance, or N.M.R., to study atoms and molecules, deducing properties from the emitted waves. In his early research, Dr. Mansfield developed N.M.R. techniques to study crystals. Later, in 1972, as he worked to refine and sharpen N.M.R. data, he had a conversation with two colleagues about what applications such advances might lead to. He soon realized that if an object were placed in a nonuniform magnetic field — one that is stronger at one end than the other — scientists might be able to piece together a three-dimensional image of its atomic structure. © 2017 The New York Times Company
Keyword: Brain imaging
Link ID: 23217 - Posted: 02.13.2017
By Matt Blois A ruthless killer may soon help brain cancer patients. The rabies virus, which kills tens of thousands of people a year, has a rare ability to enter nerve cells and use them as a conduit to infect brain tissue. Now, scientists are trying to mimic this strategy to ferry tumor-killing nanoparticles into brain tumors. So far the approach has been shown to work only in mice. If successful in people, these nanoparticles could one day help doctors send treatment directly to tumors without harming healthy cells. The rabies virus, transmitted largely through the bites of infected animals, has evolved over thousands of years to hijack nerve cells, which it uses to climb from infected muscle tissue into the brain. That allows it to bypass a major hurdle: the blood-brain barrier, a selective membrane that keeps out most pathogens that travel through the bloodstream. But the barrier also prevents treatments—like cancer drugs—from reaching infected cells, limiting options for patients. To get around this problem, scientists are looking to the virus for inspiration. Already, researchers have packaged cancer-fighting drugs into nanoparticles coated with part of a rabies surface protein that lets the virus slip into the central nervous system. Now, a team of researchers from Sungkyunkwan University in Suwon, South Korea, has taken things one step further. Nanoparticle expert Yu Seok Youn and his team have engineered gold particles so that they have the same rodlike shape and size as the virus. The nanoparticle’s shape gives it more surface area than spherical particles, improving the surface protein’s ability to bind with receptors on nerve cells that serve as a gateway to the nervous system. The particles don’t carry any drugs, but the tiny gold rods readily absorb laser light, which heats them up and kills surrounding tissue. © 2017 American Association for the Advancement of Science.
Jon Hamilton What Einstein did for physics, a Spaniard named Santiago Ramón y Cajal did for neuroscience more than a century ago. Back in the 1890s, Cajal produced a series of drawings of brain cells that would radically change scientists' understanding of the brain. And Cajal's drawings aren't just important to science. They are considered so striking that the Weisman Art Museum in Minneapolis has organized a traveling exhibition of Cajal's work called The Beautiful Brain. "Cahal was the founder of modern neuroscience," says Larry Swanson, a brain scientist at the University of Southern California who wrote an essay for the book that accompanies the exhibit. "Before Cajal it was just completely different," Swanson says. "Most of the neuroscientists in the mid-19th century thought the nervous system was organized almost like a fishing net." They saw the brain and nervous system as a single, continuous web, not a collection of separate cells. But Cajal reached a different conclusion. "Cajal looked under the microscope at different parts of the brain and said, 'It's not like a fishing net,'" Swanson says. "There are individual units called nerve cells or neurons that are put together in chains to form circuits." Cajal didn't just take notes on what he saw. He made thousands of highly detailed drawings, many of which are considered works of art. © 2017 npr
Keyword: Brain imaging
Link ID: 23152 - Posted: 01.27.2017
Esther Landhuis As big brain-mapping initiatives go, Taiwan's might seem small. Scientists there are studying the humble fruit fly, reverse-engineering its brain from images of single neurons. Their efforts have produced 3D maps of brain circuitry in stunning detail. Researchers need only a computer mouse and web browser to home in on individual cells and zoom back out to intertwined networks of nerve bundles. The wiring diagrams look like colourful threads on a tapestry, and they're clear enough to show which cell clusters control specific behaviours. By stimulating a specific neural circuit, researchers can cue a fly to flap its left wing or swing its head from side to side — feats that roused a late-afternoon crowd in November at the annual meeting of the Society for Neuroscience in San Diego, California. But even for such a small creature, it has taken the team a full decade to image 60,000 neurons, at a rate of 1 gigabyte per cell, says project leader Ann-Shyn Chiang, a neuroscientist at the National Tsing Hua University in Hsinchu City, Taiwan — and that's not even half of the nerve cells in the Drosophila brain. Using the same protocol to image the 86 billion neurons in the human brain would take an estimated 17 million years, Chiang reported at the meeting. Other technologies are more tractable. In July 2016, an international team published a map of the human brain's wrinkled outer layer, the cerebral cortex1. Many scientists consider the result to be the most detailed human brain-connectivity map so far. Yet, even at its highest spatial resolution (1 cubic millimetre), each voxel — the smallest distinguishable element of a 3D object — contains tens of thousands of neurons. That's a far cry from the neural connections that have been mapped at single-cell resolution in the fruit fly. © 2017 Macmillan Publishers Limited
Keyword: Brain imaging
Link ID: 23151 - Posted: 01.26.2017
What are you like? A look at your brain may tell you. A study has found a link between some elements of brain structure and certain personality traits. The study involved scanning the brains of 500 volunteers, and assessing their personalities in terms of five traits – neuroticism, openness, extraversion, agreeableness, and conscientiousness. The researchers focused on the structure of the cortex, the outer layer of the brain. They found that in people who are more neurotic and prone to mood changes, the cortex tends to be thicker and less wrinkly. People who appear more open – for example, curious and creative – show the opposite pattern. More mature The link between structure and personality may help explain how we mature as we get older. Folds and wrinkles are thought to increase the surface area of the brain, but make the cortex thinner. The cortex continues to stretch and fold throughout childhood and adolescence, and into adulthood. As we grow up, people generally become less neurotic, and more conscientious and agreeable. “Our work supports the notion that personality is, to some degree, associated with brain maturation,” says Roberta Riccelli, at Magna Graecia University in Catanzaro, Italy. Journal reference: Social Cognitive and Affective Neuroscience © Copyright Reed Business Information Ltd.
written by Claire Lehmann I learned about Debra through reading her LA Times op-ed on the futility of gender neutral parenting. I got in touch with Debra because I wanted to learn more about her field of sex neuroscience, her own research and her thoughts on studying sex differences in the brain. Because the study of sex and sex differences is often fraught with political roadblocks, I also wanted to get a picture of how a neuroscientist-sex researcher approaches some of these contentious issues. Hi Debra, thanks for chatting to Quillette. Can you briefly tell us who you are — where you studied, who was your supervisor and what made you interested in neuroscience, in particular sex neuroscience? I am a sex researcher at York University in Toronto and I write about the science of sex for several media outlets, including Playboy. For my PhD, which I just defended, I worked with Dr. Keith Schneider, who has pioneered new methods in high-resolution fMRI and is the Director of the University of Delaware’s Center for Biomedical and Brain Imaging, and Dr. James Cantor at the University of Toronto, who is a world expert in the brain imaging of pedophilia. I remember opening up a textbook during my first neuroscience course as an undergraduate student, seeing images from an fMRI study, and thinking it was incredible. I decided to pursue neuroscience in grad school and had the opportunity to do a placement in sexology as part of my Master’s degree. That’s how I got hooked! And I haven’t looked back. © 2017 Quillette
By NICHOLAS ST. FLEUR The tale of the Tasmanian tiger was tragic. Once numerous across Tasmania, the doglike marsupial was branded a sheep killer by colonists in the 1830s and hunted to extinction. The last of its kind, Benjamin, died in a zoo in 1936, and with it many secrets into the animals’ lives were lost. The striped creature, which is also known as the thylacine, was hardly studied when it was alive, depriving scientists of understanding the behavior of an important predator from Australia’s recent biological past. Now, for the first time, researchers have performed neural scans on the extinct carnivore’s brain, revealing insights that had been lost since the species went extinct. “Part of the myth about them is what exactly did they eat, how did they hunt and were they social?” said Dr. Gregory Berns, a neuroscientist at Emory University and lead author on the study, which was published Wednesday in the journal PLOS One. “These are questions nobody really knows the answers to.” Dr. Berns’s main research pertains to dogs and the inner workings of the canine brain, but after learning more about Tasmanian tigers, he became fascinated by the beasts. With their slender bodies, long snouts and sharp teeth, Tasmanian tigers looked as if they could be related to dogs, wolves or coyotes. But actually they are separated by more than 150 million years of evolution. It is a classic example of convergent evolution, in which two organisms that are not closely related develop similar features because of the environment they adapted to and the ecological role they played. To better understand thylacines, Dr. Berns spent two years tracking down two preserved Tasmanian tiger brains, one at the Smithsonian Institution and the other at the Australian Museum. Their brains, like those of all marsupials, are very different from the brains of placental mammals. The biggest difference is that they lack a corpus callosum, which is the part of the brain that connects the left and right hemispheres. © 2017 The New York Times Company
NEUROSCIENCE, like many other sciences, has a bottomless appetite for data. Flashy enterprises such as the BRAIN Initiative, announced by Barack Obama in 2013, or the Human Brain Project, approved by the European Union in the same year, aim to analyse the way that thousands or even millions of nerve cells interact in a real brain. The hope is that the torrents of data these schemes generate will contain some crucial nuggets that let neuroscientists get closer to understanding how exactly the brain does what it does. But a paper just published in PLOS Computational Biology questions whether more information is the same thing as more understanding. It does so by way of neuroscience’s favourite analogy: comparing the brain to a computer. Like brains, computers process information by shuffling electricity around complicated circuits. Unlike the workings of brains, though, those of computers are understood on every level. Eric Jonas of the University of California, Berkeley, and Konrad Kording of Northwestern University, in Chicago, who both have backgrounds in neuroscience and electronic engineering, reasoned that a computer was therefore a good way to test the analytical toolkit used by modern neuroscience. Their idea was to see whether applying those techniques to a microprocessor produced information that matched what they already knew to be true about how the chip works. © The Economist Newspaper Limited 2017.
Keyword: Brain imaging
Link ID: 23126 - Posted: 01.21.2017
Russell Poldrack Sex, Lies, and Brain Scans: How fMRI Reveals What Really Goes on in our Minds Barbara J. Sahakian & Julia Gottwald Oxford University Press: 2017. Since its 1992 debut, functional magnetic resonance imaging (fMRI) has revolutionized our ability to view the human brain in action and understand the processes that underlie mental functions such as decision-making. As brain-imaging technologies have grown more powerful, their influence has seeped from the laboratory into the real world. In Sex, Lies, and Brain Scans, clinical neuropsychologist Barbara Sahakian and neuroscientist Julia Gottwald give a whistle-stop tour of some ways in which neuroimaging has begun to affect our views on human behaviour and society. Their discussion balances a rightful enthusiasm for fMRI with a sober appreciation of its limitations and risks. After the obligatory introduction to fMRI, which measures blood oxygenation to image neural activity, Sahakian and Gottwald address a question at the heart of neuroimaging: can it read minds? The answer largely depends on one's definition of mind-reading. As the authors outline, in recent years fMRI data have been used to decode the contents of thoughts (such as words viewed by a study participant) and mental states (such as a person's intention to carry out an action), even in sleep. These methods don't yet enable researchers to decode the 'language of thought', which is what mind-reading connotes for many. But given the growing use of advanced machine-learning methods such as deep neural networks to analyse neuroimaging data, that may just be a matter of time. © 2017 Macmillan Publishers Limited
Keyword: Brain imaging
Link ID: 23091 - Posted: 01.13.2017
By SAM BORDEN, MIKA GRÖNDAHL and JOE WARD When player No. 81 took this blow to his head several years ago, it was just one of many concussions that have occurred throughout college football and the N.F.L. But what made this one different was that this player was wearing a mouth guard with motion sensors. The information from those sensors has given researchers a more detailed and precise window into what was happening within the player’s brain in the milliseconds after the hit. Here is what happened to his brain. One common belief has been that just after a person’s head (or helmet) makes contact with something – an airbag, a wall, another person – the brain within bounces around in the skull like an egg yolk in a shell, leaving bruises on the brain’s outer surface, or gray matter. Now, though, many scientists and medical experts believe that this understanding is incomplete. Yes, there is some movement in the skull, but the real damage from concussions, they say, actually occurs deeper in the brain – in the so-called white matter – as a result of fibers pulling and twisting after impact. To stick with the food analogy, think Jell-O, not an egg. You know what happens when you take a plate of Jell-O and give it a hard shake? The stretches and contortions approximate what is happening to all the wiring throughout the brain. To better track the brain’s reaction to these hits, scientists in several labs have been working on a variety of mechanisms, some of which, like the one used during the impact shown above, are moving away from ones connected directly to a football helmet because the helmet can move independently of the skull. “The forces you’re measuring with those are not really exactly what the brain is seeing,” said Robert Cantu, clinical professor of neurosurgery at the Boston University School of Medicine. The mouth guard that was used was developed by the bioengineer David Camarillo and his team at the Cam Lab at Stanford. Camarillo and others have speculated that the most damaging blows are those that cause the head to snap quickly from ear to ear, like the one shown above, or those that cause a violent rotation or twisting of the head through a glancing blow. “The brain’s wiring, essentially, is all running from left to right, not front to back,” Camarillo said, referring to the primary wiring that connects the brain’s hemispheres. “So the direction you are struck can have a very different effect within the brain. In football, the presence of the face mask can make that sort of twisting even more extreme.” © 2017 The New York Times Company
By Greg Miller Babies born prematurely are prone to problems later in life—they’re more likely to develop autism or attention deficit hyperactivity disorder, and more likely to struggle in school. A new study that’s among the first to investigate brain activity in human fetuses suggests that the underlying neurological issues may begin in the womb. The findings provide the first direct evidence of altered brain function in fetuses that go on to be born prematurely, and they might ultimately point to ways to remediate or even prevent such early injuries. In the new study, published 9 January in Scientific Reports, developmental neuroscientist Moriah Thomason of Wayne State University School of Medicine in Detroit, Michigan, and colleagues report a difference in how certain brain regions communicate with each other in fetuses that were later born prematurely compared with fetuses that were carried to term. Although the findings are preliminary because the study was small, Thomason and other researchers say the work illustrates the potential (and the challenges) of the emerging field of fetal neuroimaging. “Harnessing the power of these advanced tools is offering us for the very first time the opportunity to explore the onset of neurologic insults that are happening in utero,” says Catherine Limperopoulos, a pediatric neuroscientist at Children’s National Medical Center in Washington, D.C. Thomason and colleagues used functional magnetic resonance imaging (fMRI) to investigate brain activity in 32 fetuses. The pregnant mothers were participants in a larger, long-term study of brain development led by Thomason. “The majority have just normal pregnancies, but they’re drawn from a low-resource population that’s at greater risk of early delivery and developmental problems,” she says. In the end, 14 of the fetuses were born prematurely. © 2017 American Association for the Advancement of Science.
Alexander Fornito, The human brain is an extraordinarily complex network, comprising an estimated 86 billion neurons connected by 100 trillion synapses. A connectome is a comprehensive map of these links—a wiring diagram of the brain. With current technology, it is not possible to map a network of this size at the level of every neuron and synapse. Instead researchers use techniques such as magnetic resonance imaging to map connections between areas of the human brain that span several millimeters and contain many thousands of neurons. At this macroscopic scale, each area comprises a specialized population of neurons that work together to perform particular functions that contribute to cognition. For example, different parts of your visual cortex contain cells that process specific types of information, such as the orientation of a line and the direction in which it moves. Separate brain regions process information from your other senses, such as sound, smell and touch, and other areas control your movements, regulate your emotional responses, and so on. These specialized functions are not processed in isolation but are integrated to provide a unitary and coherent experience of the world. This integration is hypothesized to occur when different populations of cells synchronize their activity. The fiber bundles that connect different parts of the brain—the wires of the connectome—provide the substrate for this communication. These connections ensure that brain activity unfolds through time as a rhythmic symphony rather than a disordered cacophony. © 2017 Scientific American
Keyword: Brain imaging
Link ID: 23049 - Posted: 01.03.2017