Chapter 2. Functional Neuroanatomy: The Nervous System and Behavior
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David Cyranoski Unlike its Western counterparts, Japan’s effort will be based on a rare resource — a large population of marmosets that its scientists have developed over the past decade — and on new genetic techniques that might be used to modify these highly social animals. The goal of the ten-year Brain/MINDS (Brain Mapping by Integrated Neurotechnologies for Disease Studies) project is to map the primate brain to accelerate understanding of human disorders such as Alzheimer’s disease and schizophrenia. On 11 September, the Japanese science ministry announced the names of the group leaders — and how the project would be organized. Funded at ¥3 billion (US$27 million) for the first year, probably rising to about ¥4 billion for the second, Brain/MINDS is a fraction of the size of the European Union’s Human Brain Project and the United States’ BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative, both of which are projected to receive at least US$1 billion over the next decade. But researchers involved in those efforts say that Brain/MINDS fills a crucial gap between disease models in smaller animals that too often fail to mimic human brain disorders, and models of the human brain that need validating data. “It is essential that we have a genetic primate model to study cognition and cognitive brain disorders such as schizophrenia and depression, for which we do not have good mouse models,” says neuroscientist Terry Sejnowski at the Salk Institute in La Jolla, California, who is a member of the National Institutes of Health BRAIN Initiative Working Group. “Other groups in the United States and China have started transgenic-primate projects, but none is as large or as well organized as the Japanese effort.” © 2014 Nature Publishing Group,
|By Nathan Collins Step aside, huge magnets and radioactive tracers—soon some brain activity will be revealed by simply training dozens of red lights on the scalp. A new study in Nature Photonics finds this optical technique can replicate functional MRI experiments, and it is more comfortable, more portable and less expensive. The method is an enhancement of diffuse optical tomography (DOT), in which a device shines tiny points of red light at a subject's scalp and analyzes the light that bounces back. The red light reflects off red hemoglobin in the blood but does not interact as much with tissues of other colors, which allows researchers to recover an fMRI-like image of changing blood flow in the brain at work. For years researchers attempting to use DOT have been limited by the difficulty of packing many heavy light sources and detectors into the small area around the head. They also needed better techniques for analyzing the flood of data that the detectors collected. Now researchers at Washington University in St. Louis and the University of Birmingham in England report they have solved those problems and made the first high-density DOT (HD-DOT) brain scans. The team first engineered a “double halo” structure to support the weight of 96 lights and 92 detectors, more than double the number in earlier arrays. The investigators also dealt with the computing challenges associated with that many lights—for example, they figured out how to filter out interference from blood flow in the scalp and other tissues. The team then used HD-DOT to successfully replicate fMRI studies of vision and language processing—a task impossible for other fMRI alternatives, such as functional near-infrared spectroscopy or electroencephalography, which do not cover a large enough swath of the brain or have sufficient resolution to pinpoint active brain areas. Finally, the team scanned the brains of people who have implanted electrodes for Parkinson's disease—something fMRI can never do because the machine generates electromagnetic waves that can destroy electronic devices such as pacemakers. © 2014 Scientific American
Keyword: Brain imaging
Link ID: 20151 - Posted: 10.02.2014
Michael Häusser Use light to read out and control neural activity! This idea, so easily expressed and understood, has fired the imagination of neuroscientists for decades. The advantages of using light as an effector are obvious1: it is noninvasive, can be precisely targeted with exquisite spatial and temporal precision, can be used simultaneously at multiple wavelengths and locations, and can report the presence or activity of specific molecules. However, despite early progress2 and encouragement3, it is only recently that widely usable approaches for optical readout and manipulation of specific neurons have become available. These new approaches rely on genetically encoded proteins that can be targeted to specific neuronal subtypes, giving birth to the term 'optogenetics' to signal the combination of genetic targeting and optical interrogation4. On the readout side, highly sensitive probes have been developed for imaging synaptic release, intracellular calcium (a proxy for neural activity) and membrane voltage. On the manipulation side, a palette of proteins for both activation and inactivation of neurons with millisecond precision using different wavelengths of light have been identified and optimized. The extraordinary versatility and power of these new optogenetic tools are spurring a revolution in neuroscience research, and they have rapidly become part of the standard toolkit of thousands of research labs around the world. Although optogenetics may not yet be a household word (though try it on your mother; she may surprise you), there can be no better proof that optogenetics has become part of the scientific mainstream than the 2013 Brain Prize being awarded to the sextet that pioneered optogenetic manipulation (http://www.thebrainprize.org/flx/prize_winners/prize_winners_2013/) and the incorporation of optogenetics as a central plank in the US National Institutes of Health BRAIN Initiative5. Moreover, there is growing optimism about the prospect of using optogenetic probes not only to understand mechanisms of disease in animal models but also to treat disease in humans, particularly in more accessible parts of the brain such as the retina6. © 2014 Macmillan Publishers Limited
Keyword: Brain imaging
Link ID: 20142 - Posted: 10.01.2014
By Larry Greenemeier Former Grateful Dead percussionist Mickey Hart takes pride in his brain. Large, anatomically realistic 3-D animations representing the inner workings of his gray and white matter have graced video screens at several science and technology conferences. These “Glass Brain” visualizations use imaging and advanced computing systems to depict in colorful detail the fiber pathways that make Hart’s brain tick. The researchers behind the project hope it will also form the basis of a new type of tool for the diagnosis and treatment of neurological disorders. Each Glass Brain animation overlays electroencephalography (EEG) data collected in real time atop a magnetic resonance imaging (MRI) scan—in this case Hart’s—to illustrate how different brain areas communicate with each other. Special algorithms coded into software digitally reconstruct this activity within the brain. The result is a tour of the brain that captures both the timing and location of brain signals. Hart demonstrated the Glass Brain at a computer conference in San Jose, Calif., this past March by playing a video game called NeuroDrummer on stage. The drummer is working with the Studio Bee digital animation house in San Francisco as well as the Glass Brain’s creators to develop NeuroDrummer into a tool that can determine whether teaching someone to keep a drumbeat might help improve the neural signals responsible for cognition, memory and other functions. The Glass Brain’s brain trust includes the University of California, San Francisco’s Neuroscape Lab as well as the University of California, San Diego’s Swartz Center for Computational Neuroscience, EEG maker Cognionics, Inc. and NVIDIA, a maker of extremely fast graphics processing unit (GPU) computer chips and host of the conference where Hart performed. © 2014 Scientific American,
Keyword: Brain imaging
Link ID: 20137 - Posted: 09.30.2014
by Elijah Wolfson @elijahwolfson The class was the most difficult of the fall 2013 semester, and J.D. Leadam had missed all but one lecture. His grandfather’s health had worsened, and he left San Jose State, where he was studying for a degree in business, to return home to Los Angeles to help out. Before he knew it, midterm exams had almost arrived. At this point, Leadam had, for a while, been playing around with transcranial direct-current stimulation, or tDCS, an experimental treatment for all sorts of health issues that, at its most basic, involves running a very weak electric current through the brain. When he first came across tDCS, Leadam was immediately intrigued but thought, “There’s no way I’m gonna put electrodes on my head. It’s just not going to happen.” After extensive research, though, he changed his mind. He looked into buying a device online, but there wasn’t much available — just one extremely expensive machine and then a bare-bones $40 device that didn’t even have a switch. So he dug around online and figured he could build one himself. He bought all the pieces he needed and put it together. He tried it a few times, but didn’t notice much, so he put it aside. But now, with the test looming, he picked it back up. The professor had written a book, and Leadam knew all the information he’d be tested on was written in its pages. “But I’m an auditory learner,” he said, “so I knew it wouldn’t work to just read it.” He strapped on the device, turned it on and read the chapters. “Nothing,” he thought. But when he got to the classroom and put pen to paper, he had a revelation. “I could remember concepts down to the exact paragraphs in the textbook,” Leadam said. “I actually ended up getting an A on the test. I couldn’t believe it.”
Keyword: Learning & Memory
Link ID: 20130 - Posted: 09.29.2014
By Melissa Dahl If you are the sort of person who has a hard time just watching TV — if you’ve got to be simultaneously using your iPad or laptop or smartphone — here’s some bad news. New research shows a link between juggling multiple digital devices and a lower-than-usual amount of gray matter, the stuff that’s made up of brain cells, in the region of the brain associated with cognitive and emotional control. More details, via the press release: The researchers at the University of Sussex's Sackler Centre for Consciousness used functional magnetic resonance imaging (fMRI) to look at the brain structures of 75 adults, who had all answered a questionnaire regarding their use and consumption of media devices, including mobile phones and computers, as well as television and print media. They found that, independent of individual personality traits, people who used a higher number of media devices concurrently also had smaller grey matter density in the part of the brain known as the anterior cingulate cortex (ACC), the region notably responsible for cognitive and emotional control functions. But a predilection for using several devices at once isn’t necessarily causing a decrease in gray matter, the authors note — this is a purely correlational finding. As Earl Miller, a neuroscientist at MIT who was not involved in this research, wrote in an email, “It could be (in fact, is possibly more likely) that the relationship is the other way around.” In other words, the people who are least content using just one device at a time may have less gray matter in the first place.
By Alyssa Abkowitz If you’re wary of investing in a certain stock or exchange-traded fund, it could be because of the your brain’s physical composition. In a recent study, 61 participants from the Northeastern U.S. were asked to choose between monetary options that differed in the level of risk. Questions included: “Would you prefer a 50 percent chance of receiving $5 or would you rather take a 13 percent chance of winning $50?” and “Would you prefer $10 for sure or a 50 percent chance of receiving $50?” Researchers found that individuals with more gray matter in a specific part of their brains tend to tolerate more financial risks, says Agnieszka Tymula, an economist at the University of Sydney and co-author of the findings. Most of the participants answered questions while their brains were being scanned, while others received MRIs afterward (the timing doesn’t make a difference because the researchers were looking at brain structure, not brain function). The study involved measuring the volume of gray matter, or the outer layer of the brain, in the right posterior parietal region of the cortex. Thicker gray matter corresponded to riskier responses. Tymula worked with researchers from Yale University, University College London, New York University, and the University of Pennsylvania. Their findings, published in the Journal of Neuroscience this month, dovetail with previous work in which Tymula found that adults become more risk-averse as they age. Other neuroscience research shows that people’s cortexes become thinner as they get older, meaning there could be a link between a thinning cortex and risk aversion. ©2014 Bloomberg L.P
By Neuroskeptic Today, we are thinking – and talking – about the brain more than ever before. It is widely said that neuroscience has much to teach psychiatry, cognitive science, economics, and others. Practical applications of brain science are proposed in the fields of politics, law enforcement and education. The brain is everywhere. This “Neuro Turn” has, however, not always been accompanied by a critical attitude. We ought to be skeptical of any claims regarding the brain because it remains a mystery – we fundamentally do not understand how it works. Yet much neuro-discourse seems to make the assumption that the brain is almost a solved problem already. For example, media stories about neuroscience commonly contain simplistic misunderstandings – such as the tendency to over-interpret neural activation patterns as practical guides to human behavior. For instance, recently we have heard claims that because fMRI finds differences in the brain activity of some violent offenders, this means that their criminal tendencies are innate and unchangeable – with clear implications for rehabilitation. Neuroscientists are well aware of the faults in lay discourse about the brain – and are increasingly challenging them e.g. on social media. Unfortunately, the same misunderstandings also exist within neuroscience itself. For example, I argue, much of cognitive neuroscience is actually based on (or, only makes sense given the assumption that) the popular misunderstanding that brain activity has a psychological ‘meaning’. In fact, we just do not know what a given difference in brain activity means, in the vast majority of cases. Thus, many research studies based on finding differences in fMRI activity maps across groups or across conditions, are not really helping us to understand the brain at all – but only providing us with a canvas to project our misunderstandings onto it.
Keyword: Brain imaging
Link ID: 20082 - Posted: 09.17.2014
by Helen Thomson DON'T mind the gap. A woman has reached the age of 24 without anyone realising she was missing a large part of her brain. The case highlights just how adaptable the organ is. The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea. She told doctors she'd had problems walking steadily for most of her life, and her mother reported that she hadn't walked until she was 7 and that her speech only became intelligible at the age of 6. Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing (see scan, below left). The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease. The cerebellum – sometimes known as the "little brain" – is located underneath the two hemispheres. It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain's total volume but contains 50 per cent of its neurons. Although it is not unheard of to have part of your brain missing, either congenitally or from surgery, the woman joins an elite club of just nine people who are known to have lived without their entire cerebellum. A detailed description of how the disorder affects a living adult is almost non-existent, say doctors from the Chinese hospital, because most people with the condition die at a young age and the problem is only discovered on autopsy (Brain, doi.org/vh7). © Copyright Reed Business Information Ltd.
By Glendon Mellow University and scientific research center programs are increasingly finding it useful to employ artists and illustrators to help them see things in a new way. Few works of art from the Renaissance have been studied and pored over as meticulously as Michelangelo’s frescoes in the Sistine Chapel. Yet, the Master may still have some surprises hidden for an illustrator-scientist. Biomedical Illustrator Ian Suk (BSc, BMC) and Neurological Surgeon Rafael Tamargo (MD, FACS), both of Johns Hopkins proposed in a 2010 article in the journal Neurosurgery, that the panel above, Dividing Light from the Darkness by Michelangelo actually depicts the brain stem of God. Using a series of comparisons of the unusual shadows and contours on God’s neck to photos of actual brain stems, the evidence seems completely overwhelming that Michelangelo used his own limited anatomical studies to depict the brain stem. It’s unlikely even the educated members of Michelangelo’s audience would recognize it. I encourage you to look over the paper here, and enlarge the images in the slideshow: Suk and Tamargo are utterly convincing. Unlike R. Douglas Fields in this previous blog post from 2010 on Scientific American, I don’t think there’s room to believe this is a case of pareidolia. I imagine the thrill of feeling Michelangelo communicating directly with the authors across the centuries was immense. © 2014 Scientific American,
Keyword: Brain imaging
Link ID: 20067 - Posted: 09.12.2014
People who are obese may be more susceptible to environmental food cues than their lean counterparts due to differences in brain chemistry that make eating more habitual and less rewarding, according to a National Institutes of Health study published in Molecular Psychiatry External Web Site Policy. Researchers at the NIH Clinical Center found that, when examining 43 men and women with varying amounts of body fat, obese participants tended to have greater dopamine activity in the habit-forming region of the brain than lean counterparts, and less activity in the region controlling reward. Those differences could potentially make the obese people more drawn to overeat in response to food triggers and simultaneously making food less rewarding to them. A chemical messenger in the brain, dopamine influences reward, motivation and habit formation. “While we cannot say whether obesity is a cause or an effect of these patterns of dopamine activity, eating based on unconscious habits rather than conscious choices could make it harder to achieve and maintain a healthy weight, especially when appetizing food cues are practically everywhere,” said Kevin D. Hall, Ph.D., lead author and a senior investigator at National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of NIH. “This means that triggers such as the smell of popcorn at a movie theater or a commercial for a favorite food may have a stronger pull for an obese person — and a stronger reaction from their brain chemistry — than for a lean person exposed to the same trigger.” Study participants followed the same eating, sleeping and activity schedule. Tendency to overeat in response to triggers in the environment was determined from a detailed questionnaire. Positron emission tomography (PET) scans evaluated the sites in the brain where dopamine was able to act.
By Tanya Lewis, In an experiment that sounds more like science fiction than reality, two humans were able to send greetings to each other using only a digital connection linking their brains. Using noninvasive means, researchers made brain recordings of a person in India thinking the words "hola" and "ciao," and then decoded and emailed the messages to France, where a machine converted the words into brain stimulation in another person, who perceived the signals as flashes of light. From the sequence of flashes, the French recipient was able to successfully interpret the greetings, according to a new study published today (Sept. 5) in the journal PLOS ONE. The researchers wanted to know if it is possible for two people to communicate by reading out the brain activity of one person and injecting that activity into a second person. "Could we develop an experiment that would bypass the talking or typing part of [the] Internet and establish direct brain-to-brain communication between subjects located far away from each other, in India and France?" co-author Dr. Alvaro Pascual-Leone said in a statement. Pascual-Leone is a neurologist at Beth Israel Deaconess Medical Center in Boston, and a professor at Harvard Medical School, in Cambridge, Massachusetts. To answer that question, Pascual-Leone and his colleagues at Starlab Barcelona, in Spain, and Axilum Robotics, in Strasbourg, France, turned to several widely used brain technologies. Electroencephalogram, or EEG, recordings are taken by placing a cap of electrodes on a person's scalp, and recording the electrical activity of large regions of the brain's cortex. Previous studies have recorded EEG from a person thinking about an action, such as moving his or her arm, while a computer translates the signal into an output used to move a robotic exoskeleton or drive a wheelchair.
Yves Frégnac & Gilles Laurent Launched in October 2013, the Human Brain Project (HBP) was sold by charismatic neurobiologist Henry Markram as a bold new path towards understanding the brain, treating neurological diseases and building information technology. It is one of two 'flagship' proposals funded by the European Commission's Future and Emerging Technologies programme (see go.nature.com/icotmi). Selected after a multiyear competition, the project seemed like an exciting opportunity to bring together neuroscience and IT to generate practical applications for health and medicine (see go.nature.com/2eocv8). Contrary to public assumptions that the HBP would generate knowledge about how the brain works, the project is turning into an expensive database-management project with a hunt for new computing architectures. In recent months, the HBP executive board revealed plans to drastically reduce its experimental and cognitive neuroscience arm, provoking wrath in the European neuroscience community. The crisis culminated with an open letter from neuroscientists (including one of us, G.L.) to the European Commission on 7 July 2014 (see www.neurofuture.eu), which has now gathered more than 750 signatures. Many signatories are scientists in experimental and theoretical fields, and the list includes former HBP participants. The letter incorporates a pledge of non-participation in a planned call for 'partnering projects' that must raise about half of the HBP's total funding. This pledge could seriously lower the quality of the project's final output and leave the planned databases empty. © 2014 Nature Publishing Group
Keyword: Brain imaging
Link ID: 20033 - Posted: 09.04.2014
By PAM BELLUCK As a baby’s brain develops, there is an explosion of synapses, the connections that allow neurons to send and receive signals. But during childhood and adolescence, the brain needs to start pruning those synapses, limiting their number so different brain areas can develop specific functions and are not overloaded with stimuli. Now a new study suggests that in children with autism, something in the process goes awry, leaving an oversupply of synapses in at least some parts of the brain. The finding provides clues to how autism develops from childhood on, and may help explain some symptoms like oversensitivity to noise or social experiences, as well as why many people with autism also have epileptic seizures. It could also help scientists in the search for treatments, if they can develop safe therapies to fix the system the brain uses to clear extra synapses. The study, published Thursday in the journal Neuron, involved tissue from the brains of children and adolescents who had died from ages 2 to 20. About half had autism; the others did not. The researchers, from Columbia University Medical Center, looked closely at an area of the brain’s temporal lobe involved in social behavior and communication. Analyzing tissue from 20 of the brains, they counted spines — the tiny neuron protrusions that receive signals via synapses — and found more spines in children with autism. The scientists found that at younger ages, the number of spines did not differ tremendously between the two groups of children, but adolescents with autism had significantly more than those without autism. Typical 19-year-olds had 41 percent fewer synapses than toddlers, but those in their late teenage years with autism had only 16 percent fewer than young children with autism. © 2014 The New York Times Company
Vaughan Bell For thousands of years, direct studies of the human brain required the dead. The main method of study was dissection, which needed, rather inconveniently for the owner, physical access to their brain. Despite occasional unfortunate cases where the living brain was exposed on the battlefield or the surgeon's table, corpses and preserved brains were the source of most of our knowledge. When brain scanning technologies were invented in the 20th century they allowed the structure and function of the brain to be shown in living humans for the first time. This was as important for neuroscientists as the invention of the telescope and the cadaver slowly faded into the background of brain research. But recently, scrutiny of the post-mortem brain has seen something of a revival, a resurrection you might say, as modern researchers have become increasingly interested in applying their new scanning technologies to the brains of the deceased. Forensic pathologists have the job of working out the cause and manner of death to present as legal evidence and have been partly responsible for this curious full circle. One of their main jobs is the autopsy, where the pathologist examines the body, inside and out, to assess its condition at the point of death. Although the traditional autopsy has many advantages, not least the microscopic examination of body tissue, there are drawbacks. One is that within some religions cutting up the dead body is seen as an infringement of human dignity and may delay burial beyond the customary period. The other is that an autopsy is a one-shot deal. If someone disagrees with the way it has been carried out or its interpretation, it is usually too late to do anything except re-examine photos or, on the rare occasions when they may have been kept, tissue samples. © 2014 Guardian News and Media Limited
Keyword: Brain imaging
Link ID: 19970 - Posted: 08.18.2014
by Bethany Brookshire The clearish lump looks like some bizarre, translucent gummy candy that might have once been piña colada flavored. But this is something you definitely don’t want to eat. That see-through blob was once a mouse. In the Aug. 14 Cell, scientists at Caltech detail the difficult series of methods required to make small animals such as mice and rats completely translucent. Scientists have been trying to clear tissue for better observation since the 1800s, and, as with all science, the new techniques build on many previous experiments done in a variety of labs. The techniques make it possible to capture images both beautiful and gross. And the procedure will teach scientists more about anatomy than ever before. If you want to render an animal transparent, you first have to overcome a solid problem: lipids. This group includes molecules essential to life, such as fats, cholesterols, waxes and steroids. Lipids form the membranes that surround our cells, the hormones that make us grow and reproduce and much, much more. But lipids have a problem. You can’t see through them. So to render an organism transparent, you need to remove the lipids. Bin Yang and colleagues in Viviana Gradinaru’s lab at Caltech used detergents to dissolve the lipids. The technique is based on CLARITY, a method that Gradinaru helped to develop in Karl Deisseroth’s lab at Stanford. Scientists there rendered a mouse brain transparent using CLARITY. Gradinaru explains that for a clear organ, dissolving lipids alone alone isn’t enough. “Without lipids the tissue would just collapse, so we need to maintain the structure of the tissue,” she says. © Society for Science & the Public 2000 - 2013
Keyword: Brain imaging
Link ID: 19963 - Posted: 08.16.2014
By Jen Christiansen I threw down a bit of a challenge last month at the Association of Medical Illustrators Conference in Minnesota. But first, I had to—somewhat unexpectedly—accept some challenges presented by others. And face the reality that some of us simply do not have the constitution of an anatomist. I love classic anatomical illustrations such as the vintage works of Andreas Vesalius and the more modern stylings of Frank Netter. And on that front, this conference definitely delivered. Talks by Daniel Garrison and Francine Netter were drool-worthy, and I snapped photos of quickly advancing slides presented by W. Bruce Fye on the history of the illustrated heart, so I could reverse-image search them later and spend more time checking out the details and context. Videos of Robert Beverly Hale’s Art Students League lectures on anatomy charmed me (as presented by Glen Hintz), as well as new videos of clean architectural microstructures like the inner ear, presented by Robert Acland. I had to make myself walk quickly by one vendor table to avoid blowing my book budget for the year (and then some) on an impulse buy of Vesalius’ 1543 De Humani Corporis Fabrica, newly translated to English. But I averted my gaze when surgeons presented on the topic of facial transplantation and skull reconstruction. Shoot, I couldn’t even look at the screen through the entirety of a fascinating talk by Elizabeth Weissbrod and Valerie Henry on creating and using virtual and prosthetic simulations for military emergency response training. I avoided the hands-on human cadaveric dissection workshop sessions, telling myself and others that my travel schedule would simply not allow me to get to the Mayo Clinic in Rochester, Minn., early enough to participate or observe. © 2014 Scientific American
Keyword: Brain imaging
Link ID: 19957 - Posted: 08.14.2014
By Gary Stix A gamma wave is a rapid, electrical oscillation in the brain. A scan of the academic literature shows that gamma waves may be involved with learning memory and attention—and, when perturbed, may play a part in schizophrenia, epilepsy Alzheimer’s, autism and ADHD. Quite a list and one of the reasons that these brainwaves, cycling at 25 to 80 times per second, persist as an object of fascination to neuroscientists. Despite lingering interest, much remains elusive when trying to figure out how gamma waves are produced by specific molecules within neurons—and what the oscillations do to facilitate communication along the brains’ trillions and trillions of connections. A group of researchers at the Salk Institute in La Jolla, California has looked beyond the preeminent brain cell—the neuron— to achieve new insights about gamma waves. At one time, neuroscience textbooks depicted astrocytes as a kind of pit crew for neurons, providing metabolic support and other functions for the brain’s rapid-firing information-processing components. In recent years, that picture has changed as new studies have found that astrocytes, like neurons, also have an alternate identity as information processors. This research demonstrates astrocytes’ ability to spritz chemicals known as neurotransmitters that communicate with other brain cells. Given that both neurons and astrocytes perform some of the same functions, it has been difficult to tease out what specifically astrocytes are up to. Hard evidence for what these nominal cellular support players might contribute in forming memories or focusing attention has been lacking. © 2014 Scientific American
By Smitha Mundasad Health reporter, BBC News Human brains grow most rapidly just after birth and reach half their adult size within three months, according to a study in JAMA Neurology. Using advanced scanning techniques, researchers found male brains grew more quickly than those of female infants. Areas involved in movement developed at the fastest pace. Those associated with memory grew more slowly. Scientists say collating this data may help them identify early signs of developmental disorders such as autism. For centuries doctors have estimated brain growth using measuring tape to chart a baby's head circumference over time. Any changes to normal growth patterns are monitored closely as they can suggest problems with development. But as head shapes vary, these tape measurements are not always accurate. Led by scientists at the University of California, researchers scanned the brains of 87 healthy babies from birth to three months. They saw the most rapid changes immediately after birth - newborn brains grew at an average rate of 1% a day. This slowed to 0.4% per day at the end of the 90-day period. Researchers say recording the normal growth trajectory of individual parts of the brain might help them better understand how early disorders arise. They found the cerebellum, an area of the brain involved in the control of movement, had the highest rate of growth - doubling in size over the 90-day period. BBC © 2014
By GREGORY HICKOK IN the early 19th century, a French neurophysiologist named Pierre Flourens conducted a series of innovative experiments. He successively removed larger and larger portions of brain tissue from a range of animals, including pigeons, chickens and frogs, and observed how their behavior was affected. His findings were clear and reasonably consistent. “One can remove,” he wrote in 1824, “from the front, or the back, or the top or the side, a certain portion of the cerebral lobes, without destroying their function.” For mental faculties to work properly, it seemed, just a “small part of the lobe” sufficed. Thus the foundation was laid for a popular myth: that we use only a small portion — 10 percent is the figure most often cited — of our brain. An early incarnation of the idea can be found in the work of another 19th-century scientist, Charles-Édouard Brown-Séquard, who in 1876 wrote of the powers of the human brain that “very few people develop very much, and perhaps nobody quite fully.” But Flourens was wrong, in part because his methods for assessing mental capacity were crude and his animal subjects were poor models for human brain function. Today the neuroscience community uniformly rejects the notion, as it has for decades, that our brain’s potential is largely untapped. The myth persists, however. The newly released movie “Lucy,” about a woman who acquires superhuman abilities by tapping the full potential of her brain, is only the latest and most prominent expression of this idea. Myths about the brain typically arise in this fashion: An intriguing experimental result generates a plausible if speculative interpretation (a small part of the lobe seems sufficient) that is later overextended or distorted (we use only 10 percent of our brain). The caricature ultimately infiltrates pop culture and takes on a life of its own, quite independent from the facts that spawned it. © 2014 The New York Times Company