Chapter 2. Functional Neuroanatomy: The Nervous System and Behavior

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Virginia Gewin Corey White felt pretty fortunate during his job search late last year. Over the course of 4 months, he found at least 25 posts to apply for — even after he had filtered the possibilities to places where his wife also had job prospects. Competition for the jobs was, as he expected, fierce, but he secured three interviews. In the end, he says, it was his skills in functional magnetic resonance imaging (fMRI) that helped him to clinch a post at Syracuse University in New York, where they were eager to elevate their neuroscience profile. The human brain is something of an enigma. Much is known about its physical structure, but quite how it manages to marshal its myriad components into a powerhouse capable of performing so many different tasks remains a mystery. Neuroimaging offers one way to help find out, and universities and government initiatives are betting on it. Already, an increasing number of universities across the United States and Europe are buying scanners dedicated to neuroimaging — a clear signal that the area is set for growth. “Institutions feel an imperative to develop an imaging programme because everybody's got to have one to be competitive,” says Mark Cohen, an imaging pioneer at the Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles. At the same time, a slew of major projects focusing on various aspects of the brain is seeking to paint the most comprehensive picture yet of the organ's organizing principles — from genes to high-level cognition. As a result, young scientists with computational expertise, a fluency in multiple imaging techniques and a willingness to engage in interdisciplinary collaborations could readily carve out a career in this dynamic landscape. © 2013 Nature Publishing Group

Keyword: Brain imaging
Link ID: 18894 - Posted: 11.08.2013

Helen Shen A mixture of excitement, hope and anxiety made for an electric atmosphere in the crowded hotel ballroom. On a Monday morning in early May, neuroscientists, physicists and engineers packed the room in Arlington, Virginia, to its 150-person capacity, while hundreds more followed by webcast. Only a month earlier, US President Barack Obama had unveiled the neuroscience equivalent of a Moon shot: a far-reaching programme that could rival Europe's 10-year, €1-billion (US$1.3-billion) Human Brain Project (see page 5). The US Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative would develop a host of tools to study brain activity, the president promised, and lead to huge breakthroughs in understanding the mind. But Obama's vague announcement on 2 April had left out key details, such as what the initiative's specific goals would be and how it would be implemented. So at their first opportunity — a workshop convened on 6 May by the National Science Foundation (NSF) and the Kavli Foundation of Oxnard, California — researchers from across the neuroscience spectrum swarmed to fill in the blanks and advocate for their favourite causes. The result was chaotic, acknowledges Van Wedeen, a neurobiologist at Harvard Medical School in Boston, Massachusetts, and one of the workshop's organizers. Everyone was afraid of being left out of 'the next big thing' in neuroscience — even though no one knew exactly what that might be. “The belief is we're ready for a leap forward,” says Wedeen. “Which leap, and in which direction, is still being debated.” © 2013 Nature Publishing Group

Keyword: Brain imaging; Aggression
Link ID: 18893 - Posted: 11.08.2013

From supercomputing to imaging, technologies have developed far enough that it is now possible for us to imagine a day when we will understand the murky workings of our most complex organ: the brain. True, that day remains distant, but scientists are no longer considered crazy if they report a glimpse of it on the horizon. This turning point has been marked by the independent launches this year of two major brain projects: US President Barack Obama’s Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative and the European Commission’s Human Brain Project. Even if they fail to achieve the ambitions the research community sets for them, they are signals of a new confidence. Right now, the two projects are not equal. The BRAIN Initiative is in an early phase of development, and has so far been promised little new money. The impetus behind it was a brash proposal by a group of neuroscientists for a billion-dollar project to measure the activity of every neuron in the human brain. That ambition was lost on the starting block when peers, justifiably, deemed it scientifically inappropriate — but it is yet to be replaced by a single goal of equivalently Apollo-programme proportions (see page 26). This may make it hard to maintain the political support large projects always need. Conversely, the Human Brain Project — headquartered in Switzerland, where it will soon relocate from Lausanne to its new base in Geneva — has 135 partner institutes and is blessed with a plenitude of money and planning. And it has a romantic Moon-landing-level goal: to simulate the human brain in a computer within ten years, and provide it to scientists as a research resource. Programme leaders have committed €72 million (US$97 million) to the 30-month ramp-up stage; those monies started to flow into labs after the project’s launch last month. The project has a detailed ten-year road map, laden with explicit milestones. © 2013 Nature Publishing Group

Keyword: Brain imaging
Link ID: 18892 - Posted: 11.08.2013

By KATE MURPHY Whether it’s hitting a golf ball, playing the piano or speaking a foreign language, becoming really good at something requires practice. Repetition creates neural pathways in the brain, so the behavior eventually becomes more automatic and outside distractions have less impact. It’s called being in the zone. But what if you could establish the neural pathways that lead to virtuosity more quickly? That is the promise of transcranial direct current stimulation, or tDCS — the passage of very low-level electrical current through targeted areas of the brain. Several studies conducted in medical and military settings indicate tDCS may bring improvements in cognitive function, motor skills and mood. Some experts suggest that tDCS might be useful in the rehabilitation of patients suffering from neurological and psychological disorders, perhaps even in reducing the time and expense of training healthy people to master a skill. But the research is preliminary, and now there is concern about a growing do-it-yourself community, many of them video gamers, who are making tDCS devices with nine-volt batteries to essentially jump-start their brains. “If tDCS is powerful enough to do good, you have to wonder if, done incorrectly, it could cause harm,” said Dr. H. Branch Coslett, chief of the cognitive neurology section at the University of Pennsylvania School of Medicine and a co-author of studies showing that tDCS improves recall of proper names, fosters creativity and improves reading efficiency. Even the tDCS units used in research are often little more than a nine-volt battery with two electrodes and a controller for setting the current and the duration of the session. Several YouTube videos show how to make a rough facsimile. © 2013 The New York Times Company

Keyword: Miscellaneous
Link ID: 18848 - Posted: 10.29.2013

Kerri Smith Jack Gallant perches on the edge of a swivel chair in his lab at the University of California, Berkeley, fixated on the screen of a computer that is trying to decode someone's thoughts. On the left-hand side of the screen is a reel of film clips that Gallant showed to a study participant during a brain scan. And on the right side of the screen, the computer program uses only the details of that scan to guess what the participant was watching at the time. Anne Hathaway's face appears in a clip from the film Bride Wars, engaged in heated conversation with Kate Hudson. The algorithm confidently labels them with the words 'woman' and 'talk', in large type. Another clip appears — an underwater scene from a wildlife documentary. The program struggles, and eventually offers 'whale' and 'swim' in a small, tentative font. “This is a manatee, but it doesn't know what that is,” says Gallant, talking about the program as one might a recalcitrant student. They had trained the program, he explains, by showing it patterns of brain activity elicited by a range of images and film clips. His program had encountered large aquatic mammals before, but never a manatee. Groups around the world are using techniques like these to try to decode brain scans and decipher what people are seeing, hearing and feeling, as well as what they remember or even dream about. © 2013 Nature Publishing Group

Keyword: Vision; Aggression
Link ID: 18831 - Posted: 10.24.2013

By Gary Stix The Obama administration’s neuroscience initiative highlights new technologies to better understand the workings of brain circuits on both a small and large scale. Various creatures, from roundworms to mice, will be centerpieces of that program because the human brain is too complex—and the ethical issues too intricate—to start analyzing the actual human organ in any meaningful way. But what if there were already a means to figure out how the brain wires itself up and, in turn, to use this knowledge to study what happens in various neurological disorders of early life? Reports in scientific journals have started to trickle in on the way stem cells can spontaneously organize themselves into complex brain tissue—what some researchers have dubbed mini-brains. Christopher A. Walsh, Bullard Professor of pediatrics and neurology at Harvard Medical School, talked to Scientific American about the importance of just such work for understanding brain development and neurological disease. (Also, check out the Perspective Walsh did for Science on this topic, along with Byoung-il Bae.) In order to be able to understand the way the brain solves this tremendously complex problem of wiring itself up, we need to be able to study it rigorously in the laboratory. We need some sort of model. We can’t just take humans and put them under the microscope, so we have to find some way of modeling the brain. The mouse has been tremendously useful for understanding brain wiring and how cells in the brain form. And the mouse will continue to be very useful. The mouse is particularly useful in studying cellular effects of particular genes, but, as we get smarter and smarter about what the problems are, we’re increasingly able to think, not about things that we share with mice, but the differences that distinguish us from mice. © 2013 Scientific American

Keyword: Development of the Brain; Aggression
Link ID: 18827 - Posted: 10.24.2013

Special Note to Teachers: The content of the following lesson plans compares the “normal” brain to a “zombie” brain. Zombies are not real but there are plenty of diseases that effect real people and students may have people in their lives who have suffered because of them. The following lessons about neuroscience have been inspired by the book, “The Zombie Autopsies”, written by Steven C. Schlozman, M.D., and are intended to compliment it. “The Zombie Autopsies” was inspired by George Romero’s 1968 cult-classic horror film “Night of the Living Dead”. These original lessons build upon each other and have an accompanying plot line where the world is fighting a zombie apocalypse and the best and the brightest young people are being trained as medical students – with a specialty in neuroscience – with the hopes that they will be able to provide a cure to this terrible epidemic and save humanity. For a richer experience have the students read the book in class and as homework (see suggested reading schedule) along with the class activities. Although the materials are organized as a unit, lessons can be used as stand-alone or can be shaped to fit the needs of you and your students regarding time and content. For example, Lesson 3 is perfect for the day of Halloween. © 2013 MacNeil-Lehrer Productions

Keyword: Learning & Memory
Link ID: 18824 - Posted: 10.23.2013

By Sandra G. Boodman, Janet Ruddock was crushed: She had dreamed of greeting her first grandchild, and now that once-in-a-lifetime experience had been marred by the embarrassing problem that had derailed her life for nearly a decade. In June 2010, Ruddock, then 59, and her husband had flown to Vancouver, B.C., from Washington to meet their new grandson. But soon after they arrived, Ruddock’s in­trac­table sweating went into overdrive. As she sat in a rocking chair, perspiration drenched her head and upper body, soaking her shirt and dripping onto the 4-week-old infant. “I burst into tears,” Ruddock recalled. “All I can remember is the feeling that I’m wet, this poor baby’s wet and a moment you should always remember is ruined. You’re never going to get it back. “ For Ruddock, that event precipitated a suicidal depression. For the previous eight years she had undergone tests, taken drugs and endured the bafflement — and skepticism — of a parade of doctors she consulted about the extreme, unpredictable sweating that engulfed her head and upper body. After confiding her despair to a relative, she began seeing a psychiatrist. By chance, a few months later she learned about a woman whose experience mirrored her own and provided her a much-needed road map. “It’s a fascinoma,” said retired Washington internist Charles Abrams, using the medical slang for an unusual — or unusually interesting — case. “You usually hate for patients to come in and say, ‘I found this on the Internet,’ ” said Abrams, who treated Ruddock until his retirement last year. “But every once in a while, something is brought to your attention.” © 1996-2013 The Washington Post

Keyword: Miscellaneous
Link ID: 18787 - Posted: 10.15.2013

By WILLIAM J. BROAD SCIENCE has looked into some strange things over the centuries — reports of gargantuan sea monsters, purported images of Jesus, sightings of alien spaceships and so on. When I first heard of spontaneous orgasm, while researching a book on yoga, including its libidinal cousin, tantra, I figured it was more allegory than reality and in any event would prove beyond the reach of even the boldest investigators. Well, I was wrong. It turns out science has tiptoed around the subject for more than a century and of late has made considerable progress in determining not only the neurophysiological basis of the phenomenon but also its prevalence. Men are mentioned occasionally. But sex researchers have found that the novel type of autoerotism shows up mainly in women. Ground zero for the research is Rutgers University, where scientists have repeatedly had female volunteers put their heads into giant machines and focus their attention on erotic fantasies — the scans reveal that the pleasure centers of their brains light up in ways indistinguishable from everyday orgasms. The lab atmosphere is no-nonsense, with plenty of lights and white coats and computer monitors. Subjects often thrash about so forcefully that obtaining clear images of their brains can be difficult. “Head movement is a huge issue,” Nan Wise, a doctoral candidate at Rutgers who helps run the project, said in an interview. “It’s hard to get a decent signal.” She said a volunteer’s moving her head more than two millimeters — less than a 10th of an inch — can make for a bad day in the lab. It is easy to dismiss this as a new kind of narcissism in search of scientific respectability, a kinky pleasure coming out of the shadows. Many YouTube videos now purport to show people using controlled breathing and erotic introspection to achieve what they describe as “thinking off” and “energy orgasms.” © 2013 The New York Times Company

Keyword: Sexual Behavior; Aggression
Link ID: 18720 - Posted: 09.30.2013

By Neuroskeptic The comparative anatomy of male and female brains is an incredibly popular topic. From teachers to cartoonists, everyone’s interested in it. One supposed dude-dame dimorphism is the width of the corpus callosum, the white matter bridge that connects the brain’s left and right hemispheres. Some studies suggest that women have a larger corpus callosum, relative to overall brain size, than men. This has led to a lot of speculation about how females, with their more ‘interconnected’ brains, are therefore better at things like multitasking: The corpus callosum is 30 percent more highly developed in the female brain… allowing information to flow more easily from one side of the brain to the other, which allows a woman to focus on more than one thing at a time. However, according to Eileen Luders and colleagues, that’s all a wash, because: Differences in Brain Volume Account for Apparent Sex Differences in Callosal Anatomy It’s been argued that women’s relatively larger corpus callosa may reflect the fact that men have larger brains, on average, and that the corpus callosum is relatively smaller in larger brains. In other words, the corpus callosum difference might be a side-effect of the true gender difference (perhaps the only one) – bigger male brains overall. Luders et al confirmed this with a clever technique: they looked in a large online brain database to find some extremely small male brains, and extremely large female ones. This, the two genders were matched on total size.

Keyword: Sexual Behavior; Aggression
Link ID: 18705 - Posted: 09.26.2013

By Fritz Andersen, It was hot that Sunday morning in February 2011 in Old San Juan. I had just retired after 40 years of cardiology practice in the suburbs of Washington, and my wife and I were spending the winter in Puerto Rico. A couple of friends had arrived by cruise ship, and I took them to see the 450-year-old Spanish fortress that sits above the entrance of the harbor. The fortress walls radiated heat, and after reentering the city we walked to our home for a breather and a refreshing ceiling fan. While sitting in the kitchen and sipping a beer, I suddenly passed out. I woke up a bit dizzy and confused; my friend, an internist from Arlington, told me I had had a grand mal seizure. My wife, Carmen Alicia, called a local friend, also a cardiologist, who sent us to a nearby hospital; there, an MRI exam revealed a small spot on my brain. The neurologist felt it needed to be biopsied to obtain a tissue diagnosis. I immediately returned to Virginia and went to several specialists, who suggested further testing before I decided to have an invasive brain biopsy. I also had a blood test for cysticercosis, an infection that results from eating undercooked pork contaminated with Tenia solium. This common parasite produces cysts all over the body, including the brain. It is the most common reason for seizures in many countries, particularly in India, where children with seizures are first treated for this disease even before other studies are done. My blood test was strongly positive. I started a course of oral medicine to treat it. The test reassured me. Unfortunately, my spot grew a bit over the course of three months, reaching the size of a grape. A biopsy and excision were now indicated. © 1996-2013 The Washington Post

Keyword: Genes & Behavior
Link ID: 18692 - Posted: 09.24.2013

Joseph Brean U.S. President Barack Obama’s much-hyped BRAIN initiative to crack the mysteries of consciousness via a finely detailed map of the brain in action took its first big step this week, with the release of a strategy report that foresees “revolutionary advances” in the $100-million effort to “crack the brain’s code,” perhaps in as little as “a few years.” “We stand on the verge of a great journey into the unknown,” the report says, explicitly comparing BRAIN to the Apollo moon shot, and predicting it will “change human society forever.” As a grand challenge, Apollo was an unambiguous success, despite the vast expense and human costs, but there is a growing sense among scientists, if not legacy-minded politicians, that the road ahead for modern neuroscience will be pocked with disappointment, with more impenetrable mysteries than solvable problems. As the world approaches what some are calling “peak neuro,” after three decades of over-hyped “brain porn,” the optimistic hope is that Mr. Obama’s BRAIN project will lead to a detailed and dynamic map of the brain, and thus reveal both how it works and how it fails in such diseases as Alzheimer’s or autism. The pessimistic fear, however, is that the “speed of thought,” as Mr. Obama described it, is just too quick for our current brain imaging technologies, primarily functional magnetic resonance imaging (fMRI). As the anonymous blogger Neuroskeptic, a British brain scientist who tracks the misinterpretation of brain scan studies by both scientists and media, put it in an email, “there’s just as much hype and misrepresentation as ever.” The more we learn about the brain, the less we seem to know. With its potential overstated and its aspirations presented as foregone conclusions, the relatively new field of neuroscience is in a period of self-reflection, said Jackie Sullivan, a philosopher of neuroscience at Western University in London Ont. “The vast majority of neuroscientists are well aware that the goals going forward need to be more modest,” she said. © 2013 National Post

Keyword: Consciousness; Aggression
Link ID: 18686 - Posted: 09.23.2013

by Andy Coghlan The two major brain abnormalities that underlie Alzheimer's disease can now be viewed simultaneously in brain scans while people are still alive, providing new insight into how the disease develops and whether drugs are working. The breakthrough comes from the development of a harmless tracer chemical that is injected into the bloodstream and accumulates exclusively in "tau tangles" – one type of abnormality that occurs in the brains of people with Alzheimer's and other kinds of dementia. Fluorescent light emitted from the chemical is picked up using positron emission tomography (PET), showing exactly where the tangles are. The tracer remains in the brain for a few hours before being broken down and expelled from the body. Similar tracers already exist for beta amyloid plaques, the other major anatomical feature of Alzheimer's, so the one for tau tangles completes the picture. "This is a big step forward," says John Hardy, an Alzheimer's researcher at University College London. "This is of critical significance, as tau lesions are known to be more intimately associated with neuronal loss than plaques," says Makoto Higuchi of the National Institute of Radiological Sciences in Chiba, Japan, and head of the team who developed the new tracer. The tracer could help researchers unravel exactly how Alzheimer's develops, and enable earlier diagnosis and monitoring of treatments. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Aggression
Link ID: 18673 - Posted: 09.19.2013

Posted by Gary Marcus On Monday, the National Institutes of Health released a fifty-eight-page report on the future of neuroscience—the first substantive step in developing President Obama’s BRAIN Initiative, which seeks to “revolutionize our understanding of the human mind and uncover new ways to treat, prevent, and cure brain disorders like Alzheimer’s, schizophrenia, autism, epilepsy, and traumatic brain injury.” Assembled by an advisory panel of fifteen scientists led by Cori Bargmann, of Rockefeller University, and William Newsome, of Stanford, the report assesses the state of neuroscience and offers a vision for the field’s future. The core challenge, as the report puts it, is simply that “brains—even small ones—are dauntingly complex”: Information flows in parallel through many different circuits at once; different components of a single functional circuit may be distributed across many brain structures and be spatially intermixed with the components of other circuits; feedback signals from higher levels constantly modulate the activity within any given circuit; and neuromodulatory chemicals can rapidly alter the effective wiring of any circuit. To tackle the brain’s immense complexity, the report outlines nine goals for the initiative. No effort to study the brain is likely to succeed without devoting serious attention to all nine, which range from creating structural maps of its static, physical connections to developing new ways of recording continuous, dynamic activity as it perceives the world and directs action. A less flashy, equally critical goal is to create a “census” of the brain’s basic cell types, which neuroscientists haven’t yet established. (The committee also devotes attention to ethical questions that could arise, such as what should happen if neural enhancement—the use of engineering to alter the brain—becomes a realistic possibility.) © 2013 Condé Nast.

Keyword: Brain imaging
Link ID: 18668 - Posted: 09.18.2013

By JAMES GORMAN In the first hint of how the Brain Initiative announced by President Obama in April could take shape, an advisory group on Monday recommended that the main target of research by the National Institutes of Health should be systems and circuits involving thousands to millions of brain cells — not the entire brain or individual cells and molecules. The National Institutes of Health working group was meant to focus specifically on how the federal agency should spend its $40 million brain initiative budget in 2014. However, Dr. Rafael Yuste, a neuroscientist at Columbia University who was not a member of the group, said that the recommendations, which he agreed with, were so ambitious that it “could be a charter for neuroscience for the next 10 to 15 years.” Dr. Francis S. Collins, director of the N.I.H., who accepted the report and its recommendations, said that he had asked the group, led by Cori Bargmann of Rockefeller University and Bill Newsome of Stanford, to think big, and that it would be the job of the N.I.H. to make actual spending decisions. Dr. Bargmann agreed that the overall goal of figuring out “how circuits in the brain generate complex thoughts and behavior” was not something to be tackled with the $40 million that the N.I.H. hopes to have for 2014. “You can’t do all of that in year one, you can’t do all of that with $40 million, and you can’t do all of that at N.I.H. either,” she said. The $40 million for the N.I.H. is part of a White House proposal for $100 million in spending on the initiative in the 2014 budget. The initiative also includes money for the National Science Foundation and the Defense Advanced Research Projects Agency. Several major private research foundations are also joining in the effort with their own research. © 2013 The New York Times Company

Keyword: Brain imaging
Link ID: 18653 - Posted: 09.17.2013

By Jay Van Bavel and Dominic Packer On the heels of the decade of the brain and the development of neuroimaging, it is nearly impossible to open a science magazine or walk through a bookstore without encountering images of the human brain. As prominent neuroscientist, Martha Farah, remarked “Brain images are the scientific icon of our age, replacing Bohr’s planetary atom as the symbol of science”. The rapid rise to prominence of cognitive neuroscience has been accompanied by an equally swift rise in practitioners and snake oil salesmen who make promises that neuroimaging cannot yet deliver. Critics inside and outside of the discipline have both been swift to condemn sloppy claims that MRI can tell us who we plan to vote for, if we love our iPhones, and why we believe in God. Yet, the constant parade of overtrumped results has lead to the rise of “The new neuro-skeptics” who argue that neuroscience is either unable to answer the interesting questions, or worse, that scientists have simply been seduced by the flickering lights of the brain. The notion that MRI images have attained an undue influence over scientists, granting agencies, and the public gained traction in 2008 when psychologists David McCabe and Alan Castel published a paper showing that brain images could be used to deceive. In a series of experiments, they found that Colorado State University undergraduates rated descriptions of scientific studies higher in scientific reasoning if they were accompanied by a 3-D image of the brain (see Figure), rather than a mere bar graph or a topographic map of brain activity on the scalp (presumably from electroencephalography). © 2013 Scientific American

Keyword: Brain imaging; Aggression
Link ID: 18652 - Posted: 09.17.2013

By Ben Thomas As Albert Einstein famously said, “No problem can be solved from the same level of consciousness that created it.” The history of science is littered with so-called “intractable” problems that researchers later cracked wide open using techniques their ancestors could hardly imagine. Biologists in the 1950s looked at the staggeringly complex (and beautiful) three-dimensional shapes into which proteins fold and declared that a reliably predictive mathematical model of these convolutions might be unachievable in our lifetimes. But over the past few years, folks with home computers have joined forces to crack many longstanding protein-folding problems using the online game FoldIt. Instead of relying on the number-crunching power of a single supercomputer or network, crowdsourced games like FoldIt translate vast and complex data sets into simple online interfaces that anyone can learn to operate. The crowdsourced astronomy game Galaxy Zoo also depends on an army of “citizen scientists” for classification of stars hundreds of light years away; while Google built its image search technology on an image-labeling game. In fact, every time you “verify your humanity” on a web form by typing out nonsensical reCAPTCHA text, you’re actually helping Google transcribe books from the world’s libraries into a digital format. And now, a worldwide team of neuroscience researchers have begun using this crowdsource approach to crack open one of the greatest problems in any scientific field: The construction of a complete wiring diagram for a mammalian brain. © 2013 Scientific American,

Keyword: Brain imaging
Link ID: 18634 - Posted: 09.12.2013

By Michele Solis Like truth and beauty, pain is subjective and hard to pin down. What hurts one moment might not register the next, and our moods and thoughts color the experience of pain. According to a report in April in the New England Journal of Medicine, however, researchers may one day be able to measure the experience of pain by scanning the brain—a much needed improvement over the subjective ratings of between one and 10 that patients are currently asked to give. Led by neuroscientist Tor Wager of the University of Colorado at Boulder, researchers used functional MRI on healthy participants who were given heated touches to their arm, some pleasantly warm, others painfully hot. During the painful touches, a scattered group of brain regions consistently turned on. Although these regions have been previously associated with pain, the new study detected a striking and consistent jump in their activity when people reported pain, with much greater accuracy than previous studies had attained. This neural signature appeared in 93 percent of subjects reporting to feel painful heat, ramping up as pain intensity increased and receding after participants took a painkiller. The researchers determined that the brain activity specifically marked physical pain rather than a generally unpleasant experience, because it did not emerge in people shown a picture of a lover who had recently dumped them. Although physical pain and emotional pain involve some of the same regions, the study showed that fine-grained differences in activation separate the two conditions. © 2013 Scientific American

Keyword: Pain & Touch; Aggression
Link ID: 18632 - Posted: 09.11.2013

By Nathan Seppa A tiny probe equipped with a laser might reveal what the human eye doesn’t always see: the difference between a tumor and healthy tissue. A new study suggests the device might provide brain surgeons with a roadmap as they go about the delicate business of removing tumors. Surgeons try to excise as much of brain tumors as possible, but they risk harming the patient if they remove healthy tissue. “This problem,” says surgeon Daniel Orringer of the University of Michigan in Ann Arbor, “has vexed brain surgeons for as long as they have taken out tumors,” since the first half of the 20th century. “Basically, we do it by feel — the texture, color and vascularity of the tissues. Tumors tend to bleed a little more than normal brain.” Although removing and testing tissue samples, or biopsies, can help to characterize the tissue at the tumor margins, it’s a cumbersome and time-consuming process. In the new study, Orringer and his colleagues instead exposed such borderline brain tissues to a weak laser. Then they used Raman spectroscopy, a technique that reveals vibrations of specific chemical bonds in tissues. The revved up form of Raman spectroscopy that the researchers used is sensitive enough to distinguish between proteins and lipids. Since tumors are higher in protein than healthy brain tissue, the authors designed the technique to present protein signatures as blue images on a screen, and lipids as green. © Society for Science & the Public 2000 - 2013

Keyword: Brain imaging
Link ID: 18622 - Posted: 09.09.2013

By ERIC R. KANDEL THESE days it is easy to get irritated with the exaggerated interpretations of brain imaging — for example, that a single fMRI scan can reveal our innermost feelings — and with inflated claims about our understanding of the biological basis of our higher mental processes. Such irritation has led a number of thoughtful people to declare that we can never achieve a truly sophisticated understanding of the biological foundation of complex mental activity. In fact, recent newspaper articles have argued that psychiatry is a “semi-science” whose practitioners cannot base their treatment of mental disorders on the same empirical evidence as physicians who treat disorders of the body can. The problem for many people is that we cannot point to the underlying biological bases of most psychiatric disorders. In fact, we are nowhere near understanding them as well as we understand disorders of the liver or the heart. But this is starting to change. Consider the biology of depression. We are beginning to discern the outlines of a complex neural circuit that becomes disordered in depressive illnesses. Helen Mayberg, at Emory University, and other scientists used brain-scanning techniques to identify several components of this circuit, two of which are particularly important. One is Area 25 (the subcallosal cingulate region), which mediates our unconscious and motor responses to emotional stress; the other is the right anterior insula, a region where self-awareness and interpersonal experience come together. These two regions connect to the hypothalamus, which plays a role in basic functions like sleep, appetite and libido, and to three other important regions of the brain: the amygdala, which evaluates emotional salience; the hippocampus, which is concerned with memory; and the prefrontal cortex, which is the seat of executive function and self-esteem. All of these regions can be disturbed in depressive illnesses. © 2013 The New York Times Company

Keyword: Brain imaging; Aggression
Link ID: 18621 - Posted: 09.09.2013