Links for Keyword: Brain imaging

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By John Horgan Does anyone still remember “The Decade of the Brain“? Youngsters don’t, but perhaps some of my fellow creaky, cranky science-lovers do. In 1990, the brash, fast-growing Society for Neuroscience convinced Congress to name the ’90s the Decade of the Brain. The goal, as President George Bush put it, was to boost public awareness of and support for research on the “three-pound mass of interwoven nerve cells” that serves as “the seat of human intelligence, interpreter of senses and controller of movement.” One opponent of this public-relations stunt was Torsten Wiesel, who won a Nobel Prize in 1981 for work on the neural basis of vision. When I interviewed him in 1998 for my book The Undiscovered Mind, he grumbled that the Decade of the Brain was “foolish.” Scientists “need at least a century, maybe even a millennium,” to understand the brain, Wiesel said. “We are at the very beginning of brain science.” I recalled Wiesel’s irritable comments as I read about big new neuroscience initiatives in the U.S. and Europe. In January, the European Union announced it would sink more than $1 billion over the next decade into the Human Brain Project, an attempt to construct a massive computer simulation of the brain. The project, according to The New York Times, involves more than 150 institutions. Meanwhile, President Barack Obama is reportedly planning to commit more than $3 billion to a similar project, called the Brain Activity Map. © 2013 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17943 - Posted: 03.25.2013

Monya Baker At first glance, it looks like an oddly shaped campfire: smoky grey shapes light up with red sparks and flashes. But the video actually represents a different sort of crackle — the activity of individual neurons across a larval fish brain. It is the first time that researchers have been able to image an entire vertebrate brain at the level of single cells. “We see the big picture without losing resolution,” says Phillipp Keller, a microscopist at the Howard Hughes Medical Institute's Janelia Farm Research Campus in Ashburn, Virginia, who developed the system with Janelia neurobiologist Misha Ahrens. The researchers are able to record activity across the whole fish brain almost every second, detecting 80% of its 100,000 neurons. (The rest lie in hard-to-access areas, such as between the eyes; their activity is visible but cannot be pinned down to single cells.) The work is published today in Nature Methods1. “It’s phenomenal,” says Rafael Yuste, a neuroscientist at Columbia University in New York. “It is a bright star now in the literature, suggesting that it is not crazy to map every neuron in the brain of an animal.” Yuste has been leading the call for a big biology project2 that would do just that in the human brain, which contains about 85,000 times more neurons than the zebrafish brain. The resolution offered by the zebrafish study will enable researchers to understand how different regions of the brain work together, says Ahrens. With conventional techniques, imaging even 2,000 neurons at once is difficult, so researchers must pick and choose which to look at, and extrapolate. Now, he says, “you don't need to guess what is happening — you can see it”. © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 17922 - Posted: 03.19.2013

By TIM REQUARTH For months, Henry Markram and his team had been feeding data into a supercomputer, four vending-machine-size black boxes whirring quietly in the basement of the Swiss Federal Institute of Technology in Lausanne. The Blue Brain computer has 10,000 virtual neurons. The colors represent the neurons' electric voltage at a specific moment. The boxes housed thousands of microchips, each programmed to act like a brain cell. Cables carried signals from microchip to microchip, just as cells do in a real brain. In 2006, Dr. Markram flipped the switch. Blue Brain, a tangled web of nearly 10,000 virtual neurons, crackled to life. As millions of signals raced along the cables, electrical activity resembling real brain waves emerged. “That was an incredible moment,” he said, comparing the simulation to what goes on in real brain tissue. “It didn’t match perfectly, but it was pretty good. As a biologist, I was amazed.” Deciding then that simulating the entire brain on a supercomputer would be possible within his lifetime, Dr. Markram, now 50, set out to prove it. That is no small feat. The brain contains nearly 100 billion neurons organized into networks with 100 trillion total connections, all firing split-second spikes of voltage in a broth of complex biological molecules in constant flux. In 2009, Dr. Markram conceived of the Human Brain Project, a sprawling and controversial initiative of more than 150 institutions around the world that he hopes will bring scientists together to realize his dream. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17921 - Posted: 03.19.2013

By Ben Thomas In 1956, a legion of famed scientific minds descended on Dartmouth College to debate one of mankind’s most persistent questions: Is it possible to build a machine that thinks? The researchers had plenty to talk about – biologists and mathematicians had suggested since the 1940s that nerve cells probably served as binary logic gates, much like transistors in computer mainframes. Meanwhile, computer theorists like Alan Turing and Claude Shannon had been arguing for years that intelligence and learning could – at least in theory – be programmed into a machine of sufficient complexity. Within the next few decades, many researchers predicted, we’d be building machines capable of conscious thought. Fifty-odd years after that first Dartmouth Conference, our sharpest supercomputers still struggle to hold basic conversations. We’ve created software that can drive our cars and predict our purchases, but the dreams of a true artificial brain – and of a working neuron-by-neuron model of the human brain itself – look even more distant than they did in the 1950s. The more we learn about how the brain works, the more interwoven and inextricable we realize its components and processes are – and the less like a computer it seems. Take synapses, for example – the points where neurons link up and exchange information. Neuroscientists estimate that a human brain may contain about 150 trillion of them, and no two are quite identical – either to one another, or to any synapse in anyone else’s brain. On top of this complexity, every neuron in a brain is constantly learning, adapting, fine-tuning its sensitivity, tinkering with its synaptic connections – rarely wired the same way from one day to the next. In light of all this, it’s not hard to see why many scientists seriously doubt that we’ll map an entire human brain any time this century – much less engineer a digital version from scratch. © 2013 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17920 - Posted: 03.19.2013

By Charles Q. Choi and Txchnologist Scientists scanning the human brain can now tell whom a person is thinking of, the first time researchers have been able to identify what people are imagining from imaging technologies. Work to visualize thought is starting to pile up successes. Recently, scientists have used brain scans to decode imagery directly from the brain, such as what number people have just seen and what memory a person is recalling. They can now even reconstruct videos of what a person has watched based on their brain activity alone. Cornell University cognitive neuroscientist Nathan Spreng and his colleagues wanted to carry this research one step further by seeing if they could deduce the mental pictures of people that subjects conjure up in their heads. “We are trying to understand the physical mechanisms that allow us to have an inner world, and a part of that is how we represent other people in our mind,” Spreng says. His team first gave 19 volunteers descriptions of four imaginary people they were told were real. Each of these characters had different personalities. Half the personalities were agreeable, described as liking to cooperate with others; the other half were less agreeable, depicted as cold and aloof or having similar traits. In addition, half these characters were described as outgoing and sociable extroverts, while the others were less so, depicted as sometimes shy and inhibited. The scientists matched the genders of these characters to each volunteer and gave them popular names like Mike, Chris, Dave or Nick, or Ashley, Sarah, Nicole or Jenny. © 2013 Scientific American

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17906 - Posted: 03.15.2013

By Partha Mitra The Sherlock Holmes novel The Hound of the Baskervilles features the great Grimpen Mire, a treacherous marsh in Dartmoor, England. Holmes’ protagonist, the naturalist Stapleton, knows where the few secure footholds are, allowing him to cross the mire and reach the hills with rare plants and butterflies, but he warns Dr. Watson that a false step can be fatal, the bog inexorably consuming the unsuspecting traveller. Trying to unravel the complexities of the brain is a bit like crossing the great Grimpen Mire: one needs to know where the secure stepping-stones are, and a false step can mean sinking into a morass. As we enter the era of Big Brain Science projects, it is important to know where the next firm foothold is. As a goal worthy of a multi-billion dollar brain project, we have now been offered a motto that is nearly as rousing as “climb every mountain”: “record every action potential from every neuron.” According to recent reporting in the New York Times, this goal, proclaimed in a paper published in 2012, will be the basis of a decade-long “Brain Activity Map” project. Not content with a goal as lofty as this in worms, flies and mice, the press reports imply (and the authors also speculate) that these technologies will be used for comprehensive spike recordings in the human brain, generating a “Brain Activity Map” that will provide the answers to Alzheimers and Schizophrenia and lead us out of the “impenetrable jungles of the brain” that hapless neuroscientists have wandered over the past century. Neuroscience is most certainly in need of integration, and brain research will without doubt benefit from the communal excitement and scaled up funding associated with a Big Brain Initiative. However, success will depend on setting the right goals and guarding against irrational exuberance. Successful big science projects are engineering projects with clear, technically feasible goals: setting a human on the moon, sequencing the Human Genome, finding the Higgs Boson. The technologies proposed in the paper under discussion may or may not be feasible in a given species (they will not be feasible in the normal human brain, since the methods involved are invasive and require that the skull be surgically opened). However, technology development is notoriously difficult to predict, and may carry unforeseen benefits. What we really need to understand is whether the overall goal is meaningful. © 2013 Scientific American,

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17879 - Posted: 03.09.2013

Meredith Wadman Ron Kalil, a neuroscientist at the University of Wisconsin–Madison, didn’t expect to see his son among the 28,500 attendees at the meeting of the Society for Neuroscience in New Orleans last October. And he wondered why Tom Kalil, deputy director for policy at the White House’s Office of Science and Technology Policy (OSTP), was accompanied by Miyoung Chun, vice-president of science programmes at the Kavli Foundation in Oxnard, California. Tom Kalil told his father that the Kavli Foundation had wanted his help in bringing nanoscientists together behind an ambitious idea. Ron Kalil says he thought: “Why are you talking about it at a neuroscience meeting?” He understands now. These two people, neither of them a working scientist, had been quietly pushing into existence the Brain Activity Map (BAM), the largest and most ambitious effort in fundamental biology since the Human Genome Project — and one that would need advances in both nanoscience and neuroscience to achieve its goals. This is the kind of science — big and bold — that politicians like. President Barack Obama praised brain mapping in his State of the Union address on 12 February. Soon after, Francis Collins, director of the US National Institutes of Health (NIH) in Bethesda, Maryland, which will be the lead agency on the project, talked up the idea in a television appearance. The Obama administration is expected to provide more details about the initiative this month, possibly in conjunction with the release of the federal 2014 budget request. But already, some scientists are wondering whether the project, a concept less than two years old and still evolving, can win new funding from Congress, or whether it would crowd out projects pitched by individual scientists. “Creative science is bottom-up, not top-down,” says Cori Bargmann, a neurobiologist at the Rockefeller University in New York. “Are we talking about central planning inside the Beltway?” © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17875 - Posted: 03.07.2013

By JOHN MARKOFF In setting the nation on a course to map the active human brain, President Obama may have picked a challenge even more daunting than ending the war in Afghanistan or finding common ground with his Republican opponents. In more than a century of scientific inquiry into the interwoven cells known as neurons that make up the brain, researchers acknowledge they are only beginning to scratch the surface of a scientific challenge that is certain to prove vastly more complicated than sequencing the human genome. The Obama administration is hoping to announce as soon as next month its intention to assemble the pieces — and, even more challenging, the financing — for a decade-long research project that will have the goal of building a comprehensive map of the brain’s activity. At present, scientists are a long way from doing so. Before they can even begin the process, they have to develop the tools to examine the brain. And before they develop tools that will work on humans, they must succeed in doing so in a number of simpler species — assuming that what they learn can even be applied to humans. Besides the technological and scientific challenges, there are a host of issues involving storing the information researchers gather, and ethical concerns about what can be done with the data. Also highly uncertain is whether the science will advance quickly enough to meet the time frames being considered for what is being called the Brain Activity Map project. Many neuroscientists are skeptical that a multiyear, multibillion dollar effort to unlock the brain’s mysteries will succeed.“I believe the scientific paradigm underlying this mapping project is, at best, out of date and at worst, simply wrong,” said Donald G. Stein, a neurologist at the Emory University School of Medicine in Atlanta. “The search for a road map of stable, neural pathways that can represent brain functions is futile.” © 2013 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17850 - Posted: 02.26.2013

By Gary Stix The era of Big Neuroscience has arrived. In late January, The Human Brain Project—an attempt to create a computer simulation of the brain at every scale from the nano nano to the macro biotic—announced that it had successfully arranged a billion Euro funding package for a 10-year run. And then on Feb. 18, an article in The New York Times took the wraps off a plan to spend perhaps billions of dollars for an effort to record large collections of brain cells and figure out what exactly they are doing. Is this the Large Hadron Collider vs. the Superconducting Supercollider redux? Not yet. The billions for the Brain Activity Map, the U.S. project, are still a wish that has yet to be granted. But, despite as-always hazy government finances, brain researchers are thinking large as they never have before, and invoking the attendant rhetoric of moon shots, next-generation Human Genome Projects and the need for humankind to muster the requisite visionary zeal to tackle one of science’s “last frontiers.” Oy, spare me that last part. The challenges these projects have set for themselves, though, illustrate the challenge of going from today’s crude profiles of a biological machine of incomprehensible complexity to an accurate rendering of the goings-on of some 100 billion neurons woven together by a pulsating tapestry of 100 trillion electrical interconnections. © 2013 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17849 - Posted: 02.26.2013

By Alan Boyle, Science Editor, NBC News BOSTON — The brain-mapping project that the Obama administration wants to facilitate isn't necessarily aimed at adding billions of dollars to the money already being spent on research, according to the scientists who inspired the idea. Instead, it's aimed at harnessing new technologies to uncover the secrets of neural function less expensively and more completely. "We can bring down the cost and increase the quality of the technology," said Harvard geneticist George Church, one of the researchers who proposed the Brain Activity Map Project last year. "We are trying to work with current funding [levels] to bring down the cost." The New York Times reported on Monday that the White House has embraced the idea of having the Office of Science and Technology Policy spearhead the project, with participation by the National Institutes of Health and other federal agencies. The federal initiative is to be unveiled as early as next month, the Times quoted its sources as saying. The roots of the project go back months if not years earlier: The goals of the BAM Project were outlined last June in a white paper appearing in the journal Neuron. The researchers proposed a 15-year international effort to map the functions of the brain's complex neural circuitry to an unprecedented degree — using traditional tools such as magnetic resonance imaging in combination with novel technologies such as nanosensors and wireless fiber-optic probes that can be implanted into the brain, and genetically engineered cells that can be linked up with brain cells to record their activity. © 2013 NBCNews.com

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17822 - Posted: 02.19.2013

By Pallab Ghosh Science correspondent, BBC News, Boston Scientists are set to release the first batch of data from a project designed to create the first map of the human brain. The project could help shed light on why some people are naturally scientific, musical or artistic. Some of the first images were shown at the American Association for the Advancement of Science meeting in Boston. I found out how researchers are developing new brain imaging techniques for the project by having my own brain scanned. Scientists at Massachusetts General Hospital are pushing brain imaging to its limit using a purpose built scanner. It is one of the most powerful scanners in the world. The scanner's magnets need 22MW of electricity - enough to power a nuclear submarine. The researchers invited me to have my brain scanned. I was asked if I wanted "the 10-minute job or the 45-minute 'full monty'" which would give one of the most detailed scans of the brain ever carried out. Only 50 such scans have ever been done. I went for the full monty. It was a pleasant experience enclosed in the scanner's vast twin magnets. Powerful and rapidly changing magnetic fields were looking to see tiny particles of water travelling along the larger nerve fibres. By following the droplets, the scientists in the adjoining cubicle are able to trace the major connections within my brain. Arcs of understanding The result was a 3D computer image that revealed the important pathways of my brain in vivid colour. One of the lead researchers, Professor Van Wedeen, gave me a guided tour of the inside of my head. BBC © 2013

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17814 - Posted: 02.18.2013

By JOHN MARKOFF The Obama administration is planning a decade-long scientific effort to examine the workings of the human brain and build a comprehensive map of its activity, seeking to do for the brain what the Human Genome Project did for genetics. The project, which the administration has been looking to unveil as early as March, will include federal agencies, private foundations and teams of neuroscientists and nanoscientists in a concerted effort to advance the knowledge of the brain’s billions of neurons and gain greater insights into perception, actions and, ultimately, consciousness. Scientists with the highest hopes for the project also see it as a way to develop the technology essential to understanding diseases like Alzheimer’s and Parkinson’s, as well as to find new therapies for a variety of mental illnesses. Moreover, the project holds the potential of paving the way for advances in artificial intelligence. The project, which could ultimately cost billions of dollars, is expected to be part of the president’s budget proposal next month. And, four scientists and representatives of research institutions said they had participated in planning for what is being called the Brain Activity Map project. The details are not final, and it is not clear how much federal money would be proposed or approved for the project in a time of fiscal constraint or how far the research would be able to get without significant federal financing. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17813 - Posted: 02.18.2013

By Breanna Draxler Brain differences between the 23 participants were quantified at each surface vertex. Values below the global mean are shown in cool colors while values above this average are shown in warm colors. Image courtesy of Sophia Mueller et al. Every person thinks and acts a little differently than the other 7 billion on the planet. Scientists now say that variations in brain connections account for much of this individuality, and they’ve narrowed it down to a few specific regions of the brain. This might help us better understand the evolution of the human brain as well as its development in individuals. Each human brain has a unique connectome—the network of neural pathways that tie all of its parts together. Like a fingerprint, every person’s connectome is unique. To find out where these individual connectomes differed the most, researchers used an MRI scanning technique to take cross-sectional pictures of 23 people’s brains at rest. Researchers found very little variation in the areas of the participants’ brains responsible for basic senses and motor skills. It’s a pretty straight shot from the finger to the part of the brain that registers touch, for example, or from the eye to the vision center. Thus we apparently all sense the world in more or less the same way. The real variety arose in the parts of the brain associated with personality, like the frontoparietal lobe. This multipurpose area in the brain curates sensory data into complex thoughts, feelings or actions and allows us to interpret the things we sense (i.e., we recognize a red, round object as an apple). Because there are many ways to get from sensation to reaction, and many different ways to react to what we sense, each individual’s brain blazes its own paths.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17774 - Posted: 02.09.2013

By JUDY BATTISTA NEW ORLEANS — The N.F.L., faced with increasing concern about the toll of concussions and confronted with litigation involving thousands of former players, is planning to form a partnership with General Electric to jump-start development of imaging technology that would detect concussions and encourage the creation of materials to better protect the brain. The four-year initiative, which is expected to begin in March with at least $50 million from the league and G.E., is the result of a late October conversation between Commissioner Roger Goodell and G.E.’s chief executive, Jeffrey Immelt, a former offensive tackle at Dartmouth. When Goodell explained his idea of getting leading companies in innovation to join the N.F.L. to accelerate research, Immelt said he wanted to help. After years of insisting there was no link between head injuries sustained on the field and long-term cognitive impairment, the N.F.L. has altered rules, fined and suspended players who hit opponents in the head and contributed millions of dollars for the study of head injuries. “Is this their way of defending themselves with this cloud over the sport? I’d be lying if I told you it had nothing to do with it,” Kevin Guskiewicz, the founding director of the Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center at the University of North Carolina, said of the initiative. Guskiewicz is a member of the league’s Head, Neck and Spine Committee and the chairman of a subcommittee focused on safety equipment and playing rules. He will work with the N.F.L. and G.E. to identify areas of focus. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Language and Our Divided Brain
Link ID: 17750 - Posted: 02.04.2013

By R. Douglas Fields Imagine if your biggest health problem could be solved with the flip of a switch. Deep-brain stimulation (DBS) offers such a dramatic recovery for a range of neurological illnesses, including Parkinson's disease, epilepsy and major depression. Yet the metal electrodes implanted in the brain are too bulky to tap into intricate neural circuitry with precision and corrode in contact with tissue, so their performance degrades over time. Now neurophysiologists have developed a method of DBS that avoids these problems by using microscopic magnets to stimulate neurons. In experiments published in June 2012 in Nature Communications, neurophysiologist John T. Gale of the Cleveland Clinic and his colleague Giorgio Bonmassar, a physicist at Harvard Medical School and an expert on brain imaging, tested whether micromagnets (which are half a millimeter in diameter) could induce neurons from rabbit retinas to fire. They found that when they electrically energized a micromagnet positioned next to a neuron, it fired. In contrast to the electric currents induced by DBS, which excite neurons in all directions, magnetic fields follow organized pathways from pole to pole, like the magnetic field that surrounds the earth. The researchers found that they could direct the stimulus precisely to individual neurons, and even to particular areas of a neuron, by orienting the magnetic coil appropriately. “That may help us avoid the side effects we see in DBS,” Gale says, referring to, for instance, the intense negative emotions that are sometimes accidentally triggered when DBS is used to relieve motor problems in Parkinson's. © 2013 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 17747 - Posted: 02.02.2013

by Carrie Arnold Studying the links between brain and behavior may have just gotten easier. For the first time, neuroscientists have found a way to watch neurons fire in an independently moving animal. Though the study was done in fish, it may hold clues to how the human brain works. "This technique will really help us understand how we make sense of the world and why we behave the way we do," says Martin Meyer, a neuroscientist at King's College London who was not involved in the work. The study was carried out in zebrafish, a popular animal model because they're small and easy to breed. More important, zebrafish larvae are transparent, which gives scientists an advantage in identifying the neural circuits that make them tick. Yet, under a typical optical microscope, neurons that are active and firing look much the same as their quieter counterparts. To see what neurons are active and when, neuroscientists have therefore developed a variety of indicators and dyes. For example, when a neuron fires, it is flooded with calcium ions, which can cause some of the dyes to light up. Still, the approach has limitations. Traditionally, Meyer explains, researchers would immobilize the head or entire body of a zebrafish larvae so that they could get a clearer picture of what was happening inside the brain. Even so, it was difficult to interpret neural activity for just a few neurons and over a short period of time. Researchers needed a better way to study the zebrafish brain in real time. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 17742 - Posted: 02.02.2013

Posted by Heidi Ledford Just in time for the holidays, a team of MIT and Max Planck researchers has released EyeWire: an online game that allows users to trace neural connections through the retina. In the proud tradition of Foldit and other ‘citizen science’ endeavours, EyeWire aims to harness the power of the people to map the projections of retinal cells called JAM-B cells. JAM-B cells respond specifically to upward motion (which appears downward to the retina, because it receives inverted images), and were the first retinal ganglion cells distinguished on the basis of a molecular marker — a protein called ‘Junctional Adhesion Molecule B’ (JAM-B). Does the downward trajectory of the JAM-B cell projections relate to their function? The scientists behind EyeWire hope to find out. EyeWire, launched 10 December, is spearheaded by MIT’s Sebastian Seung, best known for taking the concept of mapping neural connections and turning it into the surprisingly digestible and well-read popular science book Connectomics: How the Brain’s Wiring Makes Us Who We Are. Seung and his colleagues chart the retinal connectome by taking serial electron micrographs of thin slices of tissue. They then trace individual neural projections through each slice and stitch it all together again into a three dimensional image. Seung’s team could use all the help it can get: in a review of Seung’s book, Caltech neuroscientist Christoph Koch estimated that to map a cubic millimetre of brain would require a billion images and a million working-years of analysis time for a trained technician. © 2012 Nature Publishing Group

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17597 - Posted: 12.11.2012

By Scicurious This past weekend, I read an interesting piece in the New Yorker. It’s another one of the current rash of pieces that are warning us (rightly!) to beware of neuro-hype. It references another recent piece in the New York Times, which referenced those fighting back against things like “How Creativity Works” (correct answer: it’s very complicated and we don’t know), and the ever-present fMRI studies hyped in the news (I’ve been guilty of a few of those, though I try very hard to be skeptical). Both pieces referenced the excellent Neuroskeptic and Neurocritic (though sadly, the NYT didn’t give them the links they definitely deserve). And both pieces warned that neuroscience is more, and better than, the gee-whiz of “This is your brain on poker“. I particularly liked the New Yorker piece, for making clear the incredible complexity of the human brain. The brain, though, rarely works that way. Most of the interesting things that the brain does involve many different pieces of tissue working together. Saying that emotion is in the amygdala, or that decision-making is the prefrontal cortex, is at best a shorthand, and a misleading one at that. Different emotions, for example, rely on different combinations of neural substrates. The act of comprehending a sentence likely involves Broca’s area (the language-related spot on the left side of the brain that they may have told you about in college), but it also draws on the parts of the brain in the temporal lobe that analyze acoustic signals, and part of sensorimotor cortex and the basal ganglia become active as well. (In congenitally blind people, some of the visual cortex also plays a role.) It’s not one spot, it’s many, some of which may be less active but still vital, and what really matters is how vast networks of neural tissue work together. © 2012 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17568 - Posted: 12.04.2012

Posted by Gary Marcus In the early nineteen-nineties, David Poeppel, then a graduate student at M.I.T. (and a classmate of mine)—discovered an astonishing thing. He was studying the neurophysiological basis of speech perception, and a new technique had just come into vogue, called positron emission tomography (PET). About half a dozen PET studies of speech perception had been published, all in top journals, and David tried to synthesize them, essentially by comparing which parts of the brain were said to be active during the processing of speech in each of the studies. What he found, shockingly, was that there was virtually no agreement. Every new study had published with great fanfare, but collectively they were so inconsistent they seemed to add up to nothing. It was like six different witnesses describing a crime in six different ways. This was terrible news for neuroscience—if six studies led to six different answers, why should anybody believe anything that neuroscientists had to say? Much hand-wringing followed. Was it because PET, which involves injecting a radioactive tracer into the brain, was unreliable? Were the studies themselves somehow sloppy? Nobody seemed to know. And then, surprisingly, the field prospered. Brain imaging became more, not less, popular. The technique of PET was replaced with the more flexible technique of functional magnetic resonance imaging (fMRI), which allowed scientists to study people’s brains without the use of the risky radioactive tracers, and to conduct longer studies that collected more data and yielded more reliable results. Experimental methods gradually become more careful. As fMRI machines become more widely available, and methods became more standardized and refined, researchers finally started to find a degree of consensus between labs. © 2012 Condé Nast.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17567 - Posted: 12.04.2012

By ALISSA QUART THIS fall, science writers have made sport of yet another instance of bad neuroscience. The culprit this time is Naomi Wolf; her new book, “Vagina,” has been roundly drubbed for misrepresenting the brain and neurochemicals like dopamine and oxytocin. Earlier in the year, Chris Mooney raised similar ire with the book “The Republican Brain,” which claims that Republicans are genetically different from — and, many readers deduced, lesser to — Democrats. “If Mooney’s argument sounds familiar to you, it should,” scoffed two science writers. “It’s called ‘eugenics,’ and it was based on the belief that some humans are genetically inferior.” Sharp words from disapproving science writers are but the tip of the hippocampus: today’s pop neuroscience, coarsened for mass audiences, is under a much larger attack. Meet the “neuro doubters.” The neuro doubter may like neuroscience but does not like what he or she considers its bastardization by glib, sometimes ill-informed, popularizers. A gaggle of energetic and amusing, mostly anonymous, neuroscience bloggers — including Neurocritic, Neuroskeptic, Neurobonkers and Mind Hacks — now regularly point out the lapses and folly contained in mainstream neuroscientific discourse. This group, for example, slammed a recent Newsweek article in which a neurosurgeon claimed to have discovered that “heaven is real” after his cortex “shut down.” Such journalism, these critics contend, is “shoddy,” nothing more than “simplified pop.” Additionally, publications from The Guardian to the New Statesman have published pieces blasting popular neuroscience-dependent writers like Jonah Lehrer and Malcolm Gladwell. The Oxford neuropsychologist Dorothy Bishop’s scolding lecture on the science of bad neuroscience was an online sensation last summer. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17524 - Posted: 11.24.2012