Links for Keyword: Brain imaging

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by Helen Thomson Zapping your brain might make you better at maths tests – or worse. It depends how anxious you are about taking the test in the first place. A recent surge of studies has shown that brain stimulation can make people more creative and better at maths, and can even improve memory, but these studies tend to neglect individual differences. Now, Roi Cohen Kadosh at the University of Oxford and his colleagues have shown that brain stimulation can have completely opposite effects depending on your personality. Previous research has shown that a type of non-invasive brain stimulation called transcranial direct current stimulation (tDCS) – which enhances brain activity using an electric current – can improve mathematical ability when applied to the dorsolateral prefrontal cortex, an area involved in regulating emotion. To test whether personality traits might affect this result, Kadosh's team tried the technique on 25 people who find mental arithmetic highly stressful, and 20 people who do not. They found that participants with high maths anxiety made correct responses more quickly and, after the test, showed lower levels of cortisol, an indicator of stress. On the other hand, individuals with low maths anxiety performed worse after tDCS. "It is hard to believe that all people would benefit similarly [from] brain stimulation," says Cohen Kadosh. He says that further research could shed light on how to optimise the technology and help to discover who is most likely to benefit from stimulation. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 20406 - Posted: 12.10.2014

Ian Sample, science editor Electrical brain stimulation equipment – which can boost cognitive performance and is easy to buy online – can have bad effects, impairing brain functioning, research from scientists at Oxford University has shown. A steady stream of reports of stimulators being able to boost brain performance, coupled with the simplicity of the devices, has led to a rise in DIY enthusiasts who cobble the equipment together themselves, or buy it assembled on the web, then zap themselves at home. In science laboratories brain stimulators have long been used to explore cognition. The equipment uses electrodes to pass gentle electric pulses through the brain, to stimulate activity in specific regions of the organ. Roi Cohen Kadosh, who led the study, published in the Journal of Neuroscience, said: “It’s not something people should be doing at home at this stage. I do not recommend people buy this equipment. At the moment it’s not therapy, it’s an experimental tool.” The Oxford scientists used a technique called transcranial direct current stimulation (tDCS) to stimulate the dorsolateral prefrontal cortex in students as they did simple sums. The results of the test were surprising. Students who became anxious when confronted with sums became calmer and solved the problems faster than when they had sham stimulation (the stimulation itself lasted only 30 seconds of the half hour study). The shock was that the students who did not fear maths performed worse with the same stimulation.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 20405 - Posted: 12.10.2014

|By Ryan Bradley Five years ago Viviana Gradinaru was slicing thin pieces of mouse brain in a neurobiology lab, slowly compiling images of the two-dimensional slivers for a three-dimensional computer rendering. In her spare time, she would go to see the Body Worlds exhibit. She was especially fascinated by the “plasticized” remains of the human circulatory system on display. It struck her that much of what she was doing in the lab could be done more efficiently with a similar process. “Tissue clearing” has been around for more than a century, but existing methods involve soaking tissue samples in solvents, which is slow and usually destroys the fluorescent proteins necessary for marking certain cells of interest. To create a better approach, Gradinaru, at the time a graduate student, and her colleagues in neuroscientist Karl Deisseroth's lab focused on replacing the tissue's lipid molecules, which make it opaque.* To keep the tissue from collapsing, however, the replacement would need to give it structure, as lipids do. The first step was to euthanize a rodent and pump formaldehyde into its body, through its heart. Next they removed the skin and filled its blood vessels with acrylamide monomers, white, odorless, crystalline compounds. The monomers created a supportive hydrogel mesh, replacing the lipids and clearing the tissue. Before long, they could render an entire mouse body transparent in two weeks. Soon they were using transparent mice to map complete mouse nervous systems. The transparency made it possible for them to identify peripheral nerves—tiny bundles of nerves that are poorly understood—and to map the spread of viruses across the mouse's blood-brain barrier, which they did by marking the virus with a fluorescent agent, injecting it into the mouse's tail and watching it spread into the brain. © 2014 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: 20382 - Posted: 12.03.2014

by Linda Geddes A tapeworm that usually infects dogs, frogs and cats has made its home inside a man's brain. Sequencing its genome showed that it contains around 10 times more DNA than any other tapeworm sequenced so far, which could explain its ability to invade many different species. When a 50-year-old Chinese man was admitted to a UK hospital complaining of headaches, seizures, an altered sense of smell and memory flashbacks, his doctors were stumped. Tests for tuberculosis, syphilis, HIV and Lyme disease were negative, and although an MRI scan showed an abnormal region in the right side of his brain, a biopsy found inflammation, but no tumour. Over the next four years, further MRIs recorded the abnormal region moving across the man's brain (see animation), until finally his doctors decided to operate. To their immense surprise, they pulled out a 1 centimetre-long ribbon-shaped worm. It looked like a tapeworm, but was unlike any seen before in the UK, so a sample of its tissue was sent to Hayley Bennett and her colleagues at the Wellcome Trust Sanger Institute in Cambridge, UK. Genetic sequencing identified it as Spirometra erinaceieuropaei, a rare species of tapeworm found in China, South Korea, Japan and Thailand. Just 300 human infections have been reported since 1953, and not all of them in the brain. © Copyright Reed Business Information Ltd.

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: 20344 - Posted: 11.21.2014

By Neuroskeptic An attempt to replicate the results of some recent neuroscience papers that claimed to find correlations between human brain structure and behavior has drawn a blank. The new paper is by University of Amsterdam researchers Wouter Boekel and colleagues and it’s in press now at Cortex. You can download it here from the webpage of one of the authors, Eric-Jan Wagenmakers. Neuroskeptic readers will know Wagenmakers as a critic of statistical fallacies in psychology and a leading advocate of preregistration, which is something I never tire of promoting either. Boekel et al. attempted to replicate five different papers which, together, reported 17 distinct positive results in the form of structural brain-behavior (‘SBB’) correlations. An SBB correlation is an association between the size (usually) of a particular brain area and a particular behavioral trait. For instance, one of the claims was that the amount of grey matter in the amygdala is correlated with the number of Facebook friends you have. To attempt to reproduce these 17 findings, Boekel et al. took 36 students whose brains were scanned with two methods, structural MRI and DWI. The students then completed a set of questionnaires and psychological tests, identical to ones used in the five papers that were up for replication. The methods and statistical analyses were fully preregistered (back in June 2012); Boekel et al. therefore had no scope for ‘fishing’ for positive (or negative) results by tinkering with the methodology. So what did they find? Nothing much. None of the 17 brain-behavior correlations were significant in the replication sample.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 1: An Introduction to Brain and Behavior
Link ID: 20330 - Posted: 11.20.2014

|By Bret Stetka The brain is protected by formidable defenses. In addition to the skull, the cells that make up the blood-brain barrier keep pathogens and toxic substances from reaching the central nervous system. The protection is a boon, except when we need to deliver drugs to treat illnesses. Now researchers are testing a way to penetrate these bastions: sound waves. Kullervo Hynynen, a medical physicist at Sunnybrook Research Institute in Toronto, and a team of physicians are trying out a technique that involves giving patients a drug followed by an injection of microscopic gas-filled bubbles. Next patients don a cap that directs sound waves to specific brain locations, an approach called high-intensity focused ultrasound. The waves cause the bubbles to vibrate, temporarily forcing apart the cells of the blood-brain barrier and allowing the medication to infiltrate the brain. Hynynen and his colleagues are currently testing whether they can use the method to deliver chemotherapy to patients with brain tumors. They and other groups are planning similar trials for patients with other brain disorders, including Alzheimer's disease. Physicians are also considering high-intensity focused ultrasound as an alternative to brain surgery. Patients with movement disorders such as Parkinson's disease and dystonia are increasingly being treated with implanted electrodes, which can interrupt problematic brain activity. A team at the University of Virginia hopes to use focused ultrasound to deliver thermal lesions deep into the brain without having patients go under the knife. © 2014 Scientific American

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 20318 - Posted: 11.17.2014

By JAMES GORMAN Research on the brain is surging. The United States and the European Union have launched new programs to better understand the brain. Scientists are mapping parts of mouse, fly and human brains at different levels of magnification. Technology for recording brain activity has been improving at a revolutionary pace. The National Institutes of Health, which already spends $4.5 billion a year on brain research, consulted the top neuroscientists in the country to frame its role in an initiative announced by President Obama last year to concentrate on developing a fundamental understanding of the brain. Scientists have puzzled out profoundly important insights about how the brain works, like the way the mammalian brain navigates and remembers places, work that won the 2014 Nobel Prize in Physiology or Medicine for a British-American and two Norwegians. So many large and small questions remain unanswered. How is information encoded and transferred from cell to cell or from network to network of cells? Science found a genetic code but there is no brain-wide neural code; no electrical or chemical alphabet exists that can be recombined to say “red” or “fear” or “wink” or “run.” And no one knows whether information is encoded differently in various parts of the brain. Brain scientists may speculate on a grand scale, but they work on a small scale. Sebastian Seung at Princeton, author of “Connectome: How the Brain’s Wiring Makes Us Who We Are,” speaks in sweeping terms of how identity, personality, memory — all the things that define a human being — grow out of the way brain cells and regions are connected to each other. But in the lab, his most recent work involves the connections and structure of motion-detecting neurons in the retinas of mice. Larry Abbott, 64, a former theoretical physicist who is now co-director, with Kenneth Miller, of the Center for Theoretical Neuroscience at Columbia University, is one of the field’s most prominent theorists, and the person whose name invariably comes up when discussions turn to brain theory. © 2014 The New York Times Company

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: 20302 - Posted: 11.11.2014

Mo Costandi The father of modern neuroscience had a sharp eye and an even sharper mind, but he evidently overlooked something rather significant about the basic structure of brain cells. Santiago Ramón y Cajal spent his entire career examining and comparing nervous tissue from different species. He observed the intricate branches we now call dendrites, and the thicker axonal fibres. He also recognised them as distinct components of the neuron, and convinced others that neurons are fundamental components of the nervous system. For Cajal, these cells were “the mysterious butterflies of the soul… whose beating of wings may one day reveal to us the secrets of the mind.” He hunted for them in “the gardens of the grey matter” and, being an accomplished artist, meticulously catalogued the many “delicate and elaborate forms” that they take. As his beautiful drawings show, all neurons have a single axon emanating from one area of the cell body, and one or more dendrites arising from another. This basic structure has been enshrined in textbooks ever since. But there appear to be unusual varieties of soul butterflies that Cajal failed to spot – neuroscientists in Germany have identified neurons that have axons growing from their dendrites, a discovery that challenges our century-old assumption about the form and function of these cells. Cajal stated that information flows through neurons in only one direction – from the dendrites, which receive electrical impulses from other neurons, to the cell body, which processes the information and conveys it to the initial segment of the axon, which then produces its own impulses that travel down it to the nerve terminal. (He indicated this with small arrows in some of his diagrams, such as the one above.) © 2014 Guardian News and Media Limited

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: 20301 - Posted: 11.11.2014

By Amy Robinson Whether you’re walking, talking or contemplating the universe, a minimum of tens of billions of synapses are firing at any given second within your brain. “The weak link in understanding ourselves is really about understanding how our brains generate our minds and how our minds generate our selves,” says MIT neuroscientist Ed Boyden. One cubic millimeter in the brain contains over 100,000 neurons connected through a billion synapses computing on a millisecond timescale. To understand how information flows within these circuits, we first need a “brain parts” list of neurons and glia. But such a list is not enough. We’ll also need to chart how cells are connected and to monitor their activity over time both electrically and chemically. Researchers can do this at small scale thanks to a technology developed in the 1970s called patch clamping. Bringing a tiny glass needle very near to a neuron living within a brain allows researchers to perform microsurgery on single neurons, piercing the cell membrane to do things like record the millivolt electrical impulses flowing through it. Patch clamping also facilitates measurement of proteins contained within the cell, revealing characteristic molecules and contributing to our understanding of why one neuron may behave differently than another. Neuroscientists can even inject glowing dyes in order to see the shape of cells. Patch clamping is a technique that has been used in neuroscience for 40 years. Why now does it make an appearance as a novel neuroscience technology? In a word: robots. © 2014 Scientific American

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 20279 - Posted: 11.05.2014

James Gorman Here is something to keep arachnophobes up at night. The inside of a spider is under pressure, like the air in a balloon, because spiders move by pushing fluid through valves. They are hydraulic. This works well for the spiders, but less so for those who want to study what goes on in the brain of a jumping spider, an aristocrat of arachnids that, according to Ronald R. Hoy, a professor of neurobiology and behavior at Cornell University, is one of the smartest of all invertebrates. If you insert an electrode into the spider’s brain, what’s inside might squirt out, and while that is not the kind of thing that most people want to think about, it is something that the researchers at Cornell had to consider. Dr. Hoy and his colleagues wanted to study jumping spiders because they are very different from most of their kind. They do not wait in a sticky web for lunch to fall into a trap. They search out prey, stalk it and pounce. “They’ve essentially become cats,” Dr. Hoy said. And they do all this with a brain the size of a poppy seed and a visual system that is completely different from that of a mammal: two big eyes dedicated to high-resolution vision and six smaller eyes that pick up motion. Dr. Hoy gathered four graduate students in various disciplines to solve the problem of recording activity in a jumping spider’s brain when it spots something interesting — a feat nobody had accomplished before. In the end, they not only managed to record from the brain, but discovered that one neuron seemed to be integrating the information from the spider’s two independent sets of eyes, a computation that might be expected to involve a network of brain cells. © 2014 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 20277 - Posted: 11.04.2014

by Clare Wilson Call them the neuron whisperers. Researchers are eavesdropping on conversations going on between brain cells in a dish. Rather than hearing the chatter, they watch neurons that have been genetically modified so that the electrical impulses moving along their branched tendrils cause sparkles of red light (see video). Filming these cells at up to 100,000 frames a second is allowing researchers to analyse their firing in unprecedented detail. Until recently, a neuron's electrical activity could only be measured with tiny electrodes. As well as being technically difficult, such "patch clamping" only reveals the voltage at those specific points. The new approach makes the neuron's entire surface fluoresce as the impulse passes by. "Now we see the whole thing sweep through," says Adam Cohen of Harvard University. "We get much more information - like how fast and where does it start and what happens at a branch." The idea is a reverse form of optogenetics – where neurons are given a gene from bacteria that make a light-sensitive protein, so the cells fire when illuminated. The new approach uses genes that make the neurons do the opposite - glow when they fire. "It's pretty cool," says Dimitri Kullmann of University College London. "It's amazing that you can dispense with electrodes." Cohen's team is using the technique to compare cells from typical brains with those from people with disorders such as motor neuron disease or amyotrophic lateral sclerosis. Rather than taking a brain sample, they remove some of the person's skin cells and grow them alongside chemicals that rewind the cells into an embryonic-like state. Another set of chemicals is used to turn these stem cells into neurons. "You can recreate something reminiscent of the person's brain in the dish," says Cohen. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 20241 - Posted: 10.25.2014

by Helen Thomson For the first time, doctors have opened and closed the brain's protector – the blood-brain barrier – on demand. The breakthrough will allow drugs to reach diseased areas of the brain that are otherwise out of bounds. Ultimately, it could make it easier to treat conditions such as Alzheimer's and brain cancer. The blood-brain barrier (BBB) is a sheath of cells that wraps around blood vessels (in black) throughout the brain. It protects precious brain tissue from toxins in the bloodstream, but it is a major obstacle for treating brain disorders because it also blocks the passage of drugs. Several teams have opened the barrier in animals to sneak drugs through. Now Michael Canney at Paris-based medical start-up CarThera, and his colleagues have managed it in people using an ultrasound brain implant and an injection of microbubbles. When ultrasound waves meet microbubbles in the blood, they make the bubbles vibrate. This pushes apart the cells of the BBB. With surgeon Alexandre Carpentier at Pitié-Salpêtrière Hospital in Paris, Canney tested the approach in people with a recurrence of glioblastoma, the most aggressive type of brain tumour. People with this cancer have surgery to remove the tumours and then chemotherapy drugs, such as Carboplatin, are used to try to kill any remaining tumour cells. Tumours make the BBB leaky, allowing in a tiny amount of chemo drugs: if more could get through, their impact would be greater, says Canney. © Copyright Reed Business Information Ltd.

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: 20235 - Posted: 10.23.2014

By Erin Allday When the United States’ top public health and political leaders declared the 1990s the “decade of the brain,” Dr. Pratik Mukherjee couldn’t help but feel a little dubious. “I was kind of laughing, because I didn’t think we’d make much progress in just a decade,” said Mukherjee, a neuro-radiologist at UCSF. Twenty-four years later, Mukherjee said he and his peers around the country are primed to plunge into what he’d like to call the century of the brain — a deep dive into the basic biology and mechanics of the impossibly complex organ that controls our every thought, action, behavior and mood. The National Institutes of Health last week announced $47 million in grants as part of President Obama’s Brain Initiative, a project announced 18 months ago to, in the simplest language, reverse-engineer the human brain. The grants were among the first in a roughly 11-year plan that could cost more than $3 billion. Most of the projects are in developing new technologies to help map the brain and study its mechanics — how cells communicate, what makes them turn on and off, and how large regions of the brain interact, for example. Ultimately, scientists hope these tools will help the next generation of neuroscientists solve the brain-centric disorders — from autism and Alzheimer’s to depression and schizophrenia — that have confounded doctors for centuries.

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: 20183 - Posted: 10.09.2014

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,

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 20179 - Posted: 10.08.2014

|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

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: 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

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

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: 20137 - Posted: 09.30.2014

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.

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: 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.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 5: The Sensorimotor System
Link ID: 20068 - Posted: 09.12.2014

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,

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 20067 - Posted: 09.12.2014