Chapter 2. Cells and Structures: The Anatomy of the Nervous System

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By GREGORY HICKOK IN the early 19th century, a French neurophysiologist named Pierre Flourens conducted a series of innovative experiments. He successively removed larger and larger portions of brain tissue from a range of animals, including pigeons, chickens and frogs, and observed how their behavior was affected. His findings were clear and reasonably consistent. “One can remove,” he wrote in 1824, “from the front, or the back, or the top or the side, a certain portion of the cerebral lobes, without destroying their function.” For mental faculties to work properly, it seemed, just a “small part of the lobe” sufficed. Thus the foundation was laid for a popular myth: that we use only a small portion — 10 percent is the figure most often cited — of our brain. An early incarnation of the idea can be found in the work of another 19th-century scientist, Charles-Édouard Brown-Séquard, who in 1876 wrote of the powers of the human brain that “very few people develop very much, and perhaps nobody quite fully.” But Flourens was wrong, in part because his methods for assessing mental capacity were crude and his animal subjects were poor models for human brain function. Today the neuroscience community uniformly rejects the notion, as it has for decades, that our brain’s potential is largely untapped. The myth persists, however. The newly released movie “Lucy,” about a woman who acquires superhuman abilities by tapping the full potential of her brain, is only the latest and most prominent expression of this idea. Myths about the brain typically arise in this fashion: An intriguing experimental result generates a plausible if speculative interpretation (a small part of the lobe seems sufficient) that is later overextended or distorted (we use only 10 percent of our brain). The caricature ultimately infiltrates pop culture and takes on a life of its own, quite independent from the facts that spawned it. © 2014 The New York Times Company

Keyword: Brain imaging; Aggression
Link ID: 19911 - Posted: 08.02.2014

By Emily Underwood Scientists don’t need superpowers to see through solid objects. For organs such as the brain, they have CLARITY, a technique for rendering tissue transparent by perfusing it with gel, then washing out the fatty molecules that make tissues opaque. Now, researchers have sped up the process, clearing whole rodent bodies within 2 weeks to create the transparent mice pictured above. Previously, it took that amount of time to clear a single mouse brain by soaking it in a bath of clearing chemicals. To accelerate the process, scientists delivered the gel and clearing agents directly into the bloodstreams of dead mice, clearing their kidneys, hearts, lungs, and intestines within days and their entire brains and bodies within weeks. Of what use is a see-through mouse corpse once completed? In a paper published online today in Cell, researchers say their new technique will allow them to map anatomical connections between the brain and body in unprecedented detail. © 2014 American Association for the Advancement of Science

Keyword: Brain imaging
Link ID: 19908 - Posted: 08.02.2014

by Douglas Heaven Hijacking how neurons of nematode worms are wired is the first step in an approach that could revolutionise our understanding of brains and consciousness CALL it the first brain hack. The humble nematode worm has had its neural connections hot-wired, changing the way it responds to salt and smells. As well as offering a way to create souped-up organisms, changing neural connectivity could one day allow us to treat brain damage in people by rerouting signals around damaged neurons. What's more, it offers a different approach to probing brain mysteries such as how consciousness arises from wiring patterns – much like exploring the function of an electronic circuit by plugging and unplugging cables. In our attempts to understand the brain, a lot of attention is given to neurons. A technique known as optogenetics, for example, lets researchers study the function of individual neurons by genetically altering them so they can be turned on and off by a light switch. But looking at the brain's connections is as important as watching the activity of neurons. Higher cognitive functions, such as an awareness of our place in the world, do not spring from a specific area, says Fani Deligianni at University College London. Deligianni and her colleagues are developing imaging techniques to map the brain's connections, as are other groups around the world (see "Start with a worm..."). "From this we can begin to answer some of the big questions about the workings of the brain and consciousness which seem to depend on connectivity," she says. Tracing how the brain is wired is a great first step but to find out how this linking pattern produces a particular behaviour we need to be able to see how changing these links affects brain function. This is what a team led by William Schafer at the MRC Laboratory of Molecular Biology in Cambridge, UK, is attempting. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Aggression
Link ID: 19877 - Posted: 07.24.2014

by Richard Frackowiak "A GRASS roots effort is under way to stop the project... 'Mediocre science, terrible science policy,' begins the spirited letter..." The year was 1990 and the journal Science was reporting on what it called a "backlash" against the Human Genome Project. Given the furore this past week you could be forgiven for thinking these words were written about another big science initiative: the Human Brain Project (HBP). Less than a year into its planned 10-year lifetime, the project was publicly criticised in an open letter posted online on 7 July, signed by more than 150 scientists. At the time of writing a further 400 individuals have added their names. The Human Genome Project weathered its criticisms and reached its goal in 2003, birthing the entire field of genomics and opening new medical, scientific and commercial avenues along the way. The Human Brain Project will similarly overcome its own teething troubles and catalyse a methodological paradigm shift towards unified brain research that weaves together neuroscience, computing and medicine. The goal of the HBP is a comprehensive understanding of brain structure and function through the development and use of computing tools. This is popularly deemed a "simulation of the whole human brain" but we prefer the analogy "CERN for the brain" (after Europe's premier particle physics lab): a large facility for diverse experiments and sharing of knowledge with a common goal of unlocking the most complex structure in the known universe. This brings me to two of the criticisms in the open letter: the apparent lack of experimental neuroscience and data generation in the HBP, and the emphasis on information and communications technologies (ICT) in what is billed as a neuroscience project. I will address a third criticism regarding funding later on. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 19842 - Posted: 07.17.2014

By Jonathan Webb Science reporter, BBC News After leaders of the billion-euro Human Brain Project hit back at critics, six top neuroscientists have expressed "dismay" at their public response. Last week an open message, signed by over 600 researchers, said the HBP was "not on course", demanding a review. An official reply said HBP members were "saddened" by the protest but Prof Henry Markram, the project's chair, has labelled it a personal crusade. In a letter to Nature, the six authors call for a more "open-minded attitude". They did not sign the original protest letter, but are disappointed by the publicly reported stance of the HBP leadership. "Instead of acknowledging that there is a problem and genuinely seeking to address scientists' concerns, the project leaders seem to be of the opinion that the letter's 580 signatories [now over 600] are misguided," wrote Prof Richard Morris, an eminent neuroscientist from the University of Edinburgh, and five colleagues. The six correspondents describe themselves as "neuroscientists in Europe who care about the success of research projects large and small in our field". Prof Richard Frackowiak, a co-executive director of the HBP, told the BBC he "strongly objects" to the idea that the project leaders were dismissive. "We've taken this extremely seriously," he said. The HBP is one of two flagship technology projects (the other being graphene research) announced in January 2013 by the European Commission (EC). BBC © 2014

Keyword: Brain imaging
Link ID: 19841 - Posted: 07.17.2014

Posted by alison abbott Cautious efforts to restore unity to the billion-euro Human Brain Project have begun. Both the European Commission and the project’s leaders have now responded to a scorching open letter in which angry neuroscientists condemn the flagship project, and pledge to boycott it. Signed by 156 top neuroscientists, including many research institute directors in Europe, the letter was sent on 7 July to the European Commission, which is funding the project’s first phase. It expresses concern about both the scientific approach in the neuroscience arm of the project, which aims to simulate brain function in supercomputers, and the general project management. The letter makes a series of demands for changes that it claims are needed to make the management and governance of the Human Brain Project more transparent and representative of the scientific views of the whole community. Since it was sent, a further 408 neuroscientists have added their signatures. On 10 July, the European Commission sent a bland statement to Nature, stating that “it is too early to draw conclusions on the success or failure of the project”, given that it has only been running for nine months. The Commission’s response also says that a “divergence of views” is not unusual in large-scale projects, particularly at their beginnings and that the Commission will “continue to engage with all partners in this ambitious project”. © 2014 Macmillan Publishers Limited

Keyword: Brain imaging
Link ID: 19821 - Posted: 07.14.2014

By GARY MARCUS ARE we ever going to figure out how the brain works? After decades of research, diseases like schizophrenia and Alzheimer’s still resist treatment. Despite countless investigations into serotonin and other neurotransmitters, there is still no method to cure clinical depression. And for all the excitement about brain-imaging techniques, the limitations of fMRI studies are, as evidenced by popular books like “Brainwashed” and “Neuromania,” by now well known. In spite of the many remarkable advances in neuroscience, you might get the sinking feeling that we are not always going about brain science in the best possible way. This feeling was given prominent public expression on Monday, when hundreds of neuroscientists from all over the world issued an indignant open letter to the European Commission, which is funding the Human Brain Project, an approximately $1.6 billion effort that aims to build a complete computer simulation of the human brain. The letter charges that the project is “overly narrow” in approach and not “well conceived.” While no neuroscientist doubts that a faithful-to-life brain simulation would ultimately be tremendously useful, some have called the project “radically premature.” The controversy serves as a reminder that we scientists are not only far from a comprehensive explanation of how the brain works; we’re also not even in agreement about the best way to study it, or what questions we should be asking. The European Commission, like the Obama administration, which is promoting a large-scale research enterprise called the Brain Initiative, is investing heavily in neuroscience, and rightly so. (A set of new tools such as optogenetics, which allows neuroscientists to control the activity of individual neurons, gives considerable reason for optimism.) But neither project has grappled sufficiently with a critical question that is too often ignored in the field: What would a good theory of the brain actually look like? Different kinds of sciences call for different kinds of theories. Physicists, for example, are searching for a “grand unified theory” that integrates gravity, electromagnetism and the strong and weak nuclear forces into a neat package of equations. Whether or not they will get there, they have made considerable progress, in part because they know what they are looking for. © 2014 The New York Times Company

Keyword: Brain imaging
Link ID: 19818 - Posted: 07.12.2014

By JOSHUA A. KRISCH The Human Brain Project is Europe’s flagship contribution to neuroscience. Established last year and funded by the European Commission, the project was meant to rally scientists and computer engineers around developing better tools to study how the brain works. But its most ambitious goal — a computer simulation of the entire brain — came under attack on Monday when hundreds of neuroscientists from around the world sent an open letter to the commission condemning what they see as an absence of feasibility and transparency. The letter said that the project’s “overly narrow approach” threatened to set Europe back in terms of its scientific progress and its investment, about $130 million a year over the next 10 years. “It’s like a moonshot, but before we knew how to build an airplane,” said Zachary Mainen, a neuroscientist at the Champalimaud Center for the Unknown, in Lisbon, and an author of the letter. “We can’t simulate the 302 neurons in a nematode brain. It’s a bit premature to simulate the 100 billion neurons in a human brain.” The letter expressed concern over the recent dissolution of the project’s Cognitive Architectures branch, which would have explored the larger behavioral implications of the research. “It’s the departure of the entire cognitive neuroscience aspect of the H.B.P.,” Dr. Mainen said. “It’s not clear why they would throw that out.” Henry Markram, a neuroscientist at the Swiss Federal Institute of Technology and the director of the Human Brain Project, said he considered the letter “a big wake-up call.” © 2014 The New York Times Company

Keyword: Brain imaging
Link ID: 19807 - Posted: 07.09.2014

Europe’s ambitious project to unpick the workings of the human brain faces a crisis less than a year after it was launched with great fanfare at the Swiss Federal Institute of Technology (EPFL) in Lausanne. Some neuroscientists involved in the billion-euro Human Brain Project (HBP) are furious that much of their research into how the brain executes its cognitive functions is to be sidelined as the initiative enters its next phase. Arguments over the strategy and direction of mega-science projects are nothing new. But the acrimony over this project is particularly unfortunate, given its status as one of two European Union (EU) flagship programmes designed to cross some of the widest interdisciplinary barriers and solve societal problems — such as brain disease. Already, some leading scientists have walked away. If more follow, the project could waste a golden opportunity to understand the brain. Dissent in the ranks about what the project should encompass and who should decide this has been raging for months. But it peaked in late May, when the project’s leaders made clear that they intended to exclude studies on cognition from their core future plans. The first funding, or ‘ramp-up’, phase of the brain project began in October last year with €54 million (US$73 million) from the European Commissionand is scheduled to run for three years. The second phase of the ten-year project will be funded to the tune of around €100 million per year for two or three years. But in their detailed plans for this second stage, submitted on 10 June to the commission for approval, the project managers eliminated research on human cognitive architecture. © 2014 Nature Publishing Group

Keyword: Brain imaging
Link ID: 19806 - Posted: 07.09.2014

Alison Abbott The European Union’s high-profile, €1-billion Human Brain Project (HBP), launched last October, has come under fire from neuroscientists, who claim that poor management has run part of the effort’s scientific plans off course. Around 150 scientists have signed a protest letter that was delivered to the European Commission on 7 July. The letter requests that the commission seriously consider whether the project is still fit for purpose as it reviews proposals for the second round of funding, to be awarded in 2016. The HBP was originally designed to promote digital technologies by supporting and learning from neuroscience. A key element of the project, which has inspired other brain-research initiatives around the world (see Nature 503, 26–28; 2013), is to develop supercomputers that neuroscientists will use to try to simulate the brain. But as the initiative has developed, its goal has become more and more diffuse. And after months of often fractious discussions about the programme’s scientific scope, tempers boiled over at the end of May, when the HBP’s three-man executive board decided to cut parts of the project, including one on cognitive neuroscience, from the second phase — in a manner that the signatories say was autocratic and scientifically inappropriate. Stanislas Dehaene, director of the Cognitive Neuroimaging Unit run by the French Institute of Health and Medical Research (INSERM) and the French Alternative Energies and Atomic Energy Commission (CEA) in Paris and one of the winners of this year’s prestigious Brain Prize, had led this part of the effort. On 30 May, he withdrew his participation from the second phase, citing lack of confidence in some of the decisions being made and in the programme’s management; he has not signed the letter. © 2014 Nature Publishing Group

Keyword: Brain imaging
Link ID: 19803 - Posted: 07.08.2014

BY Jenny Marder and Rebecca Jacobson Scientists at the NIH are mapping the activity of thousands of individual neurons inside the brain of a zebrafish as the animal hunts for food. In a small, windowless room that houses two powerful electron microscopes, a scientist is searching for the perfect fish brain. As the massive machines hum nearby, two gigantic fish eyes loom large, taking up most of a computer screen. The magnified perspective is misleading. The zebrafish is a larva, a newborn, just one week old, and barely six millimeters long. On the screen, it looks grumpy, like it’s frowning. Chris Harris, a postdoctoral researcher at the lab, is scrolling through the image. As he zooms in, the eyes become even larger and then disappear altogether, replaced by a glimpse of what lies within and behind them in its brain: a jungle of axons and dendrites and cell bodies — all the stuff that makes up individual neurons. He traces the outer edge of one of the cells with a gloved finger. “This layer is the nuclear membrane,” he says. “And just outside of that is the cell body membrane itself.” He points out the mitochondria, the individual axons, which send nerve impulses from one neuron to the next; the branching dendrites, which receive signals; and thick black dots that represent synaptic vesicles — pouches that hold neurotransmitters, or brain chemicals. © 1996 - 2014 MacNeil / Lehrer Productions.

Keyword: Brain imaging
Link ID: 19792 - Posted: 07.04.2014

By Gary Stix Tony Zador: The human brain has 100 billion neurons, a mouse brain has maybe 100 million. What we’d really like to understand is how we go from a bunch of neurons to thought, feelings, behavior. We think that the key is to understand how the different neurons are connected to one another. So traditionally there have been a lot of techniques for studying connectivity but at a fairly crude level. We can, for instance, tell that a bunch of neurons here tend to be connected to a bunch of neurons there. There are also techniques for looking at how single neurons are connected but only for individual links between those neurons. What we would love to be able to do is to tell how every single neuron in the brain is connected to every single other neuron in the brain. So if you wanted to navigate through the United States, one of the most useful things you could have is a roadmap. It wouldn’t tell you everything about the United States, but it would be very hard to get around without a complete roadmap of the country. We need something like that for the brain. Zador: Traditionally the way people study connectivity is as a branch of microscopy. Typically what people do is they use one method or another to label a neuron and then they observe that neuron at some level of resolution. But the challenge that’s at the core of all the microscopy techniques is that neurons can extend long distances. That might be millimeters in a mouse brain or, in fact, in a giraffe brain, there are neurons that go all the way from the brain to its foot, which can be over 15 feet. Brain cells are connected with one another at structures called synapses, which are below the resolution of light microscopy. That means that if you really want to understand how one neuron is connected to another, you need to resolve the synapse, which requires electron microscopy. You have to take incredibly thin sections of brain and then image them. © 2014 Scientific American

Keyword: Autism; Aggression
Link ID: 19769 - Posted: 06.25.2014

Helen Shen As US science agencies firm up plans for a national ten-year neuroscience initiative, California is launching an ambitious project of its own. On 20 June, governor Jerry Brown signed into law a state budget that allocates US$2 million to establish the California Blueprint for Research to Advance Innovations in Neuroscience (Cal-BRAIN) project. Cal-BRAIN is the first state-wide programme to piggyback on the national Brain Research through Advancing Innovative Neurotechnologies (BRAIN) initiative announced by US President Barack Obama in April 2013 (see Nature 503, 26–28; 2013). The national project is backed this year by $110 million in public funding from the National Institutes of Health (NIH), the Defense Advanced Research Projects Agency (DARPA) and the National Science Foundation (NSF). California researchers and lawmakers hope that the state’s relatively modest one-time outlay will pave the way for a larger multiyear endeavour that gives its scientists an edge in securing grants from the national initiative. “It’s a drop in the bucket, but it’s an important start,” says Zack Lynch, executive director of the Neurotechnology Industry Organization, an advocacy group in San Francisco, California. Cal-BRAIN sets itself apart from the national effort by explicitly seeking industry involvement. The proposal emphasizes the potential economic benefits of neuroscience research and calls for the formation of a programme to facilitate the translation of any discoveries into commercial applications. © 2014 Nature Publishing Group,

Keyword: Brain imaging
Link ID: 19768 - Posted: 06.25.2014

Carl Zimmer A novelist scrawling away in a notebook in seclusion may not seem to have much in common with an NBA player doing a reverse layup on a basketball court before a screaming crowd. But if you could peer inside their heads, you might see some striking similarities in how their brains were churning. That’s one of the implications of new research on the neuroscience of creative writing. For the first time, neuroscientists have used fMRI scanners to track the brain activity of both experienced and novice writers as they sat down — or, in this case, lay down — to turn out a piece of fiction. The researchers, led by Martin Lotze of the University of Greifswald in Germany, observed a broad network of regions in the brain working together as people produced their stories. But there were notable differences between the two groups of subjects. The inner workings of the professionally trained writers in the bunch, the scientists argue, showed some similarities to people who are skilled at other complex actions, like music or sports. The research is drawing strong reactions. Some experts praise it as an important advance in understanding writing and creativity, while others criticize the research as too crude to reveal anything meaningful about the mysteries of literature or inspiration. Dr. Lotze has long been intrigued by artistic expression. In previous studies, he has observed the brains of piano players and opera singers, using fMRI scanners to pinpoint regions that become unusually active in the brain. Needless to say, that can be challenging when a subject is singing an aria. Scanners are a lot like 19th-century cameras: They can take very sharp pictures, if their subject remains still. To get accurate data, Dr. Lotze has developed software that can take into account fluctuations caused by breathing or head movements. © 2014 The New York Times Company

Keyword: Language; Aggression
Link ID: 19756 - Posted: 06.21.2014

by Helen Thomson KULLERVO HYNYNEN is preparing to cross neuroscience's final frontier. In July he will work with a team of doctors in the first attempt to open the blood-brain barrier in humans – the protective layer around blood vessels that shields our most precious organ against threats from the outside world. If successful, the method would be a huge step in the treatment of pernicious brain diseases such as cancer, Parkinson's and Alzheimer's, by allowing drugs to pass into the brain. The blood-brain barrier (BBB) keeps toxins in the bloodstream away from the brain. It consists of a tightly packed layer of endothelial cells that wrap around every blood vessel throughout the brain. It prevents viruses, bacteria and any other toxins passing into the brain, while simultaneously ushering in vital molecules such as glucose via specialised transport mechanisms. The downside of this is that the BBB also completely blocks the vast majority of drugs. Exceptions include some classes of fat and lipid-soluble chemicals, but these aren't much help as such drugs penetrate every cell in the body – resulting in major side effects. "Opening the barrier is really of huge importance. It is probably the major limitation for innovative drug development for neurosciences," says Bart De Strooper, co-director of the Leuven Institute for Neuroscience and Disease in Belgium. © Copyright Reed Business Information Ltd.

Keyword: Glia
Link ID: 19748 - Posted: 06.19.2014

By Michelle Roberts Health editor, BBC News online Scientists say they have devised a helmet that can quickly determine whether a patient has had a stroke. It could speed diagnosis and treatment of stroke to boost chances of recovery, the scientists say. The wearable cap bounces microwaves off the brain to determine whether there has been a bleed or clot deep inside. The Swedish scientists who made the device plan to give it to ambulance crews to test after successful results in early studies with 45 patients. When a person has a stroke, doctors must work quickly to limit any brain damage. If it takes more than four hours to get to hospital and start treatment, parts of their brain tissue may already be dying. But to give the best treatment, doctors first need to find out if the stroke is caused by a leaky blood vessel or one blocked by a clot. A computerised tomography (CT) scan will show this, but it can take some time to organise one for a patient, even if they have been admitted as an emergency to a hospital that has one of these scanners. Any delay in this "golden hour" of treatment opportunity could hamper recovery. To speed up the process, researchers in Sweden, from Chalmers University of Technology, Sahlgrenska Academy and Sahlgrenska University Hospital, have come up with a mobile device that could be used on the way to hospital. The helmet uses microwave signals - the same as the ones emitted by microwave ovens and mobile phones but much weaker - to build a picture of what is going on throughout the brain. BBC © 2014

Keyword: Stroke; Aggression
Link ID: 19741 - Posted: 06.17.2014

In a new study, scientists at the National Institutes of Health took a molecular-level journey into microtubules, the hollow cylinders inside brain cells that act as skeletons and internal highways. They watched how a protein called tubulin acetyltransferase (TAT) labels the inside of microtubules. The results, published in Cell, answer long-standing questions about how TAT tagging works and offer clues as to why it is important for brain health. Microtubules are constantly tagged by proteins in the cell to designate them for specialized functions, in the same way that roads are labeled for fast or slow traffic or for maintenance. TAT coats specific locations inside the microtubules with a chemical called an acetyl group. How the various labels are added to the cellular microtubule network remains a mystery. Recent findings suggested that problems with tagging microtubules may lead to some forms of cancer and nervous system disorders, including Alzheimer’s disease, and have been linked to a rare blinding disorder and Joubert Syndrome, an uncommon brain development disorder. “This is the first time anyone has been able to peer inside microtubules and catch TAT in action,” said Antonina Roll-Mecak, Ph.D., an investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, Maryland, and the leader of the study. Microtubules are found in all of the body’s cells. They are assembled like building blocks, using a protein called tubulin. Microtubules are constructed first by aligning tubulin building blocks into long strings. Then the strings align themselves side by side to form a sheet. Eventually the sheet grows wide enough that it closes up into a cylinder. TAT then bonds an acetyl group to alpha tubulin, a subunit of the tubulin protein.

Keyword: Miscellaneous
Link ID: 19729 - Posted: 06.14.2014

By JAMES GORMAN The National Institutes of Health set an ambitious $4.5 billion price tag on its part of President Obama’s Brain Initiative on Thursday, stamping it as an effort on the scale of the Human Genome Project. The goals of the Brain Initiative were clearly grand when Mr. Obama announced it a year ago — nothing less than developing and applying new technology to crack the toughest unsolved puzzles of how the brains of humans and animals function. The hope is to lay a foundation for future advances in the medical treatment of brain disorders. But the initiative began with $110 million budgeted for 2014, shared by three major entities: the National Science Foundation; the Defense Advanced Research Projects Agency; and the N.I.H., which has a $40 million share. By calling for such a major commitment, to be spread over 12 years, the institutes answered concerns among neuroscientists about the initial level of funding. “This is a realistic amount of money,” said Dr. Eric R. Kandel, director of the Kavli Institute for Brain Science at Columbia University, who, like some other neuroscientists, had been skeptical of what could be accomplished with the funding committed when the initiative was announced about a year ago. Gerald Rubin, the executive director of the Janelia Farm Research Campus in Virginia, also found that this budget request allayed some of his concerns, but not all. “I am much more concerned about convincing Congress to fund the Brain Initiative at this level,” he said. © 2014 The New York Times Company

Keyword: Brain imaging
Link ID: 19697 - Posted: 06.06.2014

Sarah C. P. Williams This, in all its molecular complexity, is what the bulging end of a single neuron looks like. A whopping 300,000 proteins come together to form the structure, which is less than a micrometer wide, hundreds of times smaller than a grain of sand. This particular synapse is from a rat brain. It’s where chemical signals called neurotransmitters are released into the space between neurons to pass messages from cell to cell. To create a 3D molecular model of the structure, researchers first isolated the synapses of rat neurons and turned to classic biochemistry to identify and quantify the molecules present at every stage of the neurotransmitter release cycle. Then, they used microscopy to pinpoint the location of each protein. Some proteins—like the red patches of SNAP25 visible in the video at 0:14—aid in the release of vesicles, tiny spheres full of neurotransmitters. Others—like the green, purple, and red rods at 0:45—help the synapse maintain its overall structure. Different proteins surround vesicles when they’re inside the synapse—the circles scattered throughout the structure at 0:56—than when the vesicles are forming at the edge of the synapse—as shown at 2:08. Researchers can use the model, described online today in Science, to better understand how neurons function and what goes wrong in brain disorders. (Video credit: Wilhelm et al. 2014, Science) © 2014 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 19678 - Posted: 05.31.2014

Elizabeth Norton Cultures around the world have long assumed that women are hardwired to be mothers. But a new study suggests that caring for children awakens a parenting network in the brain—even turning on some of the same circuits in men as it does in women. The research implies that the neural underpinnings of the so-called maternal instinct aren't unique to women, or activated solely by hormones, but can be developed by anyone who chooses to be a parent. "This is the first study to look at the way dads' brains change with child care experience," says Kevin Pelphrey, a neuroscientist at Yale University who was not involved with the study. "What we thought of as a purely maternal circuit can also be turned on just by being a parent—which is neat, given the way our culture is changing with respect to shared responsibility and marriage equality." The findings come from an investigation of two types of households in Israel: traditional families consisting of a biological mother and father, in which the mother assumed most of the caregiving duties, though the fathers were very involved; and homosexual male couples, one of whom was the biological father, who'd had the child with the help of surrogate mothers. The two-father couples had taken the babies home shortly after birth and shared caregiving responsibilities equally. All participants in the study were first-time parents. Researchers led by Ruth Feldman, a psychologist and neuroscientist at Bar-Ilan University in Ramat Gan, Israel, visited with the families in their homes, videotaping each parent with the child and then the parents and children alone. The team, which included collaborators at the Tel Aviv Sourasky Medical Center in Israel, also took saliva samples from all parents before and after the videotaped sessions to measure oxytocin—a hormone that's released at times of intimacy and affection and is widely considered the "trust hormone.” Within a week of the home visit, the participants underwent functional magnetic resonance imaging scanning to determine how their brains reacted to the videotapes of themselves with their infants. © 2014 American Association for the Advancement of Science

Keyword: Sexual Behavior; Aggression
Link ID: 19669 - Posted: 05.28.2014