Mo Costandi A vast project to map neural connections in the mouse retina may have answered the long-standing question of how the eyes detect motion. With the help of volunteers who played an online brain-mapping game, researchers showed that pairs of neurons positioned along a given direction together cause a third neuron to fire in response to images moving in the same direction. It is sometimes said that we see with the brain rather than the eyes, but this is not entirely true. People can only make sense of visual information once it has been interpreted by the brain, but some of this information is processed partly by neurons in the retina. In particular, 50 years ago researchers discovered that the mammalian retina is sensitive to the direction and speed of moving images1. This showed that motion perception begins in the retina, but researchers struggled to explain how. When light enters the eye, it is captured by photoreceptor cells, which convert the information into electrical impulses and transmit them to deeper layers of the retina. Individual photoreceptors are not sensitive to the direction in which an object may be moving, so neuroscientist Jinseop Kim, of the Massachusetts Institute of Technology (MIT) in Cambridge, and his colleagues wanted to test whether the answer to the puzzle could lie in the way various types of cells in the retina are connected. Photoreceptors relay their signals via ‘bipolar neurons’, named this way because they have two stems that jut out of the cell's body in opposite directions. The signal then transits through ‘starburst amacrine cells’ — which have filaments, or dendrites, that extend in all directions similarly to light rays out of a star — before reaching the cells that form the optic nerve, which relays them into the brain. © 2014 Nature Publishing Group,

Keyword: Vision
Link ID: 19576 - Posted: 05.05.2014

Lida Katsimpardi Could the elixir of youth be as simple as a protein found in young blood? In recent years, researchers studying mice found that giving old animals blood from young ones can reverse some signs of aging, and last year one team identified a growth factor in the blood that they think is partly responsible for the anti-aging effect on a specific tissue--the heart. Now that group has shown this same factor can also rejuvenate muscle and the brain. "This is the first demonstration of a rejuvenation factor" that is naturally produced, declines with age, and reverses aging in multiple tissues, says Harvard stem cell researcher Amy Wagers, who led efforts to isolate and study the protein. Independently, another team has found that simply injecting plasma from young mice into old mice can boost learning. The results build on a wave of studies in the last decade in which investigators sewed together the skins of two mice, joining their circulation systems, and studied the effects on various tissues. “It’s still a bit creepy for many people. At meetings, people talk about vampires,” says Stanford University neuroscientist Tony Wyss-Coray, who led the study of learning. But he, Wagers, and others think unease will give way to excitement. The new work, he says, “opens the possibility that we can try to isolate additional factors” from blood, “and they have effects on the whole body.” Hope and hype are high in the anti-aging research arena, and other researchers caution that the work is preliminary. “These are exciting papers,” but “it’s a starting point,” says neuroscientist Sally Temple of the Neural Stem Cell Institute in Rensselaer, NY. Adds Matthew Kaeberlein, a biologist who studies aging at the University of Washington, Seattle, “The therapeutic implications are profound if this mechanism holds true in people.” But that “is the million dollar question here, and that may take some time to figure out.” © 2014 American Association for the Advancement of Science

Keyword: Development of the Brain; Hormones & Behavior
Link ID: 19575 - Posted: 05.05.2014

By Melissa Hogenboom Science reporter, BBC Radio Science Neuroscience is a fast growing and popular field, but despite advances, when an area of the brain 'lights up" it does not tell us as much as we'd like about the inner workings of the mind. Many of us have seen the pictures and read the stories. A beautiful picture of the brain where an area is highlighted and found to be fundamental for processes like fear, disgust or impaired social ability. There are so many stories it can be easy to be swayed into thinking that much more of the brain's mystery has been solved than is the case. The technology is impressive but one of the most popular scanning methods - functional magnetic resonance imaging (fMRI) actually measures regional regional changes of blood flow to areas of the brain, not our neurons directly. Researchers use it when they want to understand what part of the brain is involved in a particular task. They can place a person in a brain scanner and see which areas become active. The areas that light up are then inferred to be important for that task, but the resulting images and phrase "lighting up the brain" can lead to over interpretation. Neuroscientist Molly Crocket from University College London explains that while fMRI is extremely useful, we are still very far from being able to read an individual's mind from a scan. "There's a misconception that's still rather common that you can look at someone's brain imaging data and be able to read off what they're thinking and feeling. This is certainly not the case," Dr Crocket told the BBC's Inside Science programme. 19th Century brain "A study will have been done which tells us something about the brain, but what [the public] really want to do is make the leap and understand the mind." She cites an article with the headline, "You love your iPhone, literally". In this case a team saw an area previously associated with love - the insula - was active when participants watched videos of a ringing iPhone. BBC © 2014

Keyword: Brain imaging; Consciousness
Link ID: 19574 - Posted: 05.05.2014

Autism was formally described for the first time 71 years ago. The medical notes for "Case one", a 10-year-old from Mississippi, US, referred to as Donald T, describe a perplexing condition that was different from "anything reported so far". In 1943, when Donald Triplett was diagnosed, autism was considered extremely rare and treatment consisted of institutionalisation and – all too often – isolation. Today we know "autism disorder" as one of a number of autism spectrum disorders alongside Asperger's syndrome, pervasive developmental disorder and single gene disorders such as Rett syndrome. But of all neuropsychiatric conditions, autism remains one of the least understood. We now know that genetics almost certainly plays a key role, with researchers finding that if a family has one child with autism, then the likelihood of a future child having the condition is as high as 25%. But to what extent autism is defined by genes remains a mystery. "Everyone recognises that genes are part of the story but autism isn't 100% genetic," says Professor Simon Baron-Cohen of the Autism Research Centre at the University of Cambridge. "Even if you have identical twins who share all their genes, you can find that one has autism and one doesn't. That means that there must be some non-genetic factors." One of the most controversial theories about how autism develops is neuroinflammation. MRI scans of autistic patients have revealed abnormalities in the white matter – the wiring tissue responsible for connecting brains areas. Some scientists have drawn comparisons with multiple sclerosis, in which inflammatory processes attack the myelin sheath around the axons of brain cells, slowing down signalling and making it less efficient. © 2014 Guardian News and Media Limited

Keyword: Autism; Genes & Behavior
Link ID: 19573 - Posted: 05.05.2014

Daniel Cressey Organizations such as People for the Ethical Treatment of Animals (PETA) have been campaigning for the disclosure of more information on animal research in the United Kingdom. The government of the United Kingdom wants to jettison rules that prevent it releasing any confidential information it holds about animal research, as part of a continuing push towards openness about such work. Animal-rights groups have long complained about what they characterise as a “secrecy clause” that prevents details of animal research in the UK being made public. The Home Office collects huge amounts of information such as the type of work done, the people and institutions doing it, and the results of inspections at laboratories. However it is currently prevented from revealing anything potentially considered confidential under ‘section 24’ of the rules governing animal research. Today the government said that it would like repeal this blanket ban on information disclosure, as it has previously promised, and requested comment on its proposal. In place of section 24, it would like to introduce a new rule prohibiting disclosure only of information relating to “people, places and intellectual property”. Home Office minister Norman Baker said in the consultation document released today, “To maintain public trust we must be as open and transparent as possible about activities under the regulatory framework.” If implemented, the new rule would still keep names and locations of animal research out of the public domain — a key concern of many researchers who fear protests or even violent attacks from extremist animal rights protestors. © 2014 Nature Publishing Group

Keyword: Animal Rights
Link ID: 19572 - Posted: 05.05.2014

by Susan Milius Sometimes called the unicorn of the sea, the male narwhal’s tusk is actually a tooth, and it grows directly through the whale’s upper lip instead of pushing the lip aside. It’s an exuberantly large version of a canine tooth that grows in a spiral; the only tooth known to do so. Otherwise narwhals are practically toothless, with only vestigial stubs that stop growing during development and rarely emerge into the mouth. This extreme anatomy has captivated dentist Martin Nweeia, who practices in Connecticut and teaches at Harvard University. For more than a decade, he has pioneered ways to study these difficult-to-reach Arctic whales, and he and his colleagues now describe in the April Anatomical Record that narwhals can detect changes in water salinity using only their tusks. The animals “don’t have a good sense of humor,” though, about being temporarily restrained for the testing, Nweeia says. © Society for Science & the Public 2000 - 2013

Keyword: Pain & Touch
Link ID: 19571 - Posted: 05.05.2014

By SAM KEAN UNTIL the past few decades, neuroscientists really had only one way to study the human brain: Wait for strokes or some other disaster to strike people, and if the victims pulled through, determine how their minds worked differently afterward. Depending on what part of the brain suffered, strange things might happen. Parents couldn’t recognize their children. Normal people became pathological liars. Some people lost the ability to speak — but could sing just fine. These incidents have become classic case studies, fodder for innumerable textbooks and bull sessions around the lab. The names of these patients — H. M., Tan, Phineas Gage — are deeply woven into the lore of neuroscience. When recounting these cases today, neuroscientists naturally focus on these patients’ deficits, emphasizing the changes that took place in their thinking and behavior. After all, there’s no better way to learn what some structure in the brain does than to see what happens when it shorts out or otherwise gets destroyed. But these case snippets overlook something crucial about people with brain damage. However glaring their deficits are, their brains still work like ours to a large extent. Most can still read and reason. They can still talk, walk and emote. And they still have the same joys and fears — facts that the psychological caricatures passed down from generation to generation generally omit. The famous amnesiac H. M., for instance, underwent radical brain surgery in 1953 and had most of the hippocampus removed on both sides of his brain; afterward, he seemed to lose the ability to form new long-term memories. Names, dates, directions to the bathroom all escaped him now. He’d eat two breakfasts if no one stopped him. Careful testing, however, revealed that H. M. could form new motor memories — memories of things like how to ride a bicycle — because they rely on different structures in the brain. This work established that memory isn’t a single, monolithic thing, but a collection of different faculties. © 2014 The New York Times Company

Keyword: Stroke; Emotions
Link ID: 19570 - Posted: 05.04.2014

by Andy Coghlan A pregnancy hormone could prove a simple way to treat multiple sclerosis, after showing promise in a trial of 158 women with MS. MS is a neurological condition that results from damage to the brain and nerves inflicted by the body's own immune system. It affects 2.3 million people worldwide. Symptoms include extreme tiredness, blurred vision, muscle weakness and problems with balance and movement. The symptoms of women with MS tend to ease when they are pregnant, but worsen again after giving birth. This could be because of a hormone called oestriol, which is only produced in significant amounts during pregnancy. The hormone is thought to help suppress the mother's immune system to prevent it attacking the fetus. Fewer relapses Rhonda Voskuhl of the University of California, Los Angeles, and her colleagues wondered whether giving oestriol to people with MS who aren't pregnant might also help with symptoms. They gave 8 milligrams of oestriol daily to 86 women with MS, along with their medication, Copaxone (glatiramer acetate). The women had the most common form of MS, called relapsing-remitting MS, which results in periodic flare-ups of symptoms followed by recovery. After one year, they had 47 per cent fewer relapses than a control group that took Copaxone and a placebo. After two years, the relapse rate was 32 per cent lower than the control group in the group given the hormone, suggesting the effects had plateaued. "We think the oestriol group had bottomed out, and there was nothing left to improve," Voskuhl said, as she presented the preliminary results at the annual meeting of the American Academy of Neurology in Philadelphia last week. © Copyright Reed Business Information Ltd.

Keyword: Multiple Sclerosis; Hormones & Behavior
Link ID: 19569 - Posted: 05.04.2014

By Deborah Tuerkheimer Almost a decade into a 20-year prison sentence for murdering a baby in her care, 43-year-old Jennifer Del Prete was ordered freed on bond late last week. The ruling is one of a growing number that reflect skepticism on the part of judges, juries, and even prosecutors about criminal convictions based on the medical diagnosis of shaken baby syndrome. The case is also a critical turning point. The certainty that once surrounded shaken baby syndrome, or SBS, has been dissolving for years. The justice system is beginning to acknowledge this shift but should go further to re-examine and perhaps overturn more past convictions. Doctors once believed that three neurological symptoms—bleeding beneath the outer layer of membranes surrounding the brain (subdural hemorrhaging), bleeding in the retina, and brain swelling—always meant that a baby had been shaken. Because it was accepted that a baby with these three symptoms would show the effect of brain damage immediately, the “triad,” as it became known, was also used to establish the identity of the abuser—the last person with the baby. SBS was, in essence, a medical diagnosis of murder. Beginning in the 1990s, hundreds of cases were prosecuted based on this conception of SBS. The evidence of guilt was strikingly similar from case to case. This includes the Illinois prosecution of Jennifer Del Prete. In 2002, Del Prete was working at a small home day care in a Chicago suburb. One day, when she went to feed the 4-month-old baby in her care, she says she discovered the infant limp. Because the baby had the telltale triad of SBS symptoms, doctors were sure that Del Prete had shaken the baby to death. She denied it, and there were no witnesses. But based on the testimony of medical experts—primarily a pediatrician—she was convicted of murder in the first degree. © 2014 The Slate Group LLC.

Keyword: Brain Injury/Concussion; Development of the Brain
Link ID: 19568 - Posted: 05.04.2014

by Bethany Brookshire When I was a lab scientist working with mice, I spent hours controlling variables. I stood on precarious chairs to tape tarps over lights to get the light level perfectly right. I made one undergraduate who wore perfume to the lab for animal training wear the same perfume for a whole semester. I was so worried about the mice “recognizing” me over long, overlapping experiments that I did not change the scents of any of my personal care products for nine years. Many of these variables got reported in the methods sections of my papers. “All experiments conducted between 5:00 and 7:00 a.m. Maze dimensions: 4 inches wide, with walls 6 inches tall. Lighting held constant at 10 lux.” All of these variables are reported to allow other people to repeat my experiments, and hopefully get the same result. Now, a new study suggests that maybe I should have included another element in my methods section: “All mice exposed to the scent of a woman.” Jeffrey Mogil’s lab at McGill University in Montreal, Canada, reports April 28 in Nature Methods that mice respond differently to men and women, and that men in fact are a stressful influence. The results show that there’s yet another variable to control when doing sensitive mouse behavioral studies, a variable that could impact fields from pain to depression and beyond. Every department that does animal research has stories about particular experimenters. I recall hearing a story of a lab technician who could get results no one else could, because mice just loved her strawberry-scented hair conditioner. Another colleague told of one experimenter who was so good at handling rats that no one believed her anxiety results. Her rats were just so relaxed. And Mogil’s lab had its own story. In their lab, the presence of human experimenters seemed to stop mice from showing pain. © Society for Science & the Public 2000 - 2013

Keyword: Stress; Sexual Behavior
Link ID: 19567 - Posted: 05.04.2014

by Colin Barras Enough of the cheap jibes: Neanderthals may have been just as clever as modern humans. Anthropologists have already demolished the idea that Neanderthals were dumb brutes, and now a review of the archaeological record suggests they were our equals. Neanderthals were one of the most successful of all hominin species, occupying much of Europe and Asia. Their final demise about 40,000 years ago, shortly after Homo sapiens walked into their territory, is often put down to the superiority of our species. It's time to lay that idea to rest, say Paola Villa at the University of Colorado in Boulder and Wil Roebroeks at Leiden University in the Netherlands. Just as smart as you For instance, there is evidence that Homo sapiens could use fire to chemically transform natural materials into glue 70,000 years ago, but Neanderthals were performing similarly complex chemical syntheses at least 200,000 years ago. And although 70,000-year-old engraved ochre from South Africa is seen as evidence that our species had developed sophisticated symbolism and perhaps even language, similar artefacts have been found at 50,000-year-old Neanderthal sites in Spain. What's more, Neanderthals might have been able to talk. Late last year we learned that our extinct cousins had a hyoid, a small bone in the neck that plays a big role in speech, very like ours. Evidence has even emerged that Homo sapiens may have learned some skills by copying Neanderthals. Yet despite all of this evidence, the idea that Neanderthals were our inferiors still persists. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Language
Link ID: 19566 - Posted: 05.04.2014

Humans stink, and it’s wonderful. A few whiffs of a pillow in the morning can revive memories of a lover. The sweaty stench of a gym puts us in the mood to exercise. Odors define us, yet the scientific zeitgeist is that we don’t communicate through pheromones—scents that influence behavior. A new study challenges that thinking, finding that scent can change whether we think someone is masculine or feminine. Humans carry more secretion and sweat glands in their skin than any other primate. Yet 70% of people lack a vomeronasal organ, a crescent-shaped bundle of neurons at the base of each nostril that allows a variety of species—from reptiles to nonprimate mammals—to pick up on pheromones. (If you’ve ever seen your cat huff something, he’s using this organ.) Still, scientists have continued to hunt for examples of pheromones that humans might sense. Two strong candidates are androstadienone (andro) and estratetraenol (estra). Men secrete andro in their sweat and semen, while estra is primarily found in female urine. Researchers have found hints that both trigger arousal—by improving moods and switching on the brain’s “urge” center, the hypothalamus—in the opposite sex. Yet to be true pheromones, these chemicals must shape how people view different genders. That’s exactly what they do, researchers from the Chinese Academy of Sciences in Beijing report online today in Current Biology. The team split men and women into groups of 24 and then had them watch virtual simulations of a human figure walking (see video). The head, pelvis, and major joints in each figure were replaced with moving dots. Subjects in prior studies had ranked the videos as being feminine or masculine. For instance, watch the figure on the far left, which was gauged as having a quintessential female strut. Notice a distinctive swagger in the “hip” dots and how they contrast with the flat gait of the “male” prototype all the way to the right. © 2014 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 19565 - Posted: 05.03.2014

By Gabriella Rosen Kellerman By 1664, the year he published his most famous book of neuroanatomy, Cerebri Anatome, Dr. Thomas Willis was already renowned in Britain for saving lives. Fourteen years earlier, the corpse of executed murderer Anne Green had been delivered to Willis and some of his colleagues for autopsy. Upon opening the coffin—the story goes—the doctors heard a gasp. Ms. Green, they discovered, had been hanged but not executed. Thanks to the resuscitation efforts of Willis and his colleagues, Green survived, and was given a stay of execution. She died fifteen years later. The episode supposedly drew jealousy from Willis’s contemporaries, who could have had no idea just how many lives Willis’s work would one day save. Among the important discoveries included in Cerebri Anatome, considered the founding text of neurology, is the Circle of Willis, a map of the interconnecting arteries at the base of the brain. Such circular connections among arteries are called anastomoses. They enable blood to reach vital tissue along multiple routes so that when one is blocked, the blood has an alternative outlet. The Circle of Willis is perhaps most important because of its implications for stroke. Stroke, which is the third leading cause of death in this country, occurs when blood flow to the brain is disrupted. This can occur when an artery gets blocked with plaque or a clot (called an ischemic stroke) or when at artery bursts (called hemorrhagic stroke). Many of these problems, particularly the latter kind of stroke, occur in the Circle of Willis. © 2014 Scientific American

Keyword: Stroke
Link ID: 19564 - Posted: 05.03.2014

Fork-tailed drongos, glossy black African songbirds with ruby-colored eyes, are the avian kingdom’s masters of deception. They mimic the alarm calls of other species to scare animals away and then swipe their dupes’ dinner. But like the boy who cried wolf, drongos can raise the alarm once too often. Now, scientists have discovered that when one false alarm no longer works, the birds switch to another species’ warning cry, a tactic that usually does the trick. “The findings are astounding,” says John Marzluff, a wildlife biologist at the University of Washington, Seattle, who was not involved in the work. “Drongos are exceedingly deceptive; their vocabularies are immense; and they match their deception to both the target animal and [its] past response. This level of sophistication is incredible.” Since 2008, Tom Flower, an evolutionary biologist at the University of Cape Town, has followed drongos in the Kuruman River Reserve in the Kalahari Desert. He’s habituated and banded about 200 of the robin-sized birds, and, using food rewards, has trained individuals to come to him when he calls. After getting its snack, the drongo quickly returns to its natural behavior—catching insects and following other bird species or meerkats—while Flower tags along. Drongos also keep an eye out for raptors and other predators. When they spot one, they utter metallic alarm cries. Meerkats and pied babblers, a highly social bird, pay attention to the drongos and dash for cover when the drongos raise an alarm—just as they do when one of their own calls out a warning. Studies have shown that having drongos around benefits animals of other species, which don’t have to be as vigilant and can spend more time foraging. But there’s a trade-off: The drongos’ cries aren’t always honest. When a meerkat has caught a fat grub or gecko, a drongo is apt to change from trustworthy sentinel to wily deceiver. © 2014 American Association for the Advancement of Science.

Keyword: Animal Communication; Language
Link ID: 19563 - Posted: 05.03.2014

Brian Owens If you think you know what you just said, think again. People can be tricked into believing they have just said something they did not, researchers report this week. The dominant model of how speech works is that it is planned in advance — speakers begin with a conscious idea of exactly what they are going to say. But some researchers think that speech is not entirely planned, and that people know what they are saying in part through hearing themselves speak. So cognitive scientist Andreas Lind and his colleagues at Lund University in Sweden wanted to see what would happen if someone said one word, but heard themselves saying another. “If we use auditory feedback to compare what we say with a well-specified intention, then any mismatch should be quickly detected,” he says. “But if the feedback is instead a powerful factor in a dynamic, interpretative process, then the manipulation could go undetected.” In Lind’s experiment, participants took a Stroop test — in which a person is shown, for example, the word ‘red’ printed in blue and is asked to name the colour of the type (in this case, blue). During the test, participants heard their responses through headphones. The responses were recorded so that Lind could occasionally play back the wrong word, giving participants auditory feedback of their own voice saying something different from what they had just said. Lind chose the words ‘grey’ and ‘green’ (grå and grön in Swedish) to switch, as they sound similar but have different meanings. © 2014 Nature Publishing Group

Keyword: Language; Consciousness
Link ID: 19562 - Posted: 05.03.2014

A UBC neuroscientist says motherhood permanently alters the brain, exposing moms to different health risks than women without children. Liisa Galea, a professor in the university's psychology department, says some changes are temporary while others are permanent. The most obvious example is size. According to Galea, a mother's brain shrinks by up to eight per cent during pregnancy. While it bounces back about six months after birth, she notes the reaction could have repercussions. “Our research shows that, as a result of these transformations, mothers experience different cognitive abilities and health risks than women without children,” said Galea. And she warns that women who’ve borne children may even react to medication differently. “If mothers’ brains are different than other women’s brains, as our research finds, it means we must embrace greater personalization of medical care – not only for men versus women, but even among women with different life experiences,” she said. But that’s a challenge that may be insurmountable given that medical research studies at the animal model level have relied predominantly on the use of male rats. “Why would we assume that what works in a male rat automatically works in a female patient before testing it on a female rat?” questioned Galea. She claims one of the big failures of translational studies is that most fail to acknowledge how subjects’ gender, or other unique characteristics, like motherhood, plays a role. © CBC 2014

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 19561 - Posted: 05.03.2014

by Lisa Grossman Hasta la vista, nerve damage. Experiments with bullfrog nerves show that a Terminator-style liquid metal alloy could one day be placed in the body to help severed nerves reconnect. The alloy would stay in place until the nerve has healed, before being slurped back out with a syringe. The peripheral nervous system consists of nerves that carry electrical signals from the brain to the rest of the body. Because they aren't protected by the spine or the skull, peripheral nerves are more vulnerable to injuries than those in the central nervous system. Severed nerves can reconnect if treated quickly enough, but at a rate of just 1 millimetre per day. Also, existing methodsMovie Camera for grafting nerve ends back together have serious shortcomings. For instance, most existing scaffolds for grafts must ultimately be removed, requiring risky follow-up surgery. Even more worrisome, if the nerves don't pass signals to muscles during the healing process, the muscles can atrophy to the point where they never fully recover. Liu and his colleagues wondered if liquid metal could act as a backup system for damaged nerves, helping signals pass through a graft while the nerve healed. They used an alloy of gallium, indium and selenium, which is a very good electrical conductor. The alloy is liquid at room temperature, allowing it to be removed with a syringe when it's no longer needed. © Copyright Reed Business Information Ltd.

Keyword: Regeneration; Robotics
Link ID: 19560 - Posted: 05.03.2014

By Brian Palmer The Journal of Neuroscience recently published a study linking recreational marijuana use to subtle changes in brain structure. The researchers, led by Jodi Gilman of Massachusetts General Hospital, identified increased gray matter density in the left nucleus accumbens and some bordering areas. The study was fine, but the media coverage was abysmal. Reporters overstated the findings, mischaracterized the study, and failed to mention previous research done on pot smoking and health. Goldfish may not have a three-second memory, but some journalists seem to. When a new paper comes out, it’s often treated as the first ever and final word on the topic. There is a significant body of literature on the neurological and wider health effects of marijuana, and to ignore it when covering new studies seems to me a form of journalistic malpractice. A press release from the Society for Neuroscience trumpeted the Gilman study’s importance because it looked at casual users rather than regular pot smokers, who form the basis of most marijuana studies. That claim is dubious in the extreme. The subjects averaged 3.83 days of smoking and 11.2 total joints per week. Characterizing these people as casual pot smokers was a great media hook, but it defied common sense. Occasional users wondered if they’d done permanent damage, and parents were concerned that their teenagers might face profound neurological changes from experimenting with pot. Any reporter who read the study, however, should have known not to take that bait. Even by the standards of past medical studies, it’s a stretch to call these subjects casual pot smokers. © 2014 The Slate Group LLC.

Keyword: Drug Abuse
Link ID: 19559 - Posted: 05.03.2014

By Greg Miller As a journalist who writes about neuroscience, I’ve gotten a lot of super enthusiastic press releases touting a new breakthrough in using brain scans to read people’s minds. They usually come from a major university or a prestigious journal. They make it sound like a brave new future has suddenly arrived, a future in which brain scans advance the cause of truth and justice and help doctors communicate with patients whose minds are still active despite their paralyzed bodies. Amazing, right? Drop everything and write a story! Well, not so fast. Whenever I read these papers and talk to the scientists, I end up feeling conflicted. What they’ve done–so far, anyway–really doesn’t live up to what most people have in mind when they think about mind reading. Then again, the stuff they actually can do is pretty amazing. And they’re getting better at it, little by little. In pop culture, mind reading usually looks something like this: Somebody wears a goofy-looking cap with lots of wires and blinking lights while guys in white lab coats huddle around a monitor in another room to watch the movie that’s playing out in the person’s head, complete with cringe-inducing internal monologue. We are not there yet. “We can decode mental states to a degree,” said John-Dylan Haynes, a cognitive neuroscientist at Charité-Universitätsmedizin Berlin. “But we are far from a universal mind reading machine. For that you would need to be able to (a) take an arbitrary person, (b) decode arbitrary mental states and (c) do so without long calibration.” © 2014 Condé Nast.

Keyword: Brain imaging; Vision
Link ID: 19558 - Posted: 04.30.2014

Brian Owens Surveys of people's eating habits have suggested a link between fibre intake and weight loss, but exactly how fibre helps to regulate weight has been unclear. A study of mouse metabolism suggests that a product of fibre fermentation may be directly affecting the hypothalamus, a region of the brain involved in regulating appetite. People have long been told that a diet high in fibre can help to fight obesity, but how it does so has been unclear. “There has been lots of epidemiological information showing a relationship between fibre and obesity, but no one has been able to connect the epidemiological results with actual mechanisms,” says Jimmy Bell, a biochemist at Imperial College London who worked on the research, published today in Nature Communications1. Until now, a high-fibre diet was thought to help keep weight down by stimulating the release of appetite-suppressing hormones in the gut2, says Bell, but humans do not seem to show the same increase in these hormones that mice do. So Bell and his colleagues decided to look elsewhere. An obvious candidate, they thought, might be one of the products of fibre fermentation in the gut. In particular they focused on the short-chain fatty acid acetate, because it is the most abundant and is known to circulate throughout the bloodstream. They fed mice fibre labelled with carbon-13, which has an additional neutron from the more common carbon-12 that gives its nuclei a magnetic spin and therefore makes it easy to track as it progresses through the body's chemical reactions. The fibre was fermented as usual into acetate, which turned up not only in the gut, but also in the hypothalamus, a part of the brain known to be involved in regulating appetite. There, the researchers found, it was metabolized through the glutamine-glutamate cycle, which is involved in controlling the release of neurotransmitters associated with appetite control. The same model has been proposed for acetate metabolism after drinking alcohol. © 2014 Nature Publishing Group,

Keyword: Obesity
Link ID: 19557 - Posted: 04.30.2014