By NICHOLAS BAKALAR Increasing blood sugar levels are associated with cognitive decline, a long-term study has found. Researchers assessed cognitive function in 5,189 people, average age 66, and tested their blood sugar using HbA1c, a test that accurately measures blood glucose levels over a period of weeks or months. (The finger-prick blood test, in contrast, gives a reading only at a given moment in time.) They followed the group for up to 10 years, tracking blood glucose levels and periodically testing cognitive ability. The study is in the journal Diabetologia. There was no association between blood sugar levels and cognition at the start of the study. But consistently over time, scores on the tests of memory and executive function declined as HbA1c levels increased, even in people without diabetes. The study controlled for many other variables, among them age, sex, cholesterol, B.M.I., education, marital status, depression, smoking, alcohol consumption, hypertension and cardiovascular disease. This is an observational study that does not prove cause and effect, and the lead author, Wuxiang Xie, a researcher at the Peking University Health Science Center, said that the underlying mechanism is still unknown. Still, he said, “Diabetes-related microvascular complications might be, at least in part, the reason for the subsequent cognitive decline. Future studies are warranted to reveal the precise mechanisms.” © 2018 The New York Times Company

Keyword: Learning & Memory; Alzheimers
Link ID: 24649 - Posted: 02.13.2018

By John Horgan I’ve been writing for decades about the mind-body problem, the deepest of all mysteries, and I’m trying to finish a book tentatively titled Mind-Body Problems. And yet only recently have I realized that few people outside philosophy and mind-related scientific fields are familiar with the phrase “mind-body problem.” I also realized that I knew nothing about the origins of the phrase. Google didn’t provide an immediate answer, so I reached out to David Chalmers, a prominent philosopher of mind. “Good question,” he said when I asked on Facebook who coined mind-body problem. He passed my query on to other scholars. I’ve culled the information below from responses of Chalmers, Galen Strawson, Eric Schliesser, Charles T. Wolfe, Godehard Bruntrup, Victor Caston and Paolo Pecere, to whom I am very grateful. A Google N-gram on “mind-body problem” shows the phrase spiking from 1910 to 1925, dipping for a couple of decades and then rising again in the 1950s. The earliest reference I can find on Google Books dates back to 1879, when the prominent American scholar Felix Adler lectured on atheism to the Ethical Culture Society. An excerpt: Advertisement If then, consciousness, or mind, in something like its traditional sense, cannot successfully be explained away by the new epistemology, we must resolutely face the metaphysical question of the relation of the mind to the physical world in which it has its setting. The central and crucial part of this question is, of course, to be found in the mind-body problem… If we refuse to accept the pan-objective epistemology already considered which would do away with consciousness in the traditional sense, we must recognize that the relation of the mind to the body forms a real and inescapable problem… How can two things so different from each other as mind and body interact? To which, it seems to me, the sufficient answer is to be found in the rather obvious query, Why can they not? Are we so sure that unlike things cannot influence each other? The only way really to decide this question is to go to experience and see. [Bold added.] © 2018 Scientific American

Keyword: Consciousness
Link ID: 24648 - Posted: 02.12.2018

Rachel Hoge I’ve heard the misconceptions for most of my life. “Just slow down,” a stranger told me as a child. “You’re talking too fast – that’s why you stutter!” Later on, as my stutter carried on into adolescence and adulthood, strangers and loved ones alike offered up their own judgments of my speech –usually incorrect. Some have good intentions when it comes to sharing their opinions about my stutter. Others ... not so much. But everyone shares one defining characteristic: they’re misinformed. Stuttering is a communication and disfluency disorder where the flow of speech is interrupted. Though all speakers will experience a small amount of disfluency while speaking, a person who stutters (PWS) experiences disfluency more noticeably, generally stuttering on at least 10% of their words. There are approximately 70 million people who stutter worldwide, which is about 1% of the population. Stuttering usually begins in childhood between the ages of two and five, with about 5% of all children experiencing a period of stuttering that lasts six months or more. Three-quarters of children who stutter will recover by late childhood, but those who don’t may develop a lifelong condition. The male-to-female ratio of people who stutter is four to one, meaning there is a clear gender discrepancy that scientists are still attempting to understand. The severity of a stutter can vary greatly. The way it manifests can also differ, depending on the individual. Certain sounds and syllables can produce repetitions (re-re-re-repetitions), prolongations (ppppppprolongations), and/or abnormal stoppages (no sound). © 2018 Guardian News and Media Limited

Keyword: Language
Link ID: 24647 - Posted: 02.12.2018

By Susana Martinez-Conde The latest illusion to go viral in social media depicts two side-by-side stretches of a narrow road, receding in the distance. Both images depict the retreating road at an oblique angle, but the right road’s slant is a lot more pronounced than the slant on the left road. These are two identical photos of a road in Mexico. Credit: Daniel Picon Or is it? In fact, both pictures are identical. As user djeclipz put it, upon sharing the soon-to-become global sensation on Reddit: “This is the same photo, side by side. They are not taken at different angles. Both sides are the same, pixel for pixel.” Advertisement So why do they look so different? The illusion, created in 2010 by the French artist Daniel Picon and entitled “Roads in Mexico,” is a powerful variant of an earlier perceptual phenomenon discovered in 2007 by vision scientists Frederick Kingdom, Ali Yoonessi, and Elena Gheorghiu (all of them then at McGill University). Kingdom and his colleagues dubbed the effect the “Leaning Tower Illusion,” because they first noticed it in a pair of identical photos of the Leaning Tower of Pisa. But, as Kingdom, Yoonesi, and Gheorghiu noted in an excellent Scholarpedia article about their discovery, “the illusion works with any image of a receding object,” including tram lines, train tracks and roads in Mexico. The Leaning Tower Illusion won First Prize in the 2007 Best Illusion of the Year Contest, and is featured prominently in our recent book about the annual competition, Champions of Illusion. An excerpt of Champions of Illusion follows, concerning the bases of this effect: © 2018 Scientific American,

Keyword: Vision
Link ID: 24646 - Posted: 02.12.2018

People with schizophrenia can be trained by playing a video game to control the part of the brain linked to verbal hallucinations, researchers say. Patients in a small study were able to land a rocket in the game when it was connected to the brain region sensitive to speech and human voices. In time, the patients learnt to use the technique in their daily lives to reduce the power of hallucinations. But this is a small pilot study and the findings still need to be confirmed. The research team, from King's College London's Institute of Psychiatry, Psychology and Neuroscience and the University of Roehampton, says the technique could be used to help schizophrenia patients who do not respond to medication. People with the condition are known to have a more active auditory cortex, which means they are more sensitive to sounds and voices. All 12 patients in the study experienced nasty and threatening verbal hallucinations every day - a common symptom of schizophrenia. To try to control their symptoms, they were asked to play a video game while in an MRI scanner, using their own mental strategies to move a computerised rocket - and in doing so they were able to turn down the volume on the external voices they heard as well. Image copyright King's College London Image caption The auditory cortex (in yellow) is hypersensitive in the brains of people with schizophrenia Dr Natasza Orlov, from King's College London, said: "The patients know when the voices are about to start - they can feel it, so we want them to immediately put this aid into effect to lessen them, or stop the voices completely." She said all the patients in the study, who each had four turns in the MRI scanner, found that their voices became less external and more internal, making them less stressful. They were also better able to cope with them. Dr Orlov added: "Although the study sample size is small and we lacked a control group, these results are promising. "We are now planning to conduct a randomised controlled study to test this technique in a larger sample." © 2018 BBC

Keyword: Schizophrenia
Link ID: 24645 - Posted: 02.12.2018

Lee Burdette Williams The call came from a former colleague who coaches college students on the autism spectrum. “We’ve got someone who’s in trouble, and we could use some advice. It’s one of those Title IX things.” She told me the story. The student loves punk music and wanted to start a band. He put up fliers on the campus, which in itself was an issue because he violated the institutional posting policy. But even in today’s climate, I thought, that doesn’t usually rise to a Title IX complaint. She continued. “He wrote something in Morse code on the flyer, a message directed to women, because he was trying to recruit some to join the band. It was a little ‘stalky-creepy’ -- OK, pretty creepy -- but this guy is totally harmless and clueless and just doesn’t know how to meet women.” My first reaction was to smile. Morse code? How many college students even know what it is? But it didn’t surprise me to learn this about a student with Asperger’s syndrome, the commonly used term for those with high-functioning autism. Indeed, this kind of situation, I have come to realize, exemplifies a disastrous nexus of two trends on college campuses: the increased awareness of Title IX’s expectations for student behavior and institutional response, and the growing number of students with a diagnosis (or simply just characteristics) of autism who are attending college. I imagined the student had learned Morse code at the age of 5 and was no doubt still fluent in it. In his mind, a wondrous place created by the distinct neural connections common among those with this diagnosis, the use of Morse code to signal his interest in meeting women made perfect sense. To those who know him, it is one of many quirky characteristics -- some of them sweet, some of them annoying -- that require a bit of translation for him and about him as he moves within the world of higher education. © 2018

Keyword: Autism
Link ID: 24644 - Posted: 02.12.2018

Menaka Wilhelm Karen Byrne's left hand sometimes operates on its own terms. It has unbuttoned shirts and stubbed out cigarettes, without her permission. Oh, and a few times, her own hand has slapped her across the face. This is a documented medical occurrence, not a premise for a Jim Carrey movie. The condition's name? Alien hand syndrome. Invisibilia featured Byrne and her alien hand last summer, and Giant Ant Studios recently created an otherworldly animation of Byrne's story. Byrne says she's gotten used to her left hand's new attitude, but alien hand syndrome is a pesky, strange condition. Imagine, as another patient has reported, sitting down to play the piano, only to have one hand levitate far above the piano keys as you try to practice. It's not that you've changed your mind; your goal is still to play a sonata. But that hand — still yours, and now also not yours — is obeying new directions, and you didn't come up with them consciously. For the pianist and Byrne, and many other cases, alien hand symptoms appears rooted in disruption of communication through the corpus callosum. That's the set of fibers that connects the right and left sides of the brain. The pianist's corpus callosum showed missing connections on an MRI, and Byrne's left hand developed its disobedience after a surgeon severed her corpus callosum in an operation to treat epileptic seizures. © 2018 npr

Keyword: Laterality; Consciousness
Link ID: 24643 - Posted: 02.10.2018

By Marc Lewis Over the past year and a half, Scientific American has published a number of fine articles arguing that addiction is not a disease, that drugs are not the cause of addiction, and that social and societal factors are fundamental contributors to opioid addiction in general and the overdose crisis in particular. The dominant view, that addiction is a disease resulting from drug use, is gradually being eroded by these and other incisive critiques. Yet the disease model and its corollaries still prevail in the domains of research, policy setting, knowledge dissemination and treatment delivery, more in the United States than in any other country in the developed world. You might wonder: what are we waiting for? The disease model remains dominant in the U.S. because of its stakeholders. First, the rehab industry, worth an estimated $35 billion per year, uses the disease nomenclature in a vast majority of its ads and slogans. Despite consistently low success rates, that's not likely to stop because it pulls in the cash. Second, as long as addiction is labeled a disease, medical insurance providers can be required to pay for it. Of course they do so as cheaply as possible, to the detriment of service quality, but they at least save governments the true costs of dealing with addiction through education, social support, employment initiatives and anti-poverty mechanisms. Third, the National Institute on Drug Abuse (NIDA), a part of the National Institutes of Health (NIH) that funds roughly 90 percent of addiction research worldwide, is a medically oriented funder and policy setter, as are the American Society of Addiction Medicine and other similar bodies. © 2018 Scientific American

Keyword: Drug Abuse
Link ID: 24642 - Posted: 02.10.2018

National Institutes of Health scientists developing a rapid, practical test for the early diagnosis of prion diseases have modified the assay to offer the possibility of improving early diagnosis of Parkinson’s disease and dementia with Lewy bodies. The group, led by NIH’s National Institute of Allergy and Infectious Diseases (NIAID), tested 60 cerebral spinal fluid samples, including 12 from people with Parkinson’s disease, 17 from people with dementia with Lewy bodies, and 31 controls, including 16 of whom had Alzheimer’s disease. The test correctly excluded all the 31 controls and diagnosed both Parkinson’s disease and dementia with Lewy bodies with 93 percent accuracy. Importantly, test results were available within two days, compared to related assays that require up to 13 days. The group conducted the tests using Real-Time Quaking-Induced Conversion (RT-QuIC), an assay developed and refined over the past decade at NIAID’s Rocky Mountain Laboratories. Scientists from the University of California San Diego, University of Verona in Italy, Indiana University School of Medicine, Indianapolis, and the Case Western Reserve University School of Medicine, Cleveland, collaborated on the project. The research findings were published in Acta Neuropathologica Communications. Multiple neurological disorders, including Parkinson’s disease and dementia with Lewy bodies, involve the abnormal clumping of a protein called alpha-synuclein into brain deposits called Lewy bodies. The pathological processes in these diseases resembles prion diseases in mammal brains. Like prion diseases, Parkinson’s disease and dementia with Lewy bodies result in progressive deterioration of brain functions and, ultimately, death. Parkinson’s disease is about 1,000 times more common than prion diseases, affecting up to 1 million people in the United States, with 60,000 new cases diagnosed each year. Lewy body dementia affects an estimated 1.4 million people in the United States, according to the Lewy Body Dementia Association.

Keyword: Movement Disorders; Parkinsons
Link ID: 24641 - Posted: 02.10.2018

By Karl Gruber A. Fujiwara et al., “First report on the emergency dance of Apis cerana japonica, which induces odorous plant material collection in response to Vespa mandarinia japonica scouting,” Entomol Sci, doi:10.1111/ens.12285, 2017. The Waggle Dance Honeybees are famous for their waggle dances—figure-eight boogies that foragers use to inform nestmates about the locations of food or water. But entomologists were unclear about whether the dances could also be used to help ensure colony safety. Unwelcome Guests Ayumi Fujiwara, a graduate student at the University of Tokyo, and colleagues simulated wasp attacks on hives of the Japanese honeybee (Apis cerana japonica) to test the bees’ response to danger. “Giant wasps attack the nests of honeybees to feed their brood in autumn. As a result, wasps may sometimes annihilate a whole honeybee colony,” she says. Dance Off The researchers found that the bees did use a waggle dance as a warning signal, but only in response to sightings of one wasp species, Vespa mandarinia japonica. “The hive entrance dance informs bees’ nestmates of a specific emergency and of the urgent necessity to collect odorous plant materials as a counterattack strategy,” Fujiwara says. The bees collect stinky plant materials, such as leaves from Nepalese smartweed (Persicaria nepalensis), and smear them at the hive entrance to deter the wasps. Decoding the Moves The information coded in this new waggle dance is not yet completely clear, notes Margaret Couvillon, a biologist and honeybee specialist at Virginia Tech. “What would be interesting to see is if there are any differences in the conveying of directional information in this defensive context versus the regular foraging context,” she says. “Nature tends to be parsimonious in finding solutions, so we might expect that the bees use a similar mechanism in these different situations.” © 1986-2018 The Scientist

Keyword: Animal Communication; Aggression
Link ID: 24640 - Posted: 02.10.2018

By Kimberly Hickok Your webcam may know your face, but your keyboard knows your gender. Computer models can predict with 95.6% accuracy whether a man or woman is typing, according to a new study. To conduct the research, computer engineers installed keystroke-logging software onto the personal computers of 75 volunteers—36 men, 39 women—which monitored their daily computer use for 10 months. The researchers then used a program they created, called “ISqueezeU” to calculate the relative helpfulness of different typing features for determining gender—things like the time between two specific keystrokes, or the amount of time a key is pressed down during a single keystroke. A few features stood out as being more useful than others. For example, the average time between pressing the “N” key to pressing the “O” key was the most helpful, followed by the average time between pressing the “M” and “O” keys. The program isn’t capable of specifying whether a man or woman types those keys faster or more often—only that there is a difference. The researchers then tested the program’s findings using five machine learning models, which are computer programs that build models based on what they “learn” from existing data. All five models were able to predict gender accurately more than 78% of the time, with the most successful model being more than 95% accurate, the engineers report this week in Digital Investigation. The team proposes the use of keystroke dynamics as a cost-efficient and nonintrusive way to identify the gender of unknown computer users in criminal investigations, such as in cases of cyberstalking or identity theft. The researchers plan to expand their data collection with more volunteers, and see whether incorporating other variables such as handedness or education level can increase accuracy. © 2018 American Association for the Advancement of Science

Keyword: Sexual Behavior
Link ID: 24639 - Posted: 02.10.2018

By Roni Dengler Mental illness affects one in six U.S. adults, but scientists' sense of the underlying biology of most psychiatric disorders remains nebulous. That's frustrating for physicians treating the diseases, who must also make diagnoses based on symptoms that may only appear sporadically. No laboratory blood test or brain scan can yet distinguish whether someone has depression or bipolar disorder, for example. Now, however, a large-scale analysis of postmortem brains is revealing distinctive molecular traces in people with mental illness. This week, an international team of researchers reports that five major psychiatric disorders have patterns of gene activity that often overlap but also vary in disease-specific—and sometimes counterintuitive—ways. The findings, they say, might someday lead to diagnostic tests and novel therapies, and one has already inspired a clinical trial of a new way to treat overactive brain cells in autism. Outsiders say the data mark a milestone in psychiatry. "This [work] is changing fundamental views about the nature of psychiatric illness," says Kenneth Kendler, a psychiatric geneticist at Virginia Commonwealth University in Richmond. Researchers have long known that genes influence mental illness. Five years ago, for example, the global Psychiatric Genomics Consortium found that people with autism, schizophrenia, bipolar disorder, depression, and attention-deficit hyperactivity disorder frequently share certain DNA variations. But that 2013 study did not say how those genetic alterations might lead to symptoms. © 2018 American Association for the Advancement of Science

Keyword: Schizophrenia; Genes & Behavior
Link ID: 24638 - Posted: 02.09.2018

By Diana Kwon When optogenetics debuted over a decade ago, it quickly became the method of choice for many neuroscientists. By using light to selectively control ion channels on neurons in living animal brains, researchers could see how manipulating specific neural circuits altered behavior in real time. Since then, scientists have used the technique to study brain circuity and function across a variety of species, from fruit flies to monkeys—the method is even being tested in a clinical trial to restore vision in patients with a rare genetic disorder. Today (February 8) in Science, researchers report successfully conducting optogenetics experiments using injected nanoparticles in mice, inching the field closer to a noninvasive method of stimulating the brain with light that could one day have therapeutic uses. “Optogenetics revolutionized how we all do experimental neuroscience in terms of exploring circuits,” says Thomas McHugh, a neuroscientist at the RIKEN Brain Science Institute in Japan. However, this technique currently requires a permanently implanted fiber—so over the last few years, researchers have started to develop ways to stimulate the brain in less invasive ways. A number of groups devised such techniques using magnetic fields, electric currents, and sound. McHugh and his colleagues decided to try another approach: They chose near-infrared light, which can more easily penetrate tissue than the blue-green light typically used for optogenetics. “What we saw as an advantage was a kind of chemistry-based approach in which we can harness the power of near-infrared light to penetrate tissue, but still use this existing toolbox that's been developed over the last decade of optogenetic channels that respond to visible light,” McHugh says. © 1986-2018 The Scientist

Keyword: Brain imaging
Link ID: 24637 - Posted: 02.09.2018

by Ben Guarino Praying mantises do not perceive the world as you and I do. For starters, they're not very brainy — they're insects. A human brain has 85 billion neurons; insects such as mantises have fewer than a million. But mantises, despite their neuronal drought, have devised a way to see in three dimensions. They have a unique sort of vision unlike the 3-D sight used by primates or any other known creature, scientists at the University of Newcastle in Britain discovered recently. The scientists say they hope to apply this visionary technique to robots, allowing relatively unintelligent machines to see in 3-D. “Praying mantises are really specialized visual predators,” said Vivek Nityananda, an animal behavior expert at the university's Institute of Neuroscience. They are ambush hunters, waiting in stillness to strike at movement. Yet unlike other insects, they have two large, forward-facing eyes — the very feature that enables vertebrates to sense depth. Previous research had suggested that praying mantises use 3-D vision, also called stereopsis. Stereo vision, Nityananda said, is “basically comparing the slightly different views of each eye to be able to work out how far things are from you.” Uncovering the particulars of mantis stereo vision required a lot of patience and a little beeswax. Luckily, Nityananda and his teammates had both. Using the beeswax like glue — in a way that did not harm the insects — they affixed lenses to their faces. The lenses, similar to old-fashioned 3-D movie glasses, had one blue filter paired with one green filter. The mantises then were placed in front of a screen — an insect cinema, the researchers called it. © 1996-2018 The Washington Post

Keyword: Vision
Link ID: 24636 - Posted: 02.09.2018

Laura Sanders Brain scientists have filmed a first-of-a-kind birth video. It reveals specialized cells in the brains of mice dividing to create newborn nerve cells. The images, published in the Feb. 9 Science, show intricacies of how certain parts of the adult mouse brain can churn out new nerve cells. These details may help lead to a deeper understanding of the role of this nerve cell renewal in such processes as memory. Deep in the brains of mice, a memory-related structure called the hippocampus is known to be flush with new nerve cells. But because this buried neural real estate is hard to study, the circumstances of these births weren’t clear. Using living mice, Sebastian Jessberger, a neuroscientist at the University of Zurich, and colleagues removed the outer layers of brain tissue that obscure the hippocampus. The scientists marked 63 cells called radial stem cells, which can divide to create new nerve cells. Researchers then watched these stem cells for up to two months, taking pictures every 12 or 24 hours. During that time, 42 of these stem cells underwent a spurt of division, churning out two kinds of cells: intermediate cells that would go on to produce nerve cells as well as mature nerve cells themselves. Once this burst of activity ended, the radial stem cells disappeared by dividing themselves into mature nerve cells that could no longer split. |© Society for Science & the Public 2000 - 2017.

Keyword: Neurogenesis; Development of the Brain
Link ID: 24635 - Posted: 02.09.2018

By Andrew Joseph, Thousands of people with post-traumatic stress disorder have taken the drug prazosin to ease the nightmares and disturbances that stalk their sleep. Numerous studies have shown the drug to be effective at controlling those episodes. But a team of researchers from the Department of Veterans Affairs, seeking to collect more evidence, set out to study the sustained effectiveness of the treatment. They organized a large, lengthy, multisite trial—the most rigorous type of trial. The drug was no better than a placebo. The trial “seemed like a good idea, but you know, live and learn,” said Dr. Murray Raskind, a lead researcher on the trial, which was described Wednesday in the New England Journal of Medicine. Some researchers not involved with the study were quick to say that clinicians should still prescribe prazosin for some patients; Raskind, director of the VA Northwest Network Mental Illness Research, Education, and Clinical Center, agreed. There are few other treatment options and there is evidence supporting the use of the drug, a generic that was originally approved to treat high blood pressure but is prescribed off label to control nightmares and improve sleep quality in patients with PTSD. “I don’t think it should change clinical practice—there are six positive studies and one negative study,” said Raskind, who described the research team as “humbled” by the results. He estimated that 15 percent to 20 percent of veterans in the VA system with PTSD are currently prescribed prazosin, and said he did not expect that to change. © 2018 Scientific American

Keyword: Stress
Link ID: 24634 - Posted: 02.09.2018

By ANDREW JACOBS SANTIAGO, Chile — They killed Tony the Tiger. They did away with Cheetos’ Chester Cheetah. They banned Kinder Surprise, the chocolate eggs with a hidden toy. The Chilean government, facing skyrocketing rates of obesity, is waging war on unhealthy foods with a phalanx of marketing restrictions, mandatory packaging redesigns and labeling rules aimed at transforming the eating habits of 18 million people. Nutrition experts say the measures are the world’s most ambitious attempt to remake a country’s food culture, and could be a model for how to turn the tide on a global obesity epidemic that researchers say contributes to four million premature deaths a year. “It’s hard to overstate how significant Chile’s actions are — or how hard it has been to get there in the face of the usual pressures,” said Stephen Simpson, director of the Charles Perkins Centre, an organization of scholars focused on nutrition and obesity science and policy. The multibillion dollar food and soda industries have exerted those pressures to successfully stave off regulation in many other countries. Since the food law was enacted two years ago, it has forced multinational behemoths like Kellogg to remove iconic cartoon characters from sugary cereal boxes and banned the sale of candy like Kinder Surprise that use trinkets to lure young consumers. The law prohibits the sale of junk food like ice cream, chocolate and potato chips in Chilean schools and proscribes such products from being advertised during television programs or on websites aimed at young audiences. Beginning next year, such ads will be scrubbed entirely from TV, radio and movie theaters between 6 a.m. and 10 p.m. In an effort to encourage breast-feeding, a ban on marketing infant formula kicks in this spring. The linchpin of the initiative is a new labeling system that requires packaged food companies to prominently display black warning logos in the shape of a stop sign on items high in sugar, salt, calories or saturated fat. © 2018 The New York Times Company

Keyword: Obesity
Link ID: 24633 - Posted: 02.08.2018

By Catherine Offord River-dwelling populations of the Central American fish species Astyanax mexicanus sleep for more than 10 hours each day. But eyeless, cave-dwelling members of the same species barely sleep at all, and show no obvious health or developmental problems as a result. Now, researchers in the U.S. and in France have identified the signaling pathway behind this difference, offering a glimpse into the processes regulating sleep duration in vertebrates. The findings were published yesterday (February 6) in two papers in eLife. In one study, researchers at Florida Atlantic University compared the brains of cave-dwelling A. mexicanus with their surface-living cousins. They found that the number of neurons producing hypocretin—a neuropeptide linked to sleep-disorders such as narcolepsy when dysregulated—was significantly higher in the cave dwellers. What’s more, inhibiting hypocretin signaling genetically or pharmacologically increased cavefish’s sleep duration by several hours, while having minimal effect on surface-living fish. “These findings suggest that differences in hypocretin production may explain variation in sleep between animal species, or even between individual people,” study coauthor Alex Keene of Florida Atlantic University’s Brain Institute says in a statement. “It may also provide important insight into how we might build a brain that does not need to sleep.” © 1986-2018 The Scientist

Keyword: Sleep; Vision
Link ID: 24632 - Posted: 02.08.2018

Research into curious bright spots in the eyes on stroke patients’ brain images could one day alter the way these individuals are assessed and treated. A team of scientists at the National Institutes of Health found that a chemical routinely given to stroke patients undergoing brain scans can leak into their eyes, highlighting those areas and potentially providing insight into their strokes. The study was published in Neurology. “We were kind of astounded by this – it’s a very unrecognized phenomenon,” said Richard Leigh, M.D., an assistant clinical investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and the paper’s senior author. “It raises the question of whether there is something we can observe in the eye that would help clinicians evaluate the severity of a stroke and guide us on how best to help patients.” The eyes glowed so brightly on those images due to gadolinium, a harmless, transparent chemical often given to patients during magnetic resonance imaging (MRI) scans to highlight abnormalities in the brain. In healthy individuals, gadolinium remains in the blood stream and is filtered out by the kidneys. However, when someone has experienced damage to the blood-brain barrier, which controls whether substances in the blood can enter the brain, gadolinium leaks into the brain, creating bright spots that mark the location of brain damage. Previous research had shown that certain eye diseases could cause a similar disruption to the blood-ocular barrier, which does for the eye what the blood-brain barrier does for the brain. Dr. Leigh’s team discovered that a stroke can also compromise the blood-ocular barrier and that the gadolinium that leaked into a patient’s eyes could provide information about his or her stroke.

Keyword: Stroke; Vision
Link ID: 24631 - Posted: 02.08.2018

By David Grimm ANN ARBOR, MICHIGAN—If they weren't in the windowless basement of a cavernous biomedical research building, the "Aquatic Suites" might sound like a cushy vacation destination. But the zebrafish here at the University of Michigan (UM) still have it pretty good. In a large room full of aquaria, the striped, pinkie-size swimmers flit past fake green plants, white plastic tunnels, and multicolored marbles that may remind them of the bottoms of lakes and streams. These simple accoutrements are a luxury for creatures typically housed with little more than food and the water they swim in. And the enrichments may make the animals better at what they do: serving as important models for human disease. For decades, lab animals such as rodents and fish have lived in barren enclosures: a small plastic box, few—if any—companions, and little else. The smaller the number of variables, the thinking went, the greater the accuracy of the experiment. But a growing number of studies suggests that this approach may have backfired. Only one in nine drugs that works in animals ever succeeds in human clinical trials, and labs often struggle to reproduce one another's results. Could the environment these creatures live in be part of the problem? That's what a new group of advocates argues. "We're trying to control these animals so much, they're no longer useful," says Joseph Garner, a behavioral scientist who runs a program to improve the value and welfare of lab animals at Stanford University in Palo Alto, California. "If we want animals to tell us about stuff that's going to happen in people, we need to treat them more like people." © 2018 American Association for the Advancement of Science

Keyword: Animal Rights
Link ID: 24630 - Posted: 02.08.2018