Here's what the Swedish artist Oscar Reutersvard did. In 1934, he got himself a pen and paper and drew cubes, like this. He called this final version "Impossible Triangle of Opus 1 No. 293aa." I don't know what the "293aa" is about, but he was right about "impossible." An arrangement like this cannot take place in the physical universe as we know it. You follow the bottom row along with your eyes, then add another row, but when the third row pops in, where are you? Nowhere you have ever been before. At some step in the process you've been tricked, but it's very, very hard to say where the trick is, because what's happening is your brain wants to see all these boxes as units of a single triangle and while the parts simply won't gel, your brain insists on seeing them as a whole. It's YOU who's playing the trick, and you can't un-be you. So you are your own prisoner. At first, this feels like a neurological trap, like a lie you can't not believe. But when you think about for a bit, it's the opposite, it's a release. Twenty years later, the mathematician/physicist Roger Penrose (and his dad, psychologist Lionel Penrose) did it again. They hadn't seen Reutersvard's triangle. Theirs was drawn in perspective, which makes it even more challenging. Here's my version of their Penrose Triangle. What's cool about this? I'm going to paraphrase science writer John D. Barrow, in several places: We know that these drawings can't exist in the physical world. Even as we look at them, particularly when we look at them, we know they are impossible. And yet, we can imagine them anyway. Our brains, it turns out, are not prisoners of the world we live in; we can fly free! We can, any time we like, create the impossible. ©2013 NPR

Keyword: Vision; Attention
Link ID: 18484 - Posted: 08.10.2013

Some colors humans are exposed to late at night could cause symptoms of clinical depression. That is the conclusion of a study that builds on previous findings that individuals exposed to dim levels of light overnight, such as from a glowing television set, can develop signs of clinical depression. Investigators, curious as to whether the color of light contributed to depressive symptoms in humans, designed an experiment that exposed hamsters to different colors. They chose hamsters because they are nocturnal, meaning they sleep during the day and are active at night. One group of hamsters was kept in the dark during their nighttime period. Another group of rodents was exposed to blue light and a third group slept in the presence of white light. A fourth group of hamsters was exposed to glowing red light. After four weeks, researchers noted how much sugary water the hamsters drank. The more depressed rodents consumed the least amount of water. Randy Nelson, chair of Ohio State University’s Department of Neuroscience and co-author of the study, said animals that slept in blue and white light appeared to be the most depressed. “What we saw is these animals didn’t show any sleep disruptions at all but they did have mucked up circadian clock genes and they did show depressive phenotypes whereas if they were in the dim red light, they did not,” Nelson said. Nelson explained that photosensitive cells in the retina, which don’t have much to do with vision, detect light and transmit signals to the master circadian clock in the brain that controls the natural sleep-wake cycle.

Keyword: Biological Rhythms; Depression
Link ID: 18483 - Posted: 08.10.2013

Autism affects male and female brains differently, a study has suggested. UK experts studied brain scans of 120 men and women, with half of those studied having autism. The differences found in the research, published in journal Brain, show more work is needed to understand how autism affects girls, the scientists say. Experts said girls with the condition could be more stigmatised than boys - and it could be harder for them to be diagnosed at all. Autism affects 1% of the population and is more prevalent in boys, so most research has focused on them. In this study, scientists from the Autism Research Centre at the University of Cambridge used magnetic resonance imaging (MRI) to examine how autism affects the brain of males and females. The study looked at the difference between the brains of typical males and those with autism - and then females with and without autism. They found the brains of females with autism "look" more like - but still not the same as - healthy males, when compared with healthy females. But the same kind of difference was not seen in males with autism - so their brains did not show "extreme" male characteristics. Dr Meng-Chuan Lai, who worked on the study said: "What we have known about autism to date is mainly male-biased. BBC © 2013

Keyword: Autism; Sexual Behavior
Link ID: 18482 - Posted: 08.10.2013

By Fred Guterl Myths can be more harmful than lies, Nobel laureate Harry Kroto has said, because they are more difficult to recognize and often go unexamined. For many years, a diagnosis of schizophrenia was like a prison sentence, because many people (some of them in the medical profession) held to the notion that a schizophrenic could not recover from the illness and was condemned to an inexorable decline into madness. Like any myth, this one had some truth to it. Many people with severe symptoms do not recover. But some can, as Eleanor Longden discovered for herself. Longden began hearing voices when she was an undergraduate. At first they were somewhat benign, making mostly neutral, factual comments, but they grew more troublesome as she struggled to adjust to college life. Longden was diagnosed as schizophrenic and underwent conventional treatment. By her own account, in “Listening to Voices” in the September/October 2013 issue of Scientific American MIND, the label of schizophrenic and the attitudes of those around her to that label exacerbated her own internal struggles. The voices grew more menacing. Longden began her own slide into madness. But then something odd happened: she began to recover. She did so in part, she says, by accepting the voices in her head as an aspect of her own personality. She listened to them, and tried to understand them. In this way she was able to tame them, and she got enough control over her life to attend school and pursue her graduate studies. © 2013 Scientific American

Keyword: Schizophrenia
Link ID: 18481 - Posted: 08.10.2013

“OUR primary goal is for our users to see us as a gym, where they can work out and keep mentally fit,” says Michael Scanlon, the co-founder and chief scientist of Lumos Labs. For $14.95 a month, subscribers to the firm’s Lumosity website get to play a selection of online games designed to improve their cognitive performance. There are around 40 exercises available, including “speed match”, in which players click if an image matches a previous one; “memory matrix”, which requires remembering which squares on a matrix were shaded; and “raindrops”, which involves solving arithmetic problems before the raindrops containing them hit the ground. The puzzles are varied, according to how well users perform, to ensure they are given a suitably challenging brain-training session each day. The popularity of Lumosity since its launch in 2007 has been, well, mind-blowing. Its smartphone app has been the top education app in the iTunes store at some point in 38 countries. On August 1st it launched an iPad version, which it expects to boost its existing 45m registered users in 180-plus countries. Lumos Labs has already raised almost $70m in venture capital, and is one of two firms vying to become the first public company serving the new “digital brain health” market, says Alvaro Fernandez of SharpBrains, a research firm. (The firm hoping to beat it to the punch is NeuroSky, which makes “brainwave sensors”—including some shaped like cats’ ears that will apparently wiggle if you are enjoying yourself and droop if you are relaxed.) The metaphor of workouts for the mind will set alarm bells ringing for anyone familiar with Brain Gym, a series of physical exercises for children, adopted unquestioningly by many British schools, whose supposed cognitive benefits were debunked in “Bad Science”, a 2008 book by Ben Goldacre. However, Mr Scanlon, who quit his neuroscience PhD at Stanford University to co-found Lumos Labs, says he was inspired to do so by the mounting academic evidence of the plasticity of the brain and of the ability to improve cognitive function through simple exercises. © The Economist Newspaper Limited 2013

Keyword: Learning & Memory
Link ID: 18480 - Posted: 08.10.2013

Richard Johnston Scientists have mapped the dense interconnections and neuronal activity of mouse and fruitfly visual networks. The research teams, whose work is published in three separate studies today in Nature1–3, also created three-dimensional (3D) reconstructions, shown in the video above. All three studies interrogate parts of the central nervous system located in the eyes. In one, Moritz Helmstaedter, a neurobiologist at the Max Planck Institute of Neurobiology in Martinsried, Germany, and his collaborators created a complete 3D map of a 950-cell section of a mouse retina, including the interconnections among those neuronal cells. To do so, the team tapped into the help of more than 200 students, who collectively spent more than 20,000 hours processing the images1. The two other studies investigated how the retinas of the fruitfly (Drosophila melanogaster) detect motion. Shin-ya Takemura, a neuroscientist at the Howard Hughes Medical Institute in Ashburn, Virginia, and his collaborators mapped four neuronal circuits associated with motion perception and found that each is wired for detecting motion in a particular direction — up, down, left or right2. In the third study, Matthew Maisak, a computational biologist at the Max Planck Institute of Neurobiology, and his colleagues mapped the same four cellular networks and tagged the cells of each with protein markers that fluoresce in red, green, blue or yellow in response to stimulation with light3. © 2013 Nature Publishing Group,

Keyword: Vision
Link ID: 18479 - Posted: 08.08.2013

By Laura Sanders Pregnant mice buzzed on caffeine gave birth to pups with brain changes and lasting memory deficits, a new study shows. The results, published Aug. 7 in Science Translational Medicine, leave unclear whether caffeine causes a similar effect in people. The study convincingly shows that caffeine changes the brains of exposed pups, says child neurologist Barry Kosofsky of Weill Cornell Medical College in New York. But he cautions that mouse and human brains develop very differently, so direct comparisons are impossible. The study has no immediate message for pregnant women, Kosofsky says. “We are totally at a loss about what to say for caffeine.” For a mouse mother, though, the experiment’s story is clearer: Moderate caffeine intake during pregnancy changes baby brains, and not for the better. While pregnant and later lactating, mice drank water laced with caffeine — an amount comparable to that in three to four cups of coffee a day. In offspring, cells in a memory center in the brain called the hippocampus fired off too many messages, an abnormal behavior that could lead to seizures, Carla Silva, of the French National Institute of Health and Medical Research and the University of Coimbra in Portugal, and colleagues found. As adults, the caffeine-exposed mice performed worse than nonexposed mice on memory tests. Usually, mice ignore familiar objects and spend lots of time investigating something new. But mice exposed to caffeine while developing weren’t keen on exploring new objects, suggesting that they couldn’t remember which object was new. What’s more, these mice had fewer neurons in parts of the hippocampus than normal mice. © Society for Science & the Public 2000 - 2013

Keyword: Development of the Brain; Drug Abuse
Link ID: 18478 - Posted: 08.08.2013

Drinking cocoa every day may help older people keep their brains healthy, research suggests. A study of 60 elderly people with no dementia found two cups of cocoa a day improved blood flow to the brain in those who had problems to start with. Those participants whose blood flow improved also did better on memory tests at the end of the study, the journal Neurology reported. Experts said more research was needed before conclusions could be drawn. It is not the first time cocoa has been linked with vascular health and researchers believe that this is in part due to it being rich in flavanols, which are thought to have an important role. In the latest study, researchers asked 60 people with an average age of 73 to drink two cups of cocoa a day - one group given high-flavanol cocoa and another a low-flavanol cocoa - and consume no other chocolate. Ultrasound tests at the start of the study showed 17 of them had impaired blood flow to the brain. There was no difference between those who drank flavanol-rich cocoa and those who had flavanol-poor cocoa. But whichever drink they were given, 88% of those with impaired blood flow at the start of the study saw improvements in blood flow and some cognitive tests, compared with 37% of people whose blood flow was normal at the beginning of the study. BBC © 2013

Keyword: Alzheimers; Learning & Memory
Link ID: 18477 - Posted: 08.08.2013

By Nathan Seppa High blood glucose levels appear to be associated with an increased risk of dementia in older people, a new study finds. Paul Crane at the University of Washington in Seattle and his colleagues recorded blood glucose levels in 2,067 people an average of 76 years old who initially had no signs of dementia. After five years, roughly one-fourth of the participants developed some form of dementia. Among people without diabetes, the risk of developing dementia was 18 percent greater in those with high blood glucose levels than in those with low levels. In people with diabetes, the risk of dementia was 40 percent higher in the high-glucose group, the scientists report in the Aug. 8 New England Journal of Medicine. The researchers took into account differences in age, gender, education, heart disease, blood pressure, smoking history and exercise level. While the study doesn’t establish a biological link between high blood glucose and dementia, the researchers speculate that the association could be explained by either glucose-related damage to tiny blood vessels in the central nervous system or insulin resistance – in which cells lose the ability to efficiently process sugar. © Society for Science & the Public 2000 - 2013

Keyword: Alzheimers
Link ID: 18476 - Posted: 08.08.2013

By GRETCHEN REYNOLDS Over the past decade, in study after study in animals and people, exercise has been shown to improve the ability to learn and remember. But the specifics of that process have remained hazy. Is it better to exercise before you learn something new? What about during? And should the exercise be vigorous or gentle? Two new studies helpfully tackle those questions, with each reaching the conclusion that the timing and intensity of even a single bout of exercise can definitely affect your ability to remember — though not always beneficially. To reach that conclusion, scientists conducting the larger and more ambitious of the new studies, published in May in PLoS One, first recruited 81 healthy young women who were native German speakers and randomly divided them into three groups. Each group wore headphones and listened for 30 minutes to lists of paired words, one a common German noun and the other its Polish equivalent. The women were asked to memorize the unfamiliar word. But they heard the words under quite different circumstances. One group listened after sitting quietly for 30 minutes. A second group rode a stationary bicycle at a gentle pace for 30 minutes and then sat down and donned the headphones. And the third group rode a bicycle at a mild intensity for 30 minutes while wearing the headphones and listening to the new words. Two days later, the women completed tests of their new vocabulary. Everyone could recall some new words. But the women who had gently ridden a bicycle while hearing the new words — who had exercised lightly during the process of creating new memories —performed best. They had the most robust recall of the new information, significantly better than the group that had sat quietly and better than the group that had exercised before learning. Those women performed only slightly better than the women who had not exercised at all. Copyright 2013 The New York Times Company

Keyword: Learning & Memory
Link ID: 18475 - Posted: 08.08.2013

By Bora Zivkovic Sharks are not known for being good at running in running wheels. Or hopping from one perch to the other in a birdcage. Which is why, unlike hamsters or sparrows, sharks were never a very popular laboratory model for circadian research. The study of fish came late into the field of chronobiology due to technical difficulties of monitoring rhythms, at the time when comparative tradition was starting to make way to the more focused approach on choice model organisms – in this case, the zebrafish. But the comparative tradition was always very strong in the field. Reading the old papers (especially review papers and loooong theoretical papers) by the pioneers like Jurgen Asschoff and Colin Pittendrigh, it seems like researchers at the time were just going around and saying “let me try this species…and this one…and this one…”. And there were good reasons for this early approach. At the time, it was not yet known how widespread circadian rhythms were – it is this early research that showed they are ubiqutous in all organisms that live at or close to the surface of the earth or ocean. Another reason for such broad approach to testing many species was to find generalities – the empirical generalizations (e.g,. the Aschoff’s Rules) that allowed the field to get established, and that provided a template for the entire research program, including refining the proper experimental designs. © 2013 Scientific American

Keyword: Biological Rhythms
Link ID: 18474 - Posted: 08.08.2013

Jason Bruck Ever been at a party where you recognize everyone’s faces but can’t think of their names? That wouldn’t happen if you were a bottlenose dolphin (Tursiops truncatus). The marine mammals can remember each other’s signature contact whistles—calls that function as names—for more than 20 years, the longest social memory ever recorded for a nonhuman animal, according to a new study. “The ability to remember individuals is thought to be extremely important to the ‘social brain,’ ” says Janet Mann, a marine mammal biologist at Georgetown University in Washington, D.C., who was not involved in the research. Yet, she notes, no one has succeeded in designing a test for this talent in the great apes—our closest kin—let alone in dolphins. Dolphins use their signature whistles to stay in touch. Each has its own unique whistle, and they learn and can repeat the whistles of other dolphins. A dolphin will answer when another dolphin mimics its whistle—just as we reply when someone calls our name. The calls enable the marine mammals to communicate over long distances—which is necessary because they live in “fission-fusion” societies, meaning that dolphins in one group split off to join other groups and later return. By whistling, they’re able to find each other again. Scientists don’t know how long dolphins are separated in the wild, but they do know the animals can live almost 50 years. So how long do the dolphins remember the calls of their friends? To find out, Jason Bruck, a cognitive ethologist at the University of Chicago in Illinois, spent 5 years collecting 71 whistles from 43 dolphins at six captive facilities, including Brookfield Zoo near Chicago and Dolphin Quest in Bermuda. The six sites belong to a consortium that rotates the marine mammals for breeding and has decades-long records of which dolphins have lived together. © 2012 American Association for the Advancement of Science

Keyword: Learning & Memory; Animal Communication
Link ID: 18473 - Posted: 08.07.2013

by Nora Schultz A unique population in northern Finland has helped reveal that schizophrenia, some autism spectrum disorders and other forms of cognitive impairment may all share a common genetic pathway. In Finland, there exist several small communities that used to live for years in isolation. Amongst the descendants of these groups, otherwise rare genes occur more regularly than elsewhere in the country because a level of inbreeding was almost inevitable. Nelson Freimer at the University of California, Los Angeles, and colleagues studied one of these communities, where schizophrenia and other neurological disorders are unusually common. His team first searched for any genetic deletions – chunks of DNA that are missing from a chromosome – that were more common in this group than in the general population. They found a promising candidate on chromosome 22. A deletion on this chromosome was present in 18 of 173 people from this isolated group, but in just one of the 1586 samples taken from people spread throughout the rest of Finland. Tests confirmed that people with schizophrenia or cognitive impairments were more likely to be missing this chunk of DNA. Identifying this deletion as a risk factor for schizophrenia and cognitive impairment puts us one step closer to understanding the biological processes at the root of such complex syndromes, says Freimer. © Copyright Reed Business Information Ltd.

Keyword: Autism; Schizophrenia
Link ID: 18472 - Posted: 08.07.2013

By ANAHAD O'CONNOR Losing sleep tends to make people eat more and gain weight, and now a new study suggests that one reason may be the impact that sleep deprivation has on the brain. The research showed that depriving people of sleep for one night created pronounced changes in the way their brains responded to high-calorie junk foods. On days when the subjects had not had proper sleep, fattening foods like potato chips and sweets stimulated stronger responses in a part of the brain that helps govern the motivation to eat. But at the same time, the subjects experienced a sharp reduction in activity in the frontal cortex, a higher-level part of the brain where consequences are weighed and rational decisions are made. The findings suggested that one unfortunate result of sleep loss is this “double hit” in brain activity, said Matthew P. Walker, an author of the study and a professor of psychology and neuroscience at the University of California, Berkeley. A sleepy brain appears to not only respond more strongly to junk food, but also has less ability to rein that impulse in. Some experts have theorized that in a sleep-deprived state, people eat more food simply to make up for all the calories they expend as they burn the midnight oil. But the new study showed that the changes in brain activity were evident even when the subjects were fed extra food and not experiencing any increased sensations in hunger. “Their hunger was no different when they were sleep deprived and when they had a normal night of sleep,” Dr. Walker said. “That’s important because it suggests that the changes we’re seeing are caused by sleep deprivation itself, rather than simply being perhaps more metabolically impaired when you’re sleep deprived.” Copyright 2013 The New York Times Company

Keyword: Sleep; Obesity
Link ID: 18471 - Posted: 08.07.2013

// by Jennifer Viegas Single parenting takes on new extremes for certain starfish that are hermaphrodites -- male and female at the same time and, in some cases, self-fertilizing. The species faces high risk of extinction, according to new research. The dire situation faced by the non-mating starfish, Parvulastra parvivipara and Parvulastra vivipara, helps to explain why so many organisms, including humans, have sex. Genetic diversity and the dispersal of youngsters support population growth. The plight of the starfish, documented in the latest issue of the journal Biology Letters, reveals how a life without sex but with self-fertilization could result in eventual oblivion. “There are quite a few reasons why these species are vulnerable,” senior author Michael Hart of Simon Fraser University’s Department of Biological Sciences told Discovery News. “The whole species could be wiped out.” Hart and his team studied the starfish, which are restricted to high intertidal pools of South Australia and Tasmania. These starfish also go by the nickname "sea cushions," since they look a bit more like a cushion than a star when viewed from the side. Most adult starfish of other species do reproduce via a separate male and female. Females usually produce eggs that males fertilize in the seawater. At that point, the fertilized eggs develop and grow before becoming little starfish that will attach themselves to the substrate and start the whole process over again. © 2013 Discovery Communications, LLC.

Keyword: Sexual Behavior; Evolution
Link ID: 18470 - Posted: 08.07.2013

Daniel Cressey Killing research animals is one of the most unpleasant tasks in science, and it is imperative to do it as humanely as possible. But researchers who study animal welfare and euthanasia are growing increasingly concerned that widely used techniques are not the least painful and least stressful available. This week, experts from across the world will gather in Newcastle upon Tyne, UK, to debate the evidence and try to reach a consensus. “There are lots of assumptions made about the humaneness of various techniques for euthanizing animals,” says Penny Hawkins, deputy head of the research animals department at the Royal Society for the Prevention of Cruelty to Animals, a charity based in Southwater, UK. “Sometimes an animal might not appear to be suffering, but might be conscious and suffering.” Much of the debate centres on rodents, which make up the vast majority of research animals. Current techniques for killing them include inhalation methods — such as chambers that fill with carbon dioxide or anaesthetic gases — and injecting barbiturates. Physical methods include cervical dislocation (breaking of the neck), or decapitation with specialist rodent guillotines (see ‘Methods used to kill lab rats’). Experts hotly debate which method is preferable. The most-discussed question at the meeting is likely to be about the use of CO2. © 2013 Nature Publishing Group

Keyword: Animal Rights
Link ID: 18469 - Posted: 08.07.2013

A gene that affects the brain's dopamine system appears to have influenced mothers' behavior during a recent economic downturn, researchers say. At the beginning of the recession that began in 2007, mothers with the "sensitive" version of a gene called DRD2 became more likely to strike or scream at their children, the researchers say. Mothers with the other "insensitive" version of the gene didn't change their behavior. But once it appeared that the recession would not become a full-fledged depression, the "sensitive" mothers became less likely than "insensitive" mothers to engage in harsh parenting. "You have the same genes, and with a different environment it's a completely different story," says , a professor of contemporary urban problems at Columbia University. "I think that's the most amazing part of what we found." Garfinkel and four other researchers in the Proceedings of the National Academy of Sciences. The surprising finding came about because Garfinkel and the other researchers happened to be studying "fragile" families in 20 large cities when the 2007 recession began. One of the things they were tracking was reports of harsh parenting, including spanking, hitting or screaming at a child, he says. Previous research had found that harsh parenting is more common during economic hard times, so Garfinkel says that's what researchers expected to see during the 2007-2009 period, often called the Great Recession. ©2013 NPR

Keyword: Stress; Genes & Behavior
Link ID: 18468 - Posted: 08.07.2013

Women living in urban centres in Canada with more than 500,000 inhabitants are at higher risk of postpartum depression than women in other areas, suggests a new study in the Canadian Medical Association Journal. Looking at the experiences of over 6,000 women who lived in rural, semi-rural, semi-urban or urban areas from the 2006 Canadian Maternity Experiences Survey, the study suggests that women in urban areas were at higher risk, with almost 10 per cent reporting postpartum depression compared with six per cent of women in rural areas, almost seven per cent of women in semirural areas and about five per cent in semiurban areas. Urban areas were found to have higher numbers of immigrant populations, and more women in these areas reported lower levels of social support during and after pregnancy. "We found that Canadian women who lived in large urban areas … were at higher risk of postpartum depression than women living in other areas," said Dr. Simone Vigod, psychiatrist at Women's College Hospital and scientist at Women's College Research Institute in Toronto. "The risk factors for postpartum depression [including history of depression, social support and immigration status] that were unequally distributed across geographic regions accounted for most of the variance in the rates of postpartum depression." The reason why immigrant woman appear to be at higher risk is not really known, she said. "Some theories are that it's related to social support or being away from their family." They could also have cultural barriers or needs that are not being met, she added. © CBC 2013

Keyword: Depression; Stress
Link ID: 18467 - Posted: 08.07.2013

Lying in bed, unable to move a muscle, so-called locked-in patients have few ways to communicate with the outside world. But researchers have now found a way to use the widening and narrowing of the pupils to send a message, potentially helping these patients break the silence. Doctors use the constriction of pupils under bright light to test whether a patient’s brain stem is intact. But our pupils also show the opposite response—dilation—based on our thoughts and emotions, says Wolfgang Einhäuser, a neurophysicist at Philipps University of Marburg in Germany. Einhäuser had been struggling to interpret changes in pupil size during decision-making when he began to wonder about a different application. He contacted Steven Laureys, a member of the Coma Science Group at the University Hospital of Liège in Belgium, to explore how the pupil could be used to communicate a choice. Laureys works with locked-in patients, who have normal mental acuity but are paralyzed and unable to express thoughts to those around them. Many can control only the muscles that move their eyes; some, not even that. They can learn to communicate using EEG technology, in which electrodes on the scalp detect changes in brain activity. But applying the electrode cap is time-consuming, and the equipment is expensive, Einhäuser says. “If you imagine doing that every day, basically to communicate, that’s troublesome.” To find a different technique, Einhäuser, Laureys, and colleagues reached back in time. “The pieces have been there since the early ’60s,” Einhäuser says. A 1964 study showed that our pupils dilate when we perform mental arithmetic, like attempting to multiply 27 and 15 with no pencil and paper, and that harder tasks led to more dramatic dilation. The team set up a camera and a laptop to explore this automatic response. © 2012 American Association for the Advancement of Science.

Keyword: Movement Disorders; Vision
Link ID: 18466 - Posted: 08.06.2013

Researchers have achieved dynamic, atomic-scale views of a protein needed to maintain the transparency of the lens in the human eye. The work, funded in part by the National Institutes of Health, could lead to new insights and drugs for treating cataract and a variety of other health conditions. Aquaporin proteins form water channels between cells and are found in many tissues, but aquaporin zero (AQP0) is found only in the mammalian lens, which focuses light onto the retina, at the back of the eye. The lens is primarily made up of unique cells called lens fibers that contain little else besides water and proteins called crystallins. Tight packing of these fibers and of the crystallin proteins within them helps create a uniform medium that allows light to pass through the lens, almost as if it were glass. Abnormal development or age-related changes in the lens can lead to cataract — a clouding of the lens that causes vision loss. Besides age, other risk factors for cataract include smoking, diabetes, and genetic factors. Mutations in the AQP0 gene can cause congenital cataract and may increase the risk of age-related cataract. “The AQP0 channel is believed to play a vital role in maintaining the transparency of the lens and in regulating water volume in the lens fibers, so understanding the molecular details of how water flows through the channel could lead to a better understanding of cataract,” said Dr. Houmam Araj, who oversees programs on lens, cataract and oculomotor systems at NIH’s National Eye Institute (NEI), which helped fund the research.

Keyword: Vision
Link ID: 18465 - Posted: 08.06.2013