By JANE E. BRODY If you have gained a lot of unwanted pounds at any time during the last 30-odd years, you may be relieved to know that you are probably not to blame. At least not entirely. Many environmental forces, from economic interests of the food and beverage industries to the way our cities and towns are built, have conspired to subvert the body’s natural ability to match calories in with calories out. And the solution to the nation’s most pressing health problem — the ever-rising epidemic of overweight and obesity at all ages — lies in the answer to this question: Why did this happen in the first place? That is the conclusion of an impressive team of experts who spent the last two years examining obesity-promoting forces globally. They recently published their findings online in a series of reports in The Lancet. But as has happened with smoking, it will take many years, a slew of different tactics and the political will to overcome powerful lobbying by culpable industries to turn the problem around and begin to bring the prevalence of overweight and obesity back to the levels of the 1970s. When I was growing up in the 1940s and ’50s, I had to walk or bike many blocks to buy an ice cream cone. There were no vending machines dispensing candy and soda, and no fast-food emporiums or shopping malls with food courts. Nor were we constantly bombarded with televised commercials for prepared foods and drinks laden with calories of fats and sugars. © 2011 The New York Times Company

Keyword: Obesity
Link ID: 15796 - Posted: 09.13.2011

by Elizabeth Norton Humans are probably the only species on Earth who nurture their young for 20 years or more. For men in particular, the intensive demands of parenting can come as such a shock that a built-in biological mechanism has evolved to help cope with the change. A new study shows that becoming a father leads to a sharp decline in testosterone, suggesting that although high levels of the hormone may help men win a mate, testosterone-fueled traits such as aggression and competition are less useful when it comes to raising children. Previous research had shown that among new fathers, testosterone levels were lower than in men of the same age who didn't have children. But no study addressed whether parenthood itself was responsible, or whether men who became committed partners and fathers started out with lower levels of the hormone than did their single, footloose friends. To sort out cause and effect, anthropologists Lee Gettler, Christopher Kuzawa, and colleagues at Northwestern University in Evanston, Illinois, and the University of San Carlos in Cebu City, Philippines, checked testosterone levels in a group of men participating in the ongoing Cebu Longitudinal Health and Nutrition Survey. The survey began with a group of some 3000 women who were pregnant in 1983 and followed the general health, nutrition, medical care, and survival of their children; it has since expanded into an intergenerational study of health, education, and sexual behavior as those children grew up and are now having children of their own. © 2010 American Association for the Advancement of Science.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 15795 - Posted: 09.13.2011

By GINA KOLATA A small pilot study has found preliminary evidence that squirting insulin deep into the nose where it travels to the brain might hold early Alzheimer’s disease at bay, researchers said on Monday. It comes at a time when there are no effective ways to prevent or delay the progress of Alzheimer’s. And although the results are preliminary and must be viewed with caution, “it is a provocative study,” said Dr. Jason Karlawish, an Alzheimer’s researcher and ethicist at the University of Pennsylvania. But he and other experts caution that a bigger and longer study is needed to see if the initial results hold up and whether there are adverse effects that might negate any benefits. “It’s important readers realize this is a pilot trial,” said Dr. P. Murali Doraiswamy, an Alzheimer’s researcher at Duke University who was not part of the study. “It’s not ready for prime time.” The study, published online in the Archives of Neurology, included 104 people, a group small enough that the promising results could have occurred by chance. Researchers at the University of Washington divided the subjects into three groups. One got a placebo, one got 20 international units of aerosolized insulin a day, and the third got 40 international units a day. In the four-month study, the group randomly assigned to receive intranasal insulin twice a day either improved slightly or remained the same in tests of memory and assessments of their ability to handle day-to-day activities. The lower dose seemed more effective than the higher one. Those who received placebos got worse. © 2011 The New York Times Company

Keyword: Alzheimers
Link ID: 15794 - Posted: 09.13.2011

Glioma, one of the most deadly and common types of brain tumor, is often associated with seizures, but the origins of these seizures and effective treatments for them have been elusive. Now a team funded by the National Institutes of Health has found that human gliomas implanted in mice release excess levels of the brain chemical glutamate, overstimulating neurons near the tumor and triggering seizures. The researchers also found that sulfasalazine, a drug on the market for treating certain inflammatory disorders, can reduce seizures in mice with glioma. About 80 percent of people with glioma will experience at least one seizure during their illness, often as the first symptom. About one-third of patients will develop recurring seizures, known as tumor-associated epilepsy. Sen. Ted Kennedy, D-Mass., whose death was caused by a malignant glioma in August 2009, was diagnosed after having a seizure 15 months earlier. "Seizures are a frequent symptom of glioma and are often poorly controlled by epilepsy medications," said Jane Fountain, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). "Understanding why the seizures occur and how to counteract them could help us substantially improve the quality of life for people with glioma." "People have assumed that tumors cause seizures by irritating the brain, but that really isn't a scientific explanation. We have now shown that the seizures are caused by glutamate release from the tumor," said Harald Sontheimer, Ph.D., a professor of neurobiology and director of the Center for Glial Biology in Medicine at the University of Alabama Birmingham (UAB). Dr. Sontheimer and his team published their results in Nature Medicine.

Keyword: Epilepsy
Link ID: 15793 - Posted: 09.13.2011

By Lauren Ware In a clear Plexiglas laboratory cage, a mouse sleeps. A thin fiber optic cable projects upward from the top of its head and out through the cage’s lid. The cable lights with a pulse of blue light. The mouse continues to sleep; the light continues to pulse. After a few more pulses, the mouse wakes up. It rubs its face, stretches its legs and runs over to its food cup and begins to eat voraciously, as though it were starving. It keeps eating as the blue light pulses. The optical fiber that carries the blue light goes directly into the mouse’s brain. It targets a specific group of brain cells that have been modified to react to light. The experiment uses a technique called optogenetics, developed seven years ago, which can selectively activate or silence groups of nerve cells, or neurons, in real time. And it allows scientists to interact with the brain and begin to map how it works with a degree of detail that was previously unimaginable. That’s what Scott Sternson has done with the apparently starving mouse at Janelia Farm in Ashburn, Va., an interdisciplinary biomedical research center that is part of the Howard Hughes Medical Institute. In fact, this mouse was well fed and should not have been hungry. Sternson’s research group targeted a type of cell called the agouti-related peptide (AGRP) neuron. AGRP cells live in the hypothalamus and have been linked to feeding behavior in other studies. The scientists used a virus to insert the DNA of a light-sensitive protein from bacteria, channelrhodopsin-2, into the AGRP neurons. Some of the AGRP neurons take up the DNA and begin to produce the protein and send it to the cell membrane. When the blue light is flashed into the mouse’s brain via the optical fiber, the protein causes the neurons to move ions across the cell membrane, effectively stimulating them to fire an electrical signal, the action potential, which neurons use to communicate with each other. Sternson found that the more AGRP neurons are stimulated, the more the mouse eats. And as soon as the light stops, so does the feeding. Miller-McCune © 2011

Keyword: Genes & Behavior
Link ID: 15792 - Posted: 09.13.2011

By Victoria Gill Science reporter, BBC Nature Big brown bats learn to hunt by eavesdropping on the sonar of other bats, according to researchers. A team from the University of Maryland, US, tracked bats as they flew around a room hunting for a mealworm suspended from the ceiling. Young bats that flew with "experienced" bats - that had been trained to find the worm - were quickly able to find the treat alone. The results are published in the journal Animal Behaviour. They are the first to show that the bats (Eptesicus fuscus) actively attend to the sonar of others in order to learn from them. This social learning is important to many mammals, but it had not been clearly demonstrated in bats. Genevieve Spanjer Wright, a graduate student from the University of Maryland led the research. She and her colleagues trained 12 "demonstrator bats" to catch a mealworm suspended from the ceiling by a string. By repeatedly changing the location of the food item, the researchers trained the bats to actively hunt for it using their sonar or echolocation pulses. BBC © 2011

Keyword: Hearing; Development of the Brain
Link ID: 15791 - Posted: 09.12.2011

By Katherine Harmon Just watching television footage of the terrorist attacks of September 11, 2001​, was enough to cause clinically diagnosable stress responses in some people who did not even live near the attacks—let alone the millions of people who did. Like many other major disasters, 9/11 brought with it a host of psychological repercussions, one of the most severe of which has been post-traumatic stress disorder. PTSD is characterized by trouble sleeping, difficulty controlling anger, losing interest in activities, flashbacks, emotional numbness and/or other symptoms. If not treated, it can be debilitating. But these reactions are not uncommon after a major disaster—and teasing apart post-9/11 disorders has been tricky for psychologists and researchers. "We tend to use the terminology of PTSD very loosely. A lot of people will have traumatic reactions but not necessarily PTSD," says Priscilla Dass-Brailsford of Georgetown University Medical Center's psychiatry department. Researchers have been poring over the piecemeal collection of studies conducted over the past decade on the conditions of people after the attacks—how they felt and how well various treatments, and the passage of time, have helped them overcome mental afflictions. And from the literature, we are learning that old styles of early intervention, such as debriefing sessions, are not as effective as once thought—and that more often than not, people are incredibly resilient and can recover on their own and should be given the opportunity to do so. © 2011 Scientific American,

Keyword: Stress
Link ID: 15790 - Posted: 09.12.2011

Zoë Corbyn Scientists have developed a miniature fluorescence microscope small enough to implant in the head of a living mouse and gather images from its brain without hindering its movement. The 1.9-gram, 2.4-cubic-centimetre device is described today in Nature Methods1. The device has already yielded results. The authors, led by applied physicist Mark Schnitzer and electrical engineer Abbas El Gamal of Stanford University in Stanford, California, report findings regarding both the dilation of capillaries in mouse brains and the firing of motor-activity-related Purkinje neurons, as well as some potential in vitro applications for the device, such as counting cells or spotting bacteria in samples. With a maximum resolution of 2.5 microns, the microscope is not as powerful as conventional bench-top models, which have resolutions as fine as 0.5 microns. But it does have a "very good" field of view which is larger than some bench-top models, notes Schnitzer. "For neuroscientists, [this method] is going to enable some experiments that we couldn't do before – indeed it already has", he says. Schnitzer and three of his colleagues have already founded a company, called Inscopix, in hopes of capitalizing on their device. While miniature versions of fluorescence microscopes have been produced before, including one by the Stanford group in 2008 that was lighter, none have been self contained or made using mass produced components. This microscope "contains all the optical parts within a single, small and easily-transportable housing, and we use mass-fabricated components, which opens up the possibility of mass-producing the entire microscope," says Schnitzer. © 2011 Nature Publishing Group,

Keyword: Brain imaging
Link ID: 15789 - Posted: 09.12.2011

By Matt McGrath Science reporter, BBC World Service Scientists have discovered that female chickens have a remarkable ability to choose the father of their eggs. Wily hens have evolved the ability to eject the sperm of unsuitable mates say researchers working with Swedish birds. Promiscuous roosters try to ensure that their genes are passed on by mating with as many females as possible. But by removing the genetic material of males they consider socially inferior, the hens have managed to retain control of paternity. Many species ranging from zebras to insects use the strategy of sperm ejection - but the evolutionary ideas behind it are often uncertain. Among birds, male Dunnocks force females to eject the sperm of other suitors in order to protect their own genes. But this research indicates that among chickens, the battle of the sexes seems to be all about female empowerment. Working with feral fowl in Sweden, the scientists found that many matings were forced, as the roosters are twice the size of the hens. To cope with the unwanted attention, females have evolved the ability to remove the ejaculate of those males they consider undesirable. BBC © 2011

Keyword: Sexual Behavior; Evolution
Link ID: 15788 - Posted: 09.12.2011

by Aria Pearson Whence the female orgasm? After 40 years of debate evolutionary biologists are no closer to deciding whether it evolved to give women a reproductive boost, or whether it is simply a by-product of male orgasm evolution. The latest attempt to settle the dispute involves quizzing some 10,000 twins and pairs of siblings on their sexual habits. Some evolutionary biologists reckon the female orgasm is adaptive and possibly influences mate choice, strengthens pair bonds or indirectly helps to suck sperm into the uterus. Others argue that women have orgasms for the same reason that men have nipples – being highly adaptive in one sex, the traits tag along for the ride in the other. Brendan Zietsch at the University of Queensland, Australia, and Pekka Santtila at Abo Akademi University in Turku, Finland, think they can help to settle the question. If female orgasm is a simple by-product of male orgasm, the duo argue, then similar genes would underlie orgasmic function in both men and women. As a consequence, opposite-sex twins and siblings will share more similarities in their susceptibility to orgasm – "orgasmability" as Zietsch calls it – than pairs of unrelated people. To measure this orgasmability, the researchers used survey data from just under 5000 sets of identical and non-identical twins and pairs of regular siblings. The questionnaire asked about the time to orgasm in men and the frequency and ease of orgasm in women. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 15787 - Posted: 09.10.2011

Sandrine Ceurstemont, The spinning 3D shape in this video conceals six different illusions. To see it in 3D, you'll need to cross your eyes until the two images overlap and merge together. (If you're having trouble, try viewing the video in full screen or check out some tips here). The object in the video was created by Rex Young, an enthusiast with an illusions channel on YouTube, based on parts and instructions provided by artist Terry Pope. It was originally conceived to be viewed with a pseudoscope, an optical device that switches what the eyes are seeing using mirrors. But, by filming the structure with a stereoscopic camera and reversing the left and right frames, the same illusion can be seen just by crossing your eyes. So why do we perceive this brain trick? When we view a scene, the image that appears on our retina is two-dimensional, so our visual system uses a variety of cues to add depth. One of these involves comparing the position of images on the left and right retinas to determine distance. Since the images in this video have been flipped, it reverses our distance cues, causing far away points to seem closer than nearer ones and altering our perception in a variety of ways. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15786 - Posted: 09.10.2011

by Catherine de Lange Fetuses can tell the difference between pain and touch in only the last two weeks before birth, which could help to explain why babies born prematurely often have abnormal pain responses. Lorenzo Fabrizi from University College London and colleagues used EEG, a non-invasive way of measuring brain activity, on 46 newborn babies as they underwent a routine heel lance – a pinprick to the heel for taking a blood sample. They also measured how the babies' brains responded to normal touch – a light tap to the heel. Almost half of the babies were born prematurely – some at just 28 weeks – so the team were able to compare the responses of babies in the final stages of development with those of babies born at full term. Premature babies up to the age of 35 weeks had bursts of activity across the whole brain in response to both pain and touch, but a change happened around 35 weeks. Between 35 to 37 weeks – just before a fetus would normally be born – the brain seemed to become able to tell the two stimuli apart. The responses to both pain and touch now took place in specific areas on the front, back and sides of the brain, but the signal was much stronger for pain. "This is an important stage in the development of the brain," says Fabrizi, when changes occur to allow the brain to process sensory stimulation in a more sophisticated way in preparation for life outside the womb. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Development of the Brain
Link ID: 15785 - Posted: 09.10.2011

Analysis by Jennifer Viegas Shrimp, most often seen in cocktail glasses with a side of sauce, aren't exactly known for their musical talents. But a study in the journal Aquatic Biology found that, at least for mantis shrimp, each has its own unique voice, with males teaming up in groups of three either to attract females or frighten off enemies. Like rappers, these male shrimp vocal groups produce synchronized rhythmic pieces that grab the attention of others. Marine biologist Erica Staaterman of the University of Miami Rosenstiel School of Marine and Atmospheric Sciences and colleagues heard the shrimp after collecting data using various instruments. These included hydrophones and an autonomous recording unit placed in the muddy waters off the coast of Catalina Island, California. "Rarely are there studies of benthic acoustics (sounds from the ocean floor)," said Staaterman in a press release. "There has always been suspicion that burrow-dwelling creatures like the mantis shrimp make some sort of noise, and our research is going to help us better understand life and communication on the ocean floor." The study revealed that each mantis shrimp made noise, with individuals all seeming to produce their own characteristic sounds. The males were heard making loud rhythmic "rumbles" with their trios. (You can listen to certain mantis rumbles here.) Each male measures about 8 to 10 inches long, so these are sizeable shrimp that can create quite a din, especially if you imagine numerous trios all rumbling in the same area. © 2011 Discovery Communications, LLC.

Keyword: Sexual Behavior; Animal Communication
Link ID: 15784 - Posted: 09.10.2011

by Kim Krieger A mathematical model may explain how the nerves in your ear sense harmony, a team of biophysicists reports. The model suggests that pleasant harmonies cause neurons to fire in regular patterns whereas discordant notes stimulate messier neuron activity. Strike the middle C on a piano and hold it. Count two white keys to the right and hit the A. The bright and pleasing sound of a major third fills the air. That unmistakable sensation of musical harmony depends on the frequencies of the sound waves that make the two notes. Consonant chords consist of musical notes whose frequencies form simple ratios such as 2/1 for an octave, 3/2 for a major fifth, or 5/4 for a major third. Dissonant chords have frequency ratios of big numbers such as 16/15 or 45/32. But scientists don’t know precisely how the ear and brain sense this mathematical difference. Now, Bernardo Spagnolo, a biophysicist at the University of Palermo in Italy and collaborators at Lobachevsky State University of Nizhni Novgorod in Russia have come up with a simple neurological model that does the trick. A sound wave sets your eardrum vibrating, which ultimately causes a spiraling membrane within the inner ear called the basilar membrane to vibrate, too. Exactly where along its length the membrane jiggles depends on the frequency of the sound, with higher frequencies causing jiggling farther along the tapering membrane. Those vibrations stimulate neurons that convey the frequency information to the brain. © 2010 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 15783 - Posted: 09.10.2011

A gene responsible for chronic pain has been identified, with scientists saying this could lead to drugs for treating long-lasting back pain. Writing in the journal Science, University of Cambridge researchers removed the HCN2 gene from pain-sensitive nerves in mice. Deleting the gene stopped any chronic pain but did not affect acute pain. About one in seven people in the UK suffer from chronic pain, which can also include arthritis and headaches. The researchers say their findings open up the possibility that new drugs could be developed to block the protein produced by the HCN2 gene, which regulates chronic pain. The HCN2 gene, which is expressed in pain-sensitive nerve endings, has been known for several years, but its role in regulating pain was not understood. For the study, the researchers removed the HCN2 gene from pain-sensitive nerves. They then carried out studies using electrical stimuli on these nerves in cell cultures to determine how they were altered by the removal of HCN2. They then studied genetically modified mice in which the HCN2 gene had been deleted. By measuring the speed that the mice withdrew from different types of painful stimuli, the scientists were able to conclude that deleting the HCN2 gene abolished neuropathic pain. BBC © 2011

Keyword: Pain & Touch; Genes & Behavior
Link ID: 15782 - Posted: 09.10.2011

By Tina Hesman Saey A fish that swims in limestone caverns under the Somalian desert has something to tell scientists about keeping time. Despite living in permanent darkness, with no difference between day and night, this blind cave-dweller still has its own quirky sense of rhythm. The Somalian cave fish, Phreatichthys andruzzii, has an inner timekeeper that ticks out a roughly 47-hour cycle set by food rather than sunlight, scientists from Italy, Germany and Spain report online September 6 in PLoS Biology. This odd biological clock may teach scientists more about the molecular pathways that govern such clocks, why clocks are important to organisms and how living things adapt when their clocks are no longer tied to cycles set by the rising and setting of the sun. Most animals, plants and some kinds of bacteria follow the sun’s cue in setting their own daily clocks. These biological, or circadian, clocks help govern sleeping, waking and feeding times, the rise and fall of blood pressure and other daily rhythms. Generally, circadian clocks follow an approximately 24-hour cycle and are reset largely by sunlight. When people’s circadian clocks aren’t set correctly, jet lag and even long-term health problems can result. Researchers study fish and other organisms to learn how circadian clocks’ gears mesh. Somalian cave fish have been cut off from the sun for up to 2.6 million years. Adapting to life in the dark has not only caused the fish’s eyes (as well as its scales and skin coloring) to disappear, but also altered its clock, say study authors Nicholas S. Foulkes of the Karlsruhe Institute of Technology in Germany, Cristiano Bertolucci of the University of Ferrara in Italy and their colleagues. © Society for Science & the Public 2000 - 2011

Keyword: Biological Rhythms; Evolution
Link ID: 15781 - Posted: 09.08.2011

By Nathan Seppa Threading a catheter up into the brain and inserting a device that widens a dangerously narrowed artery might do more harm than good in some patients at risk of stroke. An aggressive course of medications alone appears to be safer, researchers report online September 7 in the New England Journal of Medicine. Mesh cylinders called stents have offered cardiologists an inside-out approach to opening clogged coronary arteries that is less invasive than surgery. Now researchers are using a new generation of tiny stents to tackle similarly narrowed vessels in the brain. Federal regulators approved a brain stent in 2005, and past studies have supported stents’ effectiveness against stroke (SN: 2/17/2007, p. 99). Researchers used the approved stent in the new trial. They enrolled hundreds of patients at 50 hospitals who had just survived a stroke or had a transient ischemic attack, a kind of stroke that clears up within a day, says study coauthor Marc Chimowitz, a neurologist at the Medical University of South Carolina. The average age of the patients was about 60. Brain scans of these patients pinpointed an artery with buildup that obstructed at least 70 percent of blood flow. People with such bottlenecks are at high risk of having a stroke, because a blood clot may form at the narrowed spot and block blood flow, or a loose clot might get lodged at the pinch point. All patients received clot-busting medicines — aspirin and clopidogrel (Plavix) — and were given drugs to lower cholesterol and control blood pressure. © Society for Science & the Public 2000 - 2011

Keyword: Stroke
Link ID: 15780 - Posted: 09.08.2011

By Laura Sanders To one part of the brain, a bathroom equals toilet plus tub. In mental terms, certain scenes are sums of their objects, researchers report online September 4 in Nature Neuroscience. The results help explain how people quickly and accurately recognize complicated scenes such as playgrounds, kitchens and traffic intersections. Much of what scientists know about vision comes from studies of how people see simple objects in isolation, such as a line floating on a white screen, says cognitive neuroscientist Dirk Bernhardt-Walther of Ohio State University. The new work, in contrast, deals with messy, real-world scenes. “It’s an awesome study,” he says. A number of different brain areas are involved in telling us where we are, each relying on different types of information. In cases where the general outlines of a place offer little information, it appears, the brain homes in on specific objects within that space. “A bathroom and a kitchen may have similar three-dimensional shapes of the interior, but the objects will tell you a big difference,” says study coauthor Sean MacEvoy of Boston College. MacEvoy and Russell Epstein of the University of Pennsylvania measured the brain activity of 28 people viewing one of four scenes: a bathroom, kitchen, street intersection or playground. Participants then saw isolated objects associated with each scene, allowing the researchers to record the neural signature of each object. MacEvoy and Epstein focused on a particular part of the brain called the lateral occipital cortex, or LOC, which had responded to objects in previous studies. © Society for Science & the Public 2000 - 2011

Keyword: Attention
Link ID: 15779 - Posted: 09.08.2011

by Sara Reardon They're not quite psychic yet, but machines are getting better at reading your mind. Researchers have invented a new, noninvasive method for recording patterns of brain activity and using them to steer a robot. Scientists hope the technology will give "locked in" patients—those too disabled to communicate with the outside world—the ability to interact with others and even give the illusion of being physically present, or "telepresent," with friends and family. Previous brain-machine interface systems have made it possible for people to control robots, cursors, or prosthetics with conscious thought, but they often take a lot of effort and concentration, says José del R. Millán, a biomedical engineer at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, who develops brain-machine interface systems that don't need to be implanted into the brain. Millán's goal is to make control as easy as driving a car on a highway. A partially autonomous robot would allow a user to stop concentrating on tasks that he or she would normally do subconsciously, such as following a person or avoiding running into walls. But if the robot encounters an unexpected event and needs to make a split-second decision, the user's thoughts can override the robot's artificial intelligence. To test their technology, Millán and colleagues created a telepresent robot by modifying a commercially available bot called Robotino. The robot looks a bit like a platform on three wheels, and it can avoid obstacles on its own using infrared sensors. On top of the robot, the researchers placed a laptop running Skype, a voice and video Internet chat system, over a wireless Internet connection. © 2010 American Association for the Advancement of Science

Keyword: Robotics
Link ID: 15778 - Posted: 09.08.2011

by Jennifer Couzin-Frankel Many babies born prematurely suffer from bleeding in their still-developing brains. Even when the bleeding stops, another life-threatening condition can strike: hydrocephalus, which occurs when fluid produced to keep the brain healthy builds up because it can't properly drain. For decades, doctors have known that the bleeding and hydrocephalus, also called "water on the brain," were linked, but they weren't sure why. A new study suggests the answer lies in a lipid that's common in blood but that can also profoundly disrupt brain structure and function when it's present in large quantities. Hydrocephalus strikes about one in 1500 babies, and treatment is imperfect. Doctors usually implant a shunt to drain cerebrospinal fluid out of the brain and into the spinal cord. Shunts fail over time, however, and follow-up surgeries are sometimes needed. The condition itself can also cause lifelong neurological problems. The roots of hydrocephalus remain murky, but for those linked to brain bleeds, the hypothesis was that blood clots—necessary to stop the bleeding—blocked the razor-thin pathways through which cerebrospinal fluid must travel to exit the brain. "We assumed for 100 years that it was just a mechanical block," says James McAllister II, a neuroembryologist at the University of Utah School of Medicine in Salt Lake City, who wasn't involved in the recent work. "Everybody thought that you dammed up the narrow channels." A group based at The Scripps Research Institute in San Diego, California, recently began to suspect that something else was at work. For years, Scripps neuroscientist Jerold Chun had been studying the embryonic brain and how certain lipids in the blood of both the mother and the embryo affect its development. © 2010 American Association for the Advancement of Science.

Keyword: Development of the Brain
Link ID: 15777 - Posted: 09.08.2011