by Jessica Hamzelou THE first clear evidence of how antidepressant drugs help to boost brain cell formation could lead to better treatments for depression. The hippocampus is one of just two brain regions known to grow new neurons throughout life - a process called neurogenesis. This process is disrupted in people with depression, although it is not known whether this is a cause or symptom of the condition. It is clear, however, that one of the ways that antidepressants work is by boosting neurogenesis in the hippocampus. Christoph Anacker and his colleagues at King's College London have now worked out how they do so. Previous research has shown a link between some antidepressants and stress hormones called glucocorticoids. So Anacker's team decided to test whether the antidepressant sertraline acts on the glucocorticoid receptors of brain cells. They grew human hippocampal progenitor cells in a dish and added sertraline. Ten days later, the cultures showed a 25 per cent greater than expected increase in the number of new neurons. When the researchers added a drug to block the glucocorticoid receptors before adding the antidepressant, the number of new neurons produced after 10 days was similar to that expected from natural growth. This suggests that the antidepressant does indeed exert its effect through this receptor (Molecular Psychiatry, DOI: 10.1038/mp.2011.26). © Copyright Reed Business Information Ltd.

Keyword: Depression; Neurogenesis
Link ID: 15230 - Posted: 04.18.2011

by Eliza Strickland Neurobiologist Aniruddh Patel says he often gets e-mail from people who claim that their cats, horses, or other nonfeathered pets have rhythm. Patel suspects that these cases are akin to the dancing dogs featured in YouTube videos, in which the animals don’t innately respond to the beat but instead react to cues from their human partners. However, if your pet really does have rhythm, he wants to know about it. “If someone has a dog that can dance to the beat, it will totally refute my hypothesis,” he says, “and that’s progress in science.” So you think you can dance? You probably can, thanks to a brain that is remarkably adept at perceiving rhythms and synchronizing our body movements to what we hear. The ability to get into the groove—to step to the beat—is a hallmark of our species, raising the question of why we might have evolved this ability. Neurobiologist Aniruddh Patel at the Neurosciences Institute in San Diego looks for answers in brain scans and 
laboratory tests and also in the fancy footwork of what seems to be another dance-loving species, the sulfur-crested cockatoo. By monitoring the brain regions that activate when people hear a beat, Patel and colleague John Iversen find evidence that our hearing system is entwined with the motor control systems that guide our muscles. Patel proposes that these connections are a happy accident of evolution, a by-product of the brain development that allowed humans to learn to speak. We take our ability to groove for granted, but it turns out that scientific studies show it’s quite rare. How many other animals can rock out?
 It’s a behavior that seems so simple at first glance: How complicated can it be to bob up and down to music? You can do it while you’re drunk. And yet almost no other species can. In 2009 a team of Mexican researchers conducted a study with monkeys, trying to train the animals to tap to the beat of a metronome. Even after a year or two of training, the monkeys couldn’t do it. The results surprised people, because these monkeys are routinely taught really complicated things, and following a rhythm seems as if it should be easy. © 2011, Kalmbach Publishing Co.

Keyword: Evolution
Link ID: 15229 - Posted: 04.18.2011

By Rob Stein, CHATOM, Ala. — When Timothy J. Atchison regained consciousness, he was drenched in blood and pinned in his car on the side of a dark rural road. “I was just pouring blood,” said Atchison, 21, who said he recoiled in pain when he tried to drag himself through a window of the wrecked Pontiac, a high-school graduation gift. “I didn’t know if I was going to bleed to death or not.” Then, Atchison said, he realized that his legs felt strangely huge — and completely numb. He was paralyzed from the chest down. “I was just praying — asking for forgiveness and thanking God for keeping me alive,” said Atchison, who was trapped for at least an hour before rescuers freed him. “I said, ‘From here on out, I’m going to live for you and nothing else.’ I never got down after that. I figure that’s what must have kept me up — God keeping me up.” That sense of destiny propelled Atchison when he faced another shock just seven days later: Doctors asked him to volunteer to be the first person to have an experimental drug made from human embryonic stem cells injected into his body. “We were just stunned,” said Atchison, who was with his mother and grandfather when researchers approached him. “We were like, ‘Whoa, really?’ We were all just kind of in awe.” Atchison, known to friends and family as T.J., described the events during an interview Tuesday with The Washington Post — his first detailed account since disclosing his carefully guarded identity to The Post. Atchison’s story reveals provocative insights into one of the most closely watched medical experiments, including what some might see as irony: that a treatment condemned on moral and religious grounds is viewed by the first person to pioneer the therapy, and by his family, as part of God’s plan.

Keyword: Stem Cells; Regeneration
Link ID: 15228 - Posted: 04.16.2011

By Jeremy Laurance One of life's disappointments is the recognition that we have not realised our potential; the realisation that had we tried harder, worked longer, played less, we might have achieved more. It is the foundation of the mid-life crisis. Parents say to their children preparing for an exam: "Just do your best." It is supposed to be encouraging – but is it? It is not easy to do your best. Indeed, it may be impossible. This becomes all too clear as we move into adulthood. The fiercest competition of our lives is the one we have with ourselves. There is much more involved than the small matter of will power. So could we be helped to do our best? The movie Limitless, released recently, deals directly with this conundrum. Its hero, Eddie Morra (Bradley Cooper), is an unkempt, unaccomplished writer who finds a way of bridging the gap between the nobody he is and the somebody he aspires to be – with the drug NZT, rocket fuel for the brain – a cognitive enhancer that turbo-charges memory, cranks up concentration and eliminates fatigue. After swallowing a dose, Eddie completes a hefty chunk of his book in an afternoon, learns the piano in three days, picks up Italian from a Berlitz tape and wins a street fight using moves remembered from Bruce Lee flicks. Women suddenly find him irresistible. So far so good. But NZT has a downside. Soon Eddie is double-dosing, running out of supplies and desperate for more. The movie ends in a confusion of plot twists that has left critics floundering. The strength of Limitless is the credibility of its central idea. It is not so far- fetched to imagine that "smart drugs" like NZT might one day exist. Versions of them already do – and their use is growing. The key chemical substances in this field are Ritalin, an amphetamine substitute, and its stronger relative Adderall. They are prescribed to children with attention deficit disorder but are increasingly illicitly obtained and used to boost concentration. ©independent.co.uk

Keyword: ADHD; Drug Abuse
Link ID: 15227 - Posted: 04.16.2011

By Melissa Dahl There's a reason certain episodes of "The Office" or "Curb Your Enthusiasm" -- or those painful audition episodes of "American Idol" -- make you so uncomfortable. A team of European scientists has uncovered a neural explanation for vicarious embarrassment, that cringe-inducing phenomenon of feeling embarrassed for someone. Whether Michael Scott, the boss of the fictional paper company in "The Office" (or -- even worse -- his British counterpart David Brent), realizes he's humiliating himself or not, observing his awkward moments activates the region of our brains that processes empathy. That's what's making us squirm, according to the study, published this week in the journal PLoS ONE. In one experiment, the researchers used functional magnetic resonance imaging to examine the brain's "pain matrix" -- the anterior cingulate cortex and the anterior insula -- while the 619 participants read a series of vignettes describing embarrassing moments. (Yes, that "pain matrix" is the area that processes actual, physical pain, but previous research has shown that this is where social pain, including empathy, is felt, too.) Protagonists in the vignettes slipped in mud, walked around with their fly open, burped loudly in a fancy restaurant and wore T-shirts bragging about their sexual prowess. In other words, some realized they were being ridiculous, while others did not. "Vicarious embarrassment was experienced regardless of whether the observed protagonist acted accidentally or intentionally and was aware or unaware that he/she was in an embarrassing situation," write the study authors, led by Sören Krach and Frieder M. Paulus from Philipps-University Marburg, Germany. © 2011 msnbc.com

Keyword: Emotions; Pain & Touch
Link ID: 15226 - Posted: 04.16.2011

Teen drivers who start school earlier in the morning may be prone to more automobile accidents, according to a new U.S. study. Students may not be so alert, the study suggests, since early school start times may promote sleep loss and daytime sleepiness. Published in the Journal of Clinical Sleep Medicine, the study's lead author, Dr. Robert Vorona, said that starting high school later in the morning might make young drivers more alert because they get more sleep. P.O.V. Do you think classes for high school students should start later so teens can get more sleep? The study compared school start times and automobile crash rates for students aged 16 to 18 years in Virginia Beach, Va., where high school classes began between 7:20 a.m. and 7:25 a.m., to students at schools in adjacent Chesapeake, Va., where classes started between 8:40 a.m. and 8:45 a.m. There were 65.8 automobile crashes for every 1,000 teen drivers in Virginia Beach, and 46.6 crashes for every 1,000 teen drivers in Chesapeake. The comparisons were made in 2008 and were similar to results in 2007. "We believe that high schools should take a close look at having later start times to align with circadian rhythms in teens and to allow for longer sleep times," said Vorona who is an associate professor of internal medicine at Eastern Virginia Medical School. "Too many teens in this country obtain insufficient sleep. Increasingly, the literature suggests that this may lead to problematic consequences including mood disorders, academic difficulties and behavioral issues." © CBC 2011

Keyword: Sleep; Development of the Brain
Link ID: 15225 - Posted: 04.16.2011

By Leon Neyfakh On a recent Monday afternoon, the distinguished Harvard biologist Edward O. Wilson was at his home in Lexington, talking on the phone about the knocks he’s been taking lately from the scientific community, and paraphrasing Arthur Schopenhauer to explain his current standing in his field. “All new ideas go through three phases,” Wilson said, with some happy mischief in his voice. “They’re first ridiculed or ignored. Then they meet outrage. Then they are said to have been obvious all along.” Wilson is 81, an age at which he could be forgiven for retreating to a farm and lending his name to the occasional popular book about science. Over the past year he’s tried his hand at fiction writing, publishing a novel about ants — his scientific specialty — and landing a short story in The New Yorker. But he has also been pressing a disruptive scientific idea, one he reckons is currently in phase two of the Schopenhauer progression: outrage. What Wilson is trying to do, late in his influential career, is nothing less than overturn a central plank of established evolutionary theory: the origins of altruism. His position is provoking ferocious criticism from other scientists. Last month, the leading scientific journal Nature published five strongly worded letters saying, more or less, that Wilson has misunderstood the theory of evolution and generally doesn’t know what he’s talking about. One of these carried the signatures of an eye-popping 137 scientists, including two of Wilson’s colleagues at Harvard. © 2011 NY Times Co.

Keyword: Emotions; Evolution
Link ID: 15224 - Posted: 04.16.2011

Hayley Crawford, reporter The world's first computerised map of the brain was released yesterday by scientists at the Allen Institute for Brain Science, in Seattle, Washington, after more than four years of cutting-edge research. The Human Brain Atlas is an interactive research tool that will help scientists to understand how the brain works and aid new discoveries in disease and treatments. The information used to build it comes from the analysis of two human brains, using magnetic resonance imaging (MRI) and a variation of MRI called diffusion tensor imaging. Allan Jones, the CEO of the institute, told Wired how the brains were also chopped up into small pieces, and RNA extracted from the tissue. They used this RNA to obtain a read-out of the 25,000 genes in the human genome. All this information was put together to create a detailed map of the brain. One thousand anatomical sites in the brain can be searched, supported by more than 100 million data points that indicate the gene expression and biochemistry of each site. For example, a researcher could quickly create a 3D snapshot (see image below) of all the locations in the brain where Prozac's biochemical targets are expressed. Prozac-target.jpg © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 15223 - Posted: 04.16.2011

By BRYSON VOIRIN On Isla Iguana the sun rises over the Pacific Ocean and sets, somewhat counterintuitively, over the mainland. Pausing briefly to soak in the mysterious and picturesque sunset, we gear up for a long night of bird catching. Tonight we’re hoping to outfit our first frigate bird with the newly developed sleep logger, accelerometer and GPS unit. We’ll record two-paired electroencephalograms (EEGs), constant acceleration in three directions and a GPS position every five minutes. If all goes according to plan the loggers will record for five days. The data from the loggers should help us answer the question of whether sleeping on the wing is possible for frigate birds. A close-up of a neurologger, developed by Alexei Vyssotski. The logger is completely exposed to the elements, so before each use we have to throughly waterproof it.Bryson Voirin A close-up of a neurologger, developed by Alexei Vyssotski. The logger is completely exposed to the elements, so before each use we have to thoroughly waterproof it. Before heading into the field we have to prepare the sleep logger for deployment. The loggers were recently developed by our colleague Alexei Vyssotski in Switzerland, and can record brainwaves and constant acceleration on almost any animal. But preparing them for use in the wild requires a bit of soldering and ingenuity. To minimize the amount of weight for the birds, my adviser, Niels Rattenborg, brought tiny zinc air batteries designed for hearing aids that should power the logger for five days. However, zinc air batteries require an air supply to function. When I put these loggers on the sloths, I used a lithium robotics battery that can be tightly wrapped and waterproofed. But for these new batteries, we have to allow them room to “breathe.” That wouldn’t be an issue in a laboratory, but frigate birds fly around catching fish in saltwater. © 2011 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 15222 - Posted: 04.16.2011

By MAGGIE JONES We all know that we don’t get enough sleep. But how much sleep do we really need? Until about 15 years ago, one common theory was that if you slept at least four or five hours a night, your cognitive performance remained intact; your body simply adapted to less sleep. But that idea was based on studies in which researchers sent sleepy subjects home during the day — where they may have sneaked in naps and downed coffee. Enter David Dinges, the head of the Sleep and Chronobiology Laboratory at the Hospital at University of Pennsylvania, who has the distinction of depriving more people of sleep than perhaps anyone in the world. In what was the longest sleep-restriction study of its kind, Dinges and his lead author, Hans Van Dongen, assigned dozens of subjects to three different groups for their 2003 study: some slept four hours, others six hours and others, for the lucky control group, eight hours — for two weeks in the lab. Every two hours during the day, the researchers tested the subjects’ ability to sustain attention with what’s known as the psychomotor vigilance task, or P.V.T., considered a gold standard of sleepiness measures. During the P.V.T., the men and women sat in front of computer screens for 10-minute periods, pressing the space bar as soon as they saw a flash of numbers at random intervals. Even a half-second response delay suggests a lapse into sleepiness, known as a microsleep. The P.V.T. is tedious but simple if you’ve been sleeping well. It measures the sustained attention that is vital for pilots, truck drivers, astronauts. Attention is also key for focusing during long meetings; for reading a paragraph just once, instead of five times; for driving a car. It takes the equivalent of only a two-second lapse for a driver to veer into oncoming traffic. © 2011 The New York Times Company

Keyword: Sleep
Link ID: 15221 - Posted: 04.16.2011

By Bruce Bower MINNEAPOLIS — Orangutans swim about as well as they fly, but research on three Indonesian islands shows that these long-limbed apes nonetheless catch and eat fish. Orangutans living in Borneo scavenge fish that wash up along the shore and scoop catfish out of small ponds for fresh meals, anthropologist Anne Russon of York University in Toronto reported on April 14 at a meeting of the American Association of Physical Anthropologists. Over two years, Russon saw several animals on these forested islands learn on their own to jab at catfish with sticks, so that the panicked prey would flop out of ponds and into a red ape’s waiting hands. “If orangutans can do this, then early hominids could also have practiced tool-assisted fishing,” Russon said. Although orangutans usually fished alone, Russon observed pairs of apes catching catfish on a few occasions. In one case, an orangutan cringed and pulled away as its companion extracted a fish from a pond. Russon suspects that the onlooker was learning — or at least trying to learn — how to nab aquatic snacks. Observations of fishing by orangutans raise the likelihood that hominids ate meat, including fish, before the emergence of the Homo genus around 2.5 million years ago (SN: 9/11/10, p. 8), said anthropologist David Braun of the University of Cape Town in South Africa. Anthropologists have traditionally held that meat-eating first assumed prominence among early Homo species and fueled brain expansion. © Society for Science & the Public 2000 - 2011

Keyword: Evolution
Link ID: 15220 - Posted: 04.16.2011

Joanna Marchant Female athletes may not be eligible to compete as women if they have natural testosterone levels in the male range. That's the upshot of new guidelines on female hyperandrogenism, recommended by the International Olympic Commission (IOC) on 5 April and accepted by the International Association of Athletics Federations (IAAF) on 12 April. The rules have been welcomed by experts as a reasonable compromise, but there remain some doubts over how they would work in practice. Nature looks at the science behind the tests. The regulations cover female athletes with hyperandrogenism, a condition in which the body produces higher than normal levels of hormones called androgens, particularly testosterone. This can cause the development of bulky muscles, perhaps giving athletes an unfair competitive advantage. The issue hit the headlines in 2009, when the South African athlete Caster Semenya was asked to undergo sex testing after winning the 800-metre final at the Berlin World Championships in Athletics (see 'A question of sex'). She was unable to compete for nearly a year, but has now returned to the track. The results of her tests remain confidential. Officials deny that the new rules are a direct response to Semenya's case, however. There have been other controversial cases, and they say there has long been a need to clarify the rules and procedures involved. This week's announcement is the culmination of an 18-month review carried out by the IOC Medical Commission and the IAAF, including a meeting held last October and attended by scientists as well as athletes, bioethicists, human-rights lawyers and a representative of the intersex community. © 2011 Nature Publishing Group,

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 15219 - Posted: 04.16.2011

by Rowan Hooper BLIND people could one day have their sight restored thanks to a treatment that borrows a gene from an unlikely source - algae - and inserts it into the retina. The technique has succeeded in restoring the ability to sense light and dark to blind mice, and clinical trials in humans could begin in as little as two years. "The idea is to develop a treatment for blindness," says Alan Horsager, a neuroscientist at the Institute of Genetic Medicine at the University of Southern California, Los Angeles, who leads the research. "We introduce a gene that encodes a light-sensitive protein, and we target the expression of that gene to a subset of retinal cells." Some 15 million people worldwide have some form of blindness, such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). In people with these conditions the photoreceptors, which transform light hitting the eye into electrical impulses, are damaged, preventing the brain from receiving image information. As the global population ages, it is thought that the number of people affected will increase. There are experimental attempts to develop electronic implantsMovie Camera and to use stem cells to grow new retinal tissues to restore sight, but there is currently no commercial treatment available. Horsager hopes his work will change that. His team's approach is based on gene therapy, where a "tame" virus is harnessed to transfer a gene into target cells in the recipient. In this case the gene of interest is one that makes Channelrhodopsin-2 (ChR2), a photosensitive protein used by unicellular algae to help them move towards light. The target cells are bipolar cells in the retina. © Copyright Reed Business Information Ltd.

Keyword: Vision; Regeneration
Link ID: 15218 - Posted: 04.14.2011

by Cian O'Luanaigh THE bones of your middle ear were once part of a mammalian ancestor's jaw. Now a remarkable Cretaceous fossil provides a snapshot of how this shift took place. The lower jaws of modern mammals have just one bone: the tooth-bearing dentary. Reptiles, by contrast, also sport smaller bones where the jaw meets the skull. Biologists have long postulated that as mammals evolved, the smaller, post-dentary bones shrank to form the tiny bones of the middle ear. Fossils of ancient mammals such as Morganucodon hint at this: the post-dentary bones are still attached to the dentary, and are used for both hearing and feeding. What happened next had been left to best guesses. Now Liaoconodon hui, discovered in China by Jin Meng of the American Museum of Natural History in New York, has filled the gap. "It is the first unambiguous evidence showing that transitional stage," says Meng. The 120-million-year-old mammal, about the size of a large rat, was a close relative of early mammals. Of interest is a bridge called Meckel's cartilage, which connects the small bones to the jaw (see diagram). Living mammals, including humans, have Meckel's cartilage as embryos, but it disappears as they mature. In the L. hui fossil - an adult - it is ossified and the fossil shows how it supported some of the post-dentary bones as they shifted into the ear (Nature, DOI: 10.1038/nature09921). © Copyright Reed Business Information Ltd.

Keyword: Hearing; Evolution
Link ID: 15217 - Posted: 04.14.2011

Philip Ball Languages evolve in their own idiosyncratic ways, rather than being governed by universal rules set down in human brain patterns. That is the conclusion of a study that compares the grammar of several hundred languages by looking at their evolutionary trees. Russell Gray, a psychologist at the University of Auckland in New Zealand, and his colleagues examined the relationships between traits such as the ordering of verbs and nouns in four linguistic families, and found no sign of any persistent, universal guiding principles (See 'Universal truths'). Their work is published today by Nature1. It is already proving controversial. "There is nothing in the paper that brings into question the views that they are arguing against," says Matthew Dryer, a linguist at the State University of New York at Buffalo. Fixed patterns There are thought to be around 7,000 languages in the world today, and they show tremendous diversity in structure. Some, such as Finnish, have complex ways of making composite words, whereas others, such as Mandarin Chinese, have simple, short and invariant words. Some put verbs first in a sentence, others in the middle and yet others at the end. But many linguists suspect that there is some universal logic behind this bewildering variety — that common cognitive factors underpin grammatical structures. US linguists Noam Chomsky and Joseph Greenberg proposed two of the most prominent 'universalist' theories of language. © 2011 Nature Publishing Group,

Keyword: Language
Link ID: 15216 - Posted: 04.14.2011

Douglas Fox Last year a succession of volunteers sat down in a research lab in Albuquerque, New Mexico to play DARWARS Ambush!, a video game designed to train US soldiers bound for Iraq. Each person surveyed virtual landscapes strewn with dilapidated buildings and abandoned cars for signs of trouble — a shadow cast by a rooftop sniper, or an improvised explosive device behind a rubbish bin. With just seconds to react before a blast or shots rang out, most forgot about the wet sponge affixed to their right temple that was delivering a faint electric tickle. The volunteers received a few milliamps of current at most, and the simple gadget used to deliver it was powered by a 9-volt battery. It might sound like some wacky garage experiment, but Vincent Clark, a neuroscientist at the University of New Mexico, says that the technique, called transcranial direct-current stimulation (tDCS), could improve learning. The US Defense Advanced Research Projects Agency funded the research in the hope that it could be used to sharpen soldiers' minds on the battlefield. Yet for all its simplicity, it seems to work. Volunteers receiving 2 milliamps to the scalp (about one-five-hundredth the amount drawn by a 100-watt light bulb) showed twice as much improvement in the game after a short amount of training as those receiving one-twentieth the amount of current1. "They learn more quickly but they don't have a good intuitive or introspective sense about why," says Clark. The technique, which has roots in research done more than two centuries ago, is experiencing something of a revival. © 2011 Nature Publishing Group,

Keyword: Learning & Memory; Parkinsons
Link ID: 15215 - Posted: 04.14.2011

Ewen Callaway Before committing suicide at the age of 22, an anonymous man with schizophrenia donated a biopsy of his skin cells to research. Reborn as neurons, these cells may help neuroscientists to unpick the disease he struggled with from early childhood. Experiments on these cells, as well as those of several other patients, are reported today in Nature1. They represent the first of what are sure to be many mental illnesses 'in a dish', made by reprogramming patients' skin cells to an embryonic-like state from which they can form any tissue type. Recreating neuropsychiatric conditions such as schizophrenia and bipolar disorder using such cells represents a daunting challenge: scientists do not know the underlying biological basis of mental illnesses; symptoms vary between patients; and although psychiatric illnesses are strongly influenced by genes, it has proved devilishly hard to identify many that explain more than a fraction of a person's risk. "All of us had been contacted by patients asking 'when can I get my stem cells to solve my schizophrenia'. It's not as simple as that," says Russell Margolis, a psychiatrist and neurogeneticist at Johns Hopkins University in Baltimore, Maryland, who was not involved in the study. "It's an additional piece to the puzzle as opposed to the answer." © 2011 Nature Publishing Group,

Keyword: Schizophrenia
Link ID: 15214 - Posted: 04.14.2011

People with multiple sclerosis may show blocked neck veins as a result of the disease rather than as a cause, a large study published Wednesday suggests. The findings cast doubt on the theory that blocked or narrowed veins are a main cause of MS, study author Dr. Robert Zivadinov of the University of Buffalo said. The findings published in the journal Neurology were consistent with thinking that the condition — also known as chronic cerebrospinal venous insufficiency, or CCSVI — is more common in patients with multiple sclerosis but not to the degree first reported by the Italian doctor Paolo Zamboni. "These findings indicate that CCSVI does not have a primary role in causing MS," said Zivadinov, who has worked with Zamboni. Zamboni proposed that multiple sclerosis may be linked with vascular problems, and that using angioplasty, or ballooning, to open blocked neck veins can help treat MS symptoms by changing blood flow patterns. Patients eager for surgery For more than a year, Canadians with MS have been leaving the country to get the surgery, despite reluctance from neurologists at home. An ultrasound technician, who did not know which group the subjects were in, did the test. The team found 56 per cent of people in the MS group met the criteria for CCSVI, as did 23 per cent of the healthy controls and 46 per cent of people with other neurological diseases. © CBC 2011

Keyword: Multiple Sclerosis
Link ID: 15213 - Posted: 04.14.2011

By James Gallagher Health reporter, BBC News Brain scans may be able to indicate potential Alzheimer's patients years before symptoms appear, according to the results of a small study. Research published in Neurology showed parts of some patients' brains had shrunk up to a decade before signs of Alzheimer's would otherwise be evident. Alzheimer's Research UK said there was stong evidence that the disease began to develop in mid-life. Early diagnosis may one day prove vital in enabling effective treatment. Sixty-five patients, all of whom started with normal brain function, took part in the study at Massachusetts General Hospital and the Rush University Medical Center in the US. MRI scans were taken and the thickness of regions of the brain were measured. Brain Thinning Twenty per cent of patients with brains of average thickness went on to develop Alzheimer's. However, no patients with thicker brains developed the disease, while 55% of those with thinner ones also contracted it. Dr Brad Dickerson, lead author and neuroscientist at the Massachusetts General Hospital, said: "We used what we know about the signature brain changes seen in patients with Alzheimer's dementia, measured those areas in individuals with no symptoms and eventually determined that those who ultimately developed dementia showed subtle shrinking long before they had any symptoms." BBC © 2011

Keyword: Alzheimers; Brain imaging
Link ID: 15212 - Posted: 04.14.2011

by Michael Balter About 65 million years ago, most of the dinosaurs and many other animals and plants were wiped off Earth, probably due to an asteroid hitting our planet. Researchers have long debated how and why some species survived the so-called Cretaceous-Tertiary mass extinction, marked in ancient rocks by a transition called the K-T boundary. A new study suggests that one group of survivors, the birds, may have sniffed their way across by evolving an enhanced sense of smell. Scientists had long thought that birds have a poor sense of smell. But several recent studies show that birds use smell to help them forage for food, communicate with other birds, and even orient themselves in flight. And a 2009 study of dinosaur olfaction, led by paleontologist Darla Zelenitsky of the University of Calgary in Canada, found that dinosaur lineages thought to have given rise to today's birds some 150 million years ago had a keener sense of smell than dinosaurs that went extinct without leaving feathered progeny behind. To further explore how the sense of smell might have influenced bird evolution, Zelenitsky and her colleagues looked at the olfactory abilities of 157 species of dinosaurs, extinct birds, and living birds. As in the earlier work, the team used a parameter called the olfactory ratio as a proxy for how keen a bird's sense of smell is. In the vertebrates (animals with backbones), smell is processed in the olfactory bulb, which in birds and reptiles is found in the very front of the brain. In birds, the olfactory ratio is the relative size of the bulb compared with that of the brain's cerebral hemispheres and is usually expressed as a percentage. Numerous studies in birds have shown the olfactory ratio, which ranges from less than 10% to more than 30% in a few species, to be a reliable indicator of the sense of smell. © 2010 American Association for the Advancement of Science.

Keyword: Hearing; Genes & Behavior
Link ID: 15211 - Posted: 04.14.2011