One of Nature's great phenomena is how tiny songbirds can make their way over thousands of miles each fall to their winter feeding grounds and back again the following spring. Scientists have known for years that they travel by night to avoid predators, navigating by the stars and the Earth's invisible magnetic field. Yet how these birds "see" the Earth's magnetic field — a protective field that shields Earth from radiation, and is the basis for the magnetic north and south poles, but which people can't sense at all — has remained a mystery. Now researchers based in the United States and Europe have found a brain region in night-migrating songbirds that they think can "process" information from the Earth's magnetic field and turn it into an internal compass they can see. The brain region is called "Cluster N" — "N" for night-vision because the researchers believe the birds' ability to sense the Earth's magnetic field and transform it into a navigation tool is dependent on their ability to see at night. "What we discovered was that this brain area wasn't exclusively used for sensing magnetic fields, but instead it's being used to perhaps see at night," says Duke University neurobiologist Erich Jarvis. Jarvis collaborated with animal navigation researcher Henrik Mouritsen from the University of Oldenburg, in Germany, to compare the brains of two distantly related types of migrating songbirds, the Garden Warbler and the European Robin, to two types of non-migrating song birds, Canaries and Zebra Finches. © ScienCentral, 2000-2006.

Keyword: Animal Migration; Vision
Link ID: 8745 - Posted: 06.24.2010

Like the rest of the eighteen million Alzheimer's sufferers worldwide, Lola Crosswhite must battle the disease using everyday tactics — the help of medications, written reminders, and assistance from family members, like her daughter Diana Shaw. However, unlike most Alzheimer's patients, Crosswhite also had access to something extra — an experimental gene therapy that she says delayed her decline from Alzheimer's for two years. Unfortunately, as predicted by the researchers, the treatment has since begun to wear off and now her memory loss is progressing again. "Even though I've had it all this time, but then it was better," she says. "Now I'm sliding back. So I'm going down the hill again." In 2002, Crosswhite was one of eight early-stage Alzheimer's patients to volunteer for risky brain surgery to test the safety of the first gene therapy for Alzheimer's. Researchers led by Mark Tuszynski, a neuroscience professor at the University of California, San Diego, introduced cells that had been genetically modified to make more of a substance called nerve growth factor (NGF) into the patients' brains. These cells were injected into areas of the brain where neurons were dying so that they could act as biological pumps, delivering NGF to the surrounding brain cells. © ScienCentral, 2000-2006.

Keyword: Alzheimers
Link ID: 8744 - Posted: 06.24.2010

By Jennifer Couzin Even oft-repeated gender stereotypes harbor some truth: Angry men are more likely to yell or punch a wall, whereas angry women sit silently stewing. Now, a new study is tracing these distinctions in how men and women process emotion to an almond-shaped structure deep in the brain. Not only does the structure, the amygdala, function differently by gender, but its activity in men is also coupled with very different brain regions than it is in women. The amygdala straddles both sides of the brain and helps control how emotions such as fear are processed and remembered. Several studies have found gender differences when the amygdala is stimulated--by having volunteers recall scary movies, for example. In men, the right side of the amygdala, known simply as the right amygdala, appears more likely to become active, whereas in women it's the left. Neurobiologist Larry Cahill of the University of California, Irvine, wondered whether this difference was hardwired--whether, in other words, the amygdala retained its gender-specific tendencies even when nothing was activating it. If so, this would suggest that the structure was inherently different in men than in women. Cahill and his colleagues studied PET scans of 36 men and 36 women, all of whom were right-handed. The scans had been collected for various brain studies where volunteers were asked to close their eyes and relax while the pictures were taken. The team found that, even at rest, the amygdala worked differently in men and women. In women, blood flow to the left amygdala ebbed and flowed along with other brain structures while the right amygdala did little. In men, it was blood flow to the right amygdala that varied along with blood flow elsewhere in the brain, the researchers report 1 April NeuroImage. © 2006 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Emotions
Link ID: 8743 - Posted: 06.24.2010

Christen Brownlee Scientists have prompted mouse-eye cells that aren't normally light sensitive to respond to light. This strategy could lead to new treatments for retinitis pigmentosa and related diseases, which cause blindness in 1 in 3,000 people worldwide. These diseases occur when the retina's light-sensing cells die. Called rods and cones, these cells—when healthy—convert light into an electrical signal. That signal then passes to nearby cells and eventually reaches the brain, where it's interpreted as vision. If rods and cones die, they aren't replaced. To restore vision in people who have lost these cells, scientists have suggested several strategies, such as growing rods and cones from stem cells or replacing them with synthetic chips that sense light. But so far, these approaches face myriad challenges. The new work took a gamble on some preliminary findings that indicated that other cells in the retina continue to function after the rods and cones die. These spared cells include inner retinal neurons, nerve cells that process information from rods and cones before sending it to the brain. ©2006 Science Service.

Keyword: Vision
Link ID: 8742 - Posted: 06.24.2010

Bruce Bower The road to exceptional intelligence is paved with dramatic neural alterations, a new brain-imaging study finds. Critical parts of the brain's outer layer, or cortex, thicken more rapidly during childhood and thin more drastically during adolescence in individuals with extremely high IQ scores compared with peers of average or moderately above-average intelligence, say neuroscientist Philip Shaw of the National Institute of Mental Health in Bethesda, Md., and his colleagues. The scientists propose that distinctive brain growth in superior-IQ youth reflects prolonged development of neural circuits that contribute to reasoning, planning, and other facets of analytical thinking. "Cortical thickness at any one age tells you next to nothing about intelligence," Shaw says. "What's important is that cortical development occurs differently in extremely clever kids, possibly as a result of particularly efficient sculpting of the brain." The report appears in the March 30 Nature. The researchers used a magnetic resonance imaging scanner to track brain changes in 307 children and teenagers deemed free of psychiatric or neurological disorders. Most volunteers submitted to two or more brain scans at intervals averaging 2 years. Participants also completed a verbal-and-nonverbal IQ test upon entering the study as children or teenagers. ©2006 Science Service.

Keyword: Development of the Brain; Intelligence
Link ID: 8741 - Posted: 06.24.2010

Nerve cells that normally are not light sensitive in the retinas of blind mice can respond to light when a green algae protein called channelrhodopsin-2 (ChR2) is inserted into the cell membranes, according to a National Institutes of Health (NIH)-supported study published in the April 6, 2006 issue of the journal Neuron. The study was conducted with mice that had been genetically bred to lose rods and cones, the light-sensitive cells in the retina. This condition is similar to the blinding disease retinitis pigmentosa (RP) in humans. Vision normally begins when rods and cones, also called photoreceptors, respond to light and send signals through the retina and the optic nerve to the visual cortex of the brain, where visual images are formed. Unfortunately, photoreceptors degenerate and die in some genetic diseases, such as RP. Both mice and humans go progressively blind because with the loss of rods and cones there is no signal sent to the brain. This study, funded by the National Eye Institute (NEI) of the NIH, raises the intriguing possibility that visual function might be restored by conveying light-sensitive properties to other surviving cells in the retina after the rods and cones have died. Principal investigator Zhuo-Hua Pan, Ph.D., of Wayne State University School of Medicine, and his colleagues, using a gene-transfer approach, introduced the light-absorbing protein ChR2 into the mouse retinal cells that survived after the rods and cones had died. These cells became light sensitive and sent signals through the optic nerve to the visual cortex.

Keyword: Vision
Link ID: 8740 - Posted: 04.08.2006

Praying for someone might give you hope, but it won't help them recover from heart surgery. It may even harm them. That's the surprising result from a multi-year clinical trial on the therapeutic effects of prayer. Herbert Benson and Jeffery Dusek of the Mind/Body Medical Institute at Beth Israel Deaconess Medical Center in Chestnut Hill, Massachusetts, and their colleagues followed the fates of 1802 patients undergoing coronary bypass operations. Several Christian prayer groups prayed for one set of patients, while another did not receive any prayers. Although all these patients knew they were in the trial, neither they nor their doctors knew which of the groups they were in. The prayers made no detectable difference. In the first month after surgery, 52 per cent of prayed-for patients and 51 per cent of non-prayed-for patients suffered one or more complications, the researchers found (American Heart Journal, vol 151, p 934). A third group of patients received the same prayers as the first group, but were told they were being prayed for. Of these, 59 per cent suffered complications - significantly more than the patients left unsure of whether they were receiving prayers. © Copyright Reed Business Information Ltd

Keyword: Neuroimmunology; Stress
Link ID: 8739 - Posted: 06.24.2010

Roxanne Khamsi Fast language learners have more white matter and less symmetrical brains, a new scanning study has revealed. The results among the first to link brain differences to language learning aptitude in healthy people, says Narly Golestani at University College London, UK. “The bigger picture is that we’re starting to understand that brain shape and structure can be informative about people’s abilities,” she says. Those in the study who were quickest to hear subtle differences in sounds from a foreign language were found to have the greatest amount of white, fatty tissue in a brain region responsible for sound processing. “It could be that this translates into greater efficiency in the brain,” comments Adam Brickman, who researches brain structure the Columbia University Medical Center in New York. Scientists’ understanding of white matter has improved recently, he says, thanks to better brain scanning technology. The fatty tissue provides insulation and enables signals to travel faster through nerve fibres. In contrast, the grey matter of the brain contains neurons without this protective layer. © Copyright Reed Business Information Ltd.

Keyword: Language; Glia
Link ID: 8738 - Posted: 06.24.2010

YOU'RE fat, lazy, and only the prospect of mating can propel you into action. But that's just fine - as long as you're an African mole rat. Your fellow colony members will even toil to support you. Zoologists studying the Damaraland mole rat (Cryptomys damarensis) in its native southern Africa have discovered that its colonies are split into two distinct castes of worker. One group is hard-working and industrious; the other is fat and rather work-shy. Damaraland mole rats and naked mole rats are thought to be the only mammal species that live and breed cooperatively, with some colony members devoting their lives to helping others reproduce. To explore their unusual lifestyle, Michael Scantlebury of the University of Pretoria, South Africa, and colleagues in the UK studied the creatures' energy demands and activity levels. They found that the industrious mole rats performed more than 95 per cent of the total work of the colony. The lazy mole rats built up their fat stores, placing a double burden on the colony - doing virtually no work, but requiring more food (Nature, vol 440, p 795). © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Evolution
Link ID: 8737 - Posted: 06.24.2010

Helen Pearson Sleep deprivation is costing the United States hundreds of billions of dollars each year. So say the experts behind a report that highlights this burgeoning and oft-ignored health problem. Round-the-clock television and lengthening work days mean that many people spend less time in bed. Although everyone is aware that not getting enough sleep can have ill effects, doctors and researchers are just beginning to realize the toll on our health. To estimate the size of society's sleep problem, and find ways to solve it, a group of sleep-research organizations asked the Institute of Medicine to study the issue. Its 14-person panel released their report yesterday1. The panel says that the impact of poor sleep is "shocking" even to experts in the field. They say that some 50 million to 70 million Americans are suffering from a sleep disorder and countless more from sleep deprivation. Many sleep specialists say that a good night's kip is just as important for health as diet and exercise. The problem "is underappreciated and probably underestimated", says Harvey Colten of Columbia University in New York City, who chaired the panel. ©2006 Nature Publishing Group

Keyword: Sleep
Link ID: 8736 - Posted: 06.24.2010

By Gareth Mitchell Playing virtual reality computer games may help treat the condition known as amblyopia, or lazy eye, say researchers. In patients with amblyopia, one eye works better than the other. Because the amblyopic eye is inferior for some reason, the brain decides to use the good eye. Over time, the neural connection to the bad eye becomes gradually weaker in favour of the good eye. The traditional way of fixing the problem is for patients to force the bad eye to work harder by wearing a patch over the good eye. The treatment usually involves patching for around 400 hours and can cause the eyes not to work together, resulting in double vision. Researchers at Nottingham University say that an experimental treatment using virtual reality (VR) may offer the best of both worlds, encouraging the lazy eye to be more active and getting both eyes to work together. "Traditionally VR has been used to present realistic environments in 3D so you imagine you're there because of the depth of the world around you," said Richard Eastgate of the university's Virtual Reality Applications Research Team. But we're using VR to make something unrealistic. You could call it virtual unreality," he told Digital Planet. "We're actually presenting two different versions of the world to each eye." In one experiment, the team has been trying out a racing game where the computer sends images of the player's own car to the amblyopic eye, but the other cars go to the good eye. Obstacles on the track are sent alternately to each eye, so both eyes team up to get the patient through the game. (C)BBC

Keyword: Vision
Link ID: 8735 - Posted: 03.30.2006

Adrianne Appel More than a million ant specimens—meticulously dried, pinned, and identified—lie in wooden drawers in Harvard University's Museum of Comparative Zoology. But these specimens are hardly gathering dust in their Cambridge, Massachusetts, home. The office of Edward Osborn Wilson—renowned scientist and author, father of sociobiology, and ant expert—is right down the hall. Wilson's body of work is a product of unfailing energy and focus. As a young man he traveled through Europe visiting ant collections. Then as a Harvard professor he spent years driven by what he calls "the amphetamine of ambition"—working 80-hour weeks, teaching, studying ants, and writing. From his work in the field he has personally identified more than 400 new ant species. Now in his late 70s, the man labelled "Darwin's Natural Heir" by Britain's Gaurdian newspaper has not slowed up his nearly lifelong pursuit of collecting and identifying ants, nor has he let the rest of his work lose steam. © 1996-2006 National Geographic Society.

Keyword: Evolution
Link ID: 8734 - Posted: 06.24.2010

Jim Giles Researchers say that a remarkable data set on the developing brain adds to the idea that IQ is a meaningful concept in neuroscience. The study, which is published on page 676 of this issue, suggests that performance in IQ tests is associated with changes in the brain during adolescence. Claims that IQ is a valid measure of intelligence tend to attract angry responses, in part because of studies that have attempted to link group differences in IQ with race. In their 1994 book The Bell Curve, political scientist Charles Murray and psychologist Richard Herrnstein argued that the lower-income status of some US ethnic minorities was linked to below-average IQ scores among those groups. These were in turn attributed to mainly genetic factors. Before that, Harvard University entomologist Edward Wilson provoked outrage with work that proposed evolutionary explanations for human behaviour and individual differences in intelligence; critics called the work racist. And this month, the journal Intelligence printed an editorial note defending its policy regarding the publication of controversial papers. The note comes after a study linking IQ and skin colour (D. I. Templer and H. Arikawa Intelligence 34, 121–139; 2006), published online last November, prompted a string of complaints from scientists. ©2006 Nature Publishing Group

Keyword: Intelligence; Development of the Brain
Link ID: 8733 - Posted: 06.24.2010

Youth with superior IQ are distinguished by how fast the thinking part of their brains thickens and thins as they grow up, researchers at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) have discovered. Magnetic resonance imaging (MRI) scans showed that their brain’s outer mantle, or cortex, thickens more rapidly during childhood, reaching its peak later than in their peers — perhaps reflecting a longer developmental window for high-level thinking circuitry. It also thins faster during the late teens, likely due to the withering of unused neural connections as the brain streamlines its operations. Drs. Philip Shaw, Judith Rapoport, Jay Giedd and colleagues at NIMH and McGill University report on their findings in the March 30, 2006 issue of Nature. “Studies of brains have taught us that people with higher IQs do not have larger brains. Thanks to brain imaging technology, we can now see that the difference may be in the way the brain develops,” said NIH Director Elias A. Zerhouni, M.D. While most previous MRI studies of brain development compared data from different children at different ages, the NIMH study sought to control for individual variation in brain structure by following the same 307 children and teens, ages 5-19, as they grew up. Most were scanned two or more times, at two-year intervals. The resulting scans were divided into three equal groups and analyzed based on IQ test scores: superior (121-145), high (109-120), and average (83-108). “Brainy children are not cleverer solely by virtue of having more or less gray matter at any one age,” explained Rapoport. “Rather, IQ is related to the dynamics of cortex maturation.”

Keyword: Intelligence; Development of the Brain
Link ID: 8732 - Posted: 06.24.2010

Scientists at the National Institutes of Health’s (NIH) National Institute on Alcohol Abuse and Alcoholism (NIAAA) have identified a previously unknown gene variant that doubles an individual’s risk for obsessive-compulsive disorder (OCD). The new functional variant, or allele, is a component of the serotonin transporter gene (SERT), site of action for the selective serotonin reuptake inhibitors (SSRIs) that are today’s mainstay medications for OCD, other anxiety disorders, and depression. “Improved knowledge of SERT‘s role in OCD raises the possibility of improved screening, treatment, and medications development for that disorder,” said Ting-Kai Li, M.D., Director, National Institute on Alcohol Abuse and Alcoholism. “It also provides an important clue to the neurobiologic basis of OCD and the compulsive behaviors often seen in other psychiatric diseases, including alcohol dependence.” Approximately 2 percent of U.S. adults (3.3 million people) have OCD, the fourth most prevalent mental health disorder in the United States. Individuals with OCD have intrusive, disturbing thoughts or images (obsessions) and perform rituals (compulsions) to prevent or banish those thoughts. Many other individuals demonstrate obsessive-compulsive behaviors that do not meet OCD diagnostic criteria but alter the individuals’ lives.

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 8731 - Posted: 06.24.2010

Do human newborns develop their preference for speech through in-utero eavesdropping, or is their attraction to the human voice innate? It's a bedevilling question to test, but one that's central to understanding the origins and dynamics of humans' unique propensity for speech. Now a McGill University psychologist believes she's separated out the complicating effects of the uterine sound barrier. And the results, says Dr. Athena Vouloumanos, point to a genetic predilection for listening in on speech in preference to other, similar sounds. "It's well established that neonates have a preference for speech above other sounds, but where does this come from? Is it something that's built in and there's something about the speech signal that they're tuned to listen to without the benefit of experience, or does it come from their prenatal experience in the womb? I think we've shown that there's an experience-independent component to newborns' preference for speech," says Dr. Vouloumanos, an Assistant Professor in McGill's Department of Psychology in Montreal, Canada. She'll be presenting the findings of her latest research at the annual meeting of the American Association for the Advancement of Science in St. Louis, February 17. Neural and cochlear development is such that at about six months gestation the fetus begins to hear a range of frequencies. Thus, there's the possibility that newborns prefer listening to speech just because they're used to it from their in-utero tuning in. Copyright 2002, Science in Africa,

Keyword: Language; Hearing
Link ID: 8730 - Posted: 03.29.2006

We all teeter and tip while first learning to walk but, for adults like retired electrical engineer Fred Kawabata — whose sense of balance was damaged when a childhood disease flared up as an adult — a simple stroll becomes something to learn all over again. "When it first struck me I was flat on my back," explains 65-year-old Kawabata from Beaverton, Oregon. "I had vertigo, I was dizzy, I could hardly get out of bed." Almost ten years ago the chicken pox he had suffered as a kid came back in the form of shingles. The virus that lay dormant for all those years in his nerves attacked the vestibular nerves of Kawabata's the inner ear, leaving him rather unsteady on his feet because of a balance disorder. "In about a month, I could get up and walk around although it was still very uncomfortable. It took a couple months before I could be reasonably comfortable walking around," he recalls. "[Now], when I'm walking on a flat surface, I generally don't have to think about it very much. But if I'm on an uneven surface like when I'm hiking and the trail is rough, then I really have to think about it. © ScienCentral, 2000-2006.

Keyword: Movement Disorders
Link ID: 8729 - Posted: 06.24.2010

It's usually reasonable to assume that eating more calories than you burn is what makes you gain weight. We tend to faithfully adhere to that belief, otherwise, why would we ever bother with all that dieting and exercise? But research now shows that viruses — specifically certain human adenoviruses — may actually be causing some cases of obesity. Adenoviruses are usually associated with common infections like colds and pink eye. They can also cause enteritis and diarrhea. But as nutritional scientist Leah Whigham says, "Those are the acute responses. We're finding that some of these viruses also cause a more chronic response that involves increased fatness." Whigham and her team at the University of Wisconsin, Madison tested several human adenoviruses for their ability to increase fat in both live chickens and in cell culture. The groundwork for this new study was laid by earlier research of Dr. Nikhil Dhurandhar. Dhurandhar first discovered that viruses could cause obesity while working with patients in India. He noticed that people who had been exposed to a chicken adenovirus called SMAM-1 were consistently fatter than those who had had no exposure. Later on, having moved to the U.S., Dhurandhar collaborated with other researchers to study whether human adenoviruses, which are common throughout the human population, could be having a similar effect. This led to the discovery that the human adenovirus Ad-36 caused significant fat increases in animals, and what's more, was associated with obesity in humans. © ScienCentral, 2000-2006.

Keyword: Obesity
Link ID: 8728 - Posted: 06.24.2010

By Laura Blackburn A little bit of stress can sometimes be good for us. It activates hormones that help us breathe more easily, for example. But for asthmatics, stress only makes things worse. Now, a group of researchers believe they have found a molecular mechanism that could help explain why. Stress works its effects partially through the hormones adrenaline and cortisol. Usually, adrenaline opens up airways by docking with the beta2-adrenergic receptors (beta2-AR) on cells. Cortisol helps mute allergic responses by connecting to the glucocorticoid receptors (GR). To understand why asthmatics get worse with stress, psychologists Greg Miller and Edith Chen from the University of British Columbia in Vancouver, Canada, graded the everyday stress levels of 38 healthy and 39 asthmatic children. They then looked at the levels of beta2-AR and GR gene expression in each child’s white blood cells. Healthy children who were stressed had higher levels of beta2-AR expression than did those who were chilled out. This would explain why adrenaline could ease the breathing of the stressed kids: There are more cell receptors to pick up the signal. The pattern was reversed in the asthmatic children; those with chronic stress had lower beta2-AR expression levels than those who were typically relaxed. While there wasn't a clear relationship between stress and GR expression levels, the researchers did discover that profound stress had an impact. If an already stressed child experienced a very stressful event, such as the death of a relative, gene expression of both receptors dropped. © 2006 American Association for the Advancement of Science.

Keyword: Stress; Neuroimmunology
Link ID: 8727 - Posted: 06.24.2010

A national research team led by the University of Cincinnati's Bibiana Bielekova, MD, report new insights into how anti-rejection drug helps MS patients Discovery of the mechanism of a drug being tested for the treatment of multiple sclerosis (MS) has revealed that it's not only more effective than first thought, but might also help in the management of other autoimmune diseases, organ transplant rejection and even cancer. A research team led by the University of Cincinnati's Bibiana Bielekova, MD, report new insights into the role of the MS drug daclizumab (Zenapax) in the March 27 online version of the Proceedings of the National Academy of Sciences. The article will appear in print April 11. The exact cause of MS is unknown, but one theory is that it may it be triggered by exposure to a viral infection or environmental influences. The disease takes different courses in different people and can go into remission for many years, recurring occasionally or progressing quickly into degeneration of all motor functions that control muscles, strength, vision and balance. The very progressive form of the disease can end in death. Scientists have long thought that in MS the specific white cells (T-cells) that fight off infection actually turn on the body they are supposed to protect, attacking the myelin sheath that protects the nerves.

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 8726 - Posted: 03.29.2006