By studying fruit fly ovaries, Johns Hopkins scientists have discovered that a protein known to block cell death also has the completely independent role of enabling normal cell movement. The discovery creates an unexpected new path to follow in the effort to understand the biochemical steps behind cells' movement, a critical aspect of embryonic development and the spread of cancer. The work is described in the July 8 issue of Cell. By studying fruit flies engineered to make extra use of random genes, the Hopkins team discovered that a protein called "inhibitor of apoptosis-1" (or IAP) can restore the tightly choreographed cellular movement that naturally occurs in fruit fly ovaries as egg cells mature. "This discovery was completely unexpected," says Denise Montell, Ph.D., professor of biological chemistry in Johns Hopkins' Institute for Basic Biomedical Sciences. "Based on what was known about this protein's function in blocking cell death, there would have been no way to predict its involvement in cell migration."

Keyword: Development of the Brain; Apoptosis
Link ID: 5812 - Posted: 07.15.2004

Michael Hopkin It is no coincidence that so many piano-tuners are blind. Folklore says their lack of sight gives them acute hearing, ideally suited to the task. Now neuroscientists in Canada have shown that the sightless really do hear notes more precisely if they went blind when they were very young. The idea that blindness can aid musical development is an old one, says Robert Zatorre of McGill University in Montreal, a member of the study team. Ray Charles and Stevie Wonder, who both lost their sight at an early age, were among the twentieth century's most influential musicians. But previous attempts to quantify the effect have met with mixed results. Zatorre thinks this is because they did not take account of the age at which subjects went blind. The researchers therefore divided their 14 blind subjects into two groups: those who were blind at birth or lost their sight during the first two years of life, and those for whom blindness came later. The team also tested fully sighted people to see which of the three groups performed best at pitch-recognition tasks. ©2004 Nature Publishing Group |

Keyword: Hearing; Vision
Link ID: 5811 - Posted: 06.24.2010

BABIES exposed to sign language babble with their hands, even if they are not deaf. The finding supports the idea that human infants have an innate sensitivity to the rhythm of language and engage it however they can, the researchers who made the discovery claim. Everyone accepts that babies babble as a way to acquire language, but researchers are polarised about its role. One camp says that children learn to adjust the opening and closing of their mouths to make vowels and consonants by mimicking adults, but the sounds are initially without meaning. The other side argues that babbling is more than just random noise-making. Much of it, they contend, consists of phonetic-syllabic units - the rudimentary forms of language. Laura-Ann Petitto at Dartmouth College in Hanover, New Hampshire, a leader in this camp, has argued that deaf babies who are exposed to sign language learn to babble using their hands the way hearing babies do with their mouths. Petitto believes that the hand-babbling is functionally identical to verbal babbling- only the input is different. But critics counter that deaf children cannot be directly compared with their hearing counterparts. Now Petitto and her colleagues have tested three hearing babies who, because their parents are deaf, were exposed only to sign. Three control infants had hearing, speaking parents. To analyse the hand movements of the six children, the researchers placed infrared-emitting diodes on the babies' hands, forearms and feet.

Keyword: Language
Link ID: 5810 - Posted: 07.15.2004

PORTLAND, Ore. -- An Oregon Health & Science University research team has uncovered a novel form of transmission between neurons in the brain that is mediated by dopamine. The neurons are found in parts of the brain associated with movement, substance abuse and mental disorders. Scientists at the Vollum Institute, OHSU School of Medicine, reported in a study published in the journal Neuron that the neurotransmitter dopamine is released from midbrain nerve cells in a much more precise, targeted manner than previously thought. They discovered that dopamine molecules are released as packages from stores, or vesicles, in branch-like extensions of neurons called dendrites. The dopamine travels to dopamine receptors on tiny terminals within milliseconds. Until now, scientists had only detected the release of dopamine in the midbrain and suspected that the neurotransmitter was dispersed over wide areas to reach receptors. "We've demonstrated that this synaptic current is over and done within a second," said John Williams, Ph.D., senior scientist at the Vollum Institute, OHSU School of Medicine, and a study co-author. "We knew dopamine was released in this place, we knew the cells were sensitive to dopamine, but nobody had been able to put the two together."

Keyword: Miscellaneous
Link ID: 5809 - Posted: 07.15.2004

Last year a remarkable exhibit came to light. Hidden in the vaults of a London museum was a scrap of paper containing a few strands of hair. The paper was crudely fashioned into an envelope but the words on it immediately caused a stir: "Hair of His Late Majesty, King George 3rd." For Professor Martin Warren, it was the clue that would help him finally solve the mystery of King George's illness. His investigation is featured in a BBC documentary, Medical Mysteries. "King George is largely remembered for those periods when he lost his mind. But it's been difficult to explain these attacks, so I was keen to analyse this hair sample," said Professor Warren. When the hair was tested by the Harwell International Business Centre for Science & Technology in Didcot, Oxfordshire, the results were surprising. The king's hair was laden with arsenic. It contained over 300 times the toxic level. "This level is way above anything we were expecting - it's taken us completely by surprise." Far from being an answer, this remarkable finding was just the start of Warren's detective work. In King George's time, his bizarre behaviour and wild outbursts were treated as insanity. He was bound in a straight-jacket and chained to a chair to control his ravings. King George was officially mad. It wasn't until the 1970s that a new and controversial diagnosis was made. Two psychiatrists - Ida MacAlpine and her son Richard Hunter - revisited the king's medical records and noticed a key symptom; dark red urine - a classic and unmistakable sign of a rare blood disorder called porphyria. Porphyria can be a devastating disease. In the acute form, it can cause severe abdominal pain, cramps, and even seizure-like epileptic fits. (C)BBC

Keyword: Neurotoxins
Link ID: 5808 - Posted: 07.14.2004

US scientists have developed a tool that, for the first time, monitors live brain activity down to the cellular level. It could be used to tell scientists exactly how drugs affect specific neurons involved in psychiatric disorders, say its creators. Dr Alison Barth and colleagues at Carnegie Mellon University hope this, in turn, could lead to new treatments. Their findings appear in the Journal of Neuroscience. Scientists have mapped general areas of the brain that perform certain tasks, such as memory, behaviour and perception. However, they have not been able to pinpoint individual nerve cells, or neurons, according to Dr Barth, assistant professor of biological sciences at the university's Mellon College of Science. To try to overcome this limitation, Dr Barth experimented on mice. She changed the genes of the mice so a fluorescent protein would light up whenever a particular nerve cell was activated. In this way, researchers would be able to tell when a drug or a trigger from the environment was acting on a specific neuron by looking for the glow from the fluorescent protein. Using this technique, Dr Barth was able to identify the precise area of the mouse brain, down to the cellular level, involved in processing sensory information from a single whisker.

Keyword: Brain imaging
Link ID: 5807 - Posted: 07.14.2004

COLUMBUS, Ohio – By examining the brain activity of moths, researchers have found that the behavior of these insects isn't ruled entirely by instinct. Rather, they can learn which odors mean food. The findings are more than academic: The researchers hope to develop methods for using trained moths to detect odors of interest for defense industry and law enforcement – such as odors given off by biological and chemical weapons. Animal behaviorists have historically argued that most insects have a programmed response to a variety of situations, such as knowing which odors signal the presence of food and mates. But scientists are discovering that animals don't always instinctively know what to do. In these cases, they have to learn, said Kevin Daly, the study's lead author and a research scientist in entomology at Ohio State University. He and his colleagues used tiny electrodes implanted in the heads of sphinx moths to continuously monitor the insect's neuronal activity and feeding behavior before, during and after training the animal that one odor meant food – sugar water – was on the way and another odor did not.

Keyword: Learning & Memory; Chemical Senses (Smell & Taste)
Link ID: 5806 - Posted: 06.24.2010

Some primatologists have argued that to understand human nature we must understand the behavior of apes. In the social interactions and organization of modern primates, the theory goes, we can see the evolutionary roots of our own social relationships. In the genomic era, as scientists become more adept at extracting biological meaning from an ever expanding repository of sequenced genomes, it is likely that our next of kin will again hold promising clues to our own identity. Comparing primate genomes is an approach that can help scientists understand the genetic basis of the physical and biochemical traits that distinguish primate species. James Sikela and colleagues, for example, collected DNA from humans, chimpanzees, bonobos, gorillas, and orangutans to identify variations in the number of copies of individual genes among the different species. Their work is published in this month's issue of the open-access journal, PLoS Biology. Overall, Sikela and colleagues found more than 1,000 genes with changes in copy number in specific primate lineages. All the great ape species showed more increases than decreases in gene copy numbers, but humans showed the highest number of genes with increased copy numbers, at 134, and many of these duplicated human genes are implicated in brain structure and function.

Keyword: Evolution
Link ID: 5805 - Posted: 07.14.2004

Montreal, . Scientists at the Montreal Neurological Institute at McGill University have discovered a gene that is necessary for the correct development of the part of the brain that controls autonomic functions such as heart rate, bronchial dilation and gut peristalsis. In a study published in the Proceedings of the National Academy of Sciences of the USA, Dr. Stefano Stifani and colleagues have demonstrated for the first time that disruption of this gene causes a dramatic loss of these particular nerve cells. During the development of the nervous system, there are a number of critical events that generate different types of nerve cells in particular locations of the brain and at particular times. “We found that specific types of hindbrain visceral motor nerve cells do not develop when the function of a gene called Runx1 is disrupted in mice, while other types of nerve cells develop normally”, explained Dr. Stefano Stifani, Associate Professor of Neurology and Neurosurgery and Anatomy and Cell Biology. “This has never been shown before and it is an important step in understanding how these nerve cells form during normal development.” The hindbrain visceral motor nerve cells normally control the ability to maintain a stable internal environment in response to internal or external influences. Problems associated with their development or function could have important implications for the control of vital body functions such as blood pressure, heart rate, and electrolyte balance.

Keyword: Development of the Brain
Link ID: 5804 - Posted: 06.24.2010

Patients with the movement disorder Parkinson’s disease have seen benefits from drugs that target brain chemicals. Unfortunately the advantages can decline over time. Recently, however, scientists devised and refined a different strategy, termed deep brain stimulation, which now provides patients with an additional option. Research indicates that this electricity-based technique can alter brain activity and help many patients achieve greater control over their movements. Continued investigations into how deep brain stimulation creates its benefits will allow researchers to further improve the technique for Parkinson’s and also help them find ways to use it for the treatment of other brain ailments. Electricity keeps Justin Timberlake’s tunes blaring on the CD player, the milk chilled in the refrigerator, and the living room well lit. In recent years, the power of electricity has reached a whole new level. Scientists now have discovered an electricity-based technique that can aid the malfunctioning brain. Comprised of a brain implant that delivers electrical pulses, the strategy, termed deep brain stimulation, influences cell activity and alleviates the movement problems that mark the brain disorder Parkinson’s disease (PD). Copyright © 2004 Society for Neuroscience

Keyword: Parkinsons
Link ID: 5803 - Posted: 06.24.2010

Jim Giles Tommy McHugh was sitting on the toilet when his life changed. He felt a sudden and extreme headache, but something far more serious was occurring: blood was leaking from an artery in his brain. McHugh was suffering from a cerebral haemorrhage — an event that hospitalized him, altered his personality and, he says confidently, was the best thing that ever happened to him. Standing in the bright London sunshine three years later, McHugh describes his new life. If I wasn't there, he tells me, he would be manically painting, sculpting or writing poetry. It's a statement those who knew McHugh before his stroke would find hard to believe. A former builder and heroin addict who has had stints in jail for violent offences, McHugh had no former interest in art. Now he spends almost all his time compulsively creating. "My life is 100% better," he grins. McHugh's story is extraordinary but not completely unique. A handful of similar cases have been identified by neurologists in the United States. There are even rumours that Tom Cruise may play the part of one such patient in a forthcoming film. While the number of subjects remains small, only tentative conclusions can be drawn about how these artistic urges occur. But studies of patients such as McHugh could shed light on how our brains create art. "People like Tommy could reveal the key to artistic creativity," says Mark Lythgoe, a neuroscientist at University College London (UCL). ©2004 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 5802 - Posted: 06.24.2010

MADISON - A newly published study by a University of Wisconsin research team points the way to solving two of life's seemingly eternal but unrelated mysteries: how birds that migrate thousands of miles every year accomplish the feat on very little sleep and what that ability means for humans who are seriously sleep-deprived or face significant sleep problems. The study, published online in the July 13 issue of PloS (Public Library of Science) Biology, found that a group of sparrows studied in the laboratory dramatically reduced how long they slept during the time they would ordinarily be migrating. But they were nonetheless able to function and perform normally despite their sleep deprivation. During times when the birds were not migrating, however, sleep deprivation appeared to impair their performance - similar to what happens to sleep-deprived humans. If researchers ascertain how the birds do so well on so little sleep during migration, the finding could benefit people who need to stay awake and function at a high level for long periods of time, as well as those who suffer from sleep disorders of various kinds. In addition, sleep in the migrating birds was similar to sleep changes that typically occur in humans with depression or bipolar disorder.

Keyword: Sleep; Animal Migration
Link ID: 5801 - Posted: 07.14.2004

Eight percent of men experience red-green color blindness, which results from mutations in genes that code for light-sensitive pigments. But a new study suggests that even men who aren't color blind may see the world differently than women do thanks to natural selection. Brian Verrelli of Arizona State University and Sarah Tishkoff of the University of Maryland analyzed genetic data from 236 people from around the world. Specifically, they studied a gene on the X chromosome known as OPN1LW, which codes for a protein that detects visible light in the red spectrum. Exchange of material between this gene and a neighboring gene associated with green light leads to a high amount of genetic variation but can result in color blindness if the process goes amiss. Among the study participants the researchers found 85 variants of the gene. “That's approximately three times higher than what you see at any other random gene in the human genome,” Tishkoff says. “Usually it's a bad thing to have too much change in a gene, and natural selection gets rid of it. But in this case we're seeing the reverse.” The increased variation enhances the ability to discriminate between colors in the red-orange spectrum, particularly among females because they have two copies of the X chromosome. Previous research in other primates has suggested that enhanced red vision in females allows them to better distinguish between berries and foliage when they are gathering food, Verrelli explains. If females did the gathering in prehistoric times, as many experts believe, that may explain why genetic variation promoting color sensitivity persists today. “We can't explicitly test it, but the model fits,” Verrelli says. The results will appear in the September issue of the American Journal of Human Genetics. --Sarah Graham © 1996-2004 Scientific American, Inc

Keyword: Vision; Genes & Behavior
Link ID: 5800 - Posted: 06.24.2010

Lola Crosswhite, 74, has battled Alzheimer's disease for more than five years. "I was just having a harder time hanging onto information and remembering things," she recalls of when she began to notice its onset. "It was sort of more of a feeling than anything else, of, 'Oh I've got to remember that, I've got to hang onto that'. I guess I had to acknowledge that I was just having a really hard time to remember things, and that wasn't much fun." Crosswhite was one of eight early-stage Alzheimer's patients who volunteered for brain surgery to inject genetically engineered cells taken from her skin into her brain back in 2001; it was the first-ever test of the safety of gene therapy for Alzheimer's. "It wasn't so much me as it was figuring that other people, or my children, would probably benefit from something that they would get from the study," says Crosswhite. "This clinical trial was the first step in determining whether we could safely deliver the growth factor using gene therapy to the human brain and if we could show that then to move on to subsequent trials that would really test its effectiveness," says Mark Tuszynski, neuroscientist at the University of California at San Diego, which conducted the trial. © ScienCentral, 2000- 2004.

Keyword: Alzheimers
Link ID: 5799 - Posted: 06.24.2010

When it's time to migrate, sparrows slash the amount of time they spend sleeping. But unlike long-haul truckers or college students cramming for exams, this avian insomnia may not take a serious toll on their cognitive skills. Understanding how the sparrows pull off this trick could provide a fresh insight into the nature of sleep. Each spring, the white-crowned sparrow, Zonotrichia leucophrys gambelii, sets off from its wintering site in Southern California on a 4300-kilometer migration to its breeding site in Alaska. During their wintering and breeding seasons, songbirds like this sparrow are active during the day and sleep at night. During migration however, they undergo a profound behavioral shift and fly both day and night. How the birds manage such a feat of endurance has remained a puzzle. Nobody knows, for example, whether migrating birds are able to take 40 winks on the wing. Research published 13 July in PLoS Biology suggests that they may not have to. To investigate the link between sleep and migration, Ruth Benca, a psychiatrist at the University of Wisconsin, Madison, turned to white-crowned sparrows. Instead of chasing migrating birds and watching them for signs of sleep, Benca kept an eye on captive birds when migration time rolled around. The birds become restless, Benca says, and her measurements of electrical activity in the birds' brains reveals that they sleep on average 63% less when it's time to migrate. A performance test, in which these hyperactive sparrows learn to peck on a sequence of buttons to earn seeds, suggests that they stay alert in spite of losing sleep. Understanding how they sleep less without impairment may provide insights into sleep disorders and seasonal mood disorders, she and her colleagues claim. That may be pushing things a bit far, says Ullrich Wagner, a neuroendocrinologist at the University of Lübeck in Germany, but the research does raise some intriguing questions. The birds' ability to get by without sleep is an "amazing phenomenon," he says, and future work should focus on the underlying mechanism. In the longer term, experiments like these could even shed light on the function of sleep itself, says Pierre Maquet, a neurobiologist at the University of Liège in Belgium, although he cautions that what's true for sparrows won't necessarily apply to humans. --HENRY NICHOLLS Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Sleep; Animal Migration
Link ID: 5798 - Posted: 06.24.2010

When we learn a new motor skill, we experience rapid improvement in motor performance during the initial training period and slowly improve with further training across subsequent days. Researchers at Duke University Medical Center now report evidence that certain neural circuits in the brain exhibit significant modulations in neuronal activity and connectivity during motor-skill learning and that distinct processes may mediate the neuronal changes that accompany the initial, fast phase of motor-skill learning compared to the longer-lasting, slower phase. Previous studies had revealed changes during motor-skill learning in neural activity and connectivity in several brain areas, namely motor cortex and dorsal striatum, but the nature and dynamics of the plastic changes in these brain structures during the different phases of motor learning remained unclear. In the new work, researchers Rui Costa, Dana Cohen, and Miguel Nicolelis at Duke University recorded the simultaneous neuronal activity in primary motor cortex and dorsolateral striatum of mice during the different phases of motor-skill learning. Neuronal activity was monitored in the mice as they learned, over multiple sessions, to remain on a rotating rod whose speed steadily increased. The researchers observed that cortico-striatal neural circuits undergo substantial changes during motor learning and found that this plasticity differs between fast and slow motor-skill learning. In addition, they discovered that during the initial fast, "within-session" learning, similar plastic processes evolved in parallel in motor cortex and dorsal striatum, whereas during slow, "across-session" learning, the activity changes in motor cortex and striatum differed. Perhaps somewhat surprisingly, these changes seemed to develop in the absence of alterations in the overall firing rate of the neuronal population in each brain area. These results may open interesting avenues for investigating the motor deficits observed in mouse models of neurodegenerative disorders, such as Parkinson's and Huntington's diseases.

Keyword: Learning & Memory
Link ID: 5797 - Posted: 07.14.2004

PITTSBURGH--Carnegie Mellon University neuroscientist Alison Barth has developed the first tool to identify and study individual neurons activated in a living animal. This advance, described in the July 21 issue of The Journal of Neuroscience, ultimately could lead to the development of targeted drugs that directly affect specific neurons involved in neurological diseases that alter behavior, learning and perception. While neuroscientists have made great strides in identifying the general areas of the brain that perform certain tasks, these methods have worked at the gross level and with poor resolution, according to Barth, an assistant professor of biological sciences at the university's Mellon College of Science. To overcome these limitations, Barth created a transgenic mouse that couples the green fluorescent protein (GFP) with the gene c-fos, which turns on when nerve cells are activated. Using this method, researchers can see specific neurons glow as they are activated by external stimuli such as sensory experience or drug treatment. "Our transgenic mouse is a novel tool that can be used to visualize, in living brain tissue, a single neuron that has been activated in response to an animal's experience," Barth said. Barth used the fosGFP mice to identify neurons that are activated during a specific rearing condition – experiencing the world through one whisker. By locating a cluster of glowing neurons, she was able to precisely identify the area of the brain involved in processing sensory input from the single whisker.

Keyword: Brain imaging
Link ID: 5796 - Posted: 06.24.2010

TUESDAY, (HealthDayNews) -- It's sure to be music to parents' ears: After nine months of weekly training in piano or voice, new research shows young students' IQs rose nearly three points more than their untrained peers. The Canadian study lends support to the idea that musical training may do more for kids than simply teach them their scales -- it exercises parts of the brain useful in mathematics, spatial intelligence and other intellectual pursuits. "With music lessons, because there are so many different facets involved -- such as memorizing, expressing emotion, learning about musical interval and chords -- the multidimensional nature of the experience may be motivating the [IQ] effect," said study author E. Glenn Schellenberg, of the University of Toronto at Mississauga. A decade ago, researchers led by the University of Wisconsin's Frances Rauscher found that simply listening to Mozart triggered temporary increases in spatial intelligence. While the "Mozart Effect" has proven difficult to replicate in subsequent studies, the idea that music or musical training might raise IQ took hold in the scientific community. In his study, slated for publication in the August issue of Psychological Science, Schellenberg offered 12 Toronto-area 6-year-olds free weekly voice or piano lessons at the Royal Conservatory of Music, described by Schellenberg as Canada's "most prestigious music conservatory." Copyright © 2004 Yahoo! Inc.

Keyword: Intelligence; Hearing
Link ID: 5795 - Posted: 06.24.2010

By ROBIN MARANTZ HENIG Am I the only person who still prefers doing things one at a time? My fellow New Yorkers have raised multitasking to an art form. People talk on their cellphones while jogging, do their homework on the subway, listen to books on tape while walking, put on makeup in the back seat of the taxicab and - always, everywhere, constantly - talk on their cellphones while they're busy doing something else. This isn't how things were meant to be. Our brains are not built to work this way, no matter how many times teenagers insist that they're paying full attention to their homework, despite the fact that they're also watching television, listening to music and sending electronic instant messages to friends who are doing their own homework amid comparable chaos. The brain works best "on a single task and for sustained rather than intermittent or alternating periods of time," the neurologist Richard Restak writes in "The New Brain: How the Modern Age Is Rewiring Your Mind." "This doesn't mean that we can't perform a certain amount of multitasking,'' Dr. Restak writes.. "But we do so at decreased efficiency and accuracy." Copyright 2004 The New York Times Company

Keyword: Attention
Link ID: 5794 - Posted: 07.14.2004

By SANDRA BLAKESLEE A century ago, neurologists noticed that when ladies wearing big feathered hats ducked through entryways, they would align their bodies just so. It was as if they could feel the tops of doors with the tips of the feathers. From this and other observations, the scientists concluded that each person holds within the brain a mental representation of the body and its parts - even the clothing it wears - as it moves through space. Those early scientists could not explain how the brain creates such sensations, or body schemas. But using modern methods for probing brains, researchers are uncovering the cells and circuits that are responsible. For example, research has found that brain cells become active as objects approach the space around the body. These cells will fire when, say, you see an insect fly toward your face. This so-called peripersonal space extends to arm's length; people with longer arms have a bigger peripersonal space. And when they use a tool, a rake, a joystick or an automobile, their body schema and peripersonal space expand to include it. Copyright 2004 The New York Times Company

Keyword: Vision
Link ID: 5793 - Posted: 07.14.2004