Dyslexia can impair a driver's reactions as much as a moderate drinking session. That is the conclusion of a small study which compared how quickly dyslexic and non-dyslexic drivers react to traffic signs. Those with dyslexia, which is characterised by difficulties with reading and writing, took on average 30% longer to react. The controversial finding will raise questions about whether people with dyslexia should have extra tests before being allowed behind the wheel. Drivers just over the UK's alcohol limit, which can be exceeded by drinking two pints of beer, are typically 10% slower than normal to react. In the study, Hermundur Sigmundsson at the Norwegian University of Science and Technology in Trondheim gave 17 volunteers, six of whom were dyslexic, two different tests. The first involved a 4-minute drive along a simulated country road at 50 to 80 kilometres per hour. In the second task, the volunteers drove through a city at lower speeds for 10 minutes. The simulator flashed up traffic signs in the drivers' field of view and measured how quickly they responded by pushing a button or saying "now". In the rural drive, the signs appeared directly ahead, while in the city they appeared in a variety of places. © Copyright Reed Business Information Ltd.

Keyword: Dyslexia
Link ID: 6807 - Posted: 06.24.2010

While its causes are many, stuttering used to carry with it the stigma of being a "psychological problem." Now, researchers are finding that stutterers' brains process language differently, even when they aren't speaking. "Stuttering is known to be a very complex disorder, and there has been evidence that language plays an important role in stuttering," explains Christine Weber-Fox, a cognitive neuroscientist at Purdue University. "For example, when children begin stuttering it's not when they're saying their first word, it's when they start combining words, and when language becomes more complex and they're having to formulate more. So we were very interested in knowing the role of language processing in stutterers, even when people who stutter aren't required to speak at all." Weber-Fox and her team compared the brain activity of 22 adults, half stutterers and half non-stutterers, measuring the activity of brain cells in milliseconds using what looks like a wired-up swimming cap with electrodes that sit on the scalp. The adults were shown two words on a computer screen, and their job was to identify—silently, by pressing a button—which pairs of words rhymed. Some word pairs, like "own" and "gown," were spelled similarly but did not rhyme; some, like "own" and "cone," rhymed but were not spelled similarly, and some, like "own" and "cake," neither rhymed nor were spelled similarly. © ScienCentral, 2000- 2005.

Keyword: Language
Link ID: 6806 - Posted: 06.24.2010

Could a chemical cousin of antifreeze someday help people with spinal cord injuries walk again? Researchers at Purdue University are studying this in dogs with paralyzed hind legs. They injected 19 injured dogs with a drug called polyethylene glycol (PEG)—a nontoxic liquid polymer related to antifreeze—on top of providing them with the standard drugs, surgery and rehab, and showed that PEG targets damaged nerve cells, protecting some of the injured cells from progressive damage and death. "The dogs that come in that receive conventional management, that is, just surgery and rehabilitation, about 15 to 20 percent of those dogs will have some quality of life just through spontaneous repair," says Richard Borgens, director of Purdue University Center for Paralysis Research, who reported his findings in the Journal of Neurotrauma. "But most of them, about 80 percent, will remain paraplegic for the rest of their lives. What this [PEG] compound does when we inject it is it reverses those odds, it really goes from about 20-80 to 80-20; about 80 percent are leading very normal lives, good quality of life, and only about 20 percent have any kind of real problem at the end of the study time, which was, we followed them out to about a year." In the study, 13 of the 19 dogs (about 68 percent) injected with PEG regained use of their hind legs and were able to walk within eight weeks. The dogs were injected twice—when they were brought into the lab (within three days of their injuries), and then after standard surgery and steroids to reduce inflammation. In a group of 24 dogs that only received the standard treatment, only about 25 percent regained a similar level of mobility and 62 percent remained paraplegic. © ScienCentral, 2000- 2005.

Keyword: Regeneration
Link ID: 6805 - Posted: 06.24.2010

Among the principal obstacles to regenerating spinal cord and brain cells after injury is the "braking" machinery in neurons that prevents regeneration. While peripheral nerves have no such machinery and can readily regenerate, central nervous system (CNS) neurons have their brakes firmly in place and locked. Now, two groups of scientists have independently found a new component of that braking machinery, adding to understanding of the regulation of neuronal regeneration and of possible treatments to switch off the brakes on regrowth of spinal cord or brain tissue. The two groups--one group led by Jong Bae Park, Glenn Yiu, and colleagues from Children's Hospital Boston and the other led by Sha Mi and colleagues of Biogen Idec, Inc.--discovered that a protein variously called TAJ or TROY acts as an important part of the receptor on neurons that responds to growth-inhibitory molecules in myelin. Specifically, these molecules prevent the growth of the cablelike axons of injured neurons. Myelin is the fatty sheath that encases neurons and acts as an insulator and aid to the transmission of nerve impulses. Researchers knew that CNS neurons had receptors on their surface that accepted the inhibitory molecules--like a key fitting a lock--and switched-on inhibitory signaling within the neuron. They had also shown that a protein called p75 could function as a component of the complex of proteins that make up this receptor. The puzzle, however, was that p75 is not widely made in the adult neurons in which this inhibitory receptor complex is known to function.

Keyword: Regeneration
Link ID: 6804 - Posted: 02.03.2005

Researchers have discovered an important chemical in the brain's neuronal machinery that triggers some of the withdrawal symptoms of opioid drugs like morphine and heroin. They believe that drugs to inhibit the chemical--called a transporter--could relieve some of the early physical symptoms of withdrawal, such as teeth-chattering, uncontrolled shaking, and jumpiness. Such drugs could become part of the arsenal of medicines and behavioral techniques aimed at helping addicts kick their habits. To zero in on the machinery underlying withdrawal symptoms, researchers led by Elena Bagley and Macdonald Christie of the Pain Management Research Institute at Royal North Shore Hospital (a division of the University of Sydney) performed biochemical studies on brain slices from mice that had been treated with morphine. Their objective was to understand what happens to a particular region of the midbrain--called the periaqueductal gray (PAG)--known to be involved in such withdrawal symptoms. Opiate addiction inhibits neuron activity in this region, which alters the neuronal machinery to compensate for this inhibition. Upon opiate withdrawal, the neurons rebound, becoming hyperactive. The scientists' analysis revealed that a transporter molecule for the neurotransmitter GABA was responsible for the electrical abnormalities that produce a hyperexcitability in the neurons. Neurotransmitters are the molecular ammunition that one neuron fires at its neighbor to trigger a nerve impulse in the neighbor. Propagation of such nerve impulses through the networks of neurons in the brain is the basis of all neural activity. Transporter molecules are the proteins that retrieve neurotransmitter molecules from the spaces between neurons after they trigger nerve impulse, to reload the neuron for its next signaling burst.

Keyword: Drug Abuse; Pain & Touch
Link ID: 6803 - Posted: 02.03.2005

The ancient Greeks imagined three Fates - one spun the thread of life, the second measured its length, and the third snipped it off. Science has tried to provide more plausible (if less poetic) reasons for why some of us live longer than others. Now two researchers in Scotland have made a discovery even the Greeks couldn't have imagined: Reaction time may be a core indicator of long life. Ian Deary, University of Edinburgh, and Geoff Der, MRC Social and Public Health Sciences Unit, Glasgow, report on a study from the MRC Unit that measured both the IQs and the reaction times of middle-aged subjects. Both tests of mental ability were associated with life span, but reaction time was the stronger indicator. These findings, presented in the study "Reaction Time Explains IQ's Association with Death," will appear in the January 2005 issue of Psychological Science, a journal of the American Psychological Society. The new research builds on earlier studies showing that people with lower IQs tend to die at younger ages than those with higher IQs. Deary and Der, however, wanted to use a more fundamental measure of mental ability - which they define as efficiency in processing information.

Keyword: Intelligence
Link ID: 6802 - Posted: 02.03.2005

Forget counting sheep, next time you are having trouble dropping off to sleep try putting on a jazz CD. Researchers have shown just 45 minutes of relaxing music before bedtime can make for a restful night. The Taiwanese researchers studied the sleeping patterns of 60 elderly people with sleep problems. They told the Journal of Advanced Nursing, how the technique was easy to learn and lacked the side-effects of other treatments. The study participants were either given a choice of music to listen to before going to sleep or nothing at all. The music group were able to choose from six tapes that featured soft, slow music - around 60-80 beats per minute - such as jazz, folk or orchestral pieces. Listening to music caused physical changes that aided restful sleep, including a lower heart and respiratory rate, the researchers found. The people in the music group reported a 35% improvement in their sleep, including better and longer night-time sleep and less dysfunction during the day. Lead author Professor Hui-Ling Lai, of the Buddhist Tzu-Chi General Hospital and the University of Taiwan, said: "The music group reported a 26% overall improvement in the first week and this figure continued to rise as they mastered the technique of relaxing into sedative music." (C)BBC

Keyword: Sleep
Link ID: 6801 - Posted: 02.02.2005

Michael Hopkin To a monkey, some things are worth looking at more than others. A US study has shown that rhesus macaques will pay to look at images of powerful or sexually interesting fellows. The discovery, made by neurobiologists at Duke University in Durham, North Carolina, supports the theory that monkeys will make sacrifices to gain socially useful information, much as a human might spend money on a newspaper. Male monkeys will 'pay' in fruit juice to look at a picture of a socially dominant monkey or a female's hindquarters. In the wild, the animals help their fitness by monitoring what their leaders are doing, and which females are sexually receptive. The researchers gave captive male rhesus macaques two options: a drink of cherry juice, or a different-sized shot of juice and the chance to look at one of a range of pictures of their troop members for just over half a second. By varying the amounts of juice, the team worked out how much the monkeys valued each image. "Monkeys are basically juice experts; they're very sensitive to the differences," says team member Robert Deaner. ©2005 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 6800 - Posted: 06.24.2010

Peter Fimrite, Chronicle Staff Writer There isn't much to like about fruit flies, unless you are Pankaj Kapahi. The newest scientist at Marin County's Buck Institute for Age Research is passionate about them. In fact, the 33-year-old disciple of famed fly aficionado and researcher Seymour Benzer has close to a million of the little critters in dozens of beakers lining the shelves of his laboratory in Novato. His research on flies has helped reveal potential dangers in high-protein eating plans such as the Atkins diet and could lead to treatments for such health problems as obesity. In short, by feeding, poking, prodding and putting flies through a host of scientific indignities, he is searching for ways to make people live longer. Research on the annoying insects is already responsible for a variety of recent genetic discoveries that have the scientific community buzzing, and Kapahi is at the forefront of that movement. "My eyes have been opened since I decided to move to invertebrates for genetic research," Kapahi said from his basement laboratory in the cavernous Buck research center, located on Mount Burdell overlooking Novato. "It's becoming the test bed for a lot of biomedical research. It's so much cheaper to work with flies because they're easy for us to maintain, and we can keep them in the lab." ©2005 San Francisco Chronicle

Keyword: Obesity; Genes & Behavior
Link ID: 6799 - Posted: 06.24.2010

Before there was a U.S.D.A food pyramid, there was the 19th century proverb "an apple a day keeps the doctor away." Now, researchers at Cornell University are finding that an apple a day might also keep Alzheimer's at bay. Cy Lee, a food scientist at Cornell's New York State Agricultural Experiment Station, has been studying apples for over 20 years. In 2000, he reported that apples have a healthy dose of cancer-fighting agents called antioxidants. Since then he's been studying how they might affect neurodegenerative disorders like Alzheimer's disease and Parkinson's disease. In one study, Lee pre-treated rat brain cells with extract containing a phytonutrient found in apples called quercetin (which is also found in onions and some berries). "And then we exposed these nerve cells to hydrogen peroxide, which creates oxidative stress," he says. Oxidative stress is a condition characterized by the release of free radicals and which results in cellular degeneration. It's believed to cause the damage in brain cells that leads to Alzheimer's. In Lee's study, cells pre-treated with the apple extract were 70 to 90 percent more resistant to oxidative stress than untreated cells; the higher the concentration of apple extract the cells were treated with, the greater the protection against oxidative stress was. "If we are able to prevent this oxidative stress we hope that the nerve cell damage will maybe be prevented," he says. © ScienCentral, 2000- 2005.

Keyword: Alzheimers
Link ID: 6798 - Posted: 06.24.2010

By Ronald Pies, M.D. Psychiatric Times December 2004 Vol. XXI Issue 14 The long-term treatment of patients with neuropsychiatric disorders can be quite challenging and sometimes frustrating for clinician and patient alike. Consider the following vignette: "Mr. C" is a 38-year-old former engineer with a diagnosis of chronic paranoid schizophrenia and "episodic mood lability." He had been tried on numerous conventional antipsychotics since the mid-1980s, with only partial improvement of his delusions and auditory hallucinations. Mr. C had developed severe extrapyramidal side effects, including akathisia, on most of the first-generation antipsychotics and was eventually treated with clozapine (Clozaril). Although his psychosis improved considerably, Mr. C believed that the frequent blood drawings would "rob me of my vital spirits" and ultimately refused to take clozapine. Olanzapine (Zyprexa) treatment was helpful but led to significant weight gain, and again, the patient refused to continue treatment. Trials of risperidone (Risperdal), quetiapine (Seroquel) and aripiprazole (Abilify) were partially successful but also produced a variety of side effects the patient found unacceptable. Attempts to engage Mr. C in supportive psychotherapy were also only transiently successful, and he eventually required prolonged inpatient hospitalization. He was eventually discharged on two atypical antipsychotics in combination with divalproex (Depakote). Mr. C's case is fairly typical of many chronic patients seen today by psychiatrists: a long history of partial responses to medication complicated by poor treatment adherence and troublesome side effects (Dewan and Pies, 2001). © 2005 Psychiatric Times. All rights reserved.

Keyword: Schizophrenia
Link ID: 6797 - Posted: 06.24.2010

CHAPEL HILL – Attracting a mate can be a costly endeavor, according to a University of North Carolina at Chapel Hill scientist, but new experiments he helped lead show that some male animals economize on courting when the chance of success seems low. Dr. Keith W. Sockman, assistant professor of biology in UNC's College of Arts and Sciences, studies mating behavior in songbirds and the songs that play such a central role in their reproduction. "From people to praying mantises, individuals invest everything from their homes to their heads to attract a member of the opposite sex," Sockman said. "When male songbirds sing to attract a mate, they expend energy during times they could otherwise be foraging for seeds and grubs. "They may also increase their exposure to predators," the biologist said. "This led us to predict that when females are in short supply or infertile, unmated males should reduce these 'costs' by singing less." In a paper published in the new issue of the journal Biology Letters, Sockman and colleagues Dr. Thomas P. Hahn and Kendra B. Sewall of the University of California at Davis and Dr. Gregory F. Ball of Johns Hopkins University in Baltimore, report that male songbirds are frugal in their efforts to attract a mate.

Keyword: Sexual Behavior; Language
Link ID: 6796 - Posted: 06.24.2010

Lawyers are often suspicious of so-called "eye-witness accounts" and rightly so. Hundreds of scientific studies in the past few decades have shown that the memories of people who observe complex events are notoriously susceptible to alteration if they receive misleading information about the event after it has taken place. In this month's issue of the journal Learning & Memory, scientists from Johns Hopkins University report new insights into how such "false memories" are formed. This is the first study to use neuroimaging to investigate how the brain encodes misinformation during the creation of a false memory. Using advanced, non-invasive imaging techniques, Yoko Akado and Craig Stark compared the areas of the brain that were active when a subject was encoding a complex event and afterwards, during exposure to misleading information. For example, subjects were asked to watch a vignette comprised of 50 photographic slides showing a man stealing a woman's wallet, then hiding behind a door. A little later, the subjects were shown what they thought was the same sequence of slides but unbeknownst to them the second set of slides contained a misleading item and differed in small ways from the original--the man hid behind a tree, for example, not a door. Two days later, the subjects took a memory test, which asked them to recall details such as where the man hid, and which presentation--the first, second, or both--contained that information. Memory for a misinformation item was scored as a false memory only if the subject attributed the item to either the original presentation or to both the original and second slide presentations.

Keyword: Learning & Memory
Link ID: 6795 - Posted: 02.02.2005

New Haven, Conn.--Adolescents who smoke show impairment of memory and other cognitive functions, according to a Yale study in Biological Psychiatry. More than 4.5 million teenagers smoke cigarettes in the United States, according to the Centers for Disease Control and the U.S. Census Bureau. Leslie Jacobsen, M.D., associate professor of psychiatry and pediatrics at Yale School of Medicine, and her research team tested working memory. This form of memory is used when keeping information in mind and manipulating it. They also evaluated verbal learning and memory, attention, mood, symptoms of nicotine withdrawal and tobacco cravings in 41 adolescent daily smokers and 32 nonsmokers. The groups were similar in age, gender and education. "Adolescent smokers were found to have impairments in accuracy of working memory performance," Jacobsen said. Other studies show adult non-smokers and smokers have comparable focused, sustained and selective attention, and improved working memory, suggesting enhancement of performance by nicotine. Male adolescents as a group begin smoking at an earlier age than female smokers and were significantly more impaired during tests of selective and divided attention, she said. All of the adolescent smokers also showed further disruption of working memory when they stopped smoking.

Keyword: Drug Abuse; Learning & Memory
Link ID: 6794 - Posted: 02.02.2005

ANN ARBOR, Mich.---Positive emotions like joy and humor help people "get the big picture," virtually eliminating the own-race bias that makes many people think members of other races "all look alike," according to new University of Michigan research. "Negative emotions create a tunnel vision," said U-M psychology researcher Kareem Johnson. "Negative emotions like fear or anger are useful for short-term survival when there's an immediate danger like being chased by a dangerous animal. Positive emotions like joy and happiness are for long-term survival and promote big picture thinking, make you more inclusive and notice more details, make you think in terms of 'us' instead of 'them.'" To simulate getting a quick glance of a stranger, scientists flashed photos of individuals for about a half second, finding subjects recognized members of their own race 75 percent of the time but only recognized members of another race 65 percent of the time, Johnson said. However, researchers found positive emotions boosted that recognition of cross-race faces about 10 to 20 percent, eliminating the gap. The findings will appear in an upcoming issue of the journal Psychological Science. Johnson, who is completing his PhD work in psychology, and Barbara Fredrickson, a U-M psychology professor and director of the Positive Emotion and Psychophysiology Laboratory, specialize in the power of positive emotions.

Keyword: Emotions
Link ID: 6793 - Posted: 02.02.2005

PITTSBURGH, – Puberty, that awkward phase when boys and girls are primed for their sexual reproductive years as men and women, appears to be triggered by the brain's own version of "It takes two to tango," whereby a signal literally gets turned on by a molecule that is produced by a gene aptly named KiSS-1. The couple – a biochemical equivalent to Adam and Eve – makes its sudden appearance in a region of the brain called the hypothalamus just as puberty begins, according to a study published in this week's online edition of the Proceedings of the National Academy of Sciences (PNAS). Until now, little had been known about what instigates the cascade of hormone secretions that, over time, produces puberty's tell-tale physical changes, including the development of breasts in girls and voice change in boys. As such, this research begins to answer one of the most vexing questions about human development: What causes puberty to begin? How is it that the full repertoire of reproductive hormones can exist at birth, go into hiding at about four to six months of age, then reemerge in full force some 10 to 12 years later? "Puberty is critical to human development. And while there is a fairly good understanding of how the endocrine system regulates the hormones involved, just how and when the brain activates this process has been a great mystery. An appreciation of puberty's deep-seated neurobiological mechanisms could, for instance, help prevent precocious or delayed puberty from occurring in some children," noted the study's lead author, Tony Plant, Ph.D., a professor in the departments of cell biology and physiology and obstetrics, gynecology and reproductive sciences, as well as director of the Center for Research in Reproductive Physiology at the University of Pittsburgh School of Medicine.

Keyword: Development of the Brain; Hormones & Behavior
Link ID: 6792 - Posted: 06.24.2010

Durham, N.C. – A gene that plays many fundamental roles in cells throughout the body has, for the first time, been implicated in human disease, according to researchers at the Duke Center for Human Genetics. A defect in the ubiquitous gene dynamin 2 underlies one form of the prevalent, familial nerve disorder, known as Charcot-Marie-Tooth disease (CMT). The disorder affects approximately 1 in every 2,500 people, making it one of the most common of all hereditary disorders, said the researchers. Their findings also reveal a previously unknown link between CMT and a deficiency of white blood cells, suggesting that defects in dynamin 2 might underlie both conditions, the researchers reported in the Jan. 30, 2005, issue of Nature Genetics. The discovery -- together with earlier findings of genes that can also cause the genetically heterogeneous and debilitating disease -- is providing new insight into the nervous system, said first author of the study Stephan Züchner, M.D., assistant professor of psychiatry and member of the Duke Center for Human Genetics. Also, he said, the findings bring a better understanding of the types of defects that might, in general, lead to peripheral nerve disorders. © 2001-2005 Duke University Medical Center

Keyword: Genes & Behavior
Link ID: 6791 - Posted: 06.24.2010

DALLAS – Researchers at UT Southwestern Medical Center have discovered that drugs commonly used to treat psychiatric illnesses and blood disorders in humans may protect the brain cells that die in people with Huntington's disease, possibly delaying the onset and slowing the progression of the disease. These findings, available online and in today's issue of Proceedings of the National Academy of Sciences, may offer new treatment options for Huntington's disease, which has no cure. Huntington's disease is a neurological disorder in which the medium spiny striatal neurons, the nerve cells that control movement and certain mental functions die. Patients die within 10-15 years after onset of the disease. The disease is caused by a mutation in the gene that makes the protein huntingtin. The mutation creates a long chain of the amino acid glutamine at one end of the protein. The length of the chain directly correlates with age of onset of the disease, with longer chains leading to symptoms earlier in life. In previous studies, Dr. Ilya Bezprozvanny, associate professor of physiology at UT Southwestern, established that one of the defects that leads to death of nerve cells with the mutant huntingtin protein is improper regulation of calcium due to errant signals in the cells. Calcium is inappropriately released from its storage area in the cells, and eventually the cells die.

Keyword: Huntingtons; Apoptosis
Link ID: 6790 - Posted: 06.24.2010

You're much more likely to dream about fighting with your spouse, or other aggressive interactions, during REM sleep than non-REM sleep, according to a new study. This specialization of dream states gives further credence to the theory that dreams are more than just meaningless, chaotic images. While we dream, the brain cycles through REM and non-REM sleep stages at 90-minute intervals. Dreams during both stages tend to mull over social interactions, leading some sleep researchers to speculate that dreams may help people better deal with these encounters. Researchers have also known that REM and non-REM sleep activate different areas of the brain. REM sleep, for example, stimulates the amygdala, which handles fear and aggression, while non-REM sleep kindles the forebrain, which plays a role in impulse control and more cognitive functions. Cognitive neuroscientist Patrick McNamara of Boston University School of Medicine and colleagues wondered if these distinct activations resulted in different types of dreams. To investigate, the team collected dream and wake reports from 15 subjects over the course of 2 weeks. During the day, the researchers paged the subjects every 2 hours and instructed them to tape record their thoughts. At night, they did the same, but the subjects also wore a sleep monitoring system called "the nightcap" which differentiates between REM and non-REM sleep by counting head and eyelid movements. The researchers found that of the dreams that focused only on aggressive interactions, 21 occurred during REM sleep. Some aggression did show up in non-REM sleep, but in those dream arguments, the dreamer never initiated it. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 6789 - Posted: 06.24.2010

Combining magnetic and gold nanoparticles with strands of DNA could allow the early detection of Alzheimer's disease. If successful, future treatments could then be used to prevent symptoms from ever appearing. Identifying and tracking Alzheimer's disease currently relies on brain imaging and psychological testing. A firm diagnosis can only be made by autopsy. But recent studies have revealed several biochemical markers that may provide the basis for a living diagnosis. These include tiny proteins called amyloid-beta-derived diffusible ligands (ADDLs), which exist at elevated levels in the brains of Alzheimer's patients. Dimitra Georganopoulou and her colleagues at Northwestern University in Chicago, Illinois, US, suspected ADDLs might also be present in the cerebrospinal fluid, which can be collected using a spinal tap. But the concentration of the proteins would be incredibly tiny, if they were there at all. So the team turned to a recently developed technique called bio-barcoding, shown to be thousands of times more sensitive for protein detection than conventional tests. "It's the only tool in town with the necessary sensitivity," says team member Chad Mirkin, whose lab developed the technique. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 6788 - Posted: 06.24.2010