New York - Mini-strokes lead to a major stroke within one week in 1 out of 20 people and should be treated as a medical emergency, British doctors said on Sunday. They said patients who are immediately treated for small strokes, called transient ischemic attacks (TIAs) had almost no risk of a major stroke soon afterward. But people who did nothing about a TIA had an 11-percent risk of a major stroke within one week, Dr Matthew Giles and Peter Rothwell of the Stroke Prevention Research Unit at the University of Oxford reported. TIAs are smaller versions of major strokes and cause similar symptoms such as dizziness, weakness of an arm or leg or visual disturbances. The symptoms are usually mild and transient, so it's easy for people to ignore these episodes. However, TIAs are a warning sign that a larger stroke may be on the way that can cause paralysis, loss of speech, cognitive confusion or death. For their study, published in the Lancet Neurology, Giles and Rothwell combined results from 18 different groups of patients, a total of more than 10 000 people. Overall, 5 percent of patients had a major stroke within seven days of a TIA, they found. Less than 1 percent of patients treated for a TIA at a specialist neurology clinic went on to have a major stroke within a week, compared with 11 percent of those who ignored the TIA, they found. © 2007 Independent Online.

Keyword: Stroke
Link ID: 10962 - Posted: 06.24.2010

It took hundreds of MRI brain scans to reveal the striking difference in the rate of brain development in kids with ADHD compared to kids without it. As psychiatry researcher Philip Shaw and his colleagues at the National Institute of Mental Health report in the Proceedings of the National Academy of Science, the ADHD kids eventually catch up. "I think it is good news. I think it means that this sort of basic brain biology is intact, all that's different is the timing of it," Shaw says. "If ADHD was a complete deviation away from normal brain development, you'd expect the sequence to be completely disrupted," he says. "It wasn't. So we think this is pretty strong evidence that ADHD is more of a delay in brain development." The research is part of a large study of kids with and without ADHD from age five through young adulthood. This analysis included more than 800 MRI scans of 450 kids, half of whom had ADHD. "One of the strengths of it is that it's an ongoing study so we get a chance to scan children repeatedly as they grow up," Shaw says. The kids in the study group are now at ages 17 to 18. The researchers used advanced software to measure the thickness of cortex, or grey matter, of kids' brains and compare them over time. Previous NIMH research had established how the cortex thickens and thins during childhood and adolescence. © ScienCentral, 2000-2007.

Keyword: ADHD; Brain imaging
Link ID: 10961 - Posted: 06.24.2010

Treating children who have Attention Deficit Hyperactivity Disorder with drugs is not effective in the long-term, research has shown. A study obtained by the BBC's Panorama programme says drugs such as Ritalin and Concerta work no better than therapy after three years of treatment. The findings by an influential US study also suggested long-term use of the drugs could stunt children's growth. It said that the benefits of drugs had previously been exaggerated. The Multimodal Treatment Study of Children with ADHD has been monitoring the treatment of 600 children across the US since the 1990s. In 1999, it concluded that after one year medication worked better than behavioural therapy for ADHD. This finding influenced medical practice on both sides of the Atlantic, and prescription rates in the UK have since tripled. The report's co-author, Professor William Pelham of the University of Buffalo, said: "I think that we exaggerated the beneficial impact of medication in the first study. We had thought that children medicated longer would have better outcomes. That didn't happen to be the case. The children had a substantial decrease in their rate of growth so they weren't growing as much as other kids both in terms of their height and in terms of their weight. And the second was that there were no beneficial effects -none." (C)BBC

Keyword: ADHD
Link ID: 10960 - Posted: 11.12.2007

By LISA SANDERS, M.D. The flashing icon announced that an instant message had arrived. The young woman at her computer at work clicked on it eagerly. It was from her fiancé. Silly boy. She’d only left him an hour ago. “Something’s wrong,” the message read. “What do you mean?” she shot back. “I can’t remember anything,” he wrote. “Like I can’t tell you what we did this weekend.” The young woman’s heart began to race. Her fiancé had been strangely forgetful lately. She thought maybe he was just tired. He’d been having trouble sleeping for a couple months — ever since they’d moved in together. The previous weekend they went to New York to plan their wedding. He had been excited when they set up the trip, but once there he seemed unusually quiet and hesitant. “When is our wedding date?” she quizzed. “Can you tell me that?” “No :(” “Call the doctor. Do it now. Tell them this is an emergency.” Over the next half-hour the 27-year-old man put in three calls to his doctor’s office, but each time, he would forget what they told him by the time he messaged his fiancée. Separated by miles of Interstate and several suburbs, the young woman was frantic. Finally, at her insistence, the man, now terrified, asked a friend to take him to the closest hospital. Copyright 2007 The New York Times Company

Keyword: Learning & Memory; Neuroimmunology
Link ID: 10959 - Posted: 06.24.2010

Bob Adler Rewiring nerve fibres that once served a missing arm to the muscles in an amputee's chest now offers a way to control prosthetic limbs more intuitively and effectively. In clinical trials, an improved interface for this type of prosthetic arm allowed volunteers to use their limbs to perform a variety of tasks up to seven times faster than before, after only minimal training. Previous systems only allowed people to make a few movements, one after the other, but the new one can be used to direct 16 distinct arm, hand and finger movements. The approach, called targeted muscle reinnervation (TMR), was first proposed by Gerald Loeb, a professor of biomedical engineering at the University of Southern California, in Los Angeles, US. He suggested in 1980 that it might be possible to detect and use signals from the motor and sensory nerves that once served a severed limb to control a prosthetic, by reconnecting them to nearby muscle and skin. The idea was taken up by Todd Kuiken, then a medical student and now a pioneering rehabilitation researcher at the Rehabilitation Institute of Chicago (RIC), and Northwestern University, also in Chicago, US. Surviving motor and sensory nerves are first surgically separated from the stump of a patient's arm. Nerves serving chest muscles that once helped support and move the missing limb, but that are no longer useful, are also cut. The motor nerves once used to control the patient's arm are then grafted to those connected to the chest muscles, while the sensory nerves from the missing arm are redirected to tissue under the skin of the chest. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 10958 - Posted: 06.24.2010

By Nikhil Swaminathan For the first time, researchers have developed a way to view stem cells in the brains of living animals, including humans—a finding that allows scientists to follow the process neurogenesis (the birth of neurons). The discovery comes just months after scientists confirmed that such cells are generated in adult as well as developing brains. "I was looking for a method that would enable us to study these cells through[out a] life span," says Mirjana Maletic-Savatic, an assistant professor of neurology at Stony Brook University in New York State, who specializes in neurological disorders such as cerebral palsy that premature and low-weight babies are at greater risk of developing. She says the new technique will enable her to track children at risk by monitoring the quantity and behavior of these so-called progenitor cells in their brains. The key ingredient in this process is a substance unique to immature cells that is neither found in mature neurons nor in glia, the brain's nonneuronal support cells. Maletic-Savatic and her colleagues collected samples of each of the three cell types from rat brains (stem cells from embryonic animals, the others from adults) and cultured the varieties separately in the lab. They were able to determine the chemical makeup of each variety—and isolate the compound unique to stem cells—with nuclear magnetic resonance (NMR) spectroscopy. (NMR helps to determine a molecule's structure by measuring the magnetic properties of its subatomic particles.) © 1996-2007 Scientific American, Inc.

Keyword: Neurogenesis; Brain imaging
Link ID: 10957 - Posted: 06.24.2010

By Benjamin Lester A limp handshake might say more about a man than he'd like to admit. According to new research, a firm grip is an indicator of genetic fitness. The findings link grip strength to aggressive behavior and sexual history and might provide insight into the mindsets of bullies. Hand grip strength (HGS) is an inherited trait; about 65% of a person's grip strength is genetically determined, whereas the remaining 35% depends on training and developmental factors such as nutrition. Past studies have connected HGS to various measures of physical condition, including bone density and longevity. "It's a ubiquitous measure of health and vitality," says evolutionary psychologist Gordon Gallup of the University at Albany in New York state. To find out whether HGS also reflects sexual and social behaviors, Gallup and his colleagues recruited 143 undergraduates from the university. The team measured their grip strength and anatomical variables linked to attractiveness--shoulder-to-hip ratio for men and waist-to-hip ratio for women. Each participant also completed a survey about sexual history (including age at first sexual encounter and number of partners) and middle and high school bullying behaviors. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 10956 - Posted: 06.24.2010

By Jeanne Erdmann SAN DIEGO, CALIFORNIA--Opioid drugs such as morphine are the most powerful painkillers. Unfortunately, in some patients their narcotic effects lead to addiction and the need for ever-escalating doses to quell pain. New research with rats shows that blocking morphine's action on glia--a type of support cell in the nervous system--can reduce these downsides while heightening its potency against pain. Over the past decade, scientists have discovered that glial cells heighten nerve pain, such as sciatica, by exciting the neurons that transmit pain signals. Morphine deadens pain by acting at nerve synapses, but it also activates glial cells, possibly worsening the drug's side effects, such as drowsiness, tolerance, worsening of pain, and addiction. To tease apart morphine's effects on glia and neurons, neuroscientists Linda Watkins and Mark Hutchinson of the University of Colorado, Boulder, took advantage of a drug called AV411 that blocks morphine's effects on glia but not on neurons. It boosted the painkiller: Rats injected with AV411 and morphine showed less response to a painful test than did rats given morphine alone. Watkins and Hutchinson also found that over time, morphine better retained its pain-relieving potency in the rats that also received AV411. © 2007 American Association for the Advancement of Science.

Keyword: Pain & Touch; Glia
Link ID: 10955 - Posted: 06.24.2010

Bruce Bower Scientists have achieved a breakthrough in deciphering the genetics of intelligence. Ironically, they did it by accounting for a key environmental factor. Breast-feeding boosts children's IQs by 6 to 7 points over the IQs of kids who weren't breast-fed, but only if the breast-fed youngsters have inherited a gene variant associated with enhanced chemical processing of mothers' milk, reports a team led by psychologist Avshalom Caspi of King's College London. The new finding supports the controversial hypothesis that fatty acids in breast milk enhance newborn babies' brain development. Moreover, the results demonstrate that intelligence researchers must examine how children's genetic natures interact with the ways in which they're nurtured. "Genes work via specific environmental experiences to shape intellectual development," Caspi says. He and his colleagues present their data in an upcoming Proceedings of the National Academy of Sciences. Two groups of children participated in the study: 1,037 boys and girls born 34 to 35 years ago in New Zealand, who are still living there; and 2,232 boys and girls born 12 to 13 years ago who are growing up in England. ©2007 Science Service

Keyword: Development of the Brain; Intelligence
Link ID: 10954 - Posted: 06.24.2010

By Clare Murphy From the odd capsule of fish oil to major brain surgery, the options for boosting our mental capacity are expanding all the time. Do we need to worry about the advent of a brave new world, where everyone is too clever by half? According to the British Medical Association, we must at least start thinking about the ethics of altering the organ which is so central to our being before there is no turning back. The theory is this: if people are already willing to undergo the risks of plastic surgery in search of the perfect body, who is to suggest they would not do the same to better their brains. Scientists are painting a picture of a time when toddlers pop pills on the way to playgroup while employees are forced to quaff various cocktails to boost their productivity. But sinister as that may sound, the benefits could be immense. A world where everyone is that much brighter might not just make for more enlightened conversation, it could accelerate the quest for a cure for cancer or an end to famine. "We need to balance the benefits against the risks," says Dr Vivienne Nathanson, head of ethics at the BMA. "We're not making any recommendations - but we do want people to look up and engage with this issue before it becomes the norm and it's too late to do anything about it." This is no longer a theoretical debate: to a certain extent it is already happening. Fish oil is already widely available and handed out to children by parents who have been told it could improve school performance by prolonging attention. (C)BBC

Keyword: Development of the Brain; Intelligence
Link ID: 10953 - Posted: 11.09.2007

By Jennifer Couzin When the first powerful, common gene behind obesity was reported this spring, scientists were excited but also left scratching their heads. No one, including the diabetes researchers who uncovered it, had any idea how the gene--FTO--worked. Now, a group has taken the first steps toward deciphering why the FTO protein weighs down the scales. FTO surfaced during a hunt for genes behind type 2 diabetes, but researchers soon recognized that its real role was in obesity (Science, 13 April, p. 185). Although obesity has long been considered partly genetic, genes have been tough to come by. The Science study, which included almost 39,000 people, concluded that having two copies of a certain FTO variant increased weight by about 3 kg--the first clear example of a common obesity gene. Then came the hard part: What does FTO do and how does it do it? To begin answering that, a team from several British institutions considered FTO from different vantage points. At the University of Cambridge, U.K., geneticist Stephen O'Rahilly and his colleagues tried to understand what the FTO protein might do in an animal. In mice, they found high levels of FTO in the brain's hypothalamus, which helps regulate energy balance in the body. Mice that had been denied food had 60% less FTO in one part of their hypothalamus than did those that had eaten normally, hinting that FTO might play a role in appetite. © 2007 American Association for the Advancement of Science.

Keyword: Obesity; Genes & Behavior
Link ID: 10952 - Posted: 06.24.2010

Alison Abbott Tiny trackers help to reveal a bird's thoughts in flight.H-P. LippNeuroscientists have fitted pigeons with recorders that pick up brain activity as the birds fly. The devices confirm that the birds really do use features from a landscape to find their way home. And researchers hope that they will be able to use the caps to unpick how birds use other types of navigational signals at different points in a journey. Scientists are pretty sure from tracking experiments that pigeons use the Sun, Earth’s magnetic field and possibly smells as guiding cues when navigating. In 2004, Hans-Peter Lipp, a behavioural neuroscientist from the University of Zürich in Switzerland, showed that pigeons probably also use visual information. He noted that the birds tend to turn when they hit obvious landmarks like a highway exit1. These tracking experiments collected good information about the birds' location, by fitting modern global positioning system (GPS) loggers to the pigeons’ backs. But no-one has been able to measure directly what information the pigeon are using to navigate — no one has accessed the pigeons' thoughts in flight. "If we see a bird continuing along its path after crossing a bump in the magnetic field that would normally cause it to change direction — is this because it failed to sense the information or had a good reason to ignore it?" asks Lipp. "What’s going on in their minds?" © 2007 Nature Publishing Group

Keyword: Animal Migration
Link ID: 10951 - Posted: 06.24.2010

For the first time, investigators have identified a way to detect neural progenitor cells (NPCs), which can develop into neurons and other nervous system cells, in the living human brain using a type of imaging called magnetic resonance spectroscopy (MRS). The finding, supported by the National Institutes of Health (NIH), may lead to improved diagnosis and treatment for depression, Parkinson's disease, brain tumors, and a host of other disorders. Research has shown that, in select brain regions, NPCs persist into adulthood and may give rise to new neurons. Studies have suggested that the development of new neurons from NPCs, called neurogenesis, is disrupted in disorders ranging from depression and schizophrenia to Parkinson's disease, epilepsy, and cancer. Until now, however, there has been no way to monitor neurogenesis in the living human brain. "The recent finding that neural progenitor cells exist in adult human brain has opened a whole new field in neuroscience. The ability to track these cells in living people would be a major breakthrough in understanding brain development in children and continued maturation of the adult brain. It could also be a very useful tool for research aimed at influencing NPCs to restore or maintain brain health," says Walter J. Koroshetz, M.D., deputy director of the NIH's National Institute of Neurological Disorders and Stroke (NINDS), which helped fund the work. The study was also funded by the NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Keyword: Neurogenesis; Brain imaging
Link ID: 10950 - Posted: 11.09.2007

By Lisa Stein Reefer madness? Apparently not, according to a new Swiss survey of students that concludes teenagers who smoke pot function better than those who also use tobacco. In addition, researchers at the University of Lausanne report in the Archives of Pediatrics & Adolescent Medicine, teens who only use marijuana are apparently more socially driven and have no more psychosocial problems than those who neither smoke nor toke. The scientists surveyed 5,263 Swiss students (2,439 females) aged 16 to 20 years, including 455 who said they smoked weed only; 1,703 who reported being tobacco and marijuana users; and 3,105 who said they did not imbibe at all. "The gateway theory hypothesizes that the use of legal drugs (tobacco and alcohol) is the previous step to cannabis consumption," the authors wrote. "However, recent research also indicates that cannabis use may precede or be simultaneous to tobacco use and that, in fact, its use may reinforce cigarette smoking or lead to nicotine addiction independently of smoking status." Among their findings: Compared with students who reported using both drugs, those who smoked pot only were more likely to be male (71.6 percent versus 59.7 percent); get good grades (77.5 to 66.6 percent); play sports (85.5 to 66.7 percent); and live with both parents (78.2 to 68.3 percent). © 1996-2007 Scientific American, Inc.

Keyword: Drug Abuse
Link ID: 10949 - Posted: 06.24.2010

By Jennifer Couzin As they grow up, children with heart defects often suffer from learning and attention problems, as well as other cognitive and motor troubles. Now, a team of doctors has used sophisticated imaging on newborns with heart disease and found delayed brain development akin to what's seen in premature babies--a phenomenon that helps explain why infants with heart problems are at such high risk of brain injury. The work sheds new light on an emerging challenge in treating children with congenital heart disease. Heart surgery performed in the first weeks of life was initially eyed as the culprit behind learning, attention, and other cognitive problems. But a large study in Boston showed that even when a lower-risk form of cardiac bypass was used, babies still grew up to suffer cognitive deficits. Some studies have detected brain lesions or neurological abnormalities in newborns before heart surgery, but it wasn't clear whether these might account entirely for later cognitive deficits, either. To learn more, pediatric neurologist Steven Miller, now at the University of British Columbia in Vancouver and the University of California, San Francisco (UCSF), and Patrick McQuillen, a UCSF pediatric critical care specialist, along with their colleagues, performed sophisticated brain-imaging tests on 41 babies with congenital heart defects. They relied on traditional magnetic resonance imaging (MRI); magnetic resonance spectroscopy, which shows brain metabolism; and diffusion tensor imaging, which shows the brain's microstructure. The results were compared with those from 16 healthy, full-term babies. © 2007 American Association for the Advancement of Science

Keyword: Development of the Brain
Link ID: 10948 - Posted: 06.24.2010

A lot of people have come a lot of miles to attend this year’s SfN in San Diego. So perhaps I had travel in mind when I started off with a couple of posters loosely related to going places – admittedly on rather different scales… Firstly: getting around London by taxi. Eleanor Maguire and her student Katherine Woollett of University College London have been following up on Maguire’s previous – and rather well-publicised - study (Nature’s story at the time is here) on the brains of London cabbies. Back in 2000, they found that the size of a region called the hippocampus, which is involved in navigation and memory, is larger in London’s black cab drivers (who have to pass a foreboding test of the capital’s 25,000 streets, suitably titled The Knowledge) than in other people. Unfortunately for them, however, this expertise comes at a price to new learning and memory. A different part of the hippocampus actually decreases in size as a result of the enlargement of the rest of it. “It’s a story of loss and gain if you’re a taxi driver,” Maguire says. She wouldn’t be surprised, she told me, if this ‘give-and-take’ mechanism was being employed elsewhere in the brain too. Second travel titbit: getting humans to Mars. For completely different reasons, this form of transit might also impair your memory, as Bernard Rabin’s work on the effect of cosmic rays on rat’s brains suggests.

Keyword: Learning & Memory
Link ID: 10947 - Posted: 06.24.2010

Amid the dazzling high-tech displays of new-generation brain-machine interfaces (including brain implants with which monkeys can operate robotic arms) was a less glamorous but elegantly simple study which promises to improve quality of life for stroke victims, or victims of traumatic brain injury, whose ability to balance has been obliterated. Monica Metea of the company Wicab in Wisconsin displayed her company’s new balancing device BrainPort which has been through a pilot study of 17 patients, allowing them to stand, walk, dance without falling over. It works on the principle of brain plasticity. It’s a slim 2 cm square grid of 100 electrodes connected to a head position-detecting sensor which sits directly above them. The patients sticks the device in their mouths, and quickly learns from the pattern of the pinprick sensations delivered by the electrodes which way is up and which way is down. The brain also learns this in a physical sense. Somehow certain circuits get reconfigured such that even after the device is removed – after 20 minutes or so – the patient maintains his or her sense of balance, for hours, sometimes for days. No need to open up the skull and implant the device directly into delicate brain tissue like the more dramatic stories which will eventually help the paralysed. But applicable to probably millions of people who can’t stand up without falling over.

Keyword: Stroke
Link ID: 10946 - Posted: 06.24.2010

Matt Kaplan Antioxidants are all the rage, with research suggesting that they may help to prevent cancer, strokes and heart disease. Now a study highlights how these oxygen-mopping compounds affect more than just cellular health: they also seem to effect behaviour. Male three-spined stickleback fish (Gasterosteus aculeatus) fed on a high-antioxidant diet spend more time and energy fanning oxygen-rich water onto the eggs in their nest, researchers have found. The results aren’t entirely surprising, as an indirect link between diet, well-being and behaviour makes sense. “I would expect to see some behavioural changes from antioxidants through effects on body condition or immunocompetence,” says Ulrika Candolin, an ecologist at the University of Helsinki in Finland. “But this study suggests a direct pathway, which is interesting.” A lack of antioxidants seems to make the fish’s muscles tire more readily. Candolin says she thinks it is likely that behavioural changes would be seen in other animals deprived of antioxidants. But whether these changes are the result of fatigue or deteriorating health would require further study. © 2007 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 10945 - Posted: 06.24.2010

-- Japanese scientists have created genetically-modified mice that, shorn of their ability to sense dangerous smells, will even snuggle up to a kitten, according to a study released on Wednesday by the journal Nature. The mice were engineered to lack specific nasal receptors that respond to the scent of rotting food or predators, in a project designed to help understand the mechanisms of smell. The mice were able to detect these smells using other olfactory cells but, lacking the key pathway that triggered a "fear" warning to the brain, were quite undeterred by the presence of a cat or acids and other dangerous compounds. However, the mice could be conditioned into realizing that these smells meant danger, using classic laboratory methods of exposing them to the scents and to a painful irritant at the same time. The researchers, led by the University of Tokyo's Hitoshi Sakano, believe that the findings explain important differences in the olfactory bulb, the part of the forebrain where odors are perceived. © 2007 Discovery Communications

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 10944 - Posted: 06.24.2010

This week Mind Matters visits not just a particular paper, but the massive annual meeting of the Society for Neuroscience -- 30,000+ neuroscientists, scores of major lectures, hundreds of symposia, thousands and thousands of symposia and minisymposia. Scientific American has three people here, and we haven't a prayer -- way too many things to attend. Sorting out what to do next poses severe challenges to mechanisms of time management, executive function, attentional control, sleep-cycle adjustment, shoe quality, and memory. The variety of subjects covered is daunting and wonderful: how fasting can help you build brain cells; thought-controlled machines; how walnuts can make you smarter. Some notables so far: Classical music as antidepressant This study comes out of Alzahra University, in Tehran, where a group of researchers, noting that music therapy has already been shown to reduce pain, improve sleep quality, and improve mood in cancer patients underoing therapy and multiple sclerosis patients, wondered if music might alleviate depression as well. It does. They took 56 depressed subjects, had them listen to Beethoven's 3d and 5th piano sonatas for 15 minutes twice a week in a clean, otherwise quiet room -- and saw their depression scores on the standard Beck Depression Scale go up signficantly. No side effects! And music is cheap -- a lifetime of Beethoven for the price of a couple weeks of Prozac. Empathy (not) for sweethearts in pain A few weeks ago we ran reviews by Frans de Waal and Peggy Mason of a paper about mice showing empathy; the study found that mice viewing other mice in distress were more sensitive to pain themselves. Discouraging news, folks: A poster here at the meeting suggests that humans viewing their own spouses in pain may feel ... well, good. This one's still in the grain-of-salt department, mind you: It's a poster, which means it's on evidence still getting worked up and not yet peer-reviewed. But still: Yikes. © 1996-2007 Scientific American, Inc.

Keyword: Depression; Hearing
Link ID: 10943 - Posted: 06.24.2010