If you're a sucker for sweets, it might be in your genes. Researchers at the University of Toronto discovered a genetic difference in people who consume extra sugar in their diet. "Certainly environmental factors can influence the foods that we like and dislike," says nutrigenomics researcher Ahmed El-Sohemy. “But what this line of research demonstrates is that there is also a biological or a genetic basis for some of our likes and dislikes of foods." El-Sohemy and his colleagues studied two large groups of volunteers, who completed detailed records of their daily diet. Analyzing blood samples, they found that people with a different form of a gene called GLUT 2 had consistently higher daily sugar intakes. “Initially what we were interested in finding is why some people show a more dramatic rise in blood sugar after a meal,” El-Sohemy explains. “The reason we focused on this particular gene is because it’s known to function primarily in the pancreas. That’s the organ that’s responsible for sensing changes in blood sugar and producing insulin in response to clear it. We found there was no difference in how quickly individuals with the two versions of the gene cleared glucose from their blood, but surprisingly, those who had a particular version of this gene just consumed more sugar... the fat intake was the same, protein was the same, other types of carbohydrates was the same. So it seemed to be very specific to sugar.” © ScienCentral, 2000-2008.

Keyword: Genes & Behavior; Chemical Senses (Smell & Taste)
Link ID: 11688 - Posted: 06.24.2010

-- It doesn't pay to be smart and ignorance really is bliss if you want a long life -- at least if you're a fly, according to new research by a Swiss university. Scientists Tadeusz Kawecki and Joep Burger at the University of Lausanne said Wednesday they had discovered a "negative correlation between an improvement in a fly's mental capacity and its longevity". As part of their research project, the results of which are published in the journal Evolution, they divided into two a group of flies from the Basel region of northwestern Switzerland. One half was left in a natural state while the other had its intelligence boosted by Pavlovian methods, such as associating smell and taste with particular food or experiences. Over 30 to 40 generations, these methods led to flies which clearly learned better and remembered things for longer. The flipside was that the flies left in their natural state lived longer on average than their "cleverer" counterparts, with a lifespan of 80-85 days rather than the normal 50-60.. © 2008 Discovery Communications, LLC

Keyword: Learning & Memory; Evolution
Link ID: 11687 - Posted: 06.24.2010

Katharine Sanderson Human stem cells have been used to correct abnormal brain development in mice with fatal brain disorders, offering hope for treating a range of neurological disorders including some deadly childhood genetic diseases. Those behind the new treatment hope that human clinical trials could be just a few years away. The treatment uses human glial progenitor cells — cells that can differentiate into the glial cells that, among other things, make up myelin. Myelin, a protein that insulates the long 'arms' of nerve cells, called axons, helps the conduction of neural signals throughout the nervous system. A team led by Steven Goldman, at the University of Rochester in New York, took the progenitor cells from white matter in the fetal human brain and injected them into the spinal cords of mutant shiverer mice shortly after their birth. The mice, which shiver and shake as their name suggests, have severe neurological defects caused by a genetic mutation that stops them producing myelin. Without myelin, neural signals get stuck, causing potentially fatal disease. “There’s no way we’d be able to conduct a [neural] signal very far if it weren’t for myelin,” Goldman explains. As they develop, shiverer mice become unable to walk forwards, have increasing numbers of seizures, and typically die at just 18–21 weeks of age. © 2008 Nature Publishing Group

Keyword: Multiple Sclerosis; Glia
Link ID: 11686 - Posted: 06.24.2010

By Bob Guldin "Wow!" I said. "Is that a psychedelic light show?" I was at a party, and I could see a bright shimmer of purple across the room. It reminded me of my misspent rock-and-roll youth. My wife looked at me quizzically. "There's no light show; it's just a light," she said. I looked at it hard and could tell she was right. So what had I just seen? I didn't know it, but I had entered the unsettling sphere of retinal detachment, a Twilight Zone where you can't believe your eyes. And as I had yet to learn, recognizing the symptoms of a displacement of the light-sensitive tissue lining the eye could mean the difference between saving and losing your sight. In the weeks that followed, I saw more flashes of light that I knew weren't there. I saw growing numbers of "floaters," odd shapes that drifted across my field of vision. Once, while washing dishes, I panicked at the sight of a swarm of them congregating around a basket of bananas. Surprise! My floaters were actually fruitflies. (Somehow, I was not comforted.) When I got worried enough to visit my eye doctor, he told me my eye tricks might signal a developing tear or detachment of the retina, the layer of cells that receives images and sends them to the brain via the optic nerve. If you see something like a curtain crossing your vision from any direction, he warned, come in right away. © 2008 The Washington Post Company

Keyword: Vision
Link ID: 11685 - Posted: 06.24.2010

By DAN HURLEY There was nothing very interesting in Katherine P. Rankin’s study of sarcasm — at least, nothing worth your important time. All she did was use an M.R.I. to find the place in the brain where the ability to detect sarcasm resides. But then, you probably already knew it was in the right parahippocampal gyrus. What you may not have realized is that perceiving sarcasm, the smirking put-down that buries its barb by stating the opposite, requires a nifty mental trick that lies at the heart of social relations: figuring out what others are thinking. Those who lose the ability, whether through a head injury or the frontotemporal dementias afflicting the patients in Dr. Rankin’s study, just do not get it when someone says during a hurricane, “Nice weather we’re having.” “A lot of the social cognition we take for granted and learn through childhood, the ability to appreciate that someone else is being ironic or sarcastic or angry — the so-called theory of mind that allows us to get inside someone else’s head — is characteristically lost very early in the course of frontotemporal dementia,” said Dr. Bradley F. Boeve, a behavioral neurologist at the Mayo Clinic in Rochester, Minn. “It’s very disturbing for family members, but neurologists haven’t had good tools for measuring it,” he went on. “That’s why I found this study by Kate Rankin and her group so fascinating.” Copyright 2008 The New York Times Company

Keyword: Emotions; Brain imaging
Link ID: 11684 - Posted: 06.24.2010

Ewen Callaway They may never hustle a blackjack table, but nautiluses display a simple form of memory, according to new research. Unlike more cerebral cephalopods, such as cuttlefish, octopus and squid, the humble nautilus has a puny brain without the evolutionary flourishes that hint at memory. But a simple experiment reminiscent of Pavlov's work with dogs now shows that the deep-dwelling invertebrates can learn to associate a flash of light with food – and hold onto that memory for hours. "We were quite surprised to see memory at all," says Robyn Crook, a marine biologist at Brooklyn College in New York, who led the study. She, like most researchers, assumed the nautilus's daily trips up and down a coral reef didn't require memory. "Because their brain is so simple and because it lacks the dedicated learning regions of octopus and cuttlefish and squid it had been implied they would have some deficits in learning and memory," she says. Sometimes called living fossils, nautiluses seem to have changed little over millions of years. The shelled cephalopods spend their days at depths of around 300 metres, while at night they venture near the surface to feast on dead sea life. © Copyright Reed Business Information Ltd

Keyword: Learning & Memory; Evolution
Link ID: 11683 - Posted: 06.24.2010

The body's immune system could be harnessed to fight back against Alzheimer's disease, research suggests. Turning off a part of the immune system cleared away harmful brain deposits and improved memory, the mouse study found. US scientists, reporting their discovery in the journal Nature Medicine, said it was like a "vacuum cleaner" had been working in the brain. The Alzheimer's Society said more research would reveal if the process also worked in humans. Alzheimer's disease patients are gradually deprived of their memories and their ability to live normally. The damage is caused by the formation of "amyloid plaques" in their brain cells. Scientists have been searching for ways to break up and dispose of these plaques, and perhaps halting or even reversing the symptoms. So far, while there are some drugs which can delay the progress of the disease in some patients, there is no cure. One of the biggest obstacles to a successful treatment is the blood-brain barrier, which stops large molecules getting into the brain, ruling out many complex drugs which might otherwise be used. The researchers from Yale University took a different approach. They used genetic engineering to block an immune system response in mice, but only in cells outside the brain. Researchers had expected the change to worsen the Alzheimer's by sending the immune response into overdrive, causing too much inflammation inside the brain. But they found up to 90% of the plaque material disappeared from the brains of the mice. And when the animals' memories were tested using mazes, significant improvements were found. (C)BBC

Keyword: Alzheimers; Neuroimmunology
Link ID: 11682 - Posted: 06.02.2008

By SALLY SARA His Superman T-shirt was bold and bright, but his face was creased with confusion. Gerry Thomas was stumped by a question most men can answer in an instant. “What’s your favorite beer?” asked his sister, Beth Thomas. Mr. Thomas, 50, sitting in the house he and his sister share in Queens, squinted with intense concentration. He struggled to unravel the question, let alone remember the answer. Finally, he gave his sister an apologetic smile and shook his head. “I think I’m losing it,” he said. Doctors had predicted that Mr. Thomas, born with Down syndrome, would be lucky to reach his 10th birthday. His longevity has come at a price, though. Two years ago, it was determined that Mr. Thomas, at 48, had early-onset Alzheimer’s disease, adding new challenges of dementia to his already significant disabilities. In a cruel coincidence that scientists do not yet fully understand, research has shown that people with Down syndrome, a chromosomal abnormality, have a much higher incidence of Alzheimer’s disease at an early age. Some studies have said that 60 to 75 percent of people over age 60 with Down syndrome will have Alzheimer’s, though Dr. Ira Lott, who is in charge of the Down syndrome program at the School of Medicine at the University of California, Irvine, said those studies have been limited in scope. Copyright 2008 The New York Times Company

Keyword: Development of the Brain; Alzheimers
Link ID: 11681 - Posted: 06.24.2010

By Nikhil Swaminathan Although many neuroscientists are trying to figure out how the brain works, Mark Changizi is bent on determining why it works that way. In the past, the assistant professor of cognitive science at Rensselaer Polytechnic Institute has demonstrated that the shapes of letters in 100 writing systems reflect common ones seen in nature: Take the letter "A"—it looks like a mountain, he says. And "Y" might remind one of a tree with branches. He also showed that across different languages most characters take three strokes to write out. That's because, he says, three is the highest quantity a person's brain can perceive without resorting to counting. But Changizi's theories aren't limited to writing. He also believes that primates developed the ability to see in color so that they could figure out if peers were sending emotional cues. He hatched that theory by comparing the light wavelengths given off by the facial skin of someone blushing to that of a person not flushed. The prolific Changizi recently published two papers: one that sets out to explain how our lexical systems evolved and another that suggests how the brain's visual system is adapted to anticipate the future a fraction of a second before we actually see it. (See related slideshow here.) Changizi spoke to ScientificAmerican.com about his newest research; what his forthcoming book, The Vision R(evolution): How the Latest Research Overturns Everything We Thought We Knew About Human Vision, has to do with superheroes; and what kind of scientist he is. My goal is to understand the principles underlying the design of the brain or visual system or cultural artifact, like language or writing systems. I'm not as interested in the mechanisms per se. People like me make the point that you can't even study those mechanisms without having an idea what those mechanisms are trying to compute. So you have to have some opinion about what the design or function of those mechanisms are for to even do that. So, I am focusing on the function from a teleological [purposive] point of view. Of course it's unpacked with natural selection or cultural evolution. © 1996-2008 Scientific American Inc.

Keyword: Language; Vision
Link ID: 11680 - Posted: 06.24.2010

By Patrick Barry Macaque monkeys with electrodes implanted in their brains learned to control a robotic arm with their thoughts, researchers report. Scientists gently restrained the monkeys’ own arms and positioned the mechanical arm at each animal’s left shoulder as if it were a real arm. After practicing for several days, the monkeys appeared to treat the robotic arm as their own and could feed themselves with the arm using fluid, rapid motions. “The thing that struck me was how naturally the animals interacted with the device,” comments John Kalaska, a neuroscientist from the University of Montreal who wrote a commentary that appeared with the research online May 28 in Nature. “It’s a further proof of principle that, down the line, we will be able to develop all the hardware necessary to allow paraplegic or quadriplegic patients to have prosthetic limbs that they can control in a natural way with their thoughts.” Such devices for humans are still years away, Kalaska cautions. The computers that interpreted the monkeys’ brain signals in the current experiments are bulky, making them impractical for a portable prosthetic. And in past research, electrodes implanted into the brains of animals or humans lost contact with the nerve cells after months or weeks because cells in the brain treated the electrodes as foreign objects and attacked them. Both of these obstacles would have to be overcome before thought-controlled robotic arms or legs for people would be feasible, Kalaska says. © Society for Science & the Public 2000 - 2008

Keyword: Robotics
Link ID: 11679 - Posted: 06.24.2010

Kerri Smith A computer model has been developed that can predict what word you are thinking of. The model may help to resolve questions about how the brain processes words and language, and might even lead to techniques for decoding people’s thoughts. Researchers led by Tom Mitchell of Carnegie Mellon University in Pittsburgh, Pennsylvania, 'trained' a computer model to recognize the patterns of brain activity associated with 60 images, each of which represented a different noun, such as 'celery' or 'aeroplane'. The team started with the assumption that the brain processes words in terms of how they relate to movement and sensory information. Words such as 'hammer', for example, are known to cause movement-related areas of the brain to light up; on the other hand, the word 'castle' triggers activity in regions that process spatial information. Mitchell and his colleagues also knew that different nouns are associated more often with some verbs than with others – the verb 'eat', for example, is more likely to be found in conjunction with 'celery' than with 'aeroplane'. © 2008 Nature Publishing Group

Keyword: Language; Brain imaging
Link ID: 11678 - Posted: 06.24.2010

People with schizophrenia (http://www.nimh.nih.gov/health/topics/schizophrenia/index.shtml) from families with no history of the illness were found to harbor eight times more spontaneous mutations — most in pathways affecting brain development — than healthy controls, in a study supported in part the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH). By contrast, no spontaneous mutations were found in people with schizophrenia who had family histories of the illness. "Our findings strongly suggest that rare, spontaneous mutations likely contribute to vulnerability in cases of schizophrenia from previously unaffected families," said Maria Karayiorgou, M.D., of Columbia University, who led the research team. "This may also shed light on why the illness has frustrated efforts to implicate gene variants with major effects, and seems to defy natural selection by persisting in the population even though relatively few of those affected have children." Karayiorgou and her colleagues report on their whole genome study online in Nature Genetics, May 30, 2008. "Such abnormal deletions or duplications of genetic material are increasingly being implicated in schizophrenia and autism (http://www.nimh.nih.gov/science-news/2008/autism-gene-scans-converge-on-two-suspect-sites-two-types-of-genetic-risk.shtml)," explained NIMH Director Thomas R. Insel, M.D.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 11677 - Posted: 06.24.2010

By JoNel Aleccia The next time the world starts spinning, Larry Janisch will know exactly how to make it stop. But two months ago, when the 50-year-old Phoenix man woke up one Saturday reeling from vertigo, he had no idea what to do. “I felt like I was drunk,” he said. “I couldn’t stand up. I kept falling over.” Fortunately for Janisch, he works at a hospital where a vestibular therapist, a specialist in inner ear disorders, is almost always available. Within 10 minutes of walking into the lab at Banner Good Samaritan Medical Center, Janisch was better, thanks to a simple technique that neurology experts have verified as the best way to treat benign paroxysmal positional vertigo — BPPV — a common cause of severe dizziness. A series of gentle head and neck movements known as the canalith repositioning procedure is the fastest, easiest way to cure BPPV, according to a new guideline developed by the American Academy of Neurology. About 3 million new patients a year in the United States are diagnosed with the problem characterized by dizziness, lightheadedness, imbalance and nausea that can last for days — or even months. Traditional treatments have ranged widely, from drastic measures such as sedatives to nerve surgery to nothing at all. © 2008 MSNBC Interactive

Keyword: Miscellaneous
Link ID: 11676 - Posted: 06.24.2010

By Eli Kintisch The winners of the Kavli prizes for neuroscience, nanoscience, and astrophysics were announced today in Oslo, Norway, marking the first time that the three $1 million prizes have been awarded. Norwegian-born philanthropist Fred Kavli said at a press conference that he set up the prizes to promote science in three fields that he feels would benefit from more public attention. The neuroscience prize will be shared by Sten Grillner of the Karolinska Institute in Stockholm, Sweden, Pasko Rakic of Yale University School of Medicine, and Thomas Jessell of Columbia University. Grillner spelled out how patterns of neuronal circuitry affect locomotion; Rakic and Jessell explained how neurons develop in the embryonic brain and spinal cord, respectively. "The work of Rakic and Jessell has provided, for the first time, a general framework for understanding the assembly of neural circuits within the mammalian brain," the Kavli foundation said in its commendation. © 2008 American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 11675 - Posted: 06.24.2010

Scientists have identified a mechanism in the brain that helps to explain why craving for cocaine, and the risk of relapse, seems to increase in the weeks and months after drug use is stopped. The research was supported by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health. The study, published in the May 25 issue of the journal Nature, "reveals a novel mechanism for why cocaine craving intensifies over time and suggests a new target for the development of medications to decrease the risk of relapse in abstinent cocaine abusers," says NIDA Director Dr. Nora Volkow. Exposure to environmental cues (e.g., people, places, things) previously associated with drug use can trigger drug craving, often leading to relapse. Previous research in rats has shown that the sensitivity to these environmental cues follows a defined time course progressively increasing (or incubating) during a 60-day withdrawal period. In the current study, also in rats, researchers demonstrate that after prolonged withdrawal from cocaine use, there is an increase in the number of proteins called AMPA glutamate receptors in a brain region known as the nucleus accumbens (an area involved in motivation and reward). These new AMPA receptors are atypical — they are missing a particular subunit resulting in greater responsiveness of nucleus accumbens neurons to input from other brain regions — and they appear to be responsible for the "incubation" of cocaine craving.

Keyword: Drug Abuse
Link ID: 11674 - Posted: 06.24.2010

Ewen Callaway Look Mum, no hands! Two monkeys have managed to use brain power to control a robotic arm to feed themselves. The feat marks the first time a brain-controlled prosthetic limb has been wielded to perform a practical task. Previous demonstrations in monkeys and humans have tapped into the brain to control computer cursors and virtual worlds, and even to clench a robot hand. But complicated physical activities like eating are "a completely different ball game", says Andrew Schwarz, a neurological engineer at the University of Pittsburgh, who led the new research. Tests with humans are being prepared in numerous labs, but experts caution that brain-controlled robotic limbs are far from freeing paraplegics from their wheelchairs or giving amputees their limbs back. Wired for actionMost people who become paralysed or lose limbs retain the mental dexterity to perform physical actions. And by tapping into a region of the brain responsible for movement – the motor cortex – researchers can decode a person's intentions and translate them into action with a prosthetic. This had been done mostly with monkeys and in virtual worlds or with simple movements, such as reaching out a hand. But two years ago, an American team hacked into the brain of a patient with no control over his arms to direct a computer cursor and a simple robotic arm. © Copyright Reed Business Information Ltd

Keyword: Robotics
Link ID: 11673 - Posted: 06.24.2010

Heidi Ledford A drug used to treat epilepsy could also ease cravings in alcoholics, say researchers who have investigated the effect in rats. The drug, called gabapentin, is approved for the treatment of epileptic seizures and for some conditions that cause chronic pain. And now, researchers led by Marisa Roberto, of the Scripps Research Institute in La Jolla, California, have shown that alcohol-dependent rats given gabapentin drink less alcohol and are less anxious than those not given the drug1. Preliminary small clinical trials have suggested that gabapentin could also be useful in the treatment of drug addiction, and trials are now under way to determine whether the drug can ease alcoholism in people. The current results are promising, says Robert Swift, a researcher at the Center for Alcohol and Addiction Studies at Brown University in Rhode Island. “This paper really suggests that gabapentin may be efficacious in reducing drinking [in alcoholics],” he says. Gabapentin is structurally similar to a neurotransmitter called ã-aminobutyric acid, or GABA, which can slow communication between neurons in the brain. Although the drug does not function in precisely the same way as GABA, it can prevent the chaotic electrical activity in the brain that triggers a seizure. © 2008 Nature Publishing Group

Keyword: Epilepsy; Drug Abuse
Link ID: 11672 - Posted: 06.24.2010

Adults with attention deficit hyperactivity disorder do 22 fewer days of work per year than people who do not have the condition, a study says. The research, which looked at 7,000 workers in 10 countries, found an average of 3.5% had ADHD. Writing in Occupational and Environmental Medicine, the Dutch team said workplace screening should be used to pick up people with the problem. A UK expert backed the idea, but warned they should not be stigmatised. People who have ADHD find it difficult to concentrate because they may be hyperactive, easily distracted, forgetful or impulsive. It is commonly thought of as a childhood disorder, often picked up because of problems at school. However, there are estimates that around two thirds of those affected in childhood are still experiencing symptoms in adulthood. In the study, employed and self-employed workers aged 18 - 44 years were screened for ADHD as part of the World Health Organisation World Mental Health Survey Initiative in Belgium, Colombia, France, Germany, Italy, Lebanon, Mexico, the Netherlands, Spain and the USA. They were also asked about their performance at work in the last month. Those results were extrapolated out to give annual figures. Workers with ADHD were found to take an average of eight days off sick each year. They also had, on average, 21 days where they did less work than they should have and 13 days where their work was of poorer quality - each of which was deemed to equate to half a day of lost performance. ADHD was more prevalent in men and workers in developed rather than developing countries. (C)BBC

Keyword: ADHD
Link ID: 11671 - Posted: 05.27.2008

It's a new frontier for psychiatric illness: Brain pacemakers that promise to act as antidepressants by changing how patients' nerve circuitry fires. Scientists already know the power of these devices to block the tremors of Parkinson's disease and related illnesses; more than 40,000 patients worldwide have the implants. But psychiatric illnesses are much more complex and the new experiments with so-called deep brain stimulation, or DBS, are in their infancy. Only a few dozen patients with severe depression or obsessive-compulsive disorder so far have been treated in closely monitored studies. Still, the early results are promising. Dramatic video shows one patient visibly brightening as doctors turn on her brain pacemaker and she says in surprise: "I'm starting to smile." And new reports this month show that some worst-case patients — whose depression wasn't relieved by medication, psychotherapy, even controversial shock treatment — are finding lasting relief. Six of 17 severely depressed patients were in remission a year after undergoing DBS and four more markedly improved, and more than half of 26 obsessive-compulsive patients showed substantial improvement over three years, say studies from a team at the Cleveland Clinic, Brown University, and Belgium's University of Leuven. © The Canadian Press, 2008

Keyword: Depression
Link ID: 11670 - Posted: 06.24.2010

By Daniel Carlat "So here's your brain," the doctor says, as the center of my mental life pirouettes before me, rendered in electric blues and reds. Daniel Amen, MD, manipulates the screen image with a few taps on his keyboard. "It looks good, pretty symmetrical. Red means more activity, blue means less." We're peering at a Spect scan taken a half hour ago. He takes a closer look. Spect scans are a type of brain-imaging technology that measures neural activity by looking at blood flow. "The only question I'd ask you is whether you've ever had a brain injury, because there is low activity in your occipital cortex and your parietal lobe, all on the left side." I admit to the occasional fall while snowboarding, but I've always worn a helmet. Amen shakes his head. "Your brain is 80 percent water and the consistency of tofu, and your skull is hard, so your brain was not meant to snowboard, even with a helmet. I recommend tennis or Ping-Pong." He calls up a different view, this one from below, as though looking up from the spinal cord. I see a spot on one side that is conspicuously ... empty. "What's that?" I ask. "That's a left temporal lobe ding. It's in a fairly innocuous area, but I'd still ask your wife how your temper is." © 2008 CondéNet, Inc.

Keyword: Brain imaging
Link ID: 11669 - Posted: 06.24.2010