By ANDREW POLLACK LOS OSOS, Calif. — Next week, advisers to the Food and Drug Administration will recommend whether the agency should approve the first new prescription diet pill in 13 years. The F.D.A. rejected the drug under review, Qnexa, in 2010, amid safety concerns, and the drug’s manufacturer is now presenting additional data to argue its case. But thousands of people here in central California, where Qnexa’s inventor ran a weight-loss clinic, and others across the country have not had to wait for the drug’s approval. Through a regulatory loophole of sorts, many obesity doctors prescribe two separate drugs that, when taken together, are essentially the same medicine. The widespread use of the unsanctioned combination reflects the often desperate desire for a medicine to help overcome the nation’s epidemic of obesity, doctors and patients say. The experience in this idyllic coastal community about midway between San Francisco and Los Angeles also provides a look at what might happen if Qnexa were approved. Use of the close substitute grew as word spread that some patients had experienced substantial weight loss. Some people here regained weight after stopping the treatment, and some experienced unpleasant side effects such as memory loss. © 2012 The New York Times Company

Keyword: Obesity
Link ID: 16393 - Posted: 02.18.2012

Caitlin Stier, video intern In this video game clip, it looks like Mario is jumping vertically while an enemy tortoise slides by underneath him. But keep watching when the background stops moving and you'll see that their movement is not quite what it seems. The animation, developed by cognitive psychologist Sebastiaan Mathôt from VU University in Amsterdam, is a variation of a common illusion where our perception of an object's motion is affected by a moving background. In a previous Friday Illusion post, we shared a video that exploits the same brain trick. Can you identify it? Let us know your choice by posting the headline in the Comments section below and the first correct answer will receive a New Scientist goodie bag. Good luck! © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16392 - Posted: 02.18.2012

by Wendy Zukerman ZAPPING the brain with a weak magnetic pulse can wipe out unwanted neural connections in mice at least. The discovery could be turned into a treatment for conditions associated with abnormal neural circuitry, such as schizophrenia. In transcranial magnetic stimulation a magnetic coil induces electric currents in the brain that can strengthen or suppress neural connections. This technique has been shown to improve symptoms in people with brain disorders such as autism and depression. Now, Jennifer Rodger from the University of Western Australia in Crawley and colleagues have found that stimulating the brain at intensities lower than would make a neuron fire can remove unwanted neural connections in mice. As children, our brains produce too many connections between cells. As we develop, some connections are pruned away while others are strengthened. Inept pruning has been implicated in schizophrenia. Rodger's team used genetically modified mice with abnormal connections in an area of the brain called the superior colliculus (SC), which is involved in motion detection. In these mice, 90 per cent of the axons in the SC had extended into the wrong areas. These bad connections make it difficult for the rodents to follow moving objects in their line of sight. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Brain imaging
Link ID: 16391 - Posted: 02.18.2012

By James Gallagher Health and science reporter, BBC News The time of the day could be an important factor in the risk of getting an infection, according to researchers in the US. They showed how a protein in the immune system was affected by changes in the chemistry of the body through the day. The findings, published in the journal Immunity, showed the time of an infection changed its severity. An expert said drugs were likely to take advantage of the body clock in the near future. Plants, animals and even bacteria go through a daily 24-hour routine, known as a circadian rhythm. Jet lag is what happens when the body gets out of sync with its surroundings after crossing time zones. It has been known that there are variations in the immune system throughout the day. Researchers are now drilling down into the details. The immune system needs to detect an infection before it can begin to fight it off. Researchers at Yale University School of Medicine were investigating one of the proteins involved in the detection process - Toll-like receptor nine (TLR9), which can spot DNA from bacteria and viruses. BBC © 2012

Keyword: Biological Rhythms; Neuroimmunology
Link ID: 16390 - Posted: 02.18.2012

By Fred H. Gage and Alysson R. Muotri Your brain is special. So is mine. Differences arise at every level of the organ’s astonishingly intricate architecture; the human brain contains 100 billion neurons, which come in thousands of types and collectively form an estimate of more than 100 trillion interconnections. These differences, in turn, lead to variances in the ways we think, learn and behave and in our propensity for mental illness. How does diversity in brain wiring and function arise? Variations in the genes we inherit from our parents can play a role. Yet even identical twins raised by the same parents can differ markedly in their mental functioning, behavioral traits, and risk of mental illness or neurodegenerative disease. In fact, mice bred to be genetically identical that are then handled in exactly the same way in the laboratory display differences in learning ability, fear avoidance and responses to stress even when age, gender and care are held constant. Something more has to be going on. Certainly the experiences we have in life matter as well; they can, for instance, influence the strength of the connections between particular sets of neurons. But researchers are increasingly finding tantalizing indications that other factors are at work—for instance, processes that mutate genes or affect gene behavior early in an embryo’s development or later in life. Such phenomena include alternative splicing, in which a single gene can give rise to two or more different proteins. Proteins carry out most of the operations in cells, and thus which proteins are made in cells will affect the functioning of the tissues those cells compose. Many researchers are also exploring the role of epigenetic changes—DNA modifications that alter gene activity (increasing or decreasing the synthesis of specific proteins) without changing the information in genes. © 2012 Scientific American,

Keyword: Development of the Brain; Genes & Behavior
Link ID: 16389 - Posted: 02.16.2012

Bijal P. Trivedi On a frigid winter's morning in 1992, Susan Lindquist, then a biologist at the University of Chicago in Illinois, trudged through the snow to the campus's intellectual-property office to share an unconventional idea for a cancer drug. A protein that she had been working on, Hsp90, guides misfolded proteins into their proper conformation. But it also applies its talents to misfolded mutant proteins in tumour cells, activating them and helping cancer to advance. Lindquist suspected that blocking Hsp90 would thwart the disease. The intellectual-property project manager she met with disagreed, calling Lindquist's idea “ridiculous” because it stemmed from experiments in yeast. His “sneering tone”, she says, left an indelible mark. “It was actually one of the most insulting conversations I've had in my professional life.” It led her to abandon her cancer research on Hsp90 for a decade. Today, more than a dozen drug companies are developing inhibitors of the protein as cancer treatments. Lindquist seems able to shrug off such injustices, now. Her work over the past 20 years has consistently challenged standard thinking on evolution, inheritance and the humble yeast. She has helped to show how misfolded infectious proteins called prions can override the rules of inheritance in yeast, and how this can be used to model human disease. She has also proposed a mechanism by which organisms can unleash hidden variation and evolve by leaps and bounds. She was the first female director of the prestigious Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, and has received more than a dozen awards and honours in the past five years. In a paper being published this week in Nature, she and her colleagues show that in wild yeast, prions provide tangible advantages, such as survival in harsh conditions and drug resistance1. © 2012 Nature Publishing Group

Keyword: Prions
Link ID: 16388 - Posted: 02.16.2012

By ROBERT LELEUX Seven years ago, when my grandmother JoAnn was first diagnosed with Alzheimer’s, the news sent me into a tailspin of fear and sadness. In my splintered Southern family, JoAnn had been more than my grandmother. The Auntie Mame of my Texas childhood, she taught me that happiness requires a great deal of thumbing one’s nose at convention. When I was 4, during an afternoon trip to the art museum, she told me to run my fingers along the brushstrokes of a particularly stunning Van Gogh: “They may kick us out of here, darlin,’ ” she drawled into my impressionable little ear, “but you’ll never not have touched that painting.” It was a life-affirming, if inappropriate, lesson. Without JoAnn’s outrageous example, I’m not sure I’d have had the courage to move to Manhattan, to come out of the closet, or ironically, to accompany her through the final years of her life. Little did I know that even after she was diagnosed with Alzheimer’s, my grandmother had only begun to educate me. “The wonderful thing about Alzheimer’s,” she once quipped after her diagnosis, “is that you always live in the moment.” This was a zinger intended to conceal her frustration at having forgotten the punch line to one of her signature anecdotes. But it was, nevertheless, quite true. Through the haze of our grief, my grandfather Alfred and I began noticing that, along with her memories, JoAnn’s grudges, hurt feelings, worries and regrets were disappearing. In fact, within a year, she seemed happier than ever, more present and at peace. © 2012 The New York Times Company

Keyword: Alzheimers
Link ID: 16387 - Posted: 02.16.2012

by Carl Zimmer There was no way the blind mice could see, yet somehow, they could. The year was 1923, and a Harvard grad student named Clyde Keeler had set out to compare eyes from different animals, starting with mice that he bred in his dorm room. Keeler cut open one mouse’s eye and put it under a microscope. Immediately he realized something was wrong. Missing from the eye was the layer of rods and cones, the photoreceptors that catch light. Turning back to his colony, Keeler realized that half of his animals were blind. Somehow a mutation had arisen, wiping out their rods and cones. The mutation had blinded those mice with surgical precision, yet for reasons lost to history, Keeler got the strange idea to shine a light in their eyes anyway. Based on everything that scientists knew about mammalian eyes, nothing should have happened. After all, the mice had no way to capture light and relay it to the retinal ganglion cells, the neurons that normally pass visual signals on to the brain. And yet something did happen: The mouse pupils shrank. Keeler struggled to find an explanation. “We may suppose that a rodless mouse will not see in the ordinary sense,” he wrote in one journal article. But for pupils to shrink, such mice had to have some kind of cell besides rods and cones—one that scientists knew nothing about—that could also capture light and send a signal to the brain. Most vision experts scoffed at the notion that the eyes contained hidden sensory cells and ignored Keeler’s findings. It took nearly eight decades for scientists to investigate his claim and prove him right: The eye really does contain a third type of photoreceptor cells that sense light intensity without detecting images. Kalmbach Publishing Co. Copyright © 2012,

Keyword: Vision; Biological Rhythms
Link ID: 16386 - Posted: 02.16.2012

The speed someone walks may predict the likelihood of developing dementia later in life, according to researchers in the US. They also told a conference that grip strength in middle-age was linked to the chance of a stroke. The scientists said more studies were needed to understand what was happening. Experts said the findings raised important questions, but more research was needed. Suggestions of a link between slow walking speed and poor health have been made before. A study, published in the British Medical Journal in 2009, said there was a "strong association" between slow walking speed and death from heart attacks and other heart problems. A Journal of the American Medical Association study suggested a link between walking faster over the age of 65 and a longer life. Dr Erica Camargo, who conducted the latest study at the Boston Medical Centre, said: "While frailty and lower physical performance in elderly people have been associated with an increased risk of dementia, we weren't sure until now how it impacted people of middle age." Brain scans, walking speed and grip strength were recorded for 2,410 people who were, on average, 62 years old. BBC © 2012

Keyword: Alzheimers
Link ID: 16385 - Posted: 02.16.2012

Kerry Grens Reuters NEW YORK (Reuters Health) - A series of group activities designed to stimulate thought, conversation and memory appears to improve the mental functioning of people with mild or moderate dementia, according to a new review of the evidence. "This is good news for the industry," said Robert Winningham, a professor at the University of Western Oregon, who was not involved in this study. "This is showing the people who work in memory care communities and nursing homes and assisted living facilities that they can improve cognitive function, and they need to be providing these kinds of interventions." Cognitive stimulation, as the therapy is called, involves structured activities in a group setting, usually one or more times a week for at least a month. The sessions might include a discussion of current events, a sort of show-and-tell with objects, baking, drawing or other activities that get the participants to engage their minds. Bob Woods, a professor at Bangor University in the UK who led the study, said that researchers in this field had considered cognitive stimulation to be helpful for people with dementia, based on earlier work. SOURCE: http://bit.ly/Af8nyY Cochrane Database of Systematic Reviews, February 2012. Copyright © 2012, Reuters

Keyword: Alzheimers
Link ID: 16384 - Posted: 02.16.2012

By Laura Sanders Sleep deprivation makes the brain groggy, but as waking hours mount nerve cells grow increasingly jumpy, a new study shows. This amped-up state may explain why seizures and hallucinations can accompany an all-nighter. More generally, the results help clarify what goes wrong in a brain deprived of shut-eye. “It’s an important finding,” says neuroscientist Christopher Colwell of UCLA. “Sleep deprivation is an area of huge interest because most of us do not get enough sleep.” By subjecting six people to a night of sleep deprivation and measuring their brain responses, Marcello Massimini of the University of Milan and colleagues found that people’s brains become more reactive as hours awake accumulate. To look for signs of altered brain function, the team delivered a jolt of magnetic current to the participants’ skulls that kicked off an electrical response in the nerve cells (an effect like the noise made when a hammer strikes a bell). With electrodes on the scalp, the team measured the strength of this electrical response in the frontal cortex, a brain region that’s involved in making executive decisions. After a night of sleep deprivation, participants’ electrical responses were stronger than they were the previous day, the scientists report online February 7 in Cerebral Cortex. This overreaction disappeared after a night’s sleep. The results offer support for a theory of why people sleep: During waking hours, the brain accumulates connections between nerve cells as new things are learned. Sleep, the theory says, sweeps the brain of extraneous clutter, leaving behind only the most important connections. © Society for Science & the Public 2000 - 2012

Keyword: Sleep; Epilepsy
Link ID: 16383 - Posted: 02.16.2012

by Catherine de Lange In an unlikely marriage of quantum physics and neuroscience, tiny particles called quantum dots have been used to control brain cells for the first time. Having such control over the brain could one day provide a non-invasive treatment for conditions such as Alzheimer's disease, depression and epilepsy. In the nearer term, quantum dots could be used to treat blindness by reactivating damaged retinal cells. "Many brain disorders are caused by imbalanced neural activity," says Lih Lin at the University of Washington, Seattle. "Manipulation of specific neurons could permit the restoration of normal activity levels." Methods to stimulate the brain artificially already exist, though each has its drawbacks. Deep brain stimulation is used in Parkinson's disease to trigger brain cell activity and prevent the abnormal signalling that causes debilitating tremors, but placing the electrodes required is highly invasive. Transcranial magnetic stimulation can stimulate brain cells from outside the head, but is not highly targeted and so affects large areas of the brain at once. Researchers in optogenetics can control genetically modified brain cells using light but because of these modifications, the technique is not yet deemed safe to use in humans. Lin's team has now come up with an alternative using quantum dots – light-sensitive, semiconducting particles just a few nanometres in diameter. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16382 - Posted: 02.16.2012

I am a neuroscientist, doing research and living in The Bronx. I study the brain systems of love and relationships, which are curiously related to brain systems of hunger and thirst. Valentine's Day is special for me. I live in a small town area in the Bronx called City Island. City Island resembles an old New England shipbuilding village, has many fish restaurants, boats and a nice place for exercise and personal training. As I walk through my neighborhood these days to get to the exercise place, I am charmed by exuberant shiny red hearts streaming down a front-steps railing. At another house a large Valentine heart hangs over a Christmas wreath, as if to seamlessly spread joy and gifts from one holiday to another. A flower basket of shiny red hearts hangs on another door as a reminder that the month of May and flowers will come. Romantic love knows no season, but it's great to celebrate it in the middle of winter when some of us crave a little warmth, temperature-wise and relationship-wise. What is love? How about a simpler question -- Is romantic love an emotion? I bet you would say it is. I thought so before I started my research, but now I have a different answer for the question. But also, I constantly ask, how can research on the brain physiology of love be relevant to my neighbors on City Island behind the doors with hearts, and the doors without? I love my work. There is no greater fascination for me than how the brain organizes behavior. Physiology of mind. What a concept! Even the cells of the brain have a raw beauty and instant fascination for me. It may be their complexity and likeness to trees, stars and planets. Scientists label brain cells to study them with shiny fluorescent colors of green and blue -- even red. When I look through the microscope at the brain, I see a universe in each square millimeter of tissue. For me, it is this brain-universe that underlies behavior, even romantic behavior and feelings. © 2012 TheHuffingtonPost.com, Inc.

Keyword: Emotions; Sexual Behavior
Link ID: 16381 - Posted: 02.16.2012

By JOHN TIERNEY Do you make decisions quickly based on incomplete information? Do you lose your temper quickly? Are you easily bored? Do you thrive in conditions that seem chaotic to others, or do you like everything well organized? Those are the kinds of questions used to measure novelty-seeking, a personality trait long associated with trouble. As researchers analyzed its genetic roots and relations to the brain’s dopamine system, they linked this trait with problems like attention deficit disorder, compulsive spending and gambling, alcoholism, drug abuse and criminal behavior. Now, though, after extensively tracking novelty-seekers, researchers are seeing the upside. In the right combination with other traits, it’s a crucial predictor of well-being. “Novelty-seeking is one of the traits that keeps you healthy and happy and fosters personality growth as you age,” says C. Robert Cloninger, the psychiatrist who developed personality tests for measuring this trait. The problems with novelty-seeking showed up in his early research in the 1990s; the advantages have become apparent after he and his colleagues tested and tracked thousands of people in the United States, Israel and Finland. “It can lead to antisocial behavior,” he says, “but if you combine this adventurousness and curiosity with persistence and a sense that it’s not all about you, then you get the kind of creativity that benefits society as a whole.” © 2012 The New York Times Company

Keyword: Emotions
Link ID: 16380 - Posted: 02.14.2012

by Andy Coghlan Maltreatment of children may stunt growth of the hippocampus, a brain region vital for memory. That's the conclusion of a study of 193 outwardly healthy adults aged 18 to 25 from the Boston area. The stunted hippocampi could help explain how childhood stress raises the risk of psychiatric disorders in adulthood, ranging from depression, schizophrenia and post-traumatic stress disorder to personality disorders, drug addiction and even suicide. Martin Teicher of McLean Hospital in Belmont, Massachusetts, and colleagues used standard questionnaires to reveal which volunteers had suffered abuse as children, and found size differences in regions of the hippocampus through detailed MRI brain scans. Big differences were seen in people who said that as children they had experienced verbal, physical or sexual abuse, physical or emotional neglect, bereavement, parental separation or parental discord. Three sub-regions of the hippocampus were between 5.8 and 6.5 per cent smaller in such volunteers, compared with those who reported no maltreatment. The three sub-regions – the dentate gyrus, the cornu ammonis and the subiculum – are all known to be vulnerable to the effects of stress hormones, which probably interfere with the formation of cells and new tissue as the immature brain develops. © Copyright Reed Business Information Ltd.

Keyword: Stress; Learning & Memory
Link ID: 16379 - Posted: 02.14.2012

By Bruce Bower By age 6 months, infants on the verge of babbling already know — at least in a budding sense — the meanings of several common nouns for foods and body parts, a new study finds. Vocabulary learning and advances in sounding out syllables and consonants go hand in hand starting at about age 6 months, say graduate student Elika Bergelson and psychologist Daniel Swingley of the University of Pennsylvania. Babies don’t blurt out their first words until around 1 year of age. Bergelson and Swingley’s evidence that 6-month-olds direct their gaze to images of bananas, noses and other objects named by their mothers challenges the influential view that word learning doesn’t start until age 9 months. “Our guess is that a special human desire for social connection, on the part of parents and their infants, is an important component of early word learning,” Bergelson says. The work is published online the week of February 13 in the Proceedings of the National Academy of Sciences. In the study, 33 infants ages 6 to 9 months and 50 kids ages 10 to 20 months sat on their mothers’ laps in front of a computer connected to an eye-tracking device. Even at 6 months, babies looked substantially longer, on average, at images of various foods and body parts named by their mothers when those items appeared with other objects. © Society for Science & the Public 2000 - 2012

Keyword: Language; Development of the Brain
Link ID: 16378 - Posted: 02.14.2012

By Laura Sanders Of the 100,000 nerve cells in the fruit fly brain, two have a special role in memory. Positioned on the front of the brain, one on each side, this duo of nerve cells (shown in pink) churns out proteins that are essential for fruit flies to form, store and retrieve long-term memories, Chun-Chao Chen of National Tsing Hua University in Taiwan and colleagues report in the Feb. 10 Science. When the researchers prevented these two nerve cells from making proteins after a training session, the flies’ ability to remember an odor diminished. Surprisingly, these two large nerve cells, called the dorsal-anterior-lateral neurons, reside outside brain regions that are typically thought of as the fruit fly’s memory centers — L-shaped structures called the mushroom bodies (shown in green). © Society for Science & the Public 2000 - 2012

Keyword: Learning & Memory
Link ID: 16377 - Posted: 02.14.2012

By Mark Fischetti Love, Explained: The Science of Romance Sex, speed dating, monogamy--for Valentine's Day, we look at the science behind the mating game » February 13, 2012 A dozen brain regions, working together, create feelings of passionate love. Stephanie Ortigue of Syracuse University and her colleagues worldwide compared MRI studies of people who indicated they were either in love or were experiencing maternal or unconditional love. The comparison revealed a "passion network"—the red regions shown here at various angles. The network releases neurotransmitters and other chemicals in the brain and blood that create the sensations of attraction, arousal, pleasure…and obsession. © 2012 Scientific American,

Keyword: Sexual Behavior; Brain imaging
Link ID: 16376 - Posted: 02.14.2012

By Carolyn Butler, This Valentine’s Day, as our collective thoughts shift to tender cards, heart-shaped chocolates, overpriced bouquets and other extravagant gestures of love, I can’t help but wonder what really attracts us to one mate over another. Is it hot sex? Fairy-tale romance? Destiny? Or are we merely at the beck and call of our hormones and brain circuitry? Online dating sites trumpet their knack at identifying “chemistry,” but it turns out that basic biology may play at least as strong a role in love as do socialization, environment, fate and other factors. “We like to feel independent and free of the brain systems that regulate the mating habits and regimens of animals, but the fact is that we’re not,” says neuroendocrinologist Tom Sherman, an associate professor at Georgetown University School of Medicine. “The latest research indicates that some of our very complex behaviors — like love, courtship and pair bonding — are still regulated, to some degree, by a fairly simple set of neurochemicals.” Indeed, researchers have now identified three brain systems that are at work in mating and reproduction: lust, which is primarily mediated by the sex hormone testosterone; romantic love, which is primarily mediated by dopamine, a neurotransmitter that drives the brain’s reward and pleasure centers, and is characterized by craving and focused attention for just one person at a time; and attachment, which is primarily mediated by the hormones oxytocin and vasopressin and is associated with the bonding and security you often feel with a long-term partner. © 1996-2012 The Washington Post

Keyword: Emotions; Sexual Behavior
Link ID: 16375 - Posted: 02.14.2012

By Adam Hadhazy Love might be in the air on Valentine's Day, metaphorically speaking. But scientists have long debated whether love—or, at least, sexual attraction—is literally in the air, in the form of chemicals called pheromones. Creatures from mice to moths send out these chemical signals to entice mates. And if advertisements about pheromone-laden fragrances are to be believed, one might conclude that humans also exchange molecular come-hithers. Still, after decades of research, the story in humans is not quite so clear. Rather than positing that single, pheromone-esque compounds strike us like Cupid's arrow, investigators now suggest that a suite of chemicals emitted from our bodies subliminally sways potential partnerings. Smell, it seems, plays an underappreciated role in romance and other human affairs. "We've just started to understand that there is communication below the level of consciousness," says Bettina Pause, a psychologist at Heinrich Heine University of Düsseldorf (H.H.U.), who has been studying pheromones and human social olfaction for 15 years. "My guess is that a lot of our communication is influenced by chemosignals." Animals, plants and even bacteria produce pheromones. These precise cocktails of compounds trigger various reactions in fellow members of a species—not all of which are sexual. Pheromonal messages can range from the competitive, such as the "stink fights" of male lemurs, to the collaborative, such as ants laying down chemical trails to food sources. © 2012 Scientific American,

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 16374 - Posted: 02.14.2012