Kerri Smith The way in which antidepressants exert their effects on brain cells has been revealed by two separate teams of researchers working independently of each other. Antidepressants work by preventing neurons in the brain from importing certain chemicals, such as dopamine and serotonin, which are used to pass messages from cell to cell. The route by which these chemicals are imported depends on passageways in the outer membrane of the cells called transporter proteins, and it is on these passageways that the antidepressants exert their influence. But how exactly they hold up the process has remained a mystery since the drugs were discovered 45 years ago, says Les Iversen, a pharmacologist at the University of Oxford, UK. To resolve the mystery, both teams — one led by Eric Gouaux of Oregon Health and Science University in Portland and the other based at New York University and led by Da-Neng Wang — set out to understand what happens when antidepressants lock onto a transporter at the most fundamental level. They zoomed in on the transporters' molecular structures as revealed at atomic resolution through X-ray crystallography. The researchers couldn't use human transporter proteins because they are difficult to isolate and fall apart easily. Instead they used an equivalent found in bacteria called LeuT. They then selected drugs from a class called tricyclic antidepressants and created crystals in which the drug and the transporter were bound together. Gouaux's team used a drug called clomipramine while Wang's used a similar compound called desipramine. ©2007 Nature Publishing Group

Keyword: Depression
Link ID: 10588 - Posted: 06.24.2010

Heidi Ledford A US government-appointed scientific panel has said it has "some concern" that a compound found in many plastics may cause neural and behavioural abnormalities in infants and children at concentrations normally found in humans. But the panel found negligible concern that those exposed to typical levels of the compound, called bisphenol A, would develop reproductive problems or birth defects. The panel, which announced its findings on Wednesday 8 August, was convened by a division of the National Institute of Environmental Health Sciences (NIEHS) called the Center for the Evaluation of Risks to Human Reproduction (CERHR). Its report will now undergo review by the US National Toxicology Program and there will be two additional public comment periods before it is finalized. At that point it could serve as the basis for subsequent regulation of bisphenol A. The findings stand in stark contrast to the conclusions of an independent scientific panel assembled by Jerrold Heindel, a scientist who is also at the NIEHS. That panel published a consensus statement a week ago, citing its conclusion that prenatal or neonatal bisphenol A exposure alters the prostate, breasts, testes, mammary glands, body size, and behaviour later in life. The consensus statement was published along with two new bisphenol A studies to appear in the journal Reproductive Toxicology1,2, but the reports came too late for consideration by the CERHR panel, says its chair, Robert Chapin of Pfizer. ©2007 Nature Publishing Group

Keyword: Development of the Brain
Link ID: 10587 - Posted: 06.24.2010

Using electrical energy to zap cancer cells may sound like a strange idea. But clinical trials at twelve major hospitals around the country are now testing it against the deadliest form of brain cancer. In this ScienCentral News video, you'll hear from one study participant who a year ago was given only six months to live. Michael Quatrano's head is covered with electrodes and he's tethered to cable-box-sized electrical device and battery pack -- minor inconveniences after the surgery, radiation and chemotherapy that failed to stop his aggressive brain tumor from growing. Last August, Quatrano was diagnosed with Glioblastoma Multiforme (GBM), the most common and lethal type of brain cancer. He'd had periodic headaches before, so when he went to the emergency room for what he thought was a migraine, he expected to be treated with pain medication. "I thought I was going for a regular migraine and they said I had cancer," says Quatrano. "[The surgeon] went in my head and cut it and drained it as much as he could. And he told me that it looked really bad and I had six months to live. Right away, I've had people in my family that's had cancer, so I knew I've got to fight. So I don't give up." Quatrano had radiation and chemotherapy to shrink the tumor. "Then what happened, two weeks after I stopped, the tumor grew again," he says."This was like the last alternative. And luckily, it's working out." © ScienCentral, 2000-2007.

Keyword: Miscellaneous
Link ID: 10586 - Posted: 06.24.2010

By Krista Zala Give your skeletal system some credit. Not only do your bones keep you upright, they produce red and white blood cells, store minerals, and help control pH. But that's not all: According to a new study, bones secrete a protein called osteocalcin that regulates sugar and fat absorption. The finding qualifies osteocalcin as a hormone, meaning the skeleton can now add being an endocrine organ to its impressive list of accomplishments. There have already been hints that the skeletal system and the hormone-releasing endocrine system are intertwined. Gerard Karsenty, a geneticist at Columbia University, showed that fat cells regulate bone mass, for example, by releasing the hormone leptin, which affects the number of bone-building osteoblast cells. Considering the prevalence of feedback systems in the body, he and colleagues wondered whether bones might release their own hormones to influence fat metabolism. They knew that bones secrete a protein called osteocalcin, which helps pack calcium into the skeleton, but because no one had observed this protein acting elsewhere in the body, it was not classified as a hormone. Still, Karsenty and colleagues observed that mice unable to make osteocalcin grow obese, suggesting it might work as a hormone. So Karsenty's team genetically engineered one set of mice to produce loads of osteocalcin and another set not to make it at all. When fed regular diets, the mice making extra osteocalcin had lower-than-normal blood glucose levels and higher insulin levels than regular mice. © 2007 American Association for the Advancement of Science.

Keyword: Hormones & Behavior; Obesity
Link ID: 10585 - Posted: 06.24.2010

Coping well with stress can cut the risk of a stroke by almost a quarter, research shows. A University of Cambridge team based their conclusion on a seven-year study of more than 20,000 people. The study, published in the journal Stroke, recorded 452 strokes and more than 100,000 stressful life events among the participants. Those who were able to take a well-rounded approach to problems had a 24% lower risk of stroke. This group were said to have a good sense of coherence - a term coined following research into the experiences of survivors of concentration camps. Lead researcher Dr Paul Surtees, from the University of Cambridge, said: "Our findings suggest that people who are able to adapt more rapidly to stressful circumstances in their lives had a lower risk of stroke. "Whilst many questions remain to be answered by further research, this evidence raises the possibility that improving our ability to respond to stress may have benefits for vascular health." Dr Surtees said the relationship between stress and stroke was probably complex. However, he said there was a wealth of anecdotal evidence suggesting a link between the two. For instance, in the three months following the Kobe earthquake in Japan in 1995 stroke rates among the local population rose by 90%. (C)BBC

Keyword: Stress; Stroke
Link ID: 10584 - Posted: 08.09.2007

Women do not see macho men as a sound bet for a long-term partnership, preferring those with more feminine features, a study suggests. Men with masculine features like large noses and small eyes were seen as less warm, less faithful and worse parents than more feminine counterparts. Some 400 British men and women made judgements after viewing photographs in which the features were subtly altered. The study appears in the journal Personality and Individual Differences. Lead author Dr Lynda Boothroyd of Durham University said: "This research shows a high amount of agreement between women about what they see, personality-wise, when asked to judge a book by its cover. "They may well use that impression of someone to decide whether or not to engage with that person. That decision-making process all depends on what a woman is looking for in a relationship at that stage of her life." Some 400 British men and women completed the web-based test which put a pair of pictures in front of them. Participants were asked to judge the faces on the following categories: dominance, ambition, wealth, faithfulness, commitment, parenting and warmth. They did so by clicking on the point of a scale. The differences were subtle but apparent to the trained eye. The feminine face had more curved eyebrows, an arched forehead and slightly higher cheekbones. He also wore a hint of a smile, as women smile more often than men, the researchers said. (C)BBC

Keyword: Sexual Behavior
Link ID: 10583 - Posted: 08.09.2007

By ERIC NAGOURNEY Just can’t manage to nail down the subjunctive tense in French or the difference between the Spanish verbs for “to be”? Blame your Heschl’s gyrus — or at least your left one, anyway. That is a tiny part of the brain that appears to play an important role in how well adults can learn another language, a new study finds. Writing online in the journal Cerebral Cortex, researchers said people who had a larger left Heschl’s gyrus seemed to have an easier time picking up foreign languages. As a practical matter, a beefier H.G., as it is known, may not really help with the subjunctive or the difference between “ser” and “estar” in Spanish. For this study, the researchers, led by Dr. Patrick C. M. Wong of Northwestern, were focusing on the ability to discern pitch, a key element of tonal languages, not vocabulary. In tonal languages like Chinese, which are spoken by most of the world’s population, the same word can have different meanings, depending on how it is inflected. Copyright 2007 The New York Times Company

Keyword: Language
Link ID: 10582 - Posted: 06.24.2010

By NATALIE ANGIER In this country, the most popular cosmetic surgery procedure is liposuction: doctors vacuum out something like two million pounds of fat from the thighs, bellies, buttocks, jowls and man-breasts of 325,000 people a year. What happens to all that extracted adipose tissue? It’s bagged and disposed of as medical waste; or maybe, given the recent news about socially contagious fat, it’s sent by FedEx to the patients’ old college chums. But one thing the fat surely is not, and that is given due thanks for serving as scapegoat, and for a job well done. We are now in what feels like the 347th year of the fastidiously vilified “obesity epidemic.” Health officials repeatedly warn that everywhere in the world people are gaining too much weight and putting themselves at risk of diabetes, high blood pressure, heart disease and other obesity-linked illnesses, not to mention taking up more than their fair share of molded plastic subway seat. It’s easy to fear and despise our body fat and to see it as an unnatural, inert, pointless counterpoint to all things phat and fabulous. Yet fat tissue is not the problem here, and to castigate fat for getting too big and to blame it for high blood pressure or a wheezing heart is like a heavy drinker blaming the liver for turning cirrhotic. Just as the lush’s liver was merely doing its hepatic best to detoxify the large quantities of liquor in which it was doused, and just as the alcoholic would have been far worse off had the liver not been playing Hepa-filter in the first place, so our fat tissue, by efficiently absorbing the excess packets of energy we put in our mouths, has our best interests at heart. Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10581 - Posted: 06.24.2010

Michael Hopkin Two fossils unearthed in Kenya have added a new dimension to our view of life at the birth of our Homo genus. They show that two ancestral human species seem to have lived cheek-by-jowl in the same area, much as gorillas and chimpanzees do today. Both skull fragments were found by anthropologists digging near Kenya's Lake Turkana, adding to the impressive list of early human fossils unearthed here. One of the fossils, an upper jawbone from the species Homo habilis, is dated at 1.44 million years, much younger than most fossils of this species. The other fossil is an almost complete — but faceless — Homo erectus skull. Dated at 1.55 million years, the skull is far smaller than any other from this species — suggesting to the researchers that, as is the case with modern gorillas, there was a large size differences between the sexes in H. erectus. The fact that these two species seem to have been contemporaries is a surprise to anthropologists, say Fred Spoor of University College London and his colleagues, who discovered the hominin fossils seven years ago and now describe them in this week's Nature. ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10580 - Posted: 06.24.2010

By the time they reached adulthood, graduates of an intensive early childhood education program for poor children showed higher educational attainment, lower rates of serious crime and incarceration, and lower rates of depressive symptoms than did non-participants in the program, reported researchers in a study funded in part by the National Institutes of Health. The Child-Parent Centers (CPC) program in the Chicago Public School System provided intensive instruction in reading and math from pre-kindergarten through third grade, combined with frequent educational field trips. The children’s parents received job skills training, parenting skills training, educational classes and social services. They also volunteered in their children’s classrooms, assisted with field trips and attended parenting support groups. The CPC program is distinct from the federally funded Head Start program. “These results strongly suggest that comprehensive early education programs can have benefits well into adult life,” said Duane Alexander, Director of the National Institute of Child Health and Human Development, the NIH institute that funded the study. “A comparatively small investment early in life is associated with gains in education, economic standing, mental health, and other areas.” The researchers followed the children from ages 3 or 4 through age 24 to assess the possible benefits of the CPC program in terms of the children’s educational achievement, need for remedial education, involvement with the child welfare and foster care system, economic status, involvement with the criminal justice system, health status and mental health. The study appears in the August Archives of Pediatrics & Adolescent Medicine.

Keyword: Development of the Brain; Depression
Link ID: 10579 - Posted: 06.24.2010

Roxanne Khamsi Educational DVDs may hinder rather than help a young child's learning. Infants who watch DVDs such as Brainy Baby and Baby Einstein know fewer words than those who do not watch such programmes, a new study suggests. In recent years the popularity of such infant programmes has soared, particularly in the US. Parents hope the programmes, which typically consist of brief dialogue and picture sequences, will boost the learning ability of children as young as eight months old, even though the American Academy of Pediatrics has recommended that youngsters not watch television until two years of age. To find out what effect these programmes have, Dimitri Christakis at the University of Washington in Seattle, US, and his colleagues contacted about 500 families with a child born in the previous 16 months. During telephone interviews – which each lasted around 45 minutes – parents heard a list of about 90 words, such as "truck" and "cookie", and indicated which their 8- to 16-month-old children understood. They also gave other details, including how much they read to their children, and the amount and type of television their youngsters watched. The results contradict claims that baby DVDs help toddlers to communicate with their parents. After controlling for other factors, such as parents' educational status and the number of children per household, the analysis revealed that for every hour per day spent watching baby DVDs, toddlers understood an average of six to eight words fewer than those who did not view them. On average the children recognised about 25 words, although the number varied according to age. © Copyright Reed Business Information Ltd

Keyword: Development of the Brain; Language
Link ID: 10578 - Posted: 06.24.2010

By Vaudine England A study by doctors in Hong Kong has concluded that epilepsy can be induced by the Chinese tile game of mahjong. The findings, published in the Hong Kong Medical Journal, were based on 23 cases of people who had suffered mahjong-induced seizures. The report's four authors, from Hong Kong's Queen Mary Hospital, said the best prevention - and cure - was to avoid playing mahjong. The study led the doctors to define mahjong epilepsy as a unique syndrome. Eileptic seizures can be provoked by a wide variety of triggers, but one cause increasingly evident to researchers is the playing - or even watching - of mahjong. This Chinese tile game, played by four people round a table, can involve gambling and quickly becomes compulsive. The game, which is intensely social and sometimes played in crowded mahjong parlours, involves the rapid movement of tiles in marathon sessions. The doctors conclude that the syndrome affects far more men than women; that their average age is 54; and that it can hit sufferers anywhere between one to 11 hours into a mahjong game. They say the attacks were not just caused by sleep deprivation or gambling stress. (C)BBC

Keyword: Epilepsy
Link ID: 10577 - Posted: 08.06.2007

US scientists have genetically modified mice to exhibit both the anatomical and behavioural defects associated with the complex condition schizophrenia. Previous studies that rely on drugs can only mimic the symptoms of the disease, such as delusions and paranoia. But the new work, based on a key genetic change, could aid a much greater understanding of the disease. The Johns Hopkins University study appears in Proceedings of the National Academy of Sciences. Animal models of schizophrenia have been hard to design since many different causes underlie this disease. However, the Johns Hopkins team were able to take advantage of the recent discovery of a major risk factor for the disease. Scientists pinpointed a key gene - dubbed DISC 1 - which makes a protein that helps nerve cells assume their proper positions in the brain. The Johns Hopkins team generated mice that make an incomplete, shortened form of the DISC 1 protein in addition to the regular type. The short form of the protein attaches to the full-length one, disrupting its normal duties. As these mice matured, they became more agitated when placed in an open field, had trouble finding hidden food, and did not swim as long as regular mice - behaviours that echo the hyperactivity, smell defects and apathy observed in schizophrenia patients. Magnetic resonance imaging (MRI) also revealed characteristic defects in brain structure, including enlarged lateral ventricles, a region that circulates the spinal fluid and helps protect against physical trauma. Researcher Professor Akira Sawa said the defects in these mice were not as severe as those typically seen in people with schizophrenia, because more than one gene is required to trigger the clinical disease. (C)BBC

Keyword: Schizophrenia; Genes & Behavior
Link ID: 10576 - Posted: 08.06.2007

By David Biello Female lab mice tend to be docile, passive creatures. But by either genetically shutting down or surgically removing their ability to smell pheromones, scientists transformed them into aggressive, pelvic-thrusting, vocalizing lotharios—without any significant rise in testosterone or other steroid hormones. "The female brain has the neuronal circuit both to control male and female behavior," says molecular neuroscientist Catherine Dulac of Harvard University. "What is sexually dimorphic is the switch that allows one to be silenced." The key to gender-specific behavior, in mice at least, is a cluster of receptors in their noses that allows them to smell pheromones, special chemicals that deliver information about sexual readiness, among other things, between members of the same species. Called the vomeronasal organ (VNO), it connects to the brain and registers the gender of other mice, triggering the appropriate response. But when the researchers genetically disabled the VNO, female mice began to chase their male peers, mount them and attempt to pelvic thrust [see video here ]. "From a behavioral standpoint you could not recognize the animal from being any different than the male," Dulac adds. "All the thinking until now was that female brains can produce feminine behaviors while male brains can produce masculine behaviors, with little or no cross talk between them," says Marc Breedlove, a neuroscientist at Michigan State University in East Lansing. "These results do suggest that, at least for mice, the brain retains circuitry to display both masculine and feminine behaviors into adulthood." © 1996-2007 Scientific American, Inc.

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 10575 - Posted: 06.24.2010

By GINA KOLATA IN a way it all seems so obvious. Your friend found a lump in her breast, so you have that long-delayed mammogram. One by one your friends stop smoking, so you stop, too. Of course people are affected by their friends’ habits and their health. But what seems obvious in the abstract can lead to surprising findings. A recent study found that obesity can spread from friend to friend much like a virus. When one person gains weight, close friends tend to gain weight, too. The study, published recently in The New England Journal of Medicine, involved a detailed analysis of a large social network of 12,067 people who had been closely followed for 32 years, from 1971 to 2003. Now, scientists believe that social networks not only can spread diseases, like the common cold, but also may influence many types of behavior — negative and positive — which then affect an individual’s health, as well as a community’s. “In the past few years we have been seeing a network revolution,” says Albert-Laszlo Barabasi, a physics professor at the University of Notre Dame. “People sensed that networks were out there, but they never had large enough data sets to start understanding them in a quantitative fashion.” Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10574 - Posted: 06.24.2010

By EMILY BAZELON Caitlyn & Marguerite sat knee to knee in a sunny room at the Hawks Camp in Park City, Utah. On one wall was a white board with these questions: What’s your favorite vacation and why? What’s your favorite thing about yourself? If you could have any superpower, what would it be? Caitlyn, who is 13, and Marguerite, who is 16 (I’ve used only their first names to protect their privacy), held yellow sheets of paper on which they had written their answers. It was the third day of the weeklong camp, late for icebreakers. But the Hawks are kids with autistic disorders accompanied by a normal or high I.Q. And so the main goal of the camp, run on a 26-acre ranch by a Utah nonprofit organization called the National Ability Center, is to nudge them toward the sort of back and forth — “What’s your favorite video game?” — that comes easily to most kids. Along with Caitlyn and Marguerite, there were nine boys in the camp between the ages of 10 and 18. They also sat across from one another in pairs, with the exception of one 18-year-old who was arguing with a counselor. “All I require is a purple marker,” the boy said over and over again, refusing to write with the black marker he had been given. A few feet away, an 11-year-old was yipping and grunting while his partner read his answers in a monotone, eyes trained on his yellow paper. Another counselor hurried over to them. Marguerite was also reading her answers without eye contact or inflection. “My favorite vacations were to India and Thailand my favorite thing about myself is that I’m nice to people if I could choose any superpower I’d be invisible,” she said in an unbroken stream. She looked up from her paper and past Caitlyn. The girls didn’t look uncomfortable, just unplugged. Copyright 2007 The New York Times Company

Keyword: Autism
Link ID: 10573 - Posted: 06.24.2010

By Christoph Uhlhaas Could you buy a used car online, sight unseen and without a test-drive? How about a plane? A vehicle changes hands on eBay Motors every 60 seconds, including one private business jet that sold for $4.9 million. Every second buyers collectively swap more than $1,839 for products through eBay, sending money to complete strangers with no guarantee that the goods they buy will in fact arrive, let alone in the condition they expect. As a rule, they are not disappointed. To some economists, this is a borderline miracle, because it contradicts the concept of Homo economicus (economic man) as a rational, selfish person who single-mindedly strives for maximum profit. According to this notion, sellers should pocket buyers’ payments and send nothing in return. For their part, buyers should not trust sellers—and the market should collapse. Economist Axel Ockenfels of the University of Cologne in Germany and his colleagues have spent the past several years figuring out why this does not happen. It turns out that humans do not always behave as if their sole concern is their personal financial advantage—and even when they do, they consider social motives in the profit-making equation. As Ockenfels has discovered, a sense of fairness often plays a big role in people’s decisions about what to do with their money and possessions, and it is also an essential part of what drives trust in markets full of strangers such as eBay. © 1996-2007 Scientific American, Inc

Keyword: Emotions
Link ID: 10572 - Posted: 06.24.2010

By Nikhil Swaminathan Researchers have discovered how the brain chunks an unbroken river of information. It's a classic cocktail party conundrum: How do our brains decide where we should train our attention when people are milling all about us chatting away—some to us, some to others? In an attempt to find out, researchers at Stanford University and McGill University in Montreal scanned the brains of 18 subjects who were listening to classical music by 18th-century British composer William Boyce. "You have to kind of segment these streams [of information] into chunks," says senior study author Vinod Menon, an associate professor of psychiatry and behavioral science at Stanford. The process of slicing the data, he continues, requires that you "identify something that's interesting and then you have to switch on the attentional network." "Memory doesn't work like video recorder, it's more like DVD," in how it recalls events as discrete chapters, explains study co-author Daniel Levitin, a psychology professor at McGill. But why music? Simple, says Sridhar Devarajan, a Stanford neuroscience graduate student involved in the project. "Transitions between musical movements," he notes, "offer an ideal setting to study the dynamically changing landscape of activity in the brain during this segmentation process." © 1996-2007 Scientific American, Inc.

Keyword: Hearing; Attention
Link ID: 10571 - Posted: 06.24.2010

Bruce Bower Look, up in the trees. A barrel-chested, long-limbed creature covered with wispy, reddish hair sits on a branch far above the ground. The animal rises to a fully erect posture, reaches up to grab an overhead branch for balance, and promenades across the precarious platform. Upon reaching a cluster of hanging fruit, the animal plucks off a snack with a free hand. Still standing, it consumes the treat with gusto. Then it saunters back the way it came, striding from one padded foot to the other while continuing to grasp branches above its head. Witness the red-ape stroll, as practiced by an orangutan living on the Indonesian island of Sumatra. New field observations of these animals, conducted by anthropologist Susannah K.S. Thorpe of the University of Birmingham in England and her colleagues, show that orangutans, unlike knuckle-walking chimpanzees and gorillas, at times walk upright much as people do. This suggests to the researchers that two-legged walking, or bipedalism, evolved in a common ancestor of all living apes at least 20 million years ago. Among scientists who study hominids, the fossil ancestors of people, that's a heretical notion. These investigators have long assumed that an upright stance is a unique trait of hominids, a skeletal smoking gun that separates members of our evolutionary family from other ancient primates. From this perspective, hominids that walked on two legs evolved from a chimplike ancestor with a body structure suited to scooting across the ground on all fours. ©2007 Science Service.

Keyword: Evolution
Link ID: 10570 - Posted: 06.24.2010

By Jeanna Bryner Our brains can fathom the beginning of time and the end of the universe, but is any brain capable of understanding itself? With billions of neurons, each with thousands of connections, one's noggin is a complex, and yes congested, mental freeway. Neurologists and cognitive scientists nowadays are probing how the mind gives rise to thoughts, actions, emotions and ultimately consciousness. The complex machine is difficult for even the brainiest of scientists to wrap their heads around. But the payoff for such an achievement could be huge. “If we understand the brain, we will understand both its capacities and its limits for thought, emotions, reasoning, love and every other aspect of human life,” said Norman Weinberger, a neuroscientist at the University of California, Irvine. According to Scott Huettel of the Center for Cognitive Neuroscience at Duke University, the standard answer to this question goes something like: “The human brain is the most complex object in the known universe ... complexity makes simple models impractical and accurate models impossible to comprehend.” While that stock answer is correct, Huettel said, it’s incomplete. The real snag in brain science is one of navel gazing. Huettel and other neuroscientists can’t step outside of their own brains (and experiences) when studying the brain itself. © 2007 LiveScience.com.

Keyword: Miscellaneous
Link ID: 10569 - Posted: 06.24.2010