Roxanne Khamsi When faced with uncertainty, people try to make the most logical decision, given the facts available. But a brain-imaging study has found that, when tackling these tricky decisions, the brain's emotional areas also spring into action. Ming Hsu of the California Institute of Technology in Pasadena and his colleagues compared volunteers' brain activity in two betting games. As the volunteers played, the scientists watched changes in their brain activity using functional magnetic resonance imaging. In one game, researchers gave volunteers the chance to guess the colour of a card drawn from a deck containing equal numbers of red and blue cards, and to bet on whether they were right. In the other game, the ratio of red to blue cards remained unknown. Players in this game were less likely to put money on their guess. And there was a burst of activity in their brain's emotion-processing centres, the amygdala and the orbitofrontal cortex. The study is published in this week's Science1. The volunteers didn't know that the odds of them guessing right were actually the same in both games. Because players in the second game could only say 'red' or 'blue', their chances of betting correctly remained at 50%, whatever the ratio of blue and red cards. ©2005 Nature Publishing Group

Keyword: Emotions
Link ID: 8284 - Posted: 06.24.2010

Rowan Hooper THANKS to research on "mighty mice", the lives of people suffering from muscle-wasting diseases such as muscular dystrophy could be transformed. Two treatments that block a protein called myostatin, which slows muscle growth, are now in the pipeline. The first approach, announced this week, aims to use a drug to mop up myostatin. Meanwhile a second method, which is already in clinical trials in people with muscular dystrophy, uses antibodies to disable the protein. In 1997, researchers led by Se-Jin Lee of Johns Hopkins University School of Medicine in Baltimore, Maryland, engineered mice in which the gene for myostatin had been "knocked out". The animals grew muscles twice as big as normal. A defect in the myostatin gene was what caused a German toddler, whose story was widely publicised last year, to develop prodigious muscles. Now Lee has produced a soluble molecule called activin type IIB receptor (ACVR2B) that binds to myostatin in normal mice, causing their muscles to bulk up. He hopes ACVR2B can be used to treat conditions such as Duchenne muscular dystrophy, a genetic disease that affects 1 in 3000 boys. Their muscles waste away because of a defect in the gene for the protein dystrophin, which is important in organising muscle structure. © Copyright Reed Business Information Ltd

Keyword: Muscles; Movement Disorders
Link ID: 8283 - Posted: 06.24.2010

A new study from the Monell Chemical Senses Center may shed light on why some people like salt more than others. The results suggest that a person's liking for salty taste may be related to how much they weighed when they were born. In a paper published in the European Journal of Clinical Nutrition, the Monell researchers report that individual differences in salty taste acceptance by two-month old infants are inversely related to birth weight: lighter birth weight infants show greater acceptance of salt-water solutions than do babies who were heavier at birth. According to lead author Leslie Stein, Ph.D., "The early appearance of this relationship suggests that developmental events occurring in utero may have a lasting influence on an individual's preference for salty taste." A similar relationship was found in a subset of the same children at preschool age, suggesting that the relationship between salty taste preference and birth weight persists at least through early childhood, a critical time for the formation of flavor and food preferences. By studying individual differences in liking for salty taste, scientists hope to obtain needed insights into the underlying factors driving salt preference and intake. Such information could potentially be used in programs designed to reduce salt intake, which is believed by many to contribute to the development and maintenance of high blood pressure.

Keyword: Chemical Senses (Smell & Taste); Development of the Brain
Link ID: 8282 - Posted: 12.08.2005

Playing too many video games has been reported to increase violent tendencies in some people or make some kids slow learners, but they may also create skilled surgeons and have also been used as a virtual distraction helping some kids get through painful medical treatments. Now it seems that playing certain special computer games could help prepare some kids for school. Psychologists at the University of Oregon designed the games to train the network of brain areas involved in attention, which undergoes important development between ages three and seven. "It's important, particularly in child development, for the child's ability to regulate their thoughts and to control their emotions," explains neuro-psychologist Mike Posner. "This executive network, which tends to control the child's emotions, and also allows them to continue to work on a particular task, it's also likely that that network is also deficient in ADHD children." Posner and his research team were interested in seeing whether, with a certain amount of training, they might be able to improve the efficiency of the network in children at the age when the network is developing. © ScienCentral, 2000-2005.

Keyword: ADHD; Attention
Link ID: 8281 - Posted: 06.24.2010

By Susan Brown What's behind the satisfaction we get from a tasty dessert? Researchers have long assumed it has something to do with the neurotransmitter dopamine. But a new study suggests that this so-called "pleasure molecule" isn't necessary for us to enjoy that piece of cake after all. Without the pleasurable kick dopamine is thought to provide, researchers assumed that people would be less inclined to get hooked on gambling or drugs (ScienceNOW, 10 January:). But recent evidence has called this theory into question. For example, mice lacking a type of receptor for dopamine still seek out morphine, suggesting that they find the drug rewarding even without dopamine signaling. To investigate further, neurobiologists Thomas Hnasko, Bethany Sotak, and Richard Palmiter at the University of Washington in Seattle gave morphine to dopamine-deficient mice. Once the morphine wore off, the team let the animals roam freely between two chambers: one where they had received the morphine and another one. Dopamine-deficient mice given moderate to high levels of morphine favored the morphine-associated chamber, just like normal mice did, further evidence that dopamine isn't necessary to experience the rewards of morphine, the team reports 8 December in Nature. © 2005 American Association for the Advancement of Science.

Keyword: Drug Abuse
Link ID: 8280 - Posted: 06.24.2010

Roxanne Khamsi Experiments on immature rats' brains suggest that treating epileptic children with benzodiazepine drugs could do more harm than good, scientists in France have claimed. They have found that the neurotransmitters unlocked by these drugs cause changes in brain chemistry that actually promote epileptic activity. Anticonvulsant benzodiazepines are a last-ditch treatment used to stop seizures in both infants and adults. Some medical experts think that the electrical activity associated with seizures can change brain networks, making them more susceptible to future epileptic activity. So understanding the chemistry of seizures might lead to drugs that can counteract epilepsy's development, says Yehezkel Ben-Ari, a neuroscientist at the Mediterranean Institute of Neurobiology in Marseille. His team studied the electrical and chemical activity of brains removed from baby rats. They were particularly interested in the hippocampus, a part of the brain important in epileptic seizures. The researchers found that the neurotransmitter gamma-aminobutyric acid (GABA) triggers rapid electrical signalling in the immature hippocampus - a hallmark of epileptic seizures. Benzodiazepine drugs enhance the action of this neurotransmitter. ©2005 Nature Publishing Group

Keyword: Epilepsy
Link ID: 8279 - Posted: 06.24.2010

The brainier male bats are, the smaller their testicles, according to a new study. Researchers suggest the correlation exists because both organs require a lot of energy to grow and maintain, leading individual species to find the optimum balance. The analysis of 334 species of bat found that in species where the females were promiscuous, the males had evolved larger testes but had relatively small brains. In species, where the females were monogamous, the situation was reversed. Male fidelity appeared to have no influence over testes or brain size. Both brain tissue and sperm cells require a lot of metabolic energy to produce and maintain. The different species appear to have evolved a preference for developing one organ more than the other, presumably determined by which will help them produce more offspring. “An extraordinary range of testes mass was documented across bat species - from 0.12% to 8.4% of body mass. That exceeds the range of any other mammalian order,” says Scott Pitnick, from Syracuse University in New York, US, one of the research team. Primate testes vary between species from 0.02% and 0.75% of body mass. Copyright Reed Business Information Ltd.

Keyword: Evolution; Sexual Behavior
Link ID: 8278 - Posted: 06.24.2010

A brain chemical recently found to boost trust appears to work by reducing activity and weakening connections in fear-processing circuitry, a brain imaging study at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has discovered. Scans of the hormone oxytocin’s effect on human brain function reveal that it quells the brain’s fear hub, the amygdala, and its brainstem relay stations in response to fearful stimuli. The work at NIMH and a collaborating site in Germany suggests new approaches to treating diseases thought to involve amygdala dysfunction and social fear, such as social phobia, autism, and possibly schizophrenia, report Andreas Meyer-Lindenberg, M.D., Ph.D., NIMH Genes Cognition and Psychosis Program, and colleagues, in the December 7, 2005 issue of the Journal of Neuroscience. “Studies in animals, pioneered by now NIMH director Dr. Thomas Insel, have shown that oxytocin plays a key role in complex emotional and social behaviors, such as attachment, social recognition and aggression” noted NIH Director Elias Zerhouni, M.D.. “Now, for the first time, we can literally see these same mechanisms at work in the human brain.” “The observed changes in the amygdala are exciting as they suggest that a long-acting analogue of oxytocin could have therapeutic value in disorders characterized by social avoidance,” added Insel.

Keyword: Emotions; Hormones & Behavior
Link ID: 8277 - Posted: 06.24.2010

Researchers have found evidence that may partially exonerate a protein known to be a culprit in the progression of Alzheimer's disease. Their new studies show that the protein p25, which wreaks havoc in the brains of patients with Alzheimer's disease, also has a good side in promoting the plasticity of the brain. In studies in mice, the scientists have shown that the enzyme promotes structural changes in the brain associated with learning and memory. The studies indicate that when the concentration of the protein reaches excessive levels, it contributes to the brain cell death associated with Alzheimer's disease (AD). Their discovery of the dual nature of p25 suggests that drugs that partially inhibit p25's target enzyme could protect the neurons of patients with AD. The research team, which was led by Howard Hughes Medical Institute investigator Li-Huei Tsai, reported its findings in the December 8, 2005, issue of the journal Neuron. Tsai and her colleagues at Harvard Medical School collaborated on the studies with researchers from the National Institute of Mental Health. In earlier studies, Tsai and her colleagues discovered that an enzyme called cyclin-dependent kinase 5 (Cdk5) plays a central role in AD pathology. Like other kinases, Cdk5 switches on enzymes by attaching a phosphate group to them. Under tight regulation by a protein called p35, Cdk5 controls the construction and maintenance of neuronal connections in the brain. © 2005 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 8276 - Posted: 06.24.2010

By Caroline Ryan BBC News website health reporter The man who received the first cornea transplant was given no antibiotics, no drugs to stop him rejecting the tissue - and had to endure his eyelids being sewn shut for 10 days before he knew if the procedure had worked. But this was 100 years ago. That first, groundbreaking, operation took place in Olomouc, now in the east of the Czech Republic. It was carried out by Dr Eduard Zirm, an ophthalmic specialist who had been trying to achieve a successful transplant for some time. The recipient was Alois Gloger, a labourer who had been blinded in an accident while working with lime. The corneas came from an 11-year-old boy who had been blinded by deep injuries to his eyes. A few hours after the operation, the 43-year-old patient could see again. He retained his eyesight for the rest of his life and was back working on his farm within three months. Dr Zirm, in common with other specialists across the world, had long been trying to achieve a successful cornea transplant. He transplanted corneas into both the patient's eyes. To get around the lack of fine material to sew the cornea to the eye, he used strips of the conjunctiva - the lining of the white of the eye - prising up one end of a strip and using it to "tape down" the new cornea. To cut out the cornea for transplant, he used a trephine, a circular surgical instrument with a cutting edge, powered by clockwork. He then sewed the patient's eyelids shut for 10 days to allow time for the cornea and the conjunctiva strips to "knit" together. When he unstitched the eyelids, the graft in the patient's left eye had taken - although the other had failed. (C)BBC

Keyword: Vision
Link ID: 8275 - Posted: 12.07.2005

Babies born with a larger head may have an increased risk of childhood brain cancer, research suggests. Head circumference at birth reflects brain size, and researchers suspected that in some cases this might be a sign of abnormal growth patterns. A Norwegian Institute of Public Health team tested their hypothesis by examining the health records of over a million young people. They found the larger the head at birth, the greater the risk. For every centimetre increase in head circumference at birth, the relative risk of having a tumour rose by 27%. However, the overall risk was still small. Out of 1,010,366 children in the study just 453 were diagnosed with brain cancer. In the UK, about 300 children are diagnosed with a brain tumour each year. Currently, around 30% of affected children die of the disease. The researchers said their work suggested that brain cancers might begin to develop before birth. Cancer cells - and particularly those that play a key role in developing blood supply to a tumour - are thought to be stimulated by the same growth factors as healthy tissues during development. Thus if healthy tissues grow at a faster rate than usual, then maybe growth factors are present at levels that make the development of malignant tissues more likely too. Another hypothesis is that large children may be more prone to cancer simply because they have more cells. (C)BBC

Keyword: Development of the Brain
Link ID: 8274 - Posted: 12.07.2005

By Caroline E. Mayer, Washington Post Staff Writer Food and beverage companies are using television ads to entice children into eating massive amounts of unhealthful food, leading to a sharp increase in childhood obesity and diabetes, a national science advisory panel said yesterday. The Institute of Medicine, part of the National Academies, called on food and beverage manufacturers and restaurants to make more healthful products and shift their advertising emphasis to promote them. If the companies do not do so within two years, Congress should mandate changes, especially for broadcast and cable television ads, the institute said. "There is strong evidence that exposure to television advertising is associated with" obesity, the government-chartered institute said in a congressionally requested report to determine the effects of food advertising on children's health. The report said most of the food and beverage products promoted to children are high in calories, sugar, salt and fat and low in nutrients. Many are promoted with popular cartoon characters. There are, for example, SpongeBob SquarePants cereal, Pop-Tarts, cookies and candy and Scooby-Doo fruit snacks and crackers. The institute said such characters should be used to promote only products that support healthful diets. © 2005 The Washington Post Company

Keyword: Obesity; Development of the Brain
Link ID: 8273 - Posted: 06.24.2010

— When Sonia Ruschak's 5-month-old daughter, Violet, wasn't napping much, she started to feel stressed. Then the problem got worse — her daughter became even crankier and slept less. After a while, Ruschak decided to stop worrying — and suddenly things got better. "I definitely think she relaxed more and cried less when I stopped stressing," she said. While parents have long felt their children read and react to their emotional states, scientists have only recently begun quantifying that connection and considering its importance in a child's development. Their research shows that the connection between an infant and a primary caregiver is so key that there can be drawbacks to placing the child in day care very early in life. Later on, however, there may be benefits to some separation. Allan Schore, a leading neuroscientist at the University of California, Los Angeles' Center for Culture, Brain, and Development, points out that the parent-child connection during a child's first year can not only affect a child's psychological state, it actually plays a role in physically shaping the brain. Meanwhile, a study from the University of Bath, in England, has shown that placing 3- to 5-year-olds in day care can benefit the psychological well-being of both parent and child. "The research is now moving out of theoretical science and into practical science to the point where we can begin advising pediatricians about what advice to offer parents," Schore said. © 2005 ABC News Internet Ventures

Keyword: Development of the Brain
Link ID: 8272 - Posted: 06.24.2010

BUFFALO, N.Y. -- Male water fleas that scientists have never seen have made their debut in a University at Buffalo laboratory, providing biologists with their first glimpse of these elusive organisms. The UB research, published last month in Proceedings of the Royal Society: Biological Sciences, opens a new window on the biological diversity of several species of water fleas, including those in the genus Daphnia and the genus Bosmina, that play major roles in freshwater food webs. It also demonstrates that pesticides that mimic the hormone used in the UB experiments may have much broader effects than initially believed, and could damage populations of fish and other organisms higher up in the food chain. "Most freshwater fish eat water fleas at some point in their lives," said Derek J. Taylor, Ph.D., associate professor of biological sciences in UB's College of Arts and Sciences and co-author on the paper. "They are an important food source for fish." Water fleas are nearly microscopic organisms with transparent bodies. Found in lakes, ponds and other bodies of fresh water, they are crustaceans like lobsters and not insects, as their name suggests. © 2005 University at Buffalo.

Keyword: Sexual Behavior
Link ID: 8271 - Posted: 06.24.2010

University of Florida researchers have identified one possible reason for rising obesity rates, and it all starts with fructose, found in fruit, honey, table sugar and other sweeteners, and in many processed foods. Fructose may trick you into thinking you are hungrier than you should be, say the scientists, whose studies in animals have revealed its role in a biochemical chain reaction that triggers weight gain and other features of metabolic syndrome - the main precursor to type 2 diabetes. In related research, they also prevented rats from packing on the pounds by interrupting the way their bodies processed this simple sugar, even when the animals continued to consume it. The findings, reported in the December issue of Nature Clinical Practice Nephrology and in this month's online edition of the American Journal of Physiology-Renal Physiology, add to growing evidence implicating fructose in the obesity epidemic and could influence future dietary guidelines. UF researchers are now studying whether the same mechanism is involved in people. "There may be more than just the common concept that the reason a person gets fat is because they eat too many calories and they don't do enough exercise," said Richard J. Johnson, M.D., the J. Robert Cade professor of nephrology and chief of nephrology, hypertension and transplantation at UF's College of Medicine.

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 8270 - Posted: 12.07.2005

By Mary Beckman Seniors don't need to do everything the health magazines recommend to stay fit. A new study with older women shows that either snoozing right or maintaining a good social network is enough to reduce levels of an inflammatory compound linked to bad health. It's well known that lifestyle characteristics such as sleep and relationships can affect health. For example, seniors who sleep badly or have few close friends and relations generally have more health problems and die younger than their peers. But what's behind the trend? Previous research indicates than an inflammatory molecule in the body called IL-6 is present at high levels in people who sleep badly. Just as high cholesterol puts one at risk for heart disease, high IL-6 increases the risk of a variety of ailments associated with age, such as heart disease, Alzheimer's, and arthritis. To see whether a good night's sleep and strong social networks decreased IL-6 levels in senior women, psychologist Elliot Friedman at the University of Wisconsin, Madison, and colleagues surveyed 135 women between the ages of 61 and 90 about how well they slept and how good they felt about their relationships with other people. © 2005 American Association for the Advancement of Science.

Keyword: Sleep; Stress
Link ID: 8269 - Posted: 06.24.2010

By Tracy Staedter, Discovery News —A mobile robot that uses a set of whiskers to discriminate between different textures could open the door on new sensing technologies that are more sensitive than touch and lead to better mobile devices able to move efficiently though tight, dark places where vision is useless. "It's like walking through a dark room and having your hands stretched out so that you won't bump into something ," said neurobiologist Miriam Fend, whose research is part of the AMouse project at the University of Zurich. Fend's robot is about eight centimeters in diameter and is equipped with two arrays of real rat whiskers that twitch side to side. Each whisker is glued to a membrane covering a microphone. When the whiskers sweep across an object, the membrane deforms, producing a signal that is amplified and then recorded by a computer. In experiments, the mouse robot explored a walled environment, feeling around for obstacles. When it came into contact with a surface, it stopped, whisked the surface and logged the data into its computer brain and, when necessary, repositioned itself slightly to get a better reading. © 2005 Discovery Communications Inc.

Keyword: Robotics
Link ID: 8268 - Posted: 06.24.2010

Researchers believe they have identified a molecule that could be targeted to treat mental impairment in people with Down's syndrome. A team at the Institute of Psychiatry at King's College London found people with Down's syndrome have higher levels of myo-inositol in their brains. They also found increased levels of this molecule are associated with reduced intellectual ability. The study is published in Archives of General Psychiatry. The researchers also suspect that high levels of myo-inositol could play a role in predisposing people with Down syndrome to early-onset Alzheimer's disease. The molecule is known to promote the formation of amyloid plaques - a hallmark of Alzheimer's. Once they reach the age of 40, almost all people with Down's syndrome show the brain characteristics of Alzheimer's disease - though they do not all go on to develop dementia. The combination of pre-existing mental retardation with an increasing overlying dementia is difficult to treat, and expensive to manage. Lead researcher Professor Declan Murphy said: "We have shown in this study that adults with Down's syndrome have a significantly higher concentration of myo-inositol in the hippocampal region of their brains, and this increase is associated with a reduced cognitive ability. We are now carrying out more studies to see if we can reduce the concentration of myo-inositol in the brains of people with Down's. We hope that if we can do this, it will be a new way of treating this devastating disorder." (C)BBC

Keyword: Development of the Brain
Link ID: 8267 - Posted: 12.06.2005

Brian Handwerk for National Geographic News Today's cutting-edge optical technologies could progress by leaps and bounds if scientists can better imitate animal-eye evolution spanning billions of years, two bioengineers report. Using biology as inspiration, scientists hope to make advances in optics that would enhance camera and video technology, surveillance systems, missile defense, remote navigation, and even human vision aids. "It's amazing to see the beauty of nature and see if we can apply this to everyday life," said Luke Lee, a bioengineer at the University of California, Berkeley. Lee and Berkeley colleague Robert Szema wrote on the state of animal-eye optics research in a recent issue of the journal Science. In his lab, Lee is refining three-dimensional polymer structures that can mimic the components of an eye, from lenses to light receptors. He believes soft, flexible polymers may be the key to replicating natural sight systems that outperform their mechanized competition. © 1996-2005 National Geographic Society

Keyword: Vision
Link ID: 8266 - Posted: 06.24.2010

Scientists funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health, are a step closer to unraveling the mystery of taste. In a study published in the December 2, 2005, issue of Science, researchers have pinpointed the chemical responsible for transmitting signals from the taste buds — small sensory bumps on the tongue, throat, and roof of the mouth — to the taste nerves leading to the brain. Today’s findings provide scientists with a more complete picture of this complicated process, helping advance the study of taste and taste disorders. “People with taste disorders might not be able to enjoy the fun of eating and are at risk for other health problems, such as poorly balanced nutrition, so researchers are working to understand more fully how our sense of taste works,” says James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. “Until now, there has always been a missing link between the detection of chemicals in the taste buds and the transmission of chemical signals from the taste nerves to the brain. Through an ingenious use of genetic engineering, these researchers have finally been able to solve the puzzle.” Using “knockout mice,” mice that are genetically altered to be missing one or more key genes, the researchers were able to narrow the field of possible chemicals to one: adenosine 5’-triphosphate, or ATP, a high-energy molecule that is also important for helping cells in the body to function. The scientists produced mice that are missing the genes that encode two key receptors found in taste nerves — P2X2 and P2X3 — both of which bind to ATP.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8265 - Posted: 06.24.2010