The over-prescribing of the drug Ritalin to children diagnosed with alleged behavioural problems is a growing scandal, a leading scientist said yesterday. Baroness Greenfield, a neuro-scientist and director of the Royal Institution, said the overuse of the drug should be addressed as a matter of urgency. In a House of Lords debate on science and education, she said children's inability to pay attention might simply be the result of too much time spent on a computer screen, or watching television where only short attention spans were needed. "I am not proposing that we become information technology Luddites but we could be stumbling into a powerful technology, the impact of which we understand poorly at the moment," she said. "The problem with these drugs (such as Ritalin) is that they do not target a single trait such as mood, or concentration or wakefulness. "Drugs will manipulate in a very 'broad spectrum' way the chemicals in the brain that in turn could have both widespread and also long lasting effects." © Copyright of Telegraph Group Limited 2006.

Keyword: ADHD; Development of the Brain
Link ID: 8838 - Posted: 06.24.2010

LA JOLLA – The brain, that exquisite network of billions of communicating cells, starts to take form with the genesis of nerve cells. Most newborn nerve cells, also called neurons, must travel from their birthplace to the position they will occupy in the adult brain. Researchers at the Salk Institute for Biological Studies have identified a molecule expressed on the surface of certain migrating neurons that helps them find their correct position along on the way. Decreasing levels of that protein, an adhesion molecule called MDGA1, prevents neurons that normally make this protein from assuming their proper position, resulting in brain malformation, researchers report in the April 26th issue of the Journal of Neuroscience. As Dennis D. M. O'Leary, Ph.D., senior author of the study and a Professor in the Molecular Neurobiology Laboratory put it, "proper neuronal positioning is essential for development of appropriate wiring, which is in turn critical for establishing a normal, functioning nervous system." Neurons migrate throughout the brain, but migration is particularly important for development of part of the brain known as the cerebral cortex. The cortex sits like a skullcap over the rest of the brain and is responsible for sensory perception, higher-level reasoning, and, in humans, language. In mammals, the largest and evolutionarily newest part of the cortex, the neocortex, is recognized anatomically by its six horizontal layers.

Keyword: Development of the Brain
Link ID: 8837 - Posted: 06.24.2010

Scientists have discovered that a dominant hyena puts her cubs on the road to success before they are born by passing on high levels of certain hormones that make her budding young leaders more aggressive and sexually advanced. The report, published in the April 27 issue of Nature, is the first study in mammals to demonstrate a relationship between a female's social rank and her ability to influence her offspring's behavior through prenatal hormone transfer. Previously, this phenomenon had only been documented in birds. Michigan State University's Kay Holekamp, together with her colleagues, spent almost 10 years sampling androgen levels from free-ranging hyenas in Kenya. Androgens are hormones, such as testosterone, that control development of typically masculine characteristics like aggression, muscle development and sexual behavior. The team found that alpha females had higher androgen levels late in pregnancy when compared to the subordinate, pregnant females in the pack. Consequently, the cubs of the alpha females were more aggressive and exhibited more sexual play, characteristics that elevate the chances for life-success in both sexes. In hyena packs, male-female social roles are reversed from what is normally found in nature--that is, female hyenas are larger, more aggressive and dominate the group. They even have deceptively male-like genitalia, leading to the misconception that they are hermaphrodites.

Keyword: Hormones & Behavior; Aggression
Link ID: 8836 - Posted: 04.27.2006

By Elizabeth Pennisi Politicians, teachers, and even grandmothers chatting on telephones routinely use rambling sentences full of internal asides. The ability to piece together phrases in different combinations provides unlimited communicative capacity and helps distinguish humans from other species. But this ability may not be as unique as once thought. Starlings, 21-cm tall, iridescent black songbirds native to Eurasia and North Africa, can understand similarly structured songs, according to a new study. There's no rule that a sentence must convey only a single bit of information--all we need do is make it "recursive" by embedding additional phrases and clauses. For example, "Some birds sing complex songs," becomes more informative when written "Some birds, those that advertise their suitability as mates, sing complex songs." Linguists have thought that only humans could build and understand such complex sentences. Birds, on the other hand, merely add notes to the beginning or end of any particular string of sounds. Timothy Gentner, a neuroscientist at the University of California, San Diego, now challenges this assumption. Genter's team trained starlings, accomplished singers and mimics, to recognize recursive patterns. The researchers composed 16 artificial starling songs consisting of different "warbles" and "rattles" from a live bird. After several months of training, 9 of 11 starlings had learned to peck a lever for a food reward when they heard recursive variations of the phrase "warble, rattle." © 2006 American Association for the Advancement of Science.

Keyword: Language
Link ID: 8835 - Posted: 06.24.2010

Routine ultrasounds show that heavy drinkers who continue to imbibe after learning they are pregnant may carry fetuses with reduced skull and brain growth compared to those of abstainers or quitters, says a new study. Although the alcohol-exposed babies' growth remained within normal range, the findings reveal effects of drinking on the developing human brain. The study will appear in the May issue of Alcoholism: Clinical and Experimental Research. "What this tells us is that the earlier you abstain in a pregnancy, the better the outcome," said lead author Nancy Handmaker, a University of New Mexico clinical psychologist with expertise in maternal-fetal health. Alcohol use during pregnancy is a leading preventable cause of birth defects and developmental disabilities in the United States, according to the Centers for Disease Control and Prevention. Fetal Alcohol Spectrum Disorder -- which includes a range of cognitive, emotional and behavioral problems -- may be present in as many as one of every 100 births. The study authors obtained routine ultrasound data from 167 pregnant women who had reported a history of hazardous drinking before pregnancy. Of these, 97 were classified as heavy drinkers. The study compared the fetal growth measures among drinkers who quit after learning of their impending motherhood to those among women who continued to drink.

Keyword: Drug Abuse; Development of the Brain
Link ID: 8834 - Posted: 04.27.2006

Roxanne Khamsi Widespread wishful thinking has left some US states with gross underestimates of their obesity rates, a new study suggests. People generally misreport their height and weight to paint a slimmer picture of themselves when answering health-survey questions by phone, say researchers. And as a consequence, obesity levels in some southern states have been underestimated by as much as 50%. “This study can make a serious contribution to help us get to grips with the obesity epidemic,” comments Morgan Downey, director of the American Obesity Association in Washington, DC. He adds that the findings have “enormous implications on the policy level”. An increasing number of people in the US and other parts of the globe are clinically obese. Generally, doctors consider people who have a body mass index (BMI) higher than 30 units as obese. The body mass index is defined the weight in kilograms divided by the square of the height in metres. More than 300 million adults around the world are obese according to the World Health Organization. Experts note that the rates of obesity differ drastically around the world – in some countries such as Japan it remains below 5% while in urban areas of Samoa it rises above 75%. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 8833 - Posted: 06.24.2010

Researchers have identified a protein that reins in the rogue activity of the molecules that make the amyloid-beta protein—which may prevent normal brain function in people with Alzheimer's disease. Their findings reveal a potentially powerful tool for designing novel Alzheimer's treatments. Amyloid beta-peptides are sticky, neurotoxic protein fragments that accumulate, kill nerve cells, and clump together to form the distinctive amyloid plaques in the brains of people with Alzheimer's disease. They are generated when a larger, normal protein called amyloid precursor protein (APP) is cleaved or split in a series of events. A protein complex called the presenilin complex is responsible for the final cleavage event. Presenilin complexes are thought to cause an unusual form of protein cleavage in which selected membrane proteins are split in a region that crosses cell membranes. This previously unrecognized form of protein cleavage is essential for several normal signaling processes. The same presenilin complex also generates amyloid-beta from APP. The presenilin cleavage that generates amyloid-beta may be a physiological process unrelated to signaling. In fact, it may just be a way to remove unneeded protein stubs from cellular membranes. © 2006 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 8832 - Posted: 06.24.2010

By STEPHANIE SAUL When GlaxoSmithKline began talking to Roche three years ago about commercializing the prescription diet drug Xenical, the timing could not have been better for Steven L. Burton. An executive with Glaxo's consumer heath care division, Mr. Burton had been overweight for years, carrying 270 to 275 pounds on his 6-foot-1 frame. Those measurements put him well into the "obese" category, a condition shared by 30 percent of American adults. And his doctor had just issued a stern warning to Mr. Burton. "I didn't think seriously about a serious weight-loss program until I had a couple of kids and I had a doctor who was telling me pretty bluntly that it was time to do something about my blood pressure and high cholesterol and weight for the sake of my kids," he said recently. "That's pretty motivating." Now Mr. Burton, 47, has the job of motivator in chief as Glaxo prepares to market an over-the-counter version of Xenical. During the last three years, while ramping up the marketing plans, he has been using the drug himself. And while he does not envision himself posing for the before and after shots in a diet ad, he can offer personal testimony to the drug's potential benefits. In his three years on Xenical, Mr. Burton said he has dropped to 210 pounds from 270, and kept it off. Copyright 2006 The New York Times Company

Keyword: Obesity
Link ID: 8831 - Posted: 04.26.2006

New research attempting to shed light on the evergreen question--just how do male and female brains differ?--has found that timing is everything. In a study involving over 8,000 males and females ranging in age from 2 to 90 from the across the United States, Vanderbilt University researchers Stephen Camarata and Richard Woodcock discovered that females have a significant advantage over males on timed tests and tasks. Camarata and Woodcock found the differences were particularly significant among pre-teens and teens. "We found very minor differences in overall intelligence. But if you look at the ability of someone to perform well in a timed situation, females have a big advantage," Camarata said. "It is very important for teachers to understand this difference in males and females when it comes to assigning work and structuring tests. To truly understand a person's overall ability, it is important to also look at performance in un-timed situations. For males, this means presenting them with material that is challenging and interesting, but is presented in smaller chunks without strict time limits." The findings are particularly timely, with more attention being paid by parents, educators and the media to the troubling achievement gap between males and females in U.S. schools. "Consider that many classroom activities, including testing, are directly or indirectly related to processing speed," the authors wrote.

Keyword: Sexual Behavior; Intelligence
Link ID: 8830 - Posted: 04.26.2006

EVANSTON, Ill. --- Two teams of researchers at Northwestern University have found a novel pathological hallmark of the neurodegenerative disease amyotrophic lateral sclerosis (ALS) at the molecular level. The neurologists and biochemists show how and why the mutated superoxide dismutase (SOD1) protein, which is associated with a familial form of ALS, becomes vulnerable and prone to aggregation and also provide evidence linking disease onset with the formation of intermolecular aggregates. The findings, which have implications for new therapeutics for the devastating disease, were published online this week in two related papers by the Proceedings of the National Academy of Sciences (PNAS). ALS is a progressive paralytic disorder caused by degeneration of motor neurons in the brain and spinal cord. The cause and development (pathogenesis) of the fatal disease are not known, and there is no effective treatment. Fifteen years ago, an international consortium led by Teepu Siddique, M.D., Les Turner ALS Foundation/Herbert C. Wenske Foundation Professor at Northwestern's Feinberg School of Medicine, mapped the first ALS gene to chromosome 21. Subsequently, they found that mutations in the SOD1 gene are responsible for 20 percent of familial (inherited) ALS cases. Siddique and his colleagues also made the first ALS transgenic mouse models. Although more than 100 types of a single mutation in the SOD1 gene have been identified and multiple lines of the mouse models developed, a key question remains to be answered: How does the genetic mutation alter this incredibly stable protein to make it so toxic that it kills motor neurons and causes neurodegenerative disease?

Keyword: ALS-Lou Gehrig's Disease
Link ID: 8829 - Posted: 04.26.2006

When kids try to do impossible things, like attempting to get into a tiny toy car, sit on a dollhouse chair, or slide down a miniature model of a playground slide, Judy DeLoache not only chuckles, she also investigates why. The psychology professor at the University of Virginia says toddlers treating scale models like full-sized objects is one of the most comical behaviors she and her colleagues observe at their Child Study Center. "They're funny, quite funny to watch, but we think that they also tell us something important about early development," says DeLoache, who is also a visiting professor at New York University. She says these errors are perfectly normal and occur most often in kids 18 to 30 months old. "It's a very vivid demonstration that things that are so fundamental to the behavior of adults or older children can really go dramatically awry when you've got a very immature brain underlying the behavior," she explains. As she wrote in Scientific American Mind magazine, learning to think symbolically — grasping the concept that one thing can represent another — is a challenge to young minds and a critical part of early brain development. © ScienCentral, 2000-2006.

Keyword: Development of the Brain; Language
Link ID: 8828 - Posted: 06.24.2010

Dartmouth researchers are learning more about the effects of alcohol on the brain. They've discovered more about how the brain works to mask or suppress the impact that alcohol has on motor skills, like reaching for and manipulating objects. In other words, the researchers are learning how people process visual information in concert with motor performance while under the influence of alcohol. "We found that the brain does a pretty good job at compensating for the effect that alcohol has on the brain's ability to process the visual information needed to adjust motor commands," says John D. Van Horn, a research associate professor of psychological and brain sciences and the lead author on the paper. "Alcohol selectively suppresses the brain areas needed to incorporate new information into subsequent and correct motor function." For the study, eight people, ranging in age from 21-25, were asked to maneuver a joy stick both while sober and when experiencing a blood alcohol level of 0.07 percent (just below the legal definition of intoxicated). Brain activity during this task was captured using functional magnetic resonance imaging, known as fMRI. The study was published online in the journal NeuroImage on March 6, 2006. © 2006 Trustees of Dartmouth College

Keyword: Drug Abuse
Link ID: 8827 - Posted: 06.24.2010

By Owain Bennallack Computer games have long been derided by critics as mindless, brain-rotting fun. But a new wave of games is turning the cliché on its head. Nintendo has sold nearly five million copies of its three Nintendo DS brain training games since the series launched in Japan a year ago. The first title in the series, Dr Kawashima's Brain Training: How Old Is Your Brain?, sees players follow a daily regime of brain-enhancing exercises and is due to be released in the UK in June. Dr Kawashima's Brain Training comprises a variety of mini-games designed to give brains a workout. Activities include solving simple maths problems, counting people going in and out of a house, drawing pictures on the Nintendo DS touchscreen, and reading classic literature aloud into the device's microphone. Players are given a brain age reflecting their performance. Over time, your brain age should get younger as you achieve better scores. Dr Kawashima's Brain Training has sold some 1.8 million copies, and it is still in the Japanese top 10 a year after release. But the brain training games' success is down to more than just a neat gameplay gimmick. Unlike Nintendo's fictional creations, such as Donkey Kong or Mario, Dr Kawashima really is a leading Japanese brain expert. A graduate of the Tohuku University School of Medicine, Dr Kawashima works at the same university's New Industry Creation Hatchery Centre, and is one of the country's top researchers into brain imaging. He is also a best-selling author. His two books on brain training have sold more than a million copies in Japan. (C)BBC

Keyword: Intelligence
Link ID: 8826 - Posted: 04.25.2006

By Margaret Webb Pressler Alex Perez, 2 1/2 , stared blankly as his mother pushed his little limbs into his blue footie pajamas. Alex had spent the afternoon running around the play area at a local mall and had been allowed only a short nap, so he was good and tired -- just the way his parents wanted him. For the next 40 minutes, the boy sat nearly motionless, watching a cartoon of "The Three Musketeers," as 14 electrical sensors on long wires were taped to his legs, chest, neck, temples, cheeks and scalp. "I can't believe how good you're being, Alex," his mother, Yolanda Rodriguez, cooed at him. Alex fell asleep before the connections were finished, his eyelids closing improbably as two grown-ups hovered over him. For the rest of the night, he slept attached to the mass of rainbow-colored wires, while technicians with computers in another room monitored his respiratory, neurological and physical activity throughout the night. Yolanda Rodriguez had been waiting for this night for months. She wanted to know why her youngest son snores so loudly, wakes constantly throughout the night, is always congested, gets repeated ear infections and has delayed speech. His sleep problems have ruled her life almost since he was born. © 2006 The Washington Post Company

Keyword: Sleep; Development of the Brain
Link ID: 8825 - Posted: 06.24.2010

Sarah E. Igo World As Laboratory: Experiments with Mice, Mazes, and Men. Rebecca Lemov. vii + 291 pp. Hill and Wang, 2005. $30. What do two-headed worms, laboratory experiments on babies, miniature mazes, thinking machines, "coercive stimuli," remote-controlled cats and military-sponsored anthropologists have in common? Each, according to Rebecca Lemov, was a key instance in the service of a 20th-century idea: If one could quantify and control the internal arena of the personal self—its urges and wants, its worries and fears—then the running of a modern society would require less brute external force. In the long term, putting this idea into practice would make it possible to regulate human beings in tune with the needs, demands, desires, and models of the social order, so that people would want to do whatever they were instructed to do (for example, to die for one cause, shop for another . . .). Lemov, an anthropologist by training, delves into the history of this idea, from its origins in the agricultural hybrids of Luther Burbank at the turn of the century to its expression in behaviorist psychology in the first three decades of the 20th century and eventually to the most disturbing and science fiction-like scenarios, of which Stanley Milgram's 1961 "obedience to authority" experiments, wherein the social scientist easily convinced laboratory subjects to administer electrical shocks to total strangers, are only the best known. © Sigma Xi, The Scientific Research Society

Keyword: Learning & Memory
Link ID: 8824 - Posted: 06.24.2010

By Katherine Unger Plaque on the brain doesn't sound good, but the condition may not be as crippling as once thought. Mice with the gummy deposits-- usually a symptom of Alzheimer's disease--can still have normal memories, according to a new study. The findings suggest a novel target for Alzheimer's drugs and a new way of understanding how the disease ravages the brain, say the researchers. Alzheimer's is thought to be caused in part by sticky build up of a toxic peptide called â amyloid, produced when the amyloid precursor protein (APP) is cut in two. Recent research, however, has shown that early signs of the disease are present even before these plaques show up in the brain. When APP is cut at another point, a different protein, called C31, is released. It too has toxic properties, but until now, its role in Alzheimer's has been a mystery. Neuroscientists led by Veronica Galvan and Dale Bredesen of the Buck Institute for Age Research in Novato, California, decided to examine what would happen when mice were prevented from making C31. They used a strain of mice that gets Alzheimer's-like symptoms and bred them so that APP couldn't be cut into C31. Although the animals could still make â amyloid and plaques, other signs of Alzheimer's were absent. For one, their brains were a normal size and contained a higher density of neuronal synapses compared to the shrunken brains of C31-producing mice. And they did twice as well on a standard test for memory in mice, the researchers report online this week in Proceedings of the National Academy of Sciences. © 2006 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 8823 - Posted: 06.24.2010

Men become more jealous of dominant males when their female partner is near ovulation, researchers at the University of Liverpool have found. Previous studies have found that women's preferences for male physical appearance vary according to their fertility status. During ovulation women tend to find masculine looking men more attractive and prefer their voices and odour. During this fertile phase women are more likely to have an affair with a masculine-looking man, as their features are linked to high testosterone levels, demonstrating good genetic qualities that can be passed on to offspring. New research at the University has found that men sense this preference shift in their female partners and find masculine men more threatening during their partner's most fertile phase. Rob Burriss and Dr Anthony Little, from the University's School of Biological Sciences, also found that men only behave in this way if their female partner does not use oral contraception – and is therefore more fertile. Images of male faces that were either high or low in dominant features, such as a strong jaw lines and thinner lips, were shown to male participants who provided ratings of dominance for each image. A dominant person was defined as someone who looked like they could 'get what they wanted'.

Keyword: Sexual Behavior
Link ID: 8822 - Posted: 06.24.2010

Many patients with Parkinson's Disease get worse when they are admitted to hospital, research suggests. Parkinson's Disease Society survey of 210 nurse specialists suggests patients have problems as a result of their stay as medication is missed or delayed. Not one, of the 40% of Parkinson's Disease nurse specialists across the UK who responded, said patients' medicines were guaranteed to be given on time. The Department of Health said patients missing medication was unacceptable. We want all hospitals to immediately implement the standards laid down by the Department of Health for medicines management Parkinson's Disease patients have a shortage of the brain chemical dopamine, which controls connections between nerve cells, leading to symptoms such as tremors. They rely on a number of drugs that are tailored and timed to their particular needs. These stimulate a complex and carefully timed release of chemicals in the brain and control movement Without these, a person may become very ill and may suddenly not be able to move, get out of bed or walk down a corridor as they could if they were receiving their drugs on time. Bowel and kidney function can become disturbed and digestion, mood and sleep can also be affected. Some patients will experience severe hallucinations. Once this careful balance of chemical has been upset it can take days or even weeks for the patient to stabilise enough to be able to get on with their life again. Nine out of 10 specialists surveyed by the society said patients experienced clinical problems or unnecessary long hospital stays as a result of missed medication. (C)BBC

Keyword: Parkinsons
Link ID: 8821 - Posted: 04.24.2006

The individual cells responsible for responding to sensory inputs--the strong scent of a flower, the light touch of a spring breeze--can cope with only a small amount of input. Yet the human ear can hear and process sounds ranging from a pin drop to the roar of a jet engine. Scientists have struggled to account for how this individually narrow range combines in a network to produce the wide range of sensed experience. Now physicists have shown how the mathematical models that describe phase transitions in physical systems might also explain our capacity to hear, see, smell, taste and touch. Mauro Copelli and Osame Kinouchi of the University of Sao Paulo in Brazil used a mathematical formula to show how a random network of "excitable elements," such as neurons or axons, have a collective response that is both exquisitely sensitive and broad in scope. When subtle stimuli hit the network, sensitivity is improved because of the ability of one neuron to excite its neighbor. When strong stimuli hit the network, the response is similarly strong, following what are known as power laws--mathematical relationships that do not vary with scale. But although a mathematical model seems to fit a natural phenomenon it does not necessarily follow that the two are actually related, according to some scientists. In a paper published last September in BioEssays, Evelyn Fox Keller of the Massachusetts Institute of Technology explained that just because mathematical models help explain physical systems, like the density of a gas, it does not mean that they also apply to biological systems, even if they seem to fit. "Fitting available data to such distributions is suspiciously easy," she wrote. "Even when the fit is robust, it adds little if anything to our knowledge of the actual architecture of the network." © 1996-2006 Scientific American, Inc.

Keyword: Vision; Hearing
Link ID: 8820 - Posted: 06.24.2010

A scientific paradox linking artificial sweeteners such as saccharin with a sensory experience in which plain water takes on a sweet taste has guided researchers to an increased understanding of how humans detect sweet taste. Reporting in an advance online publication in Nature, scientists from the Monell Chemical Senses Center describe how certain artificial sweeteners, including sodium saccharin and acesulfame-K, paradoxically inhibit sweet taste at high concentrations. The researchers further report that taste perception switches back to sweetness when these high concentrations are rinsed from the mouth with water, resulting in the aftertaste experience known as sweet 'water taste.' The Nature article describes the phenomenon of sweet 'water taste' and then goes on to explain it at the level of the sweet taste receptor. "These findings will open doors for tweaking the sweet taste receptor and finding new sweeteners and inhibitors that can be used both by food industry and in medicine," states senior author Paul A.S. Breslin, PhD, a Monell geneticist. Lead author Veronica Galindo-Cuspinera, PhD, noted while working on a separate study that saccharin – commonly used at low concentrations as an artificial sweetener – loses its initially sweet taste when tasted at high concentrations. Galindo-Cuspinera subsequently observed that strong sweetness returned when the high concentrations of saccharin were rinsed from the mouth with water.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8819 - Posted: 06.24.2010