Roxanne Khamsi Exposure to ultrasound while pregnant may affect brain development in the fetus, suggests a study on mice. But experts caution that it is too soon to extrapolate the findings to humans. They stress that the imaging technique has overwhelming benefits and pregnant women should not skip essential appointments. The experiment involved using a chemical to trace brain cells in growing mouse embryos. The researchers exposed the embryos to ultrasound shortly afterward, late into the third week of gestation, a crucial period for mice in which brain cells become organised. Dissections following the birth of the mice showed that a small percentage of brain cells had not migrated to their normal place. For example, 6% of the chemically tagged brain cells had not migrated normally in mice exposed to two 30-minute ultrasound sessions. It may be that the ultrasound waves somehow disrupt the connections formed between cells as they move into their proper location, suggests Pasko Rakic at Yale Medical School in New Haven, Connecticut, US, who carried out the research with colleagues. Rakic says the brains of these mice still appear healthy to the naked eye. Moreover, his team has not yet tested to see whether the mice have abnormal mental abilities. And he notes that the source of the ultrasound waves remained constant, which could have increased the risk of disrupting the cells, unlike in the checkups on female patients where medical staff continuously move the ultrasound source. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Brain imaging
Link ID: 9214 - Posted: 06.24.2010

People who make irrational decisions when faced with problems are at the mercy of their emotions, a study says. Researchers traced the origin of such decisions to the brain's emotion centre, the amygdala, in a study of 20 people using a gambling game. That brain region fires up in people faced with a difficult situation but reactions to its effects vary, the University College London team found. The study findings were published in the Science journal. The researchers found some people kept a cool head and managed to keep their emotions in check, while others were led by their emotional response. In each trial, participants motivated by the promise of real money were first offered a starting amount of £50. They were then presented with one of two "sure option" choices, either to "keep £20", or to "lose £30", as well as the opportunity to take an all-or-nothing gamble. Although both sure options left players with the same amount of cash, £20, people were more likely to gamble when faced with the prospect of losing £30. Given the "keep £20" option, volunteers played it safe and gambled only 43% of the time. When asked if they wanted to "lose £30", they gambled on 62% of occasions. The decision to gamble was irrational, since in every case the amount of money they stood to gain was the same, while everything could be lost by gambling. Brain scans revealed that the amygdala fired up when subjects either chose to keep a sure gain or decided to gamble in the face of certain loss. The brain region, which controls emotion and plays a role in the "fight or flight" reaction to perceived threats, appeared to be pushing people to keep sure money, or to gamble instead of losing. (C)BBC

Keyword: Emotions
Link ID: 9213 - Posted: 08.07.2006

By Tony Dajer "Grandpa fell on knee. Two days before. Pain," the young woman said. Her wizened grandfather dozed on a stretcher. "How are you, sir?" I inquired softly. In loud Cantonese, the granddaughter repeated the question. She smiled apologetically. "No hear good." His eyes fluttered open. When I palmed his right knee, he winced. The joint was swollen, the kneecap scuffed, but he didn't complain when I bent his knee. With the help of an interpreter, I learned that he tripped on his way to the bathroom two days ago. "No dizziness? No passing out? Didn't hit his head?" I asked. A yes to any of these questions would suggest more serious heart or neurological problems. "No," the granddaughter replied. "Only tripped." "He feels OK now?" "OK," she echoed. The rest of his physical exam, except for weakness on his right side due to a previous stroke, was pretty darn good for an 85-year-old man. © 2005 Discover Media LLC.

Keyword: Stroke
Link ID: 9212 - Posted: 06.24.2010

By STEVE HARTSOE RALEIGH, N.C. -- Scheduling surgery earlier in the day may help prevent unexpected problems related to anesthesia, including added pain and postoperative nausea and vomiting, according to a study conducted at Duke University. Researchers at Duke University Medical Center analyzed more than 90,000 surgeries performed at the hospital between 2000-2004. The study, which appears in the August issue of the journal Quality & Safety in Health Care, found that patients whose surgeries began around 4 p.m. were about four times more likely to request pain medication than those whose surgeries started around 9 a.m. "What I think this study will do, and what it should do, is stimulate additional research," said Dr. James Hicks, of Portland, Ore., a director with the American Society of Anesthesiologists. "It will give us a direction to go." Researchers analyzed a database maintained by the hospital that contains a record of each surgical patient's course of treatment from hospital admission to discharge, including adverse events. The researchers divided the problems they found into three categories: "error," "harm," and "other adverse events." The 31 incidents researchers placed in the "error" category included improper dosing of patients with anesthetic agents. © 2006 The Associated Press

Keyword: Biological Rhythms
Link ID: 9211 - Posted: 06.24.2010

Jacquie van Santen The soft and elusive velvet worm might look like a pretty caterpillar. But its brain is strikingly similar to that of a spider, new international research shows. The architecture of the worm's brain has more in common with a spider's brain than with the brains of other arthropods, researchers report in the journal Proceedings of the Royal Society B: Biological Sciences. Velvet worms have a body formation between that of a worm and an insect and for many years scientists believed they were the 'missing link' between the two. This view was supported not only by the way they look, but also by the fact that they date back 540 million years. Researchers including Associate Professor David Rowell from the Australian National University in Canberra were interested in finding out whether this was true. They found out that the worms were indeed a sister group of the arthropods and shared common ancestry. The team catalogued aspects of the microanatomy of various arthropod brains and then loaded the information into a computer program designed to sort out molecular lineages and create a 'family tree'. ©2006 ABC

Keyword: Evolution
Link ID: 9210 - Posted: 06.24.2010

Depression, coordination and speech problems, muscle weakness and disability are just a few of the symptoms of Multiple Sclerosis (MS). Researchers from the Mouse Biology Unit of the European Molecular Biology Laboratory (EMBL) in Italy and the Department of Neuropathology at the Faculty of Medicine, University of Göttingen, Germany, have now discovered that these symptoms are aggravated by a specific signal in cells in the nervous system. The study, which will appear in this week's online issue of Nature Immunology, suggests that blocking the proteins that regulate the signal might be an efficient strategy for new therapies against MS. Nerve cells in our brain and spinal cord communicate with each other using electrical signals. This communication is fast and efficient because - just like wires in an electrical circuit - the axons of our nerves are surrounded by an insulating layer. In MS this protective sheath, made up of a mixture of lipids and proteins called myelin, gets destroyed by cells of our own immune system, and the communication between nerve cells gets disrupted. A central player in the molecular mechanisms behind MS is a signaling molecule called NF-kB. "We have known for a long time that NF-kB is crucially involved in MS," says Manolis Pasparakis, a former Group Leader at EMBL's Mouse Biology Unit who now works as a Professor at the Institute for Genetics at the University of Cologne, "but until now it was not clear if it was friend or foe. We were not sure whether it protects the brain cells against the consequences of the disease or actually aggravates the damage."

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 9209 - Posted: 06.24.2010

by Lydia Fong Close your eyes and think about the word "potato." Okay, open them. Now, close your eyes and think about the word "wicket." Chances are you took a little longer with the second one—it's a small door or gate, in case you were drawing a complete blank. If you were asked to recall these two words tomorrow, according to new research from Carnegie Mellon University, chances are you'd be quicker to remember the first. Asking a group of subjects who were experiencing temporary, drug-induced amnesia to perform similar exercises, the Carnegie Mellon team attempted to determine how we form new memories. They found that the process comes down to our ability to link new information to prior experiences: In the case of the introductory example, the average person has probably had more practice eating potatoes than climbing through wickets. "One's ability to associate something to a context depends on it being a 'chunk' or unit," said psychologist Lynne Reder, lead author of the study, which appears in the July issue of Psychological Science. © Copyright 2006 Seed Media Group, LLC.

Keyword: Learning & Memory
Link ID: 9208 - Posted: 06.24.2010

Researchers have discovered that the part of the brain known as the amygdala, which is involved in emotional and social processing, is abnormally large in young autistic children. What's more, it reaches adult size far sooner than it would in non-autistic peers, despite containing fewer neurons than normal amygdalae. "The amygdala has been implicated in a variety of different functions, probably most commonly in fear," said David Amaral, a neuroscientist at the University of California, Davis and a co-author of the new report, which appeared in the July 12 issue of The Journal of Neuroscience. "If you look at lots of individuals with autism, one of the prevalent features is anxiety. It's likely that the abnormal amygdala would probably participate in these abnormal fears." Amaral and his colleague Cynthia Schumann measured and counted the neurons in the post-mortem amygdalae of nine autistic males and 10 normal males. They found that while the neurons were the same size across both groups, the males with autism had far fewer neurons in their amygdalae. A normal structure averaged 12 million neurons, Amaral said, while those of the autistic males had just 10.5 million. He added that it's unlikely that all kids with autism have amygdala abnormalities or even that such abnormalities would account for the broad spectrum of autism's effects. © Copyright 2006 Seed Media Group, LLC.

Keyword: Autism
Link ID: 9207 - Posted: 06.24.2010

By Brandon Keim When Rene Descartes said, "I think, therefore I am," the philosopher probably didn't imagine a stamp-sized clump of rat neurons grown in a dish, hooked to a computer. For years, scientists have learned about brain development by watching the firing patterns of lab-raised brain cells. Until recently, though, the brains-in-a-dish couldn't receive information. Unlike actual gray matter, they could only send signals. Scientists at the Georgia Institute of Technology figured they could learn more from neuron clumps that acted more like real brains, so they've developed "neurally controlled animats" -- a few thousand rat neurons grown atop a grid of electrodes and connected to a robot body or computer-simulated virtual environment. In theory, animats seem to cross the line from mass of goo to autonomous brain. But Steve Potter, a neuroscientist and head of the Georgia Tech lab where the animats were created, said his brain clumps won't be reciting French philosophy anytime soon. "Our goal is not to get something as conscious as a person," he said. "We're studying basic mechanisms of learning and memory." The researchers are focusing on how groups of individual cells interact and change when stimulated. © 2006 CondéNet Inc.

Keyword: Robotics
Link ID: 9206 - Posted: 06.24.2010

By Briahna Gray Most people can relate to the adage "beauty is pain," having suffered through a taxing diet or a grueling gym workout. But the male northwestern song sparrow takes things a step further. According to a new study, he's willing to risk a prolonged illness just to look good for the ladies. Noah Owen-Ashley, a wildlife biologist with the Alaska Department of Wildlife Management in Barrow, hit upon the theory while trying to learn more about how birds behave when they're sick. Scientists have made birds feel ill in the lab by injecting them with bacterial lipopolysaccharide (LPS)--a compound that induces "sickness behaviors" such as reduced appetite and less frequent interaction with other birds. Owen-Ashley was curious whether birds in the wild would respond in the same way. Using nets and a caged bird decoy with prerecorded bird song, Owen-Ashley and his team captured 30 male song sparrows in western Washington State in the spring and fall of 2001. The team injected half of the birds with LPS and the other half with saline. The researchers then let the birds go and recaptured them 24 hours later (leg bands indicated which birds had received which injection). © 2006 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Neuroimmunology
Link ID: 9205 - Posted: 06.24.2010

Eric Jaffe A statistical analysis of four national intelligence tests indicates that the difference in scores between blacks and whites decreased by about a third between 1972 and 2002. The findings challenge a century-old argument that the racial gap in performance on IQ tests is primarily genetic and therefore invulnerable to social change, say the researchers who performed the new study. They examined data that have only recently become available to researchers, says William Dickens of the Brookings Institution in Washington, D.C. Using test results from a random distribution of people in the United States, he and James R. Flynn of the University of Otago in New Zealand tallied the increases in IQ scores of blacks and whites over 3 decades. Each of the four tests analyzed included two or three groups of people that took the test at different times. Previous measures of the intelligence gap, which had used localized populations tested only once, found blacks 15 to 18 IQ points lower than whites, Dickens says. In the new analysis, all four tests reflected a similar gap in 1972 but indicated that blacks have since gained ground in IQ. "The whole distribution of black cognitive ability is moving up relative to whites," says Dickens. "There's no reason to believe [the gap] isn't going to get more narrow as we move forward and as measures of social equality continue to improve." ©2006 Science Service.

Keyword: Intelligence; Genes & Behavior
Link ID: 9204 - Posted: 06.24.2010

A method to predict a middle-aged person's chance of developing dementia has been devised by scientists. The test calculates risk by assessing factors such as blood pressure level, body mass index and cholesterol levels, along with age and education. The work, published in the journal Lancet Neurology, is based on a Finnish study that revealed several midlife risk factors were linked to dementia. A high-risk result, said the team, could encourage lifestyle changes. The scientists used data from the Cardiovascular Risk Factors, Ageing and Dementia study. This research assessed 1,409 middle-aged people from Finland and then looked at them again 20 years later for signs of dementia, including Alzheimer's disease and vascular dementia. Scientists discovered that along with the known risk factors of age and a low-level of education, high blood pressure, high cholesterol and obesity also meant people had a higher chance of suffering from dementia. Using these results, the team developed a score-based system to predict the likelihood of a middle-aged person developing dementia in later life. Lead researcher Miaa Kivipelto, from the Aging Research Center, Karolinska Institute in Sweden, said: "The idea is to have a simple tool to predict the risk for diseases, like you have for cardiovascular diseases or diabetes. "But for dementia there has been nothing like this. The idea to put this information together and have an overall estimation for dementia risk is new." The predictive test takes information about age, number of years spent in education, sex, body mass index, blood pressure level, cholesterol level, physical activity and genetic factors and assigns each with a risk score related to their association with dementia. (C)BBC

Keyword: Alzheimers
Link ID: 9203 - Posted: 08.03.2006

By ANAHAD O’CONNOR THE members of the swim team at Bloomington High School South in central Indiana cheer wildly every time Nathan Buffie races. In his two years on the team, Nathan has never won first place at a meet. Often, he finishes far behind. But it is the fact that Nathan even goes into the water and manages to compete at all that his teammates find so remarkable. Nathan, a trim 16-year-old with a boyish smile, has autism, the devastating developmental disorder that makes his participation in any sport or social activity a struggle. “He is probably the worst swimmer on the team, but he keeps getting better and he wants to win,” said his mother, Penny Githens. “He tells his teammates this, and they just get so excited for him.” For years, children with autism were left on the sidelines, a consequence of a widespread belief that they were incapable of participation in athletics. But while it is true that autistic children can be difficult to motivate and resistant to exercise, they are now being pushed to take part in physical education programs, encouraged by experts who say that certain sports can ease repetitive behaviors like pacing and head-banging as well as provide a social outlet. Copyright 2006 The New York Times Company

Keyword: Autism
Link ID: 9202 - Posted: 06.24.2010

Armand Leroi Travel the Grand Trunk Road between Lahore and Islamabad, and you come to the city of Gujrat. Awash in the smog and sewage produced by its million-odd inhabitants, it is an unlovely place best known for the manufacture of electrical fans. It is also the location of a shrine to a 17th-century Sufi Saint by the name of Shua Dulah. For at least 100 years, but perhaps for centuries, it has been, though is no longer, a depository for children with microcephaly. The word "microcephaly" comes from the Greek, "small head". But in Pakistan, such children are known as chuas or "rat people". The name is uncharitable but apt, for their sloping foreheads and narrow faces do, indeed, have a rodent quality. When I visited the shrine earlier this year, I found only one chua, a 30-year-old woman called Nazia. Mentally disabled - I would judge her intelligence to be about that of a one- or two-year-old child - her nominal function is to guard the shoes that worshippers leave at its entrance, but that work seems to be mostly done by her companion, a charming hypopituitary dwarf called Nazir. These days, most chuas are intinerant beggars. Travelling up and down the Grand Trunk Road, following a seasonal calender of religious festivals. Each chua is owned, or perhaps leased, by a minder, often a raffish, gypsy-like figure. The Chua-master looks after, and profits from, his chua rather as a peasant might a donkey; together, they may earn as much as 400 rupees per day, about £4. Most people I asked supposed that there are about 1,000 chuas in the Punjab, but no one really knows. © Copyright of Telegraph Group Limited 2006. |

Keyword: Genes & Behavior; Development of the Brain
Link ID: 9201 - Posted: 06.24.2010

Neurobiologists have known that a novel environment sparks exploration and learning, but very little is known about whether the brain really prefers novelty as such. Rather, the major "novelty center" of the brain--called the substantia nigra/ventral tegmental area (SN/VTA)--might be activated by the unexpectedness of a stimulus, the emotional arousal it causes, or the need to respond behaviorally. The SN/VTA exerts a major influence on learning because it is functionally linked to both the hippocampus, which is the brain's learning center, and the amygdala, the center for processing emotional information. Now, researchers Nico Bunzeck and Emrah Düzel report studies with humans showing that the SN/VTA does respond to novelty as such and this novelty motivates the brain to explore, seeking a reward. The researchers of University College London and Otto von Guericke University reported their findings in the August 3, 2006, issue of Neuron, published by Cell Press. In their experiments, Bunzeck and Düzel used what is known as an "oddball" experimental paradigm to study how novel images activate the SN/VTA of volunteer subjects' brains. In this method--as the subject's brains were scanned using functional magnetic resonance imaging--they were shown a series of images of the same face or outdoor scene. However, the researchers randomly intermixed in this series four types of different, or "oddball," faces or scenes. One oddball was simply a different neutral image, one was a different image that required the researchers to press a button, one was an emotional image, and one was a distinctly novel image. In fMRI, harmless radio signals and magnetic fields are used to measure blood flow in brain regions, which reflects activity in those regions.

Keyword: Learning & Memory; Attention
Link ID: 9200 - Posted: 08.03.2006

Tracy Staedter, Discovery News —A computer with thousands of microprocessors is being built to mimic and model the function of millions of nerve networks in the brain. The Spinnaker — short for "spiking neural network architecture" — system will not only help scientists better understand the complex interactions of brain cells, but it could also lead to fault-tolerant computers that, like the brain, work despite malfunctions in tiny circuits. "You lose one neuron per second during your adult life. As they die, there doesn't seem to be any gross underperformance in the brain," said Steve Furber of the University of Manchester in the U.K., leader of the Spinnaker project. The idea, said Furber, is to mimic that kind of biological robustness in components of future electronic devices — which, as they inevitably shrink to smaller and smaller sizes, are likely to experience more and more failures. But understanding how brains achieve such resilience is still a great mystery. Scientists frequently use technologies such as functional magnetic resonance (commonly known as MRI) to image regions of the brain, and can probe to acquire an even finer picture of specific cellular networks. © 2006 Discovery Communications Inc.

Keyword: Robotics
Link ID: 9199 - Posted: 06.24.2010

Tom Simonite SOMETIMES all it takes is a quick hug, and everything looks different. Now a shape-shifting lens has been developed that alters its focal length when squeezed by an artificial muscle, rather like the lens in a human eye. The muscle, a ring of polymer gel, expands and contracts in response to environmental changes, eliminating the need for electronics to power or control the devices. "The lenses harness the energy around them to control themselves," says lead researcher Hongrui Jiang at the University of Wisconsin-Madison, US, where the device has been developed (Nature, vol 442, p 551). "This would be useful for environments where it's not easy to use electronics and conditions are not constant." The devices could simplify medical imaging equipment and biosensors, he says. "The lenses harness the energy around them to control themselves"The lenses themselves, which are around 4 millimetres in diameter, use a glass-oil-water interface (see Diagram). The artificial muscle encloses the watery side of the lens. The gel expands or contracts in response to environmental changes such as a rise in temperature, forcing the water to bulge into the film of oil. This changes the lens's shape and thus its focal length. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 9198 - Posted: 06.24.2010

Nicotine replacement therapy (NRT) may be less effective at weaning smokers off their habit than previously thought, researchers say. A University of Geneva team looked at studies of 4,800 adults and found 30% of those who had used NRT were smoking again a year or more after quitting. The problem, the researchers say, is that earlier studies have failed to follow up smokers in the long-term. This latest study appears online in the journal Tobacco Control. The researchers say the evidence for existing treatment guidelines has mostly been based on the impact of a single course of NRT treatment after six to 12 months. This, they argue, fails to take account of the substantial numbers of people who revert to smoking at a later date. The Geneva team analysed trials assessing the effect of NRT on a total of almost 4,800 adults. They found relapse rates were fairly consistent. Between the one-year milestone and subsequent check-ups, almost a third (30%) of those using NRT resumed smoking. The effectiveness of NRT fell from 10.7% of smokers quitting, compared with those given dummy treatment, at one year to 7.2% at an average of four years later. Most people relapsed within the first two years of a single course of treatment. Those who made it beyond that point, tended to substantially cut their chances of starting smoking again. The aim of NRT is to wean smokers off tobacco for good, or for sufficient time to confer a substantial health gain. Bearing this in mind, the researchers argue, the effect of NRT is "modest". (C)BBC

Keyword: Drug Abuse
Link ID: 9197 - Posted: 08.02.2006

The higher risk of schizophrenia among offspring of expectant mothers living through famine could help us understand the genetic basis for that debilitating mental disorder, a group of researchers argue in a commentary piece in the Aug. 2 issue of JAMA. The finding also supports a theory of medical genetics in which diseases and conditions can be caused by hundreds of different genetic mutations in any number of human genes. Epidemiologists have studied two major famines in the 20th century: the Dutch Hunger Winter of 1944-45, which was brought about by the Nazi occupation in World War II; and the Chinese famine in 1959-61, a consequence of the failed Great Leap Forward. During both famines, birth rates dropped precipitously. In addition, among children born to women who were pregnant during the famine, the incidence of schizophrenia increased two-fold. The expectant mothers were not receiving enough folate and other vital micronutrients during the famine, researchers believe, and that deficiency caused new genetic mutations to appear at exceptionally high rates. New mutations in genes related to brain function could lead to development of schizophrenia "Folate has a major role in genetic processes -- gene transcription and regulation, DNA replication, and the repair of damaged genetic information," explained co-author Dr. Jack McClellan, an associate professor of psychiatry at the University of Washington and medical director of the Child Study and Treatment Center in Tacoma, Wash. "If folate is missing from a mother's diet, that could lead to genetic mutations in the developing fetus."

Keyword: Schizophrenia
Link ID: 9196 - Posted: 08.02.2006

Treating major depression can be quite a puzzle, and a newly published UCLA study suggests medication is just one of many potential pieces. Published in the August 2006 edition of the American Journal of Psychiatry, the study used electroencephalogram (EEG) measurements to demonstrate an association between eventual clinical outcome and regional changes in brain activity during a placebo lead-in phase prior to antidepressant treatment. The findings suggest that factors such as patient beliefs and expectations, doctor-patient relationships, or treatment history help complete the treatment picture. In this study, all subjects received blinded treatment with placebo for one week prior to receiving antidepressant medication. A "placebo lead-in" phase is commonly used to familiarize patients with study procedures and to minimize the effect of any pre-existing treatment for depression. The placebo lead-in includes patient care, participation and treatment with placebo; the clinical impact is largely unknown. This study is the first to assess the relationship between brain changes during the placebo lead-in phase and later clinical outcome of antidepressant treatment. "Treatment results appear to be predicted, in part, by changes in brain activity found during placebo lead-in--prior to the actual use of antidepressant medication," said lead author Aimee M. Hunter, a research associate at the Semel Institute for Neuroscience and Human Behavior at UCLA.

Keyword: Depression
Link ID: 9195 - Posted: 08.02.2006