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

By Gretchen Vogel The body's internal clock is set by both light and food signals--that's one reason doctors recommend fighting jetlag with sunlight and regular meals. But just how these signals dictate our circadian rhythms is still being sorted out. In this week's online edition of Proceedings of the National Academy of Sciences, scientists report that they have identified the region of the brain that seems to adjust a body's circadian clock in response to food. If confirmed, the find might help scientists explain a little-understood connection between obesity and late-night eating. Mice are nocturnal animals, sleeping much of the day and feeding and moving around at night. But when researchers offer food only during daylight hours, the animals quickly switch their day-night patterns, sleeping more in the dark and exploring and eating when it's light. These patterns persist even when the brain's main clock-setting area, the suprachiasmatic nucleus (SCN), is damaged or destroyed. Therefore, scientists have been searching for what they call a food-entrainable oscillator, a region of the brain that sets daily rhythms in response to food. To find the region, geneticist Masashi Yanagisawa and his colleagues at the University of Texas Southwestern Medical Center in Dallas looked at gene-expression patterns in two groups of mice. One group had been trained to expect food only during the day; the other could eat any time they were hungry. The researchers found that, in the day-eaters, the levels of a clock gene called mPer1 oscillated in a strong daily pattern in a brain region called the dorsomedial hypothalamic nucleus (DMH), which doesn't normally do that. The gene expression in the SCN, however, looked normal. When mice are fed during the day, says Yanagisawa, DMH hijacks the SCN signals, making food the primary arbiter of the circadian clock. © 2006 American Association for the Advancement of Science

Keyword: Biological Rhythms; Obesity
Link ID: 9194 - Posted: 06.24.2010

WEST LAFAYETTE, Ind. —Mice that couldn't be dissuaded from the object of their attention by a piece of sweet, crunchy cereal may help researchers find new treatments and cures for human disorders like autism and Parkinson's disease. For the first time, a psychiatric test for monitoring many human mental abnormalities has been adapted for use in mice, according to researchers at Purdue University, University of California-Davis and Justus-Liebig University in Giessen, Germany. The test involves the ability to switch attention from one task to another, a skill often impaired in people with autism and similar illnesses. "Without a measure of cognitive deficit in mice that is relevant to such disorders in humans, research into new diagnostic methods, treatments and cures is severely hindered," said Joseph Garner, a Purdue assistant professor of animal sciences and the study's lead author. "The level of complexity at which we assess mouse behavior is often very rudimentary, and it just does not match up with subtleties of the cognitive deficits in human mental dysfunction or with the tools we use to study the mechanisms that underlie disorders in people." Garner and his colleagues designed a task to measure a process called set shifting in which a focus on one object must be abandoned in favor of another object or task. This test long has been used to monitor brain processes involved in human psychiatric disorders and also has been tailored to a few other animals. However, researchers previously had not adapted it to the most-used of research mammals, the common laboratory mouse.

Keyword: Autism; Parkinsons
Link ID: 9193 - Posted: 06.24.2010

Michael Hopkin A survey of primate IQ has cemented apes' reputation as our most intelligent cousins. An analysis of a slew of studies designed to spot smartness has concluded that orang-utans and chimps are the chief eggheads, with monkeys and lemurs trailing in their intellectual wake. The study has produced a league table of overall cognitive ability among primates. Previous research had attempted to compare different primates' abilities at specific tasks, but no one had ever combined this data into an overall measure of intelligence. The researchers compiled results from dozens of problem-solving puzzles given to different types of primates by researchers. These included tests of ability to navigate mazes, to untangle a jumble of differently coloured threads to find food, and to spot the odd-one-out in a series of images. They ranked each species and calculated the overall average intelligence of each. Orang-utans emerged at the top of the heap, just edging out chimpanzees. Both species share a prodigious ability to use tools and impart traditional wisdom to their young. "Orang-utans are more patient and deliberative," says Robert Deaner, who led the research while at Duke University Medical Center in Durham, North Carolina. "And they're the master escape artists from zoos." ©2006 Nature Publishing Group

Keyword: Intelligence; Evolution
Link ID: 9192 - Posted: 06.24.2010

Michael Day Smoking marijuana at the time of conception could cause pregnancies to fail, new research in mice suggests. The same problem may occur as a result of taking the slimming drug, rimonabant. The warnings come from embryologists who have discovered key factors that govern an embryo’s chances of successful implantation. After fertilisation in humans and mice, the egg faces a perilous path from the place of conception in the fallopian tube down into the womb. The team from Vanderbilt University Medical Centre, Tennessee, US, has shown that precisely the right levels of a chemical called anandamide are required for this passage to be completed safely. Increasing or decreasing the amount of anandamide drastically harms mouse embryos’ chances of normal implantation and survival. Their research reveals that anandamide levels in the fallopian tubes are governed by two enzymes: one called NAPE-PLD increases levels of anandamide, while NAAH reduces them. Significantly, the team also found that exposing the mice to certain drugs disrupted this delicate balance, thereby impeding an embryo's ability to pass into the womb. One such substance is tetrahydrocannabinol (THC), the major psychoactive component of marijuana. © Copyright Reed Business Information Ltd

Keyword: Drug Abuse
Link ID: 9191 - Posted: 06.24.2010

Measuring the brain development of premature babies in their first weeks of life can show those likely to have difficulties, scientists suggest. An Imperial College team found babies with less brain surface development had poorer mental skills at the age of two. If confirmed in larger studies, the researchers say it may be possible to identify which children need more support and to provide it earlier. The research is published in the Public Library of Science Medicine. Half of all babies who survive after being born very early go on to develop a disability or learning difficulty, past research has found. The cortex, the surface area of the brain, should change from looking like a coffee bean to looking like a walnut while a foetus is in the womb. If a baby is born prematurely, that development needs to take place outside the womb - with all the different stresses the baby will be under at that time. The researchers used MRI (magnetic resonance imaging) scanning to measure brain growth of 113 babies born prematurely between 22 and 29 weeks gestation. A baby is normally born at 40 weeks. The premature babies were scanned up to the point when they would have been eight weeks old, if the pregnancies had gone to term. (C)BBC

Keyword: Development of the Brain
Link ID: 9190 - Posted: 08.01.2006

By Jennifer Couzin A new vaccine helps rats stay svelte no matter what they eat, a study has found. The findings represent the first published animal research on an "obesity vaccine." Meanwhile, a Swiss company is testing a related vaccine on people. Obesity is a major challenge for the pharmaceutical industry. But some progress has been made. Since the early 1990s, scientists have managed to identify naturally occurring molecules that control energy expenditure, satiation, and other elements that govern weight gain and loss. One of these, the hormone ghrelin, was identified 7 years ago and is produced in the stomach (ScienceNOW, 10 November 2005). Rodents given ghrelin eat more and gain weight. Puzzlingly, however, mice that lack ghrelin don't eat less: They have normal appetites, although they burn excess fat. Choosing the hormone as their target, chemical biologist Kim Janda of the Scripps Research Institute in San Diego, California, and colleagues at Scripps and Osaka City University in Japan, crafted three antighrelin vaccines. Each was designed to recognize and inactivate different parts of the hormone. The team immunized 14 male rats with one of the three vaccines; three others got a placebo. The rats received five shots over 12 weeks. © 2006 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 9189 - Posted: 06.24.2010

Richard Van Noorden Which is the most harmful: ecstasy, alcohol or tobacco? Ecstasy features in the highest class of most countries' drug legislation, but a report released today by British parliamentarians says that the current system for classifying drugs is based more on policy considerations than on science. The report, by the House of Commons Science and Technology Committee, suggests that ecstasy should be placed lower than both alcohol and tobacco in a league table based on a drug's capacity to cause harm. But pharmacologists argue that such an approach may still be difficult to implement in a scientifically rational way. In Britain, illegal drugs are classed in three categories, with class A (including heroin and ecstasy) being the most harmful, and class C (including cannabis) the least. Criminal penalties for supplying or possessing a drug depend on the drug's classification. But committee member Evan Harris has branded the current system of drug classification, instigated in 1971, an "evidence-free zone". Leslie King, a member of Britain's Advisory Council on Misuse of Drugs (ACMD), agrees: "The current system is just scientific anecdotes floating round a table," he says. ©2006 Nature Publishing Group

Keyword: Drug Abuse
Link ID: 9188 - Posted: 06.24.2010

Like detectives trying to solve a murder case, researchers searching for the biological cause of autism have come up with some surprising suspects. They've found that different genes may be responsible for causing autism in boys than in girls. In addition, the researchers also have discovered that other genes may play a role in the early onset form of the developmental disorder and in the recently verified regression, or late onset, type of autism, according to a new study published today in the online edition of the journal Molecular Genetics. The study also provides new evidence for the idea that multiple genes contribute to autism, said lead author Gerard Schellenberg, a researcher at the Puget Sound Veterans Affairs Medical Center and a research professor of medicine at the University of Washington. The research team was headed by Schellenberg, Ellen Wijsman, a UW research professor of medical genetics and Geraldine Dawson, director of the UW's Autism Center. "It is highly unlikely that there is only one gene responsible for autism," said Schellenberg. "There may be four to six major genes and 20 to 30 others that might contribute to autism to a lesser degree. "If an individual only gets three high-risk variants of these genes, it could mean a less-severe form of autism. And because autism is rarer in females, it may take more risk genes for a female to have autism. There also is the possibility that there might be a biological difference in autism for females versus males," he said.

Keyword: Autism; Genes & Behavior
Link ID: 9187 - Posted: 08.01.2006