University College London experts have shown how the brain subconsciously remembers details around past dangers. Writing in Nature, they say blocking this system could help treat pain by interrupting such a brain process. Researchers said volunteers could not recall details of a test which had led to them getting a mild electric shock. But activity in the brain revealed that they had correctly logged the data by using a series of complicated computations. Fourteen patients were given a half-hour test while lying in a functional magnetic resonance brain scanner - tests were done by researchers at the Wellcome Department of Imaging Neuroscience at UCL. They were shown a series of abstract pictures followed by a one-second electric shock - equivalent to a pin-prick. When the tests were completed many of the volunteers could not recall the sequence of images. But the scanner revealed that two key areas, the ventral striatum and part of the cerebral cortex, were working together to figure out what was coming next. Dr Ben Seymour, who led the research, said: "If we showed a square followed by a circle followed by the painful shock this part of the brain could soon learn to predict that the circle was bad news. "However, after a while, it would learn that the square wasn't that good either, as it was followed by the circle. "By recording these chains of events, the brain was able to set early alarm bells ringing in the volunteer." (C)BBC

Keyword: Emotions
Link ID: 5643 - Posted: 06.13.2004

Genes which play a key role in keeping our minds sharp gradually begin to turn off as we age, research has found. Scientists at the Children's Hospital in Boston hope the discovery could lead to new ways to preserve brain function and ward off Alzheimer's disease. They used a sophisticated screening technique to analyse brain samples from 30 people aged 26 to 106 at post-mortem. The research is published in the journal Nature. Lead researcher Professor Bruce Yankner said: "We found that genes that play a role in learning and memory were among those most significantly reduced in the ageing human cortex. "These include genes that are required for communication between neurons." Gene activity was assessed by measuring the amount of proteins that they produce. Protein levels were reduced in older individuals - and changes seemed to start for some in their 40s. However, the rate of deterioration seemed to vary between individuals. (C)BBC

Keyword: Alzheimers; Genes & Behavior
Link ID: 5642 - Posted: 06.13.2004

Sheep can recognise emotions in facial expression, not only in their species but also in humans, researchers say. Researchers at Cambridge University have discovered sheep prefer smiling or relaxed human faces, over angry or stressed ones. Neuroscientist Dr Keith Kendrick and his team believe the findings may offer insights into some human conditions. Three years ago, the team found sheep could recognise 50 individual sheep faces and remember them for two years. "Sheep are able to recognise faces that differ by less than 5% so we thought perhaps they could recognise emotions which are much more subtle," Dr Kendrick said. "It turns out they can, both human, smiling versus angry; and sheep, stressed versus calm." Scientists presented the sheep with two doors they could push open to gain food. On one would be a picture of a smiling human or a happy sheep, on the other an angry human or a stressed out sheep. "They vastly preferred to press the smiling human or the animal that has just had a meal and is feeling all right with life," said Dr Kendrick. (C)BBC

Keyword: Emotions
Link ID: 5641 - Posted: 06.13.2004

Paul Brown In December 2003, the U.S. Department of Agriculture discovered a case of bovine spongiform encephalopathy (BSE), often called mad-cow disease, in a dairy cow from Washington state. The news was more than a little disturbing to the American cattle industry. The mad-cow scare had previously devastated the cattle business in the few countries where BSE had been reported, especially Great Britain and Canada. The Canadian cattle industry has yet to recover from the discovery of BSE in a single cow on an Alberta farm in May of last year. A 400-kilogram cow that used to fetch 500 Canadian dollars on the open market now sells for as little as 79 Canadian cents—less than the price of a fast-food burger. The economic fallout is, of course, a consequence of the discovery in 1996 that mad-cow disease could cross the species barrier to inflict human beings with variant Creutzfeldt-Jakob disease (vCJD). This disease is characterized by a progression of psychiatric and neurological symptoms that culminate in death, usually a year or two after the onset of the first indications of illness. As of May 2000, a total of 155 cases of vCJD had been identified: 144 in Great Britain (where the outbreak began), 6 in France, 1 in Ireland, and 1 in Italy. Additional single victims in Hong Kong, Canada and the U.S. were infected in the U.K., where they had been residing during the years of peak risk, in the late 1980s or early 1990s. The extraordinary commercial and public-health consequences of BSE, as well as the near-global distribution of products derived from cattle, have generated a considerable amount of attention from industry, government and the general public. As a result, there is a daunting volume of information—not all of it reliable—surrounding the nature of mad-cow disease. © Sigma Xi, The Scientific Research Society

Keyword: Prions
Link ID: 5640 - Posted: 06.24.2010

Bruce Bower On a European television broadcast 2 years ago, a border collie named Rico wowed viewers by correctly retrieving items from an array of children's toys at the request of one of his German owners. For example, if instructed to "get the panda," that's what the black-and-white canine brought back. Julia Fisher, a psychologist at the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and two of her colleagues watched Rico's performance with keen interest. In ensuing experiments with the dog, they found that he recognizes the names of about 200 objects and learns names for new items as well as 3-year-old children have been reported to do. "Our results support the view that rapid word learning by toddlers is mediated by simple cognitive building blocks that are present in another species," Fisher says. The dog's word-learning skill is as good as chimpanzees' and parrots', the researchers conclude in the June 11 Science. Copyright ©2004 Science Service.

Keyword: Language; Animal Communication
Link ID: 5639 - Posted: 06.24.2010

German Pet's Vocabulary Stuns Scientists By Rob Stein, Washington Post Staff Writer A series of careful studies concluded that the energetic German house dog has a stunningly large vocabulary of about 200 words and can even do something scientists thought only humans could do: figure out by the process of elimination that a sound he has never heard before must be the name of a toy he has never seen before. That feat, described in today's issue of the journal Science, suggests that dog owners who claim their pets understand what they are saying and are trying to respond may have been right all along. "Maybe this is the Albert Einstein of dogs. Or maybe this is something that other dogs can do, too," said Julia Fischer, a biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who helped test Rico. "We just don't know. We need to find out." While many species can be trained to recognize the names of objects, what makes Rico unusual is that he knows so many words, can puzzle out the names of new objects on the first try and weeks later is surprisingly good at remembering what he learned, the researchers said. © 2004 The Washington Post Company

Keyword: Language; Animal Communication
Link ID: 5638 - Posted: 06.24.2010

PEOPLE are woefully bad at recalling details of their own traumatic experiences. When military personnel were subjected to threatening behaviour during mock interrogations, most failed to identify the questioner a day or so later, and many even got the gender wrong. The finding casts serious doubt on the reliability of victim testimonies in cases involving psychological trauma. Numerous studies have questioned the accuracy of recall of traumatic events, but the research is often dismissed as artificial and not intense enough to simulate real-life trauma. Other studies have suggested that intense, personal experiences might produce near photographic recollection, something that prosecutors and juries in legal cases often assume. But some researchers think this is an illusion. "People come away from these experiences feeling they will never forget what happened," says Gary Wells, an expert on eyewitness testimony at Iowa State University in Ames, "but they confuse that with thinking they remember the details."

Keyword: Learning & Memory; Stress
Link ID: 5637 - Posted: 06.11.2004

Some of the 250,000 Americans who have been paralyzed by spinal cord injuries are pressing medical researchers for a cure. The most prominent is actor and director Christopher Reeve, who was paralyzed after a fall from his horse in 1995. At a symposium on spinal cord research at Rockefeller University, held on November 24, 2003, Reeve commented on "a certain frustration" that he and other paralyzed patients feel over the current pace of American research, which has been hampered by political debate over the use of stem cells. "I think that we need to inject more urgency into the whole process here," Reeve observed. Another speaker at the Rockefeller symposium was Michael Di Scipio, 34, who was paralyzed after a diving accident in July 1999, when he was 29. A single father, he says his two young children have been injured, too—by what he can't do: "Not being able to run around and play with them, hold them, tickle them, tuck them in, give them a kiss good night. Things we're supposed to do as parents." One reason that prospects for recovery are dim at present for patients with spinal cord injury is that unlike other cells, nerve cells, or neurons in the central nervous system (the brain and spinal cord) are unique in that they cannot replicate themselves in their mature state. So repairing spinal cords means finding a way to get nerve cells to grow back across the gap in a spinal cord that has been severed. © ScienCentral, 2000-2004.

Keyword: Regeneration
Link ID: 5636 - Posted: 06.24.2010

Young Adult Minorities Emerge As High-Risk Subgroups The number of American adults who abuse alcohol or are alcohol dependent rose from 13.8 million (7.41 percent) in 1991-1992 to 17.6 million (8.46 percent) in 2001-2002, according to results from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a study directed by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). The NESARC study — a representative survey of the U.S. civilian noninstitutionalized population aged 18 years and older — showed that the rate of alcohol abuse* increased from 3.03 to 4.65 percent across the decade while the rate of alcohol dependence**, commonly known as alcoholism, declined from 4.38 to 3.81 percent. The study appears in the current issue of Drug and Alcohol Dependence (Volume 74, Number 3, pages 223-234). NESARC survey questions are based on diagnostic criteria for alcohol abuse and alcohol dependence contained in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV). Field work for the NESARC was performed by the United States Census Bureau, which administered face to face interviews with 43,093 respondents. The combined household and individual response rate was 81 percent. Like its predecessor, the 1991-1992 National Longitudinal Alcohol Epidemiologic Survey (NLAES), the NESARC assessed the prevalence of alcohol disorders during the year prior to the survey. Since DSM diagnostic criteria remained unchanged across the decade, the NIAAA research team, led by Bridget Grant, Ph.D., Ph.D., Chief, Laboratory of Epidemiology and Biometry, Division of Intramural Clinical and Biological Research, was able to assess changes in the prevalence of alcohol disorders across a 10-year period.

Keyword: Drug Abuse
Link ID: 5635 - Posted: 06.24.2010

Mutt's memory feats aid studies of language development. HELEN R. PILCHER A German border collie has surprised scientists with his 200-word vocabulary and uncanny knack for learning new words, shedding light on the evolution of language. Nine-year-old Rico knows the names of each toy in his hundred-strong collection and can retrieve items called out to him with over 90% accuracy. He can also learn and remember the names of unfamiliar toys after just one encounter, putting him on a par with a three-year-old child. The dog's magnificent memory shows that canines share some aspects of the language skill that evolved in humans, says Julia Fischer from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who reports her findings in Science1. But canines' ability to comprehend speech can only have manifested itself after they were domesticated, some 15,000 years ago, and human speech is thought to have evolved 100,000 to 200,000 years ago. So Fischer's findings suggest that the ability to match novel words and items has evolved twice, first in humans and then in dogs. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Language; Animal Communication
Link ID: 5634 - Posted: 06.24.2010

With the threat of an obesity crisis looming, a study led by UCL researchers reveals today that fat tissue isn't always the enemy. Reporting in the journal Science they show that a molecular signalling pathway in fat tissue is an important mediator in extending lifespan. The study, conducted on one of scientists' favourite model organisms - the fruit fly - found that reducing activity of the insulin/insulin-like growth factor (IIS) signalling pathway in fat tissue of adults extended life by up to 50 per cent. Previously it has been shown that reducing the activity of the IIS pathway extends lifespan in fruit flies, mice and the worm C. elegans. But the cellular processes that determine longevity were not understood. Results suggest the system that governs longevity evolved in a precursor of all three species and is likely to be conserved in humans. Professor Linda Partridge of UCL's Department of Biology, and senior author of the study, says: "Basically, we are learning that nearly everything in biology is highly conserved. For years biologists studying ageing were convinced that it just happened and there wouldn't be genes that controlled it - you just wore out. But it became apparent independent of weight or size, some animals live much longer than others.

Keyword: Obesity
Link ID: 5633 - Posted: 06.11.2004

By RANDOLPH E. SCHMID, Associated Press Writer WASHINGTON - As many a dog owner will attest, our furry friends are listening. Now, for the doubters, there is scientific proof they understand much of what they hear. German researchers have found a border collie named Rico who understands more than 200 words and can learn new ones as quickly as many children. Patti Strand, an American Kennel Club board member, called the report "good news for those of us who talk to our dogs." "Like parents of toddlers, we learned long ago the importance of spelling key words like bath, pill or vet when speaking in front of our dogs," Strand said. "Thanks to the researchers who've proven that people who talk to their dogs are cutting-edge communicators, not just a bunch of eccentrics." The researchers found that Rico knows the names of dozens of play toys and can find the one called for by his owner. That is a vocabulary size about the same as apes, dolphins and parrots trained to understand words, the researchers say. Rico can even take the next step, figuring out what a new word means. The researchers put several known toys in a room along with one that Rico had not seen before. From a different room, Rico's owner asked him to fetch a toy, using a name for the toy the dog had never heard. Copyright © 2004 Yahoo! Inc.

Keyword: Language
Link ID: 5632 - Posted: 06.24.2010

Scientists have raised fears that a mercury-based preservative used in vaccines may cause symptoms of autism. US researchers at Columbia University found autism-like damage in the brains of mice exposed to thimerosal. In the UK it is used in the DTP jab for diphtheria, tetanus and whooping cough and some flu jabs. The study, in Molecular Psychiatry, has been challenged by various expert groups, who say there is no evidence that the preservative poses any risk. A major review carried out by the US Institute of Medicine published last month found no evidence that thimerosal was linked to autism. Similarly, investigations by the UK Committee on Safety of Medicine, Europe's Agency for the Evaluation of Medicinal Products and the World Health Organization concluded the preservative was safe. However, the Columbia team said they found that mice exposed to thimerosal showed signs of changed behaviour, and brain abnormalities. The animals had been bred to be vulnerable to developing disorders of the immune system. They argued it was possible that children with similarly compromised immunity may also be at risk. (C) BBC

Keyword: Autism
Link ID: 5631 - Posted: 06.10.2004

Having unprotected sex once is far more likely to result in a pregnancy than was previously thought, finds research. Scientists found evidence that women are subconsciously driven to have more sex during the most fertile time of their monthly cycle. An analysis by the US National Institute of Environmental Health Sciences found intercourse was 24% more frequent on fertile days. The study is published in the journal Human Reproduction. The study focused on women who had either been sterilised or were using an intrauterine device (IUD). The frequency of intercourse increased during the six most fertile days of the menstrual cycle and peaked at ovulation - despite the fact that these women clearly did not want a baby. Lead research Professor Allen Wilcox said: "There apparently are biological factors promoting intercourse during a woman's six fertile days, whether she wants a baby or not. (C)BBC

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 5630 - Posted: 06.10.2004

Scientists discover that some brains age more rapidly than others; noticed change after age 40 Unraveling the mysteries of the aging brain is a major goal for brain science, especially given the exploding population of senior citizens and the obvious desire to preserve brain function as long as possible. Now, researchers at Children's Hospital Boston and Harvard Medical School have uncovered a kind of genetic signature associated with the aging human brain that may contribute to cognitive decline associated with aging. The study appears June 9 as an advance on-line publication of the journal Nature. One of the study's more surprising results was that these gene changes start in the 40s for some individuals. The results raise intriguing questions about when and why the brain begins to age and the possibility of developing strategies to protect critical genes early in life in an attempt to preserve brain function and delay the onset of age-related conditions such as Alzheimer's disease. To investigate age-associated molecular changes in the human brain, Dr. Bruce A. Yankner, professor in the Department of Neurology and Division of Neuroscience at Children's Hospital Boston and Harvard Medical School, and colleagues examined patterns of gene expression in postmortem samples collected from thirty individuals ranging in age from 26 to 106 years.

Keyword: Genes & Behavior
Link ID: 5629 - Posted: 06.10.2004

The biological clocks that control the daily lives of every living thing Russell Foster and Leon Kreitzman We are all fascinated with rhythms: repetitive patterns in art, vibrations of a cello string, waves of water and sand, and all sorts of similar regularities in living organisms such as zebra stripes and the segments of a worm. Many of these involve time either directly (as in a cello string or ocean waves) or at the moment of their formation (as in animal stripes and segments). Rhythms of Life is about biological rhythms that involve time exclusively: heartbeats, daily rhythms in particular, as well as monthly ones, annual ones, and even those that span many years. Russell Foster and Leon Kreitzman are experts in the field of biological clocks and, with great skill, give us an up-to-date and readable account of what we know today about the time cycles that affect the majority of all living organisms, including ourselves. They tell us the basis of jet lag, how our clocks affect our sleeping, and why there is a best time to take certain pills so that they are maximally effective. To see what underlies these human phenomena, they give us a picture of the whole field for a better understanding of the basis of all biological rhythms. In doing so they convincingly make it evident that the basic phenomenon of time cycles in living organisms is in itself a fascinating subject. ©2004 THE TLS

Keyword: Biological Rhythms
Link ID: 5628 - Posted: 06.24.2010

DURHAM, N.C. -- If the emotional memory of a traumatic car accident or the thrill of first love are remembered with a special resonance, it is because they engage different brain structures than do normal memories, Duke University researchers have discovered. Their new study provides clear evidence from humans that the brain's emotional center, called the amygdala, interacts with memory-related brain regions during the formation of emotional memories, perhaps to give such memories their indelible emotional resonance. The researchers said their basic insights could contribute to understanding of the role that the neural mechanisms underlying emotional memory formation play in post traumatic stress disorder and depression. According to Florin Dolcos, in their experiments the researchers were seeking evidence for the "modulation hypothesis," which holds that the brain's emotional and memory centers interact during the formation of emotional memories.

Keyword: Emotions; Learning & Memory
Link ID: 5627 - Posted: 06.10.2004

Since one of the basic risk factors for alcoholism is a tolerance to alcohol, researchers have long sought to understand the genetic differences among people that affect their sensitivity to alcohol. So far, scientists have met with little success. However, by exposing populations of the roundworm C. elegans to alcohol and pinpointing subtle genetic differences among strains that respond differently, researchers have identified one gene that affects alcohol sensitivity. In an article in the June 10, 2004, issue of Neuron, Andrew Davies and his colleagues describe their findings that subtle differences between worm strains in the gene for a brain protein called NPR-1 explains differences in the worms' alcohol sensitivity. The researchers chose the worm as their subject because there is evidence that alcohol has effects on worm behavior. Although the mechanisms that mediate alcohol response in humans or other animals are not well understood, most human neuronal proteins have worm versions and it seems likely that at least some of the mechanisms are shared. Additionally, the worm has been the subject of massive genetic study by scientists, and genetically distinct strains are available from around the world.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 5626 - Posted: 06.10.2004

— Howard Hughes Medical Institute (HHMI) researchers have made the surprising discovery that people with Alzheimer's disease retain the capability for a specific form of memory used for rote learning of skills, even as their memories of people and events are extinguished. The scientists' discovery suggests new strategies to improve training and rehabilitative programs that may bolster the retained cognitive function of those with Alzheimer's disease as well as healthy older people. “From this and other studies we have done, it appears that a number of brain systems are more intact in Alzheimer's than we had anticipated,” said Howard Hughes Medical Institute researcher Randy L. Buckner at Washington University in St. Louis. “The findings suggest that if we can help people use these brain systems optimally by providing the right kinds of cues or task instructions, we may be able to improve their function.” In an article published in the June 10, 2004, issue of the journal Neuron, Buckner and Cindy Lustig, also at Washington University, compared implicit memory capabilities in young adults, healthy older adults and those in the early stages of Alzheimer's disease. ©2004 Howard Hughes Medical Institute

Keyword: Alzheimers; Learning & Memory
Link ID: 5625 - Posted: 06.24.2010

Women are significantly more likely to have sex during the fertile part of their monthly cycle, suggests new research. "If you're a couple trying to get pregnant, that's great news. There's a hidden biological process working in your favour," says Allen Wilcox, a reproductive epidemiologist at the US National Institute of Environmental Health Sciences in Durham, North Carolina, and lead researcher of the study. "If you are not trying to pregnant the news is not so good," he told New Scientist. The work indicates that having unprotected sex once is more likely to result in pregnancy than previously thought. The underlying reason for the coincidence of intercourse and heightened fertility is not clear. Previous research suggests women feel sexier in the days before ovulation, which may increase their own libido or make them more attractive to their partners. And men have been found to be more attentive to their female partners around ovulation. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 5624 - Posted: 06.24.2010