A group of researchers has re-created with remarkable accuracy part of the genome of the common ancestor of all placental mammals, a small shrew-like creature that prowled the forests of what is now Asia more than 80 million years ago. By comparing DNA sequences of 19 species of existing mammals, including humans, the researchers have reconstructed a large segment of DNA in the species from which all of today's placental mammals arose. They estimate that the reconstruction is 98 percent accurate. The project, which was led by David Haussler, a Howard Hughes Medical Institute investigator at the University of California, Santa Cruz, based their reconstruction efforts around a region of the genome that covers about 1.1 million bases flanking the cystic fibrosis transmembrane conductance regulator (CFTR) gene. That region of the genome has been sequenced in a large number of species as part of a comparative sequencing program being conducted by the National Institutes of Health. Coauthors of the article, which will be published in the December 2004 issue of Genome Research, are Mathieu Blanchette of McGill University, Eric Green of the National Human Genome Research Institute, and Webb Miller of Pennsylvania State University. When geneticists hear that most DNA from the genome of a species extinct for many millions of years can be re-created with 98 percent accuracy, “jaws occasionally drop,” said Haussler. “It sounds implausible. But there's enough information to reconstruct the ancestral genome on the basis of mammals that live today. We just need to sequence the genomes of these living mammals.” The reconstructed ancestral genome will offer an invaluable vantage point from which to watch evolution at work. © 2004 Howard Hughes Medical Institute.

Keyword: Evolution; Genes & Behavior
Link ID: 6505 - Posted: 06.24.2010

Michael Hopkin A vocabulary analysis of the final book by British novelist Iris Murdoch reveals the early stages of the Alzheimer's disease that killed her, neuroscientists have found. The discovery shows that even before she was diagnosed with the disease, her work betrayed the subtle signs of her condition. The vocabulary of Jackson's Dilemma, published shortly before Murdoch was officially diagnosed with Alzheimer's in 1995, is less rich than that of an earlier work The Sea, The Sea, published at the height of her powers in 1978. A team of British researchers made the discovery by using text-analysis software to compare the variety of words used in three of her novels. The language is richest in The Sea, The Sea, which contains many rare and obscure words, the researchers report in the online version of the journal Brain1. What's more, the rate at which new words are introduced is greater in this work and in Murdoch's 1954 first novel, Under the Net, than in Jackson's Dilemma. ©2004 Nature Publishing Group

Keyword: Alzheimers; Language
Link ID: 6504 - Posted: 06.24.2010

By Mary Carmichael Newsweek - To say that Aplysia Californicus is one of nature's least glamorous beasts would be too kind. A hermaphroditic marine snail with mottled purple skin, it keeps to itself, responding to disturbances by emitting a murky fluid that stains the water around it. Its "brain," if you can call it that, is stunningly simple, with only a few thousand oversize neurons. It is not, in short, a likely candidate for glory in the animal kingdom. But a few years from now, much of the baby-boom generation may be greatly indebted to this unprepossessing little creature. Aplysia may look homely, but to scientists hoping to develop memory-enhancing medicine, it is a thing of beauty. Thanks to the neurological research of Nobel laureate Eric Kandel and others, Aplysia's minimal nervous system is helping scientists to make sense of how memory works on the biochemical level. The molecules of memory in sea slugs, it turns out, aren't that different from some of those in humans. They are now one of the many inspirations for drugs that may someday ward off the forgetfulness that plagues so many people as they grow older. As Americans' average age creeps upward, the search for medicines that will keep them sharp is accelerating. "We're all very, very avidly grinding up cells trying to get at the molecules," says Dr. Scott Small of Columbia University Medical Center. No pill to improve memory, aside from alternative remedies of dubious effectiveness, is currently on the market. But several small biotech companies are launching drugs grounded in the latest research, with a few already in the early stages of clinical trials that could be finished in as little as "two years, if we're lucky," says Kandel, who is now at CUMC and the Howard Hughes Medical Institute. Some of the most promising candidates have their roots in Aplysia studies. Others take their cues from even more improbable sources like the molecular consequences of smoking, focusing on some of the same receptors that nicotine targets. (Who knew it had benefits?) "These are very exciting times for treating memory loss," says Steven Siegelbaum, a neuroscientist at CUMC and HHMI. And with trials soon to yield results, they're about to get even more exciting. © 2004 Newsweek, Inc.

Keyword: Learning & Memory
Link ID: 6503 - Posted: 06.24.2010

In contrast to people who do not have autism, people with autism remember letters of the alphabet in a part of the brain that ordinarily processes shapes, according to a study from a collaborative program of the National Institute of Child Health and Human Development of the National Institutes of Health. The study was conducted by researchers in the NICHD Collaborative Program of Excellence in Autism (CPEA) at the University of Pittsburgh and Carnegie Mellon University. It supports a theory by CPEA scientists that autism results from a failure of the various parts of the brain to work together. In autism, the theory holds, these distinct brain areas tend to work independently of each other. The theory accounts for observations that while many people with autism excel at tasks involving details, they have difficulty with more complex information. The study and the theory are the work of Marcel Just, Ph.D., Professor of Psychology at Carnegie Mellon University in Pittsburgh, Pennsylvania and Nancy Minshew, M.D., Professor of Psychiatry and Neurology at the University of Pittsburgh School of Medicine and their colleagues. The study is scheduled for on-line publication November 29 in the journal Neuroimage, at http://www.sciencedirect.com. "This finding provides more evidence to support a promising theory of autism," said Duane Alexander, M.D., Director of the NICHD. "If confirmed, this theory suggests that therapies emphasizing problem solving skills and other tasks that activate multiple brain areas at the same time might benefit people with autism."

Keyword: Autism
Link ID: 6502 - Posted: 12.01.2004

Study finds evidence mind is connected to changes in body David Perlman, Chronicle Science Editor Researchers at UC San Francisco say they have found the first direct evidence that severe and chronic emotional stress can age people biologically. Everyone knows that stress is tough, and prolonged stress can be even worse -- it can disrupt the human immune system, increase the risk of heart disease and take its toll on the body in many other ways. Now the scientists think they know why: Stress, or the perception of stress, can alter key genetic molecules in a cell. In a controlled experiment involving mothers caring for chronically ill children, a team from UCSF and other research centers found that mothers who perceived that they were under persistent psychological stress aged by the equivalent of a full decade -- their cells were damaged and even killed by their own perceptions of stress. The scientists focused on key protein molecules in the body's cells called telomeres that cap the ends of chromosomes and on an enzyme called telomerase that controls the length of those telomeres. Every time cells divide normally, their telomeres shorten, and when the telomeres have dwindled away completely, the cells die. The telomerase enzyme, in turn, can boost the length of the telomeres and thus keep cells dividing indefinitely. ©2004 San Francisco Chronicle

Keyword: Stress
Link ID: 6501 - Posted: 06.24.2010

EAST LANSING, Mich. – A recent discovery unveils the chemical secret that gives old bees the authority to keep young bees home babysitting instead of going out on the town. A hard-to-detect pheromone explains a phenomenon Michigan State University entomologist Zachary Huang published 12 years ago – that somehow older forager bees exert influence over the younger nurse bees in a hive, keeping them grounded until they are more mature, and thus more ready to handle the demands of buzzing about. The work that identifies the chemical, "Regulation of Behavioral Maturation in Honey Bees by a New Primer Pheromone" is publishing in Proceedings of the National Academy of Science Biological Sciences, Population Biology, Early Edition the week of Nov. 29. "If the older ones don't keep them in check, the young ones can mature too quickly," Huang said. "It's kind of the same thing as with people, you need the elders to check on the young, even if the young are physically able to go out on their own, it's not the best situation for anybody and now we know how it works." Huang worked with a team that spanned from the United States, France and Canada to explain how the bees kept an exquisitely consistent balance between the ones that go out to collect nectar and pollen and defend the hive, and those that stay home and nurture the larvae. Huang had documented that this balance is controlled by the elder bees, those that typically spend the final one to three weeks of their five-week lifespan out in the field.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6500 - Posted: 06.24.2010

By ROBIN MARANTZ HENIG Imagine a 20-year-old woman who refuses to eat anything except carrots and toast because she is afraid of gaining weight, even though she is 5-foot-8 and weighs only 99 pounds. She exercises to the point of exhaustion five mornings a week because, though she is bone-thin, she thinks her thighs are too flabby. Her periods are irregular, but she has never gone more than three months without menstruating. Another woman, who is also 20 and also 5-foot-8, has an opposite eating pattern. She goes without eating all day, and starting at 6 p.m. she eats nonstop, whatever she can get her hands on. Her favorite pastime is to sit in front of the television with a gallon of mocha-chip ice cream. She maintains a normal weight of 130 by occasionally forcing herself to vomit. But purging is not always easy in her college dormitory, with four young women sharing a single bathroom, so she ends up vomiting, on average, about once a week. Everyone can agree that these women have some sort of disordered eating. But psychiatrists would say that neither one falls into the strict definition of anorexia nervosa, the most severe eating disorder, or its relative, bulimia nervosa. According to the bible of psychiatric diagnosis, the American Psychiatric Association's Diagnostic and Statistical Manual, anorexia must be accompanied by cessation of menstrual periods for at least three months in a row, and bulimia must involve vomiting or other forms of purging at least two times a week, on average. Copyright 2004 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 6499 - Posted: 11.30.2004

By CARL ZIMMER Swallows are getting sexier. Male barn swallows attract females with long tail feathers, and European researchers have observed that over the last 20 years those feathers have become much longer. "We've demonstrated quite a dramatic change in a short period of time," said Dr. Anders Pape Moller, an evolutionary biologist at Pierre and Marie Curie University in Paris, who conducted the research with Dr. Tibor Szep of the College of Nyiregyhaza in Hungary. The findings are to be published in The Journal of Evolutionary Biology. Experiments suggest that the males' tails act as advertising for good genes because males must be in good health to spend the energy growing them. The females, the researchers say, are particularly attracted by the tail's two outer feathers. Dr. Moller, who has been documenting this preference for more than two decades, found that the outer feathers had lengthened by almost half an inch (11.4 millimeters), an increase of 10 percent, one of the biggest evolutionary shifts ever documented in a living population of wild animals. By contrast, the central tail feathers, which don't produce a reaction in females, haven't changed. Copyright 2004 The New York Times Company

Keyword: Evolution; Sexual Behavior
Link ID: 6498 - Posted: 11.30.2004

Carl T. Hall, Chronicle Science Writer Dr. Richard Olney first got interested in the neuromuscular disease known as amyotrophic lateral sclerosis, or ALS, when the daughter of his favorite teacher in junior high school died of it. He soon came to regard ALS, also known as Lou Gehrig's disease, as one of the most compelling -- and justly feared -- disorders of the nervous system. And so, during 25 years as a neurologist, Olney devoted his career to the care of ALS patients, founding a specialized clinic at UCSF. He resigned as clinic director this summer and has stopped treating all his patients with ALS. But he has even more reason these days to be interested in their disease. Now, it is his disease. In June, Olney, 56, regarded as one of the top ALS clinicians in the country, was diagnosed with ALS. ALS is not contagious. He didn't catch it from close contact with a patient. It's just a matter of unhappy fortune -- just one more case in one of the biggest ongoing mysteries of brain research. ©2004 San Francisco Chronicle

Keyword: ALS-Lou Gehrig's Disease
Link ID: 6497 - Posted: 06.24.2010

AUSTIN, Texas--A protein found on the surface of nerve cells makes fruit flies tolerant to a drug after just a single, brief exposure, which may reveal ways to address this early step toward addiction in humans. Neuroscientist Nigel Atkinson at The University of Texas at Austin and his laboratory determined this by studying the response of fruit flies (Drosophila) to a 15-minute exposure to benzyl alcohol coated on the inner walls of test tubes. Flies that had had one previous exposure to the organic solvent recovered more quickly from being knocked out by the drug than flies that were first-timers. The flies that developed tolerance also had increased activity of the slo gene. The gene produces the surface protein, which helps stimulate signaling between nerve cells in the brain. Genetically modified flies that lacked the slo gene failed to develop tolerance, while flies modified to have increased slo activity were more drug resistant than normal, providing added proof of the gene's importance for tolerance. Because the human slo gene is almost identical to the one in fruit flies, Atkinson said, "If we could describe the series of steps involved in changing slo gene expression, then all the components involved in producing that change could become potential targets for anti-addiction drugs." The findings will be published online the week of Monday, Nov. 29, by the Proceedings of the National Academy of Sciences.

Keyword: Drug Abuse
Link ID: 6496 - Posted: 11.30.2004

ALS is an incurable, paralyzing neurodegenerative disorder that strikes 5 persons in every 100,000. The disease commonly affects healthy people in the most active period of their lives - without warning or previous family history. Researchers from VIB (the Flanders Interuniversity Institute for Biotechnology), under the direction of Prof. Peter Carmeliet (Catholic University of Leuven), have previously shown the importance of the VEGF protein in this disease. Now, new research from this group shows that rats with a severe form of ALS live longer following the administration of the VEGF protein as a remedy. These results open up new possibilities for the use of VEGF in the treatment of ALS. An incurable disease of the muscles Amyotrophic Lateral Sclerosis (ALS) can strike anyone. The Chinese leader Mao Tse Tung, Russian composer Dimitri Sjostakowitz, the legendary New York Yankee baseball player Lou Gehrig, and astro-physicist Stephen Hawkins have all been afflicted with ALS. In addition, an unusually large number of Italian professional soccer players, airline pilots, and soldiers from the Golf War have been stricken by this fatal disease. About half of them have died within three years - some even in the first year - and usually as a consequence of asphyxiation, while still 'in full possession of their faculties'. In ALS, the patient's nerve bundles that extend to the muscles deteriorate. This causes the patient to lose control over his/her muscles, growing progressively paralyzed - but remaining (disconcertingly) fully alert mentally. The originating mechanism of this deadly disease of deterioration - which has an enormous medico-social impact - remains obscure. At present, the disease is totally untreatable - causing many ALS patients to choose euthanasia, a very controversial solution. However, previous genetic research by Peter Carmeliet and his team at the Catholic University of Leuven has led to the surprising discovery that the vascular endothelial growth factor (VEGF) plays a major role in this disease.

Keyword: ALS-Lou Gehrig's Disease ; Trophic Factors
Link ID: 6495 - Posted: 11.30.2004

COLUMBUS, Ohio – A drug withdrawn from pharmacy shelves over 20 years ago may point the way to a new treatment for spinal muscular atrophy, or SMA, a muscle-wasting and often life-threatening childhood disease. A new study suggests that the drug, called indoprofen, increases the production of a protein that is key to the survival of the nerve cells affected by the disease. Indoprofen was taken off the market in the early 1980s due to reports of serious gastrointestinal reactions as well as reports that the drug caused cancer in laboratory rats. Researchers are now looking into ways to modify the drug to make it less toxic to humans, said Arthur Burghes, a study co-author and a professor of molecular and cellular biochemistry at Ohio State University. While SMA strikes only about one in 6,000 newborn Americans each year, it is the leading genetic cause of infant and toddler death in the United States as well as Western Europe. There is no cure or standard treatment, and children with the most severe form of the disease usually die before their second birthday. Motor neurons – nerve cells that send signals from the spinal cord to muscles throughout the body – rapidly deteriorate in SMA due to reduced levels of survival motor neuron (SMN) protein. Patients with the disease lack SMN1, a gene that produces SMN protein. For reasons that aren't clear, this protein deficiency affects only motor neurons of the spinal cord – all other cells in the body function normally.

Keyword: Pain & Touch; Movement Disorders
Link ID: 6494 - Posted: 06.24.2010

CHICAGO – People suffering from paralysis due to stroke or traumatic brain injury may be able to reprogram their brains to improve motor skills and to control artificial limbs, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). Using functional magnetic resonance imaging (fMRI) and a "cyberglove" to record brain changes during motor activities, researchers demonstrated that people can learn to remap, or redirect, motor commands. This is an important step in stroke recovery and in training strategies for brain-machine interfaces--conduits between the brain and artificial limbs. "For stroke patients and others who have a brain deficit, coordinating what they see with body movement is very difficult," said the study's lead author Kristine Mosier, D.M.D., Ph.D., assistant professor of radiology at Indiana University in Indianapolis. "The brain must remap or relearn the process of matching visual input with sensory input. Our study demonstrated that individuals can learn to remap motor commands." When neurons--the primary cells of the nervous system that make all thought, feeling and movement possible--are damaged by a stroke or brain injury, other neurons take over for them. But until now, scientists weren't sure which neurons compensated for damaged neurons, or how the brain cells learned their new jobs.

Keyword: Stroke; Regeneration
Link ID: 6493 - Posted: 06.24.2010

Susan Milius Of all the vertebrates, a gecko has just become the first to ace behavioral tests for seeing color in very low illumination. People, for example, go color-blind in light equivalent to dim moonlight, but helmet geckos, Tarentola chazaliae, don't. They can still tell a blue from a gray of the same intensity, report Lina S.V. Roth and Almut Kelber, both of the University of Lund in Sweden, in an upcoming Biology Letters. Earlier physiology had shown that most vertebrates deploy two systems of light-sensitive cells in their eyes. Two or more types of cone cells work together to sense color in abundant light, and a single type of rod cell detects light more sensitively, but only in black and white. Thus, when the seeing gets tough, people forgo color vision and rely on their rods. Lizards, however, lack rods, presumably because they evolved for a long period as strictly daytime creatures. Copyright ©2004 Science Service

Keyword: Vision
Link ID: 6492 - Posted: 06.24.2010

Mark Peplow Lying activates tell-tale areas of the brain that can be tracked using functional magnetic resonance imaging (fMRI), according to scientists who believe the technique could replace traditional lie detectors. Conventional detectors, or polygraphs, are extremely controversial. Proponents of the polygraph argue that it measures the body's physiological responses to stress induced by lying. Trained operators can supposedly match spikes in respiration, blood pressure and sweating with false answers. But although some US government agencies still use the tests, the US National Academy of Sciences published a damning report in 2003 concluding that the instrument was very unreliable1. With practice, subjects are able to moderate their physical response and conceal their deceit, the report said. So scientists are looking for more reliable alternatives to the test, which was first conceived in 1915 by psychologist William Marston (see "The truth about lying"). Functional MRI might be the key, says Scott Faro, a radiologist at the brain-imaging centre of Temple University in Philadelphia, Pennsylvania. Faro presented the new study on 29 November at the annual meeting of the Radiological Society of North America in Chicago. "I believe this is a vital approach to understanding this very complex type of cognitive behaviour," he says. ©2004 Nature Publishing Group

Keyword: Stress
Link ID: 6491 - Posted: 06.24.2010

Telomeres and telomerase affected in study of women’s immune system cells Increasing scientific evidence suggests that prolonged psychological stress takes its toll on the body, but the exact mechanisms by which stress influences disease processes have remained elusive. Now, scientists report that psychological stress may exact its toll, at least in part, by affecting molecules believed to play a key role in cellular aging and, possibly, disease development. In the study, published in the November 30 issue of Proceedings of the National Academy of Sciences, the UCSF-led team determined that chronic stress, and the perception of life stress, each had a significant impact on three biological factors -- the length of telomeres, the activity of telomerase, and levels of oxidative stress -- in immune system cells known as peripheral blood mononucleocytes, in healthy premenopausal women. Telomeres are DNA-protein complexes that cap the ends of chromosomes and promote genetic stability. Each time a cell divides, a portion of telomeric DNA dwindles away, and after many rounds of cell division, so much telomeric DNA has diminished that the aged cell stops dividing. Thus, telomeres play a critical role in determining the number of times a cell divides, its health, and its life span. These factors, in turn, affect the health of the tissues that cells form. Telomerase is an enzyme that replenishes a portion of telomeres with each round of cell division, and protects telomeres. Oxidative stress, which causes DNA damage, has been shown to hasten the shortening of telomeres in cell culture.

Keyword: Stress
Link ID: 6490 - Posted: 06.24.2010

Roxanne Khamsi When attempting to master a task, sometimes it's best not to try too hard. Researchers have confirmed this folk wisdom, using brain imaging to show that thinking too hard about simple actions interferes with the learning process. Scientists already knew that consciously trying too hard to learn can cause trouble. The earliest demonstration of this came from a study in 1976, in which college students were asked to memorize strings of letters. Those who were told from the start that there was a regular pattern within the letters found it harder to discriminate between strings that did or did not contain the pattern. But until now, no one understood why this happened. Paul Fletcher, a psychiatrist at the University of Cambridge, UK, and his colleagues watched the brain activity of people who were learning without consciously trying (implicit learning) and compared it with activity in people who were putting deliberate effort into mastering the challenge. ©2004 Nature Publishing Group

Keyword: Learning & Memory; Attention
Link ID: 6489 - Posted: 06.24.2010

By Tom Geoghegan, BBC News Magazine The ethical debate about identity cards has been reignited following the Queen's Speech, but its facial recognition technology is being used in other areas. Police are hailing it as a forensic breakthrough and a new "foolproof" 3D version could eventually become a routine procedure at cash machines or workplaces. Once the preserve of science fiction, biometric facial recognition has now become a reality. Despite its association with the controversy of identity cards, it is predicted to become part of everyday life. A few corporations are already scanning pictures of staff for access control or to tackle swipe card fraud. And six police forces have so far recognised its use in identifying CCTV pictures of suspects - one claims it to be the biggest forensic breakthrough since DNA. As companies become more security conscious, the process of having our faces scanned is set to become more commonplace. And new technology which can produce this in a more accurate 3D form could accelerate this trend. A firm which has developed the 3D software, Aurora, claims it is sophisticated enough to distinguish between identical twins. I underwent the procedure myself and it only took a few seconds. A camera used a near-infrared light to put a virtual mesh on my face 16 times. It merged these into one unique template and calculated all the measurements of my features. These could theoretically then be instantly checked against a database to control access to a building or allow a cash machine withdrawal. Existing biometric face tests, which are two-dimensional, are affected by changes in lighting and facial expressions. And critics say it is susceptible to fraud. The government's biometric trials for passports and identity cards have reportedly experienced a 10% error rate in face recognition. The Home Office denies this and insists the trials were only testing the procedures and the public response, not the technology. (C)BBC

Keyword: Emotions
Link ID: 6488 - Posted: 11.25.2004

If you can't get a good night's sleep it's likely that your parents are at least partly to blame. Researchers have found genetic factors play a major role in sleep disorders such as severe snoring and involuntary leg jerking. The findings are based on a study of almost 2,000 pairs of female twins by the Twin Research Unit at St Thomas' Hospital, London. Details will be published in the journal Twin Research. Previously it had been thought that problems such as snoring were probably due to factors such as being overweight, or sleeping in the wrong position. Among the conditions examined by the St Thomas' team were obstructive sleep apnoea (OSA) and restless leg syndrome (RLS). OSA is a severe form of snoring in which the throat narrows to the point where breathing becomes momentarily impossible. The condition, which affects approximately 24% of men and 9% of women aged 30 to 60, can destroy the ability to sleep soundly, and leaves sufferers exhausted. It has been blamed for road traffic accidents where people have fallen asleep behind the wheel. RLS causes an irritating, non-painful sensation in the legs, which compels suferers to keep moving them, and keeps them awake throughout the night. Researcher Dr Adrian Williams said: "Sleep disorders are surprisingly common and it is increasingly recognised that they can have a devastating impact on sufferers' everyday lives - they are no laughing matter." (C)BBC

Keyword: Sleep; Genes & Behavior
Link ID: 6487 - Posted: 11.25.2004

By ANDREW POLLACK The Food and Drug Administration yesterday approved a drug for multiple sclerosis that has shown early evidence of being more effective than existing drugs. The drug, Tysabri, was developed by Biogen Idec and Elan and was called Antegren until the F.D.A. requested a name change to avoid confusion with other drugs. Some analysts predict annual sales will eventually surpass $2 billion. Doctors and analysts say the drug represents an advance but is far from a cure. Long-term data on safety and efficacy are still lacking. "The initial data suggests that it's better than the other drugs but it doesn't shut it off completely," said Howard L. Weiner, a professor at Harvard and head of the multiple sclerosis center at Brigham and Women's Hospital in Boston. The F.D.A. approved the drug based on only one year's worth of data from clinical trials, rather than the two customarily required, because of positive results. In one trial, Tysabri reduced the rate of relapses - the flaring up of symptoms - by two-thirds, to 25 per 100 patients per year compared with 74 per 100 patients per year for a placebo. Copyright 2004 The New York Times Company

Keyword: Multiple Sclerosis
Link ID: 6486 - Posted: 11.25.2004