A highly sensitive post-mortem test could help scientists more accurately determine if a person died of Creutzfeldt-Jakob disease (CJD), a human neurological disorder caused by the same class of infectious proteins that trigger mad cow disease, according to a new study supported in part by the National Institutes of Health (NIH). The finding opens the possibility that such testing might be refined in the future so it can be used to detect prion disease in living people and animals before the onset of symptoms. The test, called conformation-dependent immunoassay (CDI), was originally developed to detect various forms of disease-causing proteins called prions in cows, sheep, deer and other animals. In the new study, researchers led by Jiri Safar, M.D., Bruce Miller, M.D., Michael Geschwind, M.D., Stephen DeArmond, M.D., and Nobel Laureate Stanley B. Prusiner, M.D., of the University of California, San Francisco, found that CDI not only identifies prions in human brain tissue but is faster and far more precise than the standard immunological detection methods, which only detect a small fraction of the infectious prions that may be in the brain. The finding appears in the March 1, 2005 issue of the Proceedings of the National Academy of Sciences, www.pnas.org. Two components of the NIH, the National Institute of Neurological Disorders and Stroke (NINDS)* and the National Institute on Aging (NIA), supported the study. Additional support was provided by the John Douglas French Foundation for Alzheimer's research, the McBean Foundation, and the Alzheimer's Disease Research Center of California.

Keyword: Prions
Link ID: 6869 - Posted: 02.15.2005

By Jennifer Viegas, Discovery News — If a man and a woman are in love, the bewitched fellow loses testosterone — a hormone linked to strength and aggressiveness — while his female partner actually gains some of the potent male hormone and its effects, according to a recent study. The findings, published in the current Harvard Health Letter, suggest that love brings members of the opposite sex together by reducing some of their differences. Researchers made the determination after comparing 24 young adults who had recently fallen in love with the same number of people currently not feeling love pangs. Blood was drawn from all of the test subjects. It then was analyzed for hormonal contents, which revealed the testosterone female spike and male drop. Donatella Marazziti and colleague Domenico Canale, University of Pisa scientists who conducted the study, are not sure why men in love lose testosterone while women in love gain it. Marazziti told Discovery News that the changes might be linked to sexual behavior. The blood test also revealed that all people in love, both men and women, gain heightened levels of cortisol, a hormone linked to stress. Copyright © 2005 Discovery Communications Inc

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 6868 - Posted: 06.24.2010

A pioneering form of gene therapy has apparently cured deafness in guinea pigs, raising hopes that the same procedure might work in people. "It's the first time anyone has biologically repaired the hearing of animals," says Yehoash Raphael at the University of Michigan in Ann Arbor, Michigan, and head of the US-Japanese team that developed the technique. The therapy promotes the regrowth of crucial hair cells in the cochlea, the part of the inner ear which registers sound. After treatment, the researchers used sensory electrodes around the animals' heads to show that the auditory nerves of treated - but not untreated - animals were now registering sound. Deafness is a major problem in people: millions of people worldwide become deaf or hearing impaired every year. This can occur if a person's inner-ear hair cells are destroyed by exposure to loud noise, to some antibiotic drugs, or simply through old age. The hair cells act like miniature microphones, capturing sound vibrations from fluid in the ear and translating the movement into nerve signals. Raphael says one future possibility would be to use the therapy to improve hearing in people who already wear cochlear implants. These electrical devices are of some help to people lacking hair cells, but the regrowth of even some hairs could boost their hearing further. Raphael says that the next experiments in guinea pigs will focus on this combination. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 6867 - Posted: 06.24.2010

Philip Ball An inability to process language needn't stop you from doing maths, UK researchers have found. They say that three men with severe aphasia, a linguistic impairment, can understand 'grammatical' rules in mathematics even though they cannot handle analogous rules in language. Aphasia leaves people unable to use or comprehend words, and is often triggered by stroke or other brain injuries. The discovery challenges a commonly held view that linguistic and mathematical mental processing draw on the same cognitive resources. "Our findings very strongly turn that idea on its head," says Rosemary Varley, a cognitive neuroscientist at the University of Sheffield, UK. The research is published in Proceedings of the National Academy of Sciences1. According to the view of cognition developed by linguist Noam Chomsky, language processing is a fundamental skill that is used for related grammatical tasks in the brain, such as certain mathematical ones. Previous studies of the relationship between linguistic and mathematical ability have lent some support to this notion. ©2005 Nature Publishing Group

Keyword: Language
Link ID: 6866 - Posted: 06.24.2010

David Perlman, Chronicle Science Editor There stood Jack Dumbacher, innocently trying to trap a gorgeous bird of paradise in the mist net he'd set up for his research in a New Guinea forest, when the net entangled a flying stranger, all vivid orange and black. The unwanted bird clawed Dumbacher's fingers, nipped them with its beak, and when the startled scientist put a bleeding finger to his mouth, he suddenly felt a burning, tingling sensation on his tongue and lips -- which soon became briefly numb. The bird was a hooded pitohui (pronounced PIT-a-hooey), and the encounter in Papua New Guinea 15 years ago led the ornithologist to abandon his research into birds of paradise and to follow a mysterious, deadly poison that links the birds in the highland Papuan villages to frogs in the lowland South American jungles of Colombia -- and to beetles in both far-off habitats. Dumbacher and his colleagues have now discovered that a family of beetles in New Guinea and their distant relatives more than 9,500 miles away, on the other side of the Pacific, are apparently responsible for the toxins in Dumbacher's pitohui birds -- the first poisonous birds discovered anywhere - - and Phyllobates terribilis, the poison-dart frogs of Colombia. The frogs got their name because the Choco Indians use the same poison to tip their arrows and blowpipe darts when they hunt for monkeys and other game animals. ©2005 San Francisco Chronicle

Keyword: Neurotoxins
Link ID: 6865 - Posted: 06.24.2010

Arthur L. Caplan Is the pharmaceutical industry a dangerous and crooked business that federal and state authorities need to bring to heel? Should those who develop, market or prescribe drugs hang their heads in shame when faced with the stark reality of what they do to earn a living? Is Big Pharma in fact the moral equivalent of the tobacco industry? One could well come away from Marcia Angell's The Truth about the Drug Companies or Jerome Kassirer's On the Take thinking so. In both books, the sort of moral opprobrium once directed against Big Tobacco is aimed squarely at the pharmaceutical industry, along with its legions of lobbyists, the politicians awash in its campaign contributions and the doctors it has bought, free meal by free meal, junket by junket, free sample by free sample and trinket by trinket. Kassirer and Angell, who are physicians at Tufts and Harvard, respectively, and who are both former editors of the New England Journal of Medicine, are not the only authors currently taking a critical look at industry excesses. Harvard physician and pharmacoepidemiologist Jerry Avorn also has a new book examining some of the problems with the way prescription drugs are brought to market, the thoughtful and incisive Powerful Medicines. It's not hard to see why demonization of the pharmaceutical industry has become such a popular sport. As Avorn points out, drug companies are now so obsessed with profits that they are no longer willing to pay for the innovative research that they claim justifies the high cost of their products. He and Angell each demonstrate that the numbers do not support the contention that without high prices there would be no money for the next generation of miracle drugs. © Sigma Xi, The Scientific Research Society

Keyword: Drug Abuse
Link ID: 6864 - Posted: 06.24.2010

Take a moment and look at a picture near you. What did you see? How long did it take you to understand what was in the image, meaning how long did it take you to realize the green blob was a tree? Or that the orange circle was a piece of fruit? Most likely you assume that it took you no time at all, you just knew. Psychologists who study how we perceive images used to think that, before the process of object recognition and categorization could begin, the brain must first separate the figure in the image—such as a tree, or a piece of fruit—from its background. However, new research shows we actually categorize objects before we identify them. It means that, by the time your brain even realizes you are looking at something, you already know what that thing is. The new research was conducted by Kalanit Grill-Spector of Stanford University and Nancy Kanwisher of the Massachusetts Institute of Technology. Their article, "Visual Recognition: As Soon as You Know It’s There, You Know What It Is," will appear in the February 2005 issue of Psychological Science, a journal of the American Psychological Society.

Keyword: Attention; Vision
Link ID: 6863 - Posted: 06.24.2010

Sometimes the mere act of eating can make us happy, but new research suggests that consuming the right foods is enough to relieve depression. Two nutrients found in foods such as fish, walnuts, and beets worked as well as prescription antidepressants in preventing depression in rats. The findings may shed new light what causes the disorder and may lead to new therapies for depression. Despite decades of research, scientists are still puzzled about what exactly happens in the brain during bouts of depression. Some cultures suffer less from the disorder, and many researchers believe diet plays a role. But teasing out the culinary panacea has been slow going. Research has linked omega-3 oil, available as an over-the-counter nutritional supplement, to cardiovascular health, and it also appears to improve mood and cognitive function. Other studies suggest that the nutrient uridine also affects brain function. A team of researchers led by neurobiologist William Carlezon at Harvard's McLean Hospital in Belmont, Massachusetts, studied how omega-3 fatty acids and uridine affect the behavior of rats using a standard depression test. Rats forced to swim in chilled water with no way to escape will normally become hopeless and float motionlessly. But when treated with prescription antidepressants, rats remain active longer, searching for an escape. The team found that rats whose diets were supplemented with high levels of omega-3 oil for at least 30 days stayed active and focused on escape. Similarly, rats injected with high levels of uridine were equally tenacious. These results were not seen in untreated rats, the team reports in the 15 February issue of Biological Psychiatry. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Depression
Link ID: 6862 - Posted: 06.24.2010

Hamilton, ON - A meticulous diary kept by a mother of twins has revealed indicators of autistic behaviour in children as young as six months of age. The findings are published today in Neurocase. Mel Rutherford, assistant professor of psychology at McMaster University, says the diary provides a rare and unprecedented opportunity to observe the early development of autism. She says the mother of fraternal twins recorded her observations almost daily for about five years, beginning before the twins’ birth. She charted the children’s development in speech, social interactions, growth, and sleep disturbances, unaware that one twin was autistic until a diagnosis was made at three years of age. “It appears that children with autism develop normally for six months, and then begin developing atypically,” says Rutherford. “As typical children begin to accelerate in social development, the child with autism makes only minor gains.” During the first six months, both twins smiled, engaged in socially responsive vocalization, and showed a preference for family members over other people. By the age of one, however, the male twin showed less eye contact, less verbal communication, and less affection toward others than did his sister. His sleep patterns were also noticeably different from his sister’s. By the age of two, the boy had developed a fixation on particular patterns and puzzles; at age three, a child psychologist noted the boy “did not offer comfort if others are in distress and will not come for comfort is he is hurt.” The mother’s diary tells of her son’s facial expressions that ranged from limited to “spaced-out'.

Keyword: Autism
Link ID: 6861 - Posted: 06.24.2010

Treatments for mood and anxiety disorders are thought to work, in part, by helping patients control the stresses in their lives. A new study in rats by National Institutes of Health (NIH) grantees provides insight into the brain mechanisms likely involved. When it deems a stressor controllable, an executive hub in the front of the brain quells an alarm center deep in the brainstem, preventing the adverse behavioral and physiological effects of uncontrollable stress. "It's as if the prefrontal cortex says: 'Cool it, brainstem! We have control over this and there is no need to get so excited'," quipped Steven Maier, Ph.D., University of Colorado, whose study was funded by the National Institute of Mental Health (NIMH) and the National Institute on Drug Abuse (NIDA). Maier and colleagues posted their findings online in Nature Neuroscience, February 6, 2005. Lack of control over stressful life experiences has been implicated in mood and anxiety disorders. Rats exposed to uncontrollable stress develop learned helplessness, a syndrome similar to depression and post traumatic stress disorder (PTSD). They lose the ability to learn how to escape stressors. Activation of a brainstem area (dorsal raphe nucleus) has been implicated in such reactions. But this area is too small and lacks the proper sensory inputs to judge whether a stressor is controllable. Many of its inputs come conspicuously from the mid-prefrontal cortex area (medial prefrontal cortex), seat of higher order functions, such as problem-solving and learning from experience. These signals are sent via the chemical messenger serotonin, which is involved in mood regulation and in mediating the effects of the most widely prescribed antidepressants. The medial prefrontal cortex has also been implicated as the source of an "all clear" signal that quells fear in rats.

Keyword: Stress
Link ID: 6860 - Posted: 02.12.2005

BUFFALO, N.Y. -- A behavioral neuroscientist at the University at Buffalo holds that the ingestion of afterbirth by a mother, a feature of pregnancy in nearly all non-human mammals, not only relieves postpartum pain, but optimizes the onset of maternal behavior by mediating the activity of specific opioid activity circuits in the brain. Mark Kristal, Ph.D., professor of psychology at UB and director the graduate program in behavioral neuroscience, has received a two-year $200,000 grant from the National Science Foundation, to test his hypothesis. In 1986 Kristal discovered an opioid-enhancing molecule he called the Placental Opioid-Enhancing Factor or POEF. His discovery led to a series of studies that shed light on the way in which POEF modulates how opioids inhibit nociceptive processing in the nervous system -- processing in specific areas of the brain that recognize certain kinds of pain. Kristal says this research may lead to novel ways of treating addiction in humans by manipulating the effectiveness of the opiates we produce in our own bodies. It also may enable physicians to obtain current levels of pain relief, he says, "by administering much, much, much smaller amounts of opioid analgesics."

Keyword: Pain & Touch; Sexual Behavior
Link ID: 6859 - Posted: 02.12.2005

Nathan Seppa Terrible sadness, a sudden fright, or other emotional stress can bring on heart attack symptoms in people not actually experiencing a heart attack, according to two new reports. The researchers examined people who showed up at hospitals with chest pain and an impaired capacity to pump blood but no heart-tissue damage or clogged coronary arteries. Rather, the patients turned out to be experiencing physical effects after stressful events, such as the death of a loved one. Cardiologist Hunter C. Champion of Johns Hopkins Medical Institutions in Baltimore and his colleagues treated 18 women and 1 man with severe symptoms. After initial tests had ruled out a heart attack, bedside talks revealed that all the patients had recently had a stressful experience. These included the death of spouse, a car accident, an armed robbery, a family dispute, a court appearance, and a surprise party. The patients had blood concentrations of catecholamine hormones that were more than seven times normal and two to three times as great as those in five patients having heart attacks triggered by coronary artery blockages. Catecholamines, which include adrenaline and dopamine, are powerful hormones that regulate heart rate, blood pressure, and other body processes. The researchers report their findings in the Feb. 10 New England Journal of Medicine. Copyright ©2005 Science Service.

Keyword: Stress; Emotions
Link ID: 6858 - Posted: 06.24.2010

A German study has added weight to the argument that a herbal remedy is an effective treatment for depression. Researchers compared the effectiveness of St John's wort to anti-depressant drug paroxetine in treating moderate and severe depression. The team found half of those with the condition improved when given the herb, compared with a third using the drug, the British Medical Journal reported. UK experts said the study of 244 people should be treated with caution. The study also found patients on paroxetine - also known as Seroxat - suffered more side effects. In both cases the most common side effect was stomach upsets, the study by Karlsruhe-based Dr Willmar Schwabe Pharmaceuticals and the Institute for Medical Research Management and Biometrics in Nurnberg found. Report co-author Dr Meinhard Kieser said: "Our results support the use of St John's wort as an alternative to standard anti-depressants in moderate to severe depression, especially as it is well tolerated." The herb is not recommended for use by the UK's National Institute for Clinical Excellence (Nice) because of uncertainty about what constitutes an appropriate dose, and its potential side effects when mixed with other drugs. However its guidelines do acknowledge there is some evidence to suggest St John's wort could benefit people with mild or moderate depression. Previous studies have produced mixed results about whether it is effective in treating more serious forms of depression. The herb, which is extracted from bright yellow star-shaped flowers, has been used for centuries as a folk medicine for anxiety and stress. (C)BBC

Keyword: Depression
Link ID: 6857 - Posted: 02.11.2005

By GARDINER HARRIS and BENEDICT CAREY ASHINGTON, - A day after Canadian officials suspended the use of a hyperactivity drug amid reports of deaths associated with its use, Senator Charles E. Grassley of Iowa contended that United States health officials had asked the Canadian regulators not to do so. Senator Grassley, a Republican, said on Thursday that the Food and Drug Administration had made the request of Canadian health officials because the F.D.A. could not handle another "drug safety crisis." Mr. Grassley said he was basing his contentions on reports from whistle-blowers within the agency. Dr. Robert Peterson, director general of the therapeutic products directorate at Health Canada, said through a spokeswoman that reports that F.D.A. had asked Health Canada to refrain from suspending the drug "are untrue." Brad Stone, a spokesman for the F.D.A., declined to respond directly to Mr. Grassley's contention but said of Dr. Peterson's rejection that, "We believe the Canadian response is the correct one."Canadian health officials, citing 20 deaths among patients taking the British-made drug Adderall XR, said on Wednesday night that they were suspending sales of the hyperactivity drug indefinitely. The F.D.A. is allowing the drug to continue to be sold in the United States, saying there is little evidence that Adderall XR caused the deaths. Copyright 2005 The New York Times Company

Keyword: ADHD
Link ID: 6856 - Posted: 02.11.2005

Psychologists from McMaster University have discovered that the aging process improves certain abilities -- the ability to grasp the 'big picture'. The study, published in the journal Neuron dispels the myth that older people perform slower and worse than younger people. "Going into the study, we knew that ageing changes the way people see the world," says Allison Sekuler, one senior author of the study. "But these results are an unusual twist on the standard 'ageing makes you worse' story, and they provide clear insight into what is changing in the ageing brain." The researcers measured how long it took for study participants to indicate which direction a set of bars moved across a computer screen. Younger participants were faster when the bars were small or low in contrast. When the bars were large and high in contrast, however, the older people were faster. "The results are exciting not only because they show an odd case in which older people have better vision than younger people, but also because it may tell us something about how ageing affects the way signals are processed in the brain" says Patrick Bennett, the other senior author. Copyright © 2005 Plebius Presstm

Keyword: Alzheimers
Link ID: 6855 - Posted: 06.24.2010

Carved out in our collective imagination is a carpenter's workshop in the Italian story "Pinocchio," where a wooden puppet with an ever-growing nose informs millions of children what might happen if they lie. In real life, who hasn't wished the liars in their world were as transparent? The good news is that researchers are finding clues in the body that—with the right training—might tell you how to spot when someone's trying to pull a fast one. Psychologist Paul Ekman, a professor at the University of California, San Francisco is working with the Department of Defense on software that analyzes facial muscles to help detect liars. "There are movements of the face that can show an emotion that doesn't fit with what the person's saying," Ekman explains. "We call that a 'hot spot,' which means that you are not getting a full account." To first prove that people's faces differ when they lie, Ekman videotaped 11 men truthfully discussing a topic they felt strongly about and nine men lying about their stance. Volunteers watched the tapes and tried to spot liars. Ekman reported that 90 percent of the liars' faces showed fear and disgust whereas only 30 percent of truth tellers displayed these emotions. He calls these concealed emotions 'microexpressions.' "They look just like ordinary expressions except that they are on the face for about a 25th of a second," explains Ekman. © ScienCentral, 2000- 2005.

Keyword: Emotions
Link ID: 6854 - Posted: 06.24.2010

How do you make babies, give them a decent start in life, and send them off to perpetuate the species from a lightless, toxic environment in the bowels of the ocean? Scientists studying deep-sea tubeworms have unmasked one secret to their success: Females fertilize their eggs internally and release the resulting embryos at an early developmental stage, optimizing their chances for survival and long-distance dispersal. Ever since the discovery of gutless vestimentiferan worms in 1977, researchers have puzzled over how the worms colonize highly ephemeral, unstable hydrothermal vent habitats spaced hundreds of kilometers apart. The prevailing theory holds that, like other marine invertebrates, tubeworms release masses of eggs and sperm in a hit-or-miss manner, called broadcast spawning, into the surrounding waters. But the new study indicates that this isn't the case. Biology graduate student Ana Hilįrio of the University of Southampton in the United Kingdom, and her colleagues used a deep-sea submersible to collect tubeworms of five species from Pacific vents and cold seeps in the Gulf of Mexico. In thin slices of the females' reproductive tracts, Hilįrio found a hook-shaped region, called the spermatheca, where sperm are stashed and eggs undergo fertilization before spawning. At the study sites, fertilized eggs released naturally and collected over a period of days proved to be in very early stages of development, indicating that fertilization occurs internally rather than outside the worms. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 6853 - Posted: 06.24.2010

Communication in the brain travels from one nerve cell to another through critical connections called synapses. These neuron-to-neuron junctions form early in brain development, and their construction was thought to be guided by the nerve cells themselves. Now, investigators supported by the National Institute on Drug Abuse (NIDA), National Institutes of Health, have discovered that cells called glia, known to provide support for neurons in the mature brain, also play a crucial role in formation of synapses during the surge of development following birth. This key insight into the process of normal synapse development may lead to improved treatment of conditions such as drug addiction and epilepsy, which are characterized in part by too many synapses. The research, led by Dr. Ben Barres of Stanford University School of Medicine in Stanford, California, is reported in the February 11, 2005 issue of the journal Cell. “Synapses are the key connections between cells in the brain. We know that drugs alter these connections, and that the developing brain is vulnerable to addictive drugs’ disruption of normal communication,” says NIDA Director Dr. Nora D. Volkow. “Compounds that direct synapse formation may offer a therapeutic option for people fighting drug addiction or other neurologic conditions.” Glia account for 90 percent of the cells in a mammalian brain, but until recently scientists focused mainly on the supportive role that glial cells play in helping mature neurons survive. Dr. Barres, along with Stanford postdoctoral fellows Dr. Karen Christopherson and Dr. Erik Ullian, developed a method for growing neurons in a laboratory without glial cells.

Keyword: Development of the Brain
Link ID: 6852 - Posted: 06.24.2010

ATLANTA – When it comes to aging, women may have another reason to be thankful. Research conducted in nonhuman primates at the Yerkes National Primate Research Center of Emory University shows male nonhuman primates are more susceptible to age-related cognitive decline. The February issue of Behavioral Neuroscience reports this finding, which the researchers say has implications for developing sex-specific therapies to help humans guard against age-related memory loss. By observing that older male nonhuman primates' spatial memory, which is responsible for recording environmental and spatial-orientation information, declines at a greater rate than that of females, researchers led by Agnčs Lacreuse, PhD, assistant research professor, and James Herndon, PhD, associate research professor, both in Yerkes' Division of Neuroscience, concluded a species' sex may influence age-related cognitive decline. "Given that spatial memory is sensitive to sex differences in humans and in nonhuman primates, we decided to focus our study on determining how cognitive aging differs between the sexes," said Lacreuse. According to Lacreuse, such sex differences have not been studied frequently in humans, and when they have, the data has been inconsistent.

Keyword: Alzheimers; Sexual Behavior
Link ID: 6851 - Posted: 06.24.2010

Roxanne Khamsi Listen up: mammals seem to have evolved the delicate bone structure of the middle ear at least twice. The surprising discovery comes from a fossil, found off the southern coast of Australia, that belongs to an ancestor of the platypus. Modern mammals are unique among vertebrates for possessing three tiny bones in the middle ear. The malleus, incus and stapes (commonly known as the hammer, anvil and stirrup) work as part of a chain that transmits sound towards the skull. Birds and reptiles have only one bone to perform this function. Because the mammalian arrangement is so complex, scientists believed that the set-up had evolved on just a single occasion, in an ancestor that gave rise to placental animals (including humans), marsupials and monotremes (such as the duck-billed platypus). All this changed when James Hopson, a vertebrate palaeontologist at University of Chicago, Illinois, took a trip to Australia. There he met a team of researchers including Thomas Rich of Museum Victoria in Melbourne. ©2005 Nature Publishing Group

Keyword: Evolution; Hearing
Link ID: 6850 - Posted: 06.24.2010