By Susan Milius Donkeys sleep about three out of each 24 hours. Certain reef fish spend the night moving their fins as if swimming in their sleep. Some biologists argue that all animals sleep in some form or another. But identifying sleep can get complicated. Insects have brain architecture so different from humans’, for example, that electrophysiological recordings during “sleep” won’t match human patterns. The real problem may be that researchers haven’t agreed on what sleep does for people, so it’s hard to agree on the animal equivalent. Studying animal sleep, though, offers the prospect of discerning evolutionary patterns in sleep pointing to some ancient function. Fruit fly 8–10 hours of inactivity each day Lab fruit flies droop into less-responsive, sleeplike periods mostly at night. If deprived of these quiet bouts, flies spend extra time stationary later, as if catching up. Caffeine keeps them awake, and antihistamines increase downtime. Studies haven’t found REM patterns, but brain activity does shift during the droops. White-crowned sparrow 3–8 hours (depends on season) During migration season, white-crowned sparrows perplex researchers with the birds’ apparent power to cheat on sleep. Birds get not quite 40 percent as much sleep as usual, with drops in both slow-wave and REM sleep. Yet the birds don’t get stupid in performance tests. © Society for Science & the Public 2000 - 2009

Keyword: Sleep; Evolution
Link ID: 13341 - Posted: 06.24.2010

By Michael Torrice Even with their tiny bird brains, rooks comprehend basic principles of physics at the same level as a 6-month-old baby--and beyond that of chimpanzees--a new study reports. But whether this understanding conveys any advantages remains an open question. Rooks and other members of the crow family can manipulate tools and solve laboratory puzzles like those of Aesop's fables. Some scientists believe that these feats suggest the birds have a sophisticated understanding of physical principles—--an understanding that allows them to solve problems they wouldn't encounter in the real world. To further test the theory, Christopher Bird, a zoologist at the University of Cambridge in the United Kingdom, and his colleague Nathan Emery at of Queen Mary, University of London, "quizzed" rooks on a basic concept of physics they call "support." The duo adapted a standard experiment: Infants and other primates know that an object will fall if something is not holding it up; they stare for longer than normal at images of a ball or banana floating in mid air, for example, suggesting they know that something unusual is going on. Rooks, it turns out, do the same. The researchers set up a peep hole for the birds to peer into. (Rooks are natural peeping tToms and will spy through small holes or cracks looking for other rooks.) On the other side were images depicting eggs in various situations, both possible and impossible. Some eggs rested on a table, whilereas others floated above it. And in a more subtle twist, the researchers added a picture of an egg hovering in the air while its side or bottom touched the table's side. © 2009 American Association for the Advancement of Science

Keyword: Intelligence; Evolution
Link ID: 13340 - Posted: 06.24.2010

By Bruce Bower Rhesus macaque mothers and their babies like to get in each others’ faces, exchanging looks and smacking their lips. They’re neither rude nor hungry. Just as their human counterparts do, these monkeys communicate in a mutually pleasing way that prepares infants to navigate the social world, a new study suggests. Interactions between macaque moms and babies often begin with exaggerated lip smacking by the adult, who gently touches her infant’s lips and face with her mouth, ethologist Pier Ferrari of the University of Parma in Italy, and his colleagues report online October 8 in Current Biology. Mothers also lower their heads and then move them up and down while looking at babies seated nearby, as a prelude to lip smacking and mutual eye contact. For their part, macaque babies imitate lip smacking displayed by their mothers — but not by other females — within the first few days of life, Ferrari’s group reports. Infants then sometimes smack their lips at their mothers to initiate sustained eye contact. This distinctive form of communication disappears near the end of an infant’s first month of life, the researchers say. Macaque youngsters become highly mobile by that time and begin to forge peer relationships. Ferrari hypothesizes that macaque and human babies share an inborn capacity to communicate using emotional displays and gestures, to share experiences with others and to understand adults’ behaviors as having a purpose. © Society for Science & the Public 2000 - 2009

Keyword: Language; Animal Communication
Link ID: 13339 - Posted: 06.24.2010

By DENISE GRADY Many people with chronic fatigue syndrome are infected with a little known virus that may cause or at least contribute to their illness, researchers are reporting. The syndrome, which causes prolonged and severe fatigue, body aches and other symptoms, has long been a mystery ailment, and patients have sometimes been suspected of malingering or having psychiatric problems rather than genuine physical ones. Worldwide, 17 million people have the syndrome, including at least one million Americans. An article published online Thursday in the journal Science reports that 68 of 101 patients with the syndrome, or 67 percent, were infected with an infectious virus, xenotropic murine leukemia virus-related virus, or XMRV. By contrast, only 3.7 percent of 218 healthy people were infected. Continuing work after the paper was published has found the virus in nearly 98 percent of about 300 patients with the syndrome, said Dr. Judy A. Mikovits, the lead author of the paper. XMRV is a retrovirus, a member of the same family of viruses as the AIDS virus. These viruses carry their genetic information in RNA rather than DNA, and they insert themselves into their hosts’ genetic material and stay for life. Dr. Mikovits and other scientists cautioned that they had not yet proved that the virus causes the syndrome. In theory, people with the syndrome may have some other, underlying health problem that makes them prone to being infected by the virus, which could be just a bystander. More studies are needed to explain the connection. Copyright 2009 The New York Times Company

Keyword: Stress
Link ID: 13338 - Posted: 06.24.2010

Health Canada is informing consumers and health professionals of labelling changes for certain prescription sleep-aid medications. The new labelling describes reports of patients who have walked and talked in their sleep, or who even have cooked, eaten and driven while not fully awake. Patients typically did not remember these events afterwards, said Health Canada. The department is encouraging sleeping-pill users and people close to them to be aware of these types of sleep-related behaviours. Patients should report any suspected events to their health-care professional. The drugs are often prescribed as a short-term treatment for people who have difficulty falling asleep or who wake often through the night. Health Canada wants users to read the new labels because they emphasize the proper use of these medications. If patients experience such complex sleep-related behaviours, Health Canada suggests discontinuing the drug to avoid harming themselves and others. However, patients are advised to talk to their doctor before quitting cold turkey as abrupt discontinuation may cause withdrawal symptoms. The drugs, zolpidem, and zaleplon, are also included in the warning, but are not currently sold in Canada. © CBC 2009

Keyword: Sleep
Link ID: 13337 - Posted: 06.24.2010

by Jessica Hamzelou Birds prefer not to play out of their league. Some female zebra finches have been found to choose low-quality males rather than their superior competitors. It's the first time anything like this has been observed in nature. Marie-Jeanne Holveck and Katharina Riebel of Leiden University, the Netherlands, separated zebra finch chicks into either small groups of two to three chicks or larger groups of five to six chicks. The idea is that birds that grow up in big broods have fewer resources devoted to them and will be of a lower quality: weaker, weedier and poorer singers. Once the chicks had grown up, both low and high-quality females were placed in a cage where they could choose to listen to either a low or high-quality male song by pecking one of two red buttons. Of the 24 birds observed, every low-quality female chose the low-quality male song, and the high-quality females opted for males with high-quality songs. Holveck and Riebel then tested how birds of the same and different quality mated. When in a cage together, birds of the same quality were much quicker to mate than mismatched birds. When a low-quality female did mate with a high-quality partner, her eggs were larger. The authors reckon this is because the female knows she is doing better than she deserves, and will invest more nutrients into the eggs she lays. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Evolution
Link ID: 13336 - Posted: 06.24.2010

by Linda Geddes The contraceptive pill alters monthly fluctuations in hormones associated with the menstrual cycle, mimicking the more stable hormonal conditions associated with pregnancy. This might not only disrupt the natural processes which influence women's choice of partner, but it could also make them less able to compete with women who have a natural menstrual cycle, a paper published this week in Trends in Ecology and Evolution suggests. How worried should we be, and what other strategies can men and women use to tip the odds in their favour? New Scientist investigates. What do we know about how women choose a mate? Recent studies have confirmed that women tend to prefer taut bodies, broad shoulders, clear skin and defined, masculine facial features – all of which may indicate sexual potency and good genes. Women also tend to be attracted to men who look as if they have wealth, or the ability to acquire it. Smell may also be a factor: women seem to prefer the scent of men who have immune systems dissimilar to their own, as measured by genes for the major histocompatibility complex (MHC). A number of companies have sprung up recently that even claim to be able to match couples on the basis of their genes. How might the contraceptive pill interfere with this? © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 13335 - Posted: 06.24.2010

by Laura Spinney EARLIER this year, a puzzling report appeared in the journal Sleep Medicine. It described two Italian people who never truly slept. They might lie down and close their eyes, but read-outs of brain activity showed none of the normal patterns associated with sleep. Their behaviour was pretty odd, too. Though largely unaware of their surroundings during these rest periods, they would walk around, yell, tremble violently and their hearts would race. The remainder of the time they were conscious and aware but prone to powerful, dream-like hallucinations. Both had been diagnosed with a neurodegenerative disorder called multiple system atrophy. According to the report's authors, Roberto Vetrugno and colleagues from the University of Bologna, Italy, the disease had damaged the pair's brains to such an extent that they had entered status dissociatus, a kind of twilight zone in which the boundaries between sleep and wakefulness completely break down (Sleep Medicine, vol 10, p 247). That this can happen contradicts the way we usually think about sleep, but it came as no surprise to Mark Mahowald, medical director of the Minnesota Regional Sleep Disorders Center in Minneapolis, who has long contested the dogma that sleep and wakefulness are discrete and distinct states. "There is now overwhelming evidence that the primary states of being are not mutually exclusive," he says. The blurring of sleep and wakefulness is very clear in status dissociatus, but he believes it can happen to us all. If he is right, we will have to rethink our understanding of what sleep is and what it is for. Maybe wakefulness is not the all-or-nothing phenomenon we thought it was either. © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 13334 - Posted: 06.24.2010

People who believe that the mind can be replicated on a computer tend to explain the mind in terms of a computer. When theorizing about the mind, especially to outsiders but also to one another, defenders of artificial intelligence (AI) often rely on computational concepts. They regularly describe the mind and brain as the “software and hardware” of thinking, the mind as a “pattern” and the brain as a “substrate,” senses as “inputs” and behaviors as “outputs,” neurons as “processing units” and synapses as “circuitry,” to give just a few common examples. Those who employ this analogy tend to do so with casual presumption. They rarely justify it by reference to the actual workings of computers, and they misuse and abuse terms that have clear and established definitions in computer science—established not merely because they are well understood, but because they in fact are products of human engineering. An examination of what this usage means and whether it is correct reveals a great deal about the history and present state of artificial intelligence research. And it highlights the aspirations of some of the luminaries of AI—researchers, writers, and advocates for whom the metaphor of mind-as-machine is dogma rather than discipline. Conceptions of the Computer Before any useful discussion about artificial intelligence can proceed, it is important to first clarify some basic concepts. When the mind is compared to a computer, just what is it being compared to? How does a computer work? Ari N. Schulman, "Why Minds Are Not Like Computers," The New Atlantis, Number 23, Winter 2009, pp. 46-68.

Keyword: Robotics
Link ID: 13333 - Posted: 06.24.2010

By Virginia Morell A few years ago, researchers discovered that the babies of at least one species of bat make babbling sounds, much like human infants. Now, it turns out those babbling baby bats aren't just mindlessly cooing--they're imitating the songs of the big guys in their colonies: adult males with territories and harems. Such vocal imitation is rare in the animal kingdom, and it has never been found in nonhuman primates. The discovery should open a new window on the evolution of speech and language, scientists say. Scientists define complex vocal imitation as the ability to learn a call or song from a tutor--and they regard this talent as a key innovation in the evolution of speech. The rarified list of complex vocal imitators includes birds, elephants, cetaceans, seals, and humans. Researchers had long predicted that bats might also be capable of such imitation because of their extraordinary vocal flexibility; they use echolocation calls to navigate the physical world, for example, and social calls to communicate with their fellow bats. As behavioral ecologist Mirjam Knörnschild of the University of Ulm in Germany listened to sac-winged bats (Saccopteryx bilineata), she thought she heard complicated vocal imitation. These insectivorous Costa Rican bats live in harems of one male and as many as eight females, each of which can have one pup annually. The males defend small territories in their day-roosts with unique multiple-syllabic songs. Adult females don't sing, but their pups (males and females) do plenty of babbling. During such "babbling bouts," the pups often sing nearly complete renditions of the territorial songs, Knörnschild says, albeit shakier renditions. But were the pups simply combining fragments or actually listening and imitating their complete songs? © 2009 American Association for the Advancement of Science

Keyword: Animal Communication; Language
Link ID: 13332 - Posted: 06.24.2010

By BENEDICT CAREY More than 1 in 100 American children and teenagers may have autism, Asperger’s syndrome or a related developmental problem, although such diagnoses often do not hold up, according to a government report released on Monday. The estimate, based on a telephone survey of some 78,000 households and published in the journal Pediatrics, is the highest yet of the prevalence of so-called autism spectrum disorders, which include everything from severe autism to milder social difficulties to “pervasive developmental disorder,” a description given to many troubled children. Nearly 40 percent of the children in the study who were given such a diagnosis grew out of it or no longer qualified for it, the study found. The estimate is based on those whose parents said they were currently struggling with one of the disorders. Prevalence estimates for autism-related disorders have increased so quickly over the past decade — to 1 in 150 in 2007, from 1 in 300 in the early 2000s — that researchers have debated whether the disorder is in fact becoming more common or is simply diagnosed more often. The new survey is not likely to settle the question. “This is an excellent study, but what it looks at is the prevalence of the diagnosis, not the disorder,” said Dr. Susan L. Hyman, a pediatrician at Golisano Children’s Hospital in Rochester. “The next step scientifically is to see whether those diagnoses are being made accurately.” Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 13331 - Posted: 06.24.2010

By ROBIN MARANTZ HENIG Jerome Kagan’s “Aha!” moment came with Baby 19. It was 1989, and Kagan, a professor of psychology at Harvard, had just begun a major longitudinal study of temperament and its effects. Temperament is a complex, multilayered thing, and for the sake of clarity, Kagan was tracking it along a single dimension: whether babies were easily upset when exposed to new things. He chose this characteristic both because it could be measured and because it seemed to explain much of normal human variation. He suspected, extrapolating from a study he had just completed on toddlers, that the most edgy infants were more likely to grow up to be inhibited, shy and anxious. Eager to take a peek at the early results, he grabbed the videotapes of the first babies in the study, looking for the irritable behavior he would later call high-reactive. No high-reactors among the first 18. They gazed calmly at things that were unfamiliar. But the 19th baby was different. She was distressed by novelty — new sounds, new voices, new toys, new smells — and showed it by flailing her legs, arching her back and crying. Here was what Kagan was looking for but was not sure he would find: a baby who essentially fell apart when exposed to anything new. Baby 19 grew up true to her temperament. This past summer, Kagan showed me a video of her from 2004, when she was 15. We sat in a screening room in Harvard’s William James Hall — a building named, coincidentally, for the 19th-century psychologist who described his own struggles with anxiety as “a horrible dread at the pit of my stomach ... a sense of the insecurity of life.” Kagan is elfin and spry, balding and bespectacled. He neither looks nor acts his age, which is 80. He is one of the most influential developmental psychologists of the 20th century. Copyright 2009 The New York Times Company

Keyword: Emotions; Genes & Behavior
Link ID: 13330 - Posted: 06.24.2010

By RONI CARYN RABIN When Sherean Malekzadeh Allen of Marietta, Ga., learned she was pregnant, she was 43, had been married for two years, had gone through two miscarriages and had all but given up hope of having a baby. But instead of being overjoyed, Ms. Allen was immobilized: panic-ridden, nauseated, listless and thoroughly depressed. She could not rouse herself to go to work in the marketing business she founded and ran, or even get through the newspaper. And she faced the pregnant woman’s quintessential dilemma: take drugs that might pose a risk to the developing baby, or struggle through an anguishing pregnancy that could harm the baby in other ways? “Every single thing you put in your body when you’re pregnant, you wonder, ‘Oh, my God, am I growing my baby an extra finger?’ ” Ms. Allen said. “I was worried that I would hurt the baby if I took the pills, and I was worried I would hurt the baby if I didn’t.” As many as a quarter of all pregnant women suffer from depression, and about an eighth use an antidepressant at some time during pregnancy, according to 2003 figures. Although many antidepressants appear to be fairly safe, studies have reported links between maternal use and a small increased risk of some fetal malformations. Other potential problems for the newborn include drug withdrawal and persistent pulmonary hypertension, which can impair blood flow to the lungs. Copyright 2009 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 13329 - Posted: 06.24.2010

Pregnant women exposed to a common chemical found in plastics are more likely to have daughters with aggressive and hyperactive behaviours, suggests a new study that tested two-year-olds. The University of North Carolina study, which included a senior scientist from Simon Fraser University in British Columbia, is the first to examine the link between exposure to bisphenol A during pregnancy and behaviour problems in kids. The results are consistent with other studies showing the impact of the chemical on juvenile female animals. Bisphenol A, also known as BPA, has also been linked to reproductive problems and diabetes. It's used to make hard, clear reusable water bottles, baby bottles and resins that line the inside of metal food and beverage cans. Last October, Canada became the first country in the world to ban BPA-containing baby bottles. Some U.S. jurisdictions, including Cincinnati, have legislation that bans or limits the use of the chemical in consumer products. Bruce Lanphear, a Simon Fraser University professor of children's environmental health, said the study suggests pregnant women should start thinking about the effects of bisphenol A long before they lug home baby bottles. The study, published Tuesday in the journal Environmental Health Perspectives, measured the BPA levels in urine samples taken from 249 pregnant women in Cincinnati at 16 and 26 weeks pregnancy and again when they gave birth. © CBC 2009

Keyword: Aggression; Neurotoxins
Link ID: 13328 - Posted: 06.24.2010

Immunization with an experimental anti-cocaine vaccine resulted in a substantial reduction in cocaine use in 38 percent of vaccinated patients in a clinical trial supported by the National Institute on Drug Abuse (NIDA), a component of the National Institutes of Health. The study, published in the October issue of the Archives of General Psychiatry, is the first successful, placebo-controlled demonstration of a vaccine against an illicit drug of abuse. Like vaccines against infectious diseases such as measles and influenza, the anti-cocaine vaccine stimulates the immune system to produce antibodies. Unlike antibodies against infectious diseases, which destroy or deactivate the disease-causing agents, anti-cocaine antibodies attach themselves to cocaine molecules in the blood, preventing them from passing through the blood-brain barrier. By preventing the drug’s entry into the brain, the vaccine inhibits or blocks the cocaine-induced euphoria. This study included 115 patients from a methadone maintenance program who were randomly assigned to receive the anti-cocaine vaccine or a placebo (inactive) vaccine. Participants were recruited from a methadone maintenance program because their retention rates are substantially better than programs focused primarily on treatment for cocaine abuse. Participants in both groups received five vaccinations over a 12-week period and were followed for an additional 12 weeks. All participants also took part in weekly relapse-prevention therapy sessions with a trained substance abuse counselor, had their blood tested for antibodies to cocaine, and had their urine tested three times a week for the presence of opioids and cocaine.

Keyword: Drug Abuse
Link ID: 13327 - Posted: 06.24.2010

By Nira Liberman and Oren Shapira Love has inspired countless works of art, from immortal plays such as Romeo and Juliet, to architectural masterpieces such as the Taj Mahal, to classic pop songs, like Queen's “Love of My Life”. This raises the obvious question: why is love such a stimulating emotion? Why does the act of falling in love – or at least thinking about love – lead to such a spur of creative productivity? One possibility is that when we’re in love we actually think differently. This romantic hypothesis was recently tested by the psychologists Jens Förster, Kai Epstude, and Amina Özelsel at the University of Amsterdam. The researchers found that love really does alter our thoughts, and that this profound emotion affects us in a way that is different than simply thinking about sex. The clever experiments demonstrated that love makes us think differently in that it triggers global processing, which in turn promotes creative thinking and interferes with analytic thinking. Thinking about sex, however, has the opposite effect: it triggers local processing, which in turn promotes analytic thinking and interferes with creativity. Why does love make us think more globally? The researchers suggest that romantic love induces a long-term perspective, whereas sexual desire induces a short-term perspective. This is because love typically entails wishes and goals of prolonged attachment with a person, whereas sexual desire is typically focused on engaging in sexual activities in the "here and now". Consistent with this idea, when the researchers asked people to imagine a romantic date or a casual sex encounter, they found that those who imagined dates imagined them as occurring farther into the future than those who imagined casual sex.

Keyword: Emotions; Sexual Behavior
Link ID: 13326 - Posted: 06.24.2010

by Kathleen McGowan Why does being bad feel so good? Pride, envy, greed, wrath, lust, gluttony, and sloth: It might sound like just one more episode of The Real Housewives of New Jersey, but this enduring formulation of the worst of human failures has inspired great art for thousands of years. In the 14th century Dante depicted ghoulish evildoers suffering for eternity in his masterpiece, The Divine Comedy. Medieval muralists put the fear of God into churchgoers with lurid scenarios of demons and devils. More recently George Balanchine choreographed their dance. Today these transgressions are inspiring great science, too. New research is explaining where these behaviors come from and helping us understand why we continue to engage in them—and often celebrate them—even as we declare them to be evil. Techniques such as functional magnetic resonance imaging (fMRI), which highlights metabolically active areas of the brain, now allow neuroscientists to probe the biology behind bad intentions. The most enjoyable sins engage the brain’s reward circuitry, including evolutionarily ancient regions such as the nucleus accumbens and hypothalamus; located deep in the brain, they provide us such fundamental feelings as pain, pleasure, reward, and punishment. More disagreeable forms of sin such as wrath and envy enlist the dorsal anterior cingulate cortex (dACC). This area, buried in the front of the brain, is often called the brain’s “conflict detector,” coming online when you are confronted with contradictory information, or even simply when you feel pain. The more social sins (pride, envy, lust, wrath) recruit the medial prefrontal cortex (mPFC), brain terrain just behind the forehead, which helps shape the awareness of self.

Keyword: Emotions; Drug Abuse
Link ID: 13325 - Posted: 06.24.2010

By Angela Harrison Students could one day face dope tests to prove they have not boosted their academic performance with so called "smart drugs", a psychologist suggests. More students are turning to drugs in an attempt to boost their grades, writes Vince Cakic of Sydney University in the Journal of Medical Ethics. Among drugs apparently being used are those designed to treat hyperactivity and dementia. Some academics think their use can be a positive thing, if regulated. They say that although much written about the extent of drug use in the UK is anecdotal, studies at American universities suggest as many as one in four students on some campuses are taking stimulants. Mr Cakic said: "The possibility of purchasing 'smartness in a bottle' is likely to have broad appeal to students seeking to gain an advantage in an increasingly competitive world." The drugs would be near impossible to ban, he said. "As laughable as it may seem, it is possible that scenarios such as this [urine testing] could very well come to fruition in the future. "However, given that the benefits of [smart drugs] could also be derived from periods of study at any time leading up to examinations, this would also require drug testing during non-exam periods," he writes. "If the current situation in competitive sport is anything to go by, any attempt to prohibit the use ... will probably be difficult or inordinately expensive to police effectively," he warns. Experts working in the UK are divided on the issue between those who believe such drugs, if taken under supervision, are a legitimate way of boosting performance and those who warn of the health and social dangers of such use. (C)BBC

Keyword: Learning & Memory; ADHD
Link ID: 13324 - Posted: 10.05.2009

By Bruce Bower It’s been 4.4 million years since a female now nicknamed Ardi lived in eastern Africa, but she still knows how to make an entrance. Analyses of her partial skeleton and the remains of at least 36 of her comrades, described in 11 papers in the Oct. 2 Science, provide the first comprehensive look at an ancient hominid species. Ardipithecus ramidus evolved a few million years after humanity’s evolutionary family diverged from a lineage that led to chimpanzees, but it is not clear exactly how this species is related to other early hominids. Ardi’s skeleton, which includes a skull with teeth, arms, hands, pelvis, legs and feet, indicates that the common ancestors of people and African apes (which include chimpanzees and gorillas) did not resemble chimpanzees, as many scientists have assumed, says anthropologist and project director Tim White of the University of California, Berkeley. Ardi displays an unexpected mix of apelike and monkeylike traits suitable for both tree climbing and upright walking. Overall, Ardipithecus looks unlike any living primate, White adds. Early hominids evolved in distinctive ways, so modern apes and monkeys provide poor models of a creature such as Ardi, in his view. “Ardipithecus is so rife with anatomical surprises that no one could have imagined it without direct fossil evidence,” White says. © Society for Science & the Public 2000 - 2009

Keyword: Evolution
Link ID: 13323 - Posted: 06.24.2010

by Amy Barth; Biochemist Peter Davies began investigating Alzheimer’s disease in the 1970s, long before its full impact became clear. By 2030 roughly 7.5 million Americans will have this debilitating neurodegenerative disorder. Already Alzheimer’s costs the country $148 billion a year; we urgently need to find the cause—and a cure. For years the prevailing theory was that memory loss was caused by protein fragments, so-called plaques and tangles, that accumulate in the brain. Davies, now at the Litwin-Zucker Center for the Study of Alzheimer’s Disease and Memory Disorders in Manhasset, New York, suspects a different culprit. His hunch is that the mechanisms controlling cell division have gone wrong—somewhat like what happens in cancer—and that plaques and tangles are the result. In the quest for answers, Davies has led hundreds of studies and examined more than 6,000 brains. What is the central mystery of Alzheimer’s? The two main abnormalities of the disease are microscopic lesions called plaques and tangles, which occur in the brains of patients. This is how the disease was first recognized, in 1906. We want to know if these abnormalities are the result of the disease process or if they are abnormalities that cause the disease. That’s been the number-one question in the field for a long time, and there’s a lot of debate and disagreement about it—are the plaques and tangles cause or effect? If we have known about Alzheimer’s since 1906, why do we still not understand it? By the time we get to look at the brain of a patient with Alzheimer’s, it’s really end-stage disease. Alzheimer’s is an agonizingly slow process, so by the time we get to study the disease itself during its late stages, all kinds of things have gone on that may be just consequences of disease rather than causal.

Keyword: Alzheimers
Link ID: 13322 - Posted: 06.24.2010