By Nikhil Swaminathan In late 2004 the Internet Movie Database reported that Dustin Hoffman suddenly had the urge to breast-feed. Had the then-67-year-old Hoffman—who brought mainstream culture face to face with autism in Rain Man and went mano a mano with an Ebola-like filovirus in Outbreak—never quite broken character from his 1982 film Tootsie? Nope. He was just really keen to help out with his first grandchild. Interestingly, he could have possibly lent a helping, er, breast, if he had held the suckling newborn to his nipples for a couple weeksalthough he could also have tried starving himself or taking a medication that would affect his brain's pituitary gland. There have been countless literary descriptions of men miraculously breast-feeding, from The Talmud to Tolstoy, where, in Anna Karenina, there is a short anecdote of a baby suckling an Englishman for sustenance while on board a ship. The little anthropological evidence documented suggests it is possible. In the 1896 compendium Anomalies and Curiosities of Medicine, George Gould and Walter Pyle catalogue several instances of male nursing being observed. Among them was a South American man, observed by Prussian naturalist Alexander von Humboldt, who subbed as wet nurse after his wife fell ill as well as male missionaries in Brazil that were the sole milk supply for their children because their wives had shriveled breasts. More recently, Agence France-Presse reported a short piece in 2002 on a 38-year-old man in Sri Lanka who nursed his two daughters through their infancy after his wife died during the birth of her second child. © 1996-2007 Scientific American, Inc

Keyword: Hormones & Behavior
Link ID: 10701 - Posted: 06.24.2010

Matt Kaplan It may seem strange, but many monkeys wash their hands and feet with urine. Researchers now think they know why. Since this odd behaviour was first observed, explanatory theories have varied wildly from suggesting that it helps monkeys improve their grip when climbing to saying it is a method of cleaning. One widely supported theory argues that monkeys use urine washing to cool themselves down when temperatures get too high. But new research hints that it's all about social communication. The notion of animals using chemical scents to communicate with each other is hardly new. Dogs classically use urine to mark their territory, for example, as do many other creatures. But when it comes to peeing on oneself, researchers had thought physiological reasons might be as important as social ones. It seems they were wrong. Primatologist Kimran Miller and her research colleagues at the National Institutes of Health Animal Center in Poolesville, Maryland, monitored capuchin monkeys for ten months in a captive environment. The researchers would record daily the enclosure temperature and humidity and then note rates of urine washing. Their report, to be published in the American Journal of Primatology, shows that urine washing behaviours did not change with either temperature or humidity. ©2007 Nature Publishing Group

Keyword: Sexual Behavior; Aggression
Link ID: 10700 - Posted: 06.24.2010

Depression is a more disabling condition than angina, arthritis, asthma and diabetes, World Health Organization research shows. And those with depression plus a chronic illness, such as diabetes, fare particularly badly, the study of more than 245,000 people suggests. Better treatment for depression would improve people's overall health, the researchers concluded in the Lancet. Experts called for better funding for mental health services. Dr Somnath Chatterji and colleagues asked people from 60 countries taking part in the World Health Survey a variety of questions about their health, such as how they sleep, how much pain they have, and whether they have any problems with memory or concentration. Participants were also asked about how they manage with day-to-day tasks. After taking into account factors such as poverty and other health conditions, the researchers found that depression had the largest effect on worsening health. And people with depression who also had one or more chronic diseases had the worst health scores of all the diseases looked at or combinations of diseases. Dr Somnath Chatterji said: "The co-morbid state of depression incrementally worsens health compared with depression alone, with any of the chronic diseases alone, and with any combination of chronic diseases without depression. "These results indicate the urgency of addressing depression as a public health priority to reduce disease burden and disability, and to improve the overall health of populations." The team called on doctors around the world to be more alert in the diagnosis and treatment of the condition, noting that it is fairly easy to recognise and treat. (C)BBC

Keyword: Depression; Neuroimmunology
Link ID: 10699 - Posted: 09.08.2007

By Jennifer Couzin It's no secret that we humans are smarter than our primate relatives. But exactly how are we smarter? Experiments with chimpanzees, orangutans, and more than 100 German toddlers suggest that our social intelligence is what sets us apart from other apes, allowing us to build on our inborn intelligence. As intuitive as this might sound, the conclusion is controversial. Ph.D. student Esther Herrmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, along with her adviser, psychologist Michael Tomasello, and their colleagues, compared 106 juvenile and adult chimpanzees living in sanctuaries in Uganda and in the Republic of the Congo, 32 orangutans at a care center in Indonesia, and 105 2.5-year-olds from Germany. The participants were asked to perform an involved series of tests lasting 3 to 5 hours. Six tasks were social, meaning that one of the scientists took part and the children, chimps, or orangutans needed to discern social cues. The other 10 were physical, such as tracking down a reward (food for the apes and toys for the children) after it had been hidden. On the physical tasks, children performed no better than the chimps or orangutans. The chimps even outperformed the children on three tasks. © 2007 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 10698 - Posted: 06.24.2010

By Greg Miller Mice with a gene mutation linked to rare human cases of autism show a hallmark symptom of the disorder: impaired social interactions. The finding, published online today in Science, adds to recent evidence that defects in the synaptic connections between neurons can contribute to autism and related conditions. Autism is a widespread disorder characterized by social and communication difficulties and obsessive or repetitive behaviors. Scientists don't know what causes it, but genetics appears to be important. Variations in several genes have been implicated. For example, a 2003 study identified a mutation--a single-letter switch in the genetic code for a protein called neuroligin-3--in two Swedish brothers, one with autism and one with the related but milder Asperger syndrome. Neuroligin-3 resides at synapses, the communication points between neurons, but little is known about its function, let alone how it contributes to symptoms of autism. To investigate, researchers led by Katsuhiko Tabuchi and Thomas Südhof at the University of Texas Southwestern Medical Center in Dallas created a strain of mice with the same mutation found in the Swedish brothers. The mutant mice had normal activity levels and coordination, but when the researchers put mutant mice in an enclosure with a mouse that had been restrained in a small cage, they were unusually shy, spending less time sniffing and interacting with the caged mouse than did normal mice. (The mouse had to be restrained, because otherwise it would have initiated interactions with the mutants, confounding the test.) There was no difference between mutant and normal mice when it came to investigating an empty cage, however, and the mutants even outperformed normal mice on a test of spatial learning and memory, suggesting that their deficit was specific for social behavior. © 2007 American Association for the Advancement of Science.

Keyword: Autism
Link ID: 10697 - Posted: 06.24.2010

By Rebecca Morelle The mystery behind the tree rubbing antics of North America's grizzly bears may at last have been solved. A few select trees are used by grizzlies to perform strange rubbing rituals, but for years the reasons for this behaviour have baffled ecologists. Now, a study suggests that male grizzlies seeking mates are marking the trees to communicate with other males - possibly to dodge deadly bear battles. The work will be presented next week at a British Ecological Society meeting. Owen Nevin, a behavioural ecologist at Cumbria University, UK, who carried out the study, said: "A handful of trees ('rub trees') are used for years by different grizzlies who each approach the trees in exactly the same way. "They will step into the footprints of other bears that have approached the trees, urinating as they approach. "Then they rub their back on the tree, turn around and then bite the tree and claw it. Then they give it a 'bear hug' by rubbing their chest against it, and then they rub it with their back again." Many theories have been put forward as to why grizzlies are rubbing these trees: some thought they were using them to scratch an itch, others that they were trying to rub on tree sap to repel insects, while some thought they were using the trees to attract mates. Dr Nevin told the BBC News website: "Until now, we haven't really known which bears use these trees and why they use them." To investigate the bears' behaviour, Dr Nevin looked at a grizzly population living in a 150 sq km (58 sq miles) valley in British Columbia, Canada. He set up digital cameras, activated by infra-red sensors, at four frequently used rub trees and attached satellite collars to bears to track their movements. (C)BBC

Keyword: Sexual Behavior
Link ID: 10696 - Posted: 09.06.2007

By Andrea Thompson We remember the bad times better than the good because our emotions influence how we process memories, a new review of research shows. When people recall significant, emotional events in their lives, such as their wedding day or the birth of their first child, they're generally very confident about how well they remember the details of the event. But whether or not this confidence is warranted is debatable, because details remembered with confidence often aren’t exactly correct, according to the review of research on emotional memories. Memories are generally prone to distortion over time, but researchers have found some evidence to suggest that emotional memories are more resistant to the decay processes that wear away at all memories with time, says review author Elizabeth Kensinger of Boston College. "It's clear that there's something very kind of special and prioritized about how we remember those emotional experiences," said Kensinger, whose review is published in the August issue of the journal Current Directions in Psychological Science. Negative events may edge out positive ones in our memories, according to research by Kensinger and others. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Learning & Memory
Link ID: 10695 - Posted: 06.24.2010

By ELISABETH ROSENTHAL Common food additives and colorings can increase hyperactive behavior in a broad range of children, a study being released today found. It was the first time researchers conclusively and scientifically confirmed a link that had long been suspected by many parents. Numerous support groups for attention deficit hyperactivity disorder have for years recommended removing such ingredients from diets, although experts have continued to debate the evidence. But the new, carefully controlled study shows that some artificial additives increase hyperactivity and decrease attention span in a wide range of children, not just those for whom overactivity has been diagnosed as a learning problem. The new research, which was financed by Britain’s Food Standards Agency and published online by the British medical journal The Lancet, presents regulators with a number of issues: Should foods containing preservatives and artificial colors carry warning labels? Should some additives be prohibited entirely? Should school cafeterias remove foods with additives? After all, the researchers note that overactivity makes learning more difficult for children. “A mix of additives commonly found in children’s foods increases the mean level of hyperactivity,” wrote the researchers, led by Jim Stevenson, a professor of psychology at the University of Southampton. “The finding lends strong support for the case that food additives exacerbate hyperactive behaviors (inattention, impulsivity and overactivity) at least into middle childhood.” Copyright 2007 The New York Times Company

Keyword: ADHD
Link ID: 10694 - Posted: 06.24.2010

By Shankar Vedantam Warnings from federal regulators four years ago that antidepressants were increasing the risk of suicidal behavior among young people led to a precipitous drop in the use of the drugs. Now a new study has found that the drop coincides with an unprecedented increase in the number of suicides among children. From 2003 to 2004, the suicide rate among Americans younger than 19 rose 14 percent, the most dramatic one-year change since the government started collecting suicide statistics in 1979, the study found. The rise followed a sharp decrease in the prescribing of antidepressants such as Prozac, Zoloft and Paxil after parents and physicians were confronted by a barrage of warnings from the Food and Drug Administration and international agencies. The data suggest that for every 20 percent decline in antidepressant use among patients of all ages in the United States, an additional 3,040 suicides per year would occur, said Robert Gibbons, a professor of biostatistics and psychiatry at the University of Illinois at Chicago, who did the study. About 32,000 Americans commit suicide each year. Thomas Insel, director of the National Institute of Mental Health, said, "We may have inadvertently created a problem by putting a 'black box' warning on medications that were useful." He added, "If the drugs were doing more harm than good, then the reduction in prescription rates should mean the risk of suicide should go way down, and it hasn't gone down at all -- it has gone up." © 2007 The Washington Post Company

Keyword: Depression
Link ID: 10693 - Posted: 06.24.2010

Using new software developed to investigate how the brains of dyslexic children are organized, University of Washington researchers have found that key areas for language and working memory involved in reading are connected differently in dyslexics than in children who are good readers and spellers. However, once the children with dyslexia received a three-week instructional program, their patterns of functional brain connectivity normalized and were similar to those of good readers when deciding if sounds went with groups of letters in words. “Some brain regions are too strongly connected functionally in children with dyslexia when they are deciding which sounds go with which letters,” said Todd Richards, a UW neuroimaging scientist and lead author of a study published in the current issue of the Journal of Neurolinguistics. “We had hints in previous studies that the ability to decode novel words improves when a specific brain region in the right hemisphere decreases in activation. This study suggests that the deactivation may result in a disconnection in time from the comparable region in the left hemisphere, which in turn leads to improved reading. Reading requires sequential as well as simultaneous processes.” Richards and co-author Virginia Berninger, a neuropsychologist, said temporal connectivity, or the ability of different parts of the brain to “talk” with each other at the same time or in sequence, is a key in overcoming dyslexia. Berninger, who directs the UW’s Learning Disabilities Center, compared dyslexia to an orchestra playing with an ineffective conductor who does not keep all the musicians playing in synchrony with each other.

Keyword: Dyslexia
Link ID: 10692 - Posted: 06.24.2010

By Matt Kaplan Does the anticipation of sex make animals better breeders? It appears to for quails. When researchers placed male quails in environments they learned to associate with mating, the birds sired more offspring than their untrained counterparts. The findings may provide clues to the evolution of conditioned learning in a variety of animals, including humans. Conditioned learning--or conditioning--was most famously demonstrated by Ivan Pavlov more than 100 years ago. Pavlov would ring a bell and then feed a dog. After a while, the dog began salivating every time he heard the bell, suggesting he had learned to associate the sound with food. Since then, researchers have studied how conditioning develops, but few have looked at how it might have evolved. Psychologist Michael Domjan and colleagues at the University of Texas, Austin, set out to explore the question. If conditioning improves the odds of reproducing, they reasoned, the trait would be adaptive and spread through the population. The researchers placed male quails, which readily breed in captivity, in boxes with green walls or tilted floors for 5 minutes and then introduced them to a female for a romantic liaison. After 5 days of conditioning, one male was placed in a green or tilted box for 5 minutes, and another male was placed in an unfamiliar box. Then both were introduced to a single female within minutes of each other. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 10691 - Posted: 06.24.2010

Ewen Callaway A type of drug has been found that starts working much faster against depression than current medications. Behavioural and molecular tests in rats show that the compounds kick into action in days, rather than weeks. But the drugs — called serotonin receptor agonists — won't be replacing Paxil (paroxetine) soon. None has yet been approved for treating depression in humans, and some have been scrapped because of concerns over side effects. But researchers are still keen to pursue them, because the most popular type of antidepressant, called selective serotonin reuptake inhibitors (SSRI), can take up to two months to start easing symptoms. And for one-third of people with depression, they don't work at all. "This is a very good first step in identifying and potentially having a rapidly acting antidepressant," says Ronald Duman, a drug expert at Yale University in New Haven, Connecticut. "But there's a lot of work to done." SSRI's such as Prozac have become a household name over the past three decades, garnering many millions of prescriptions every year in adults, children and even pets. The drugs work by stopping neurons from greedily keeping hold of a neurotransmitter called serotonin, so allowing more of the pleasure-providing molecule to reach protein receptors in nearby brain cells. ©2007 Nature Publishing Group

Keyword: Depression
Link ID: 10690 - Posted: 06.24.2010

Our ability to hear is made possible by way of a Rube Goldberg-style process in which sound vibrations entering the ear shake and jostle a successive chain of structures until, lo and behold, they are converted into electrical signals that can be interpreted by the brain. Exactly how the electrical signal is generated has been the subject of ongoing research interest. In a study published in the September 6 issue of the journal Nature, researchers have shed new light on the hearing process by identifying two key proteins that join together at the precise location where energy of motion is turned into electrical impulses. The discovery, described by some scientists as one of the holy grails of the field, was made by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health (NIH), and the Scripps Research Institute in La Jolla, CA. When a noise occurs, such as a car honking or a person laughing, sound vibrations entering the ear first bounce against the eardrum, causing it to vibrate. This, in turn, causes three bones in the middle ear to vibrate, amplifying the sound. Vibrations from the middle ear set fluid in the inner ear, or cochlea, into motion and a traveling wave to form along a membrane running down its length. Sensory cells (called hair cells) sitting atop the membrane "ride the wave" and in doing so, bump up against an overlying membrane. When this happens, bristly structures protruding from their tops (called stereocilia) deflect, or tilt to one side. The tilting of the stereocilia cause pore-sized channels to open up, ions to rush in, and an electrical signal to be generated that travels to the brain, a process called mechanoelectrical transduction.

Keyword: Hearing
Link ID: 10689 - Posted: 09.06.2007

By NICHOLAS BAKALAR Elderly people taking statins had fewer of the twisted nerve-cell fibers that are common in the brains of patients with Alzheimer’s disease, researchers reported last week in a study based on brain autopsies. The significance of the finding remains unclear, but this is the first time the potential effects of the cholesterol-lowering statins on brain pathology have been assessed by autopsy. Epidemiological studies of statins and Alzheimer’s have had mixed results. The researchers examined the brains of 110 men and women ages 65 to 79 who were enrolled in a larger study of dementia and had donated their brains for research. All were under 80 at enrollment, and one-third had taken statins for an average of five years before death. Simvastatin (Zocor) and lovastatin (Mevacor or Altocor) were the most common prescriptions. Even though there was no difference in the incidence of apparent dementia in statin users compared with nonusers, the statin users had fewer small brain lesions and fewer of the twisted fibers called neurofibrillary tangles, even after controlling for sex, age at death, brain weight and other variables. There was also an association between statin use and the presence of fewer amyloid plaques, the dead and dying nerve cells that are also typical of Alzheimer’s, but it did not reach statistical significance. Copyright 2007 The New York Times Company

Keyword: Alzheimers
Link ID: 10688 - Posted: 06.24.2010

By Linda Carroll Janine Geredes is the kind of person many of us love to hate. No matter how much the Northern California woman eats, she never gets fat. While the rest of us obsess over every morsel passing through our lips, convinced we’ll pack on the pounds if we let our guard down for just one moment, Geredes worries she’ll become unappealingly bony if she doesn’t eat enough. “I’ve always had to work to keep weight on,” says Geredes, 43, who is 5 feet 6 inches tall and weighs 118 pounds. “When I was a growing up I was teased for being so thin. But now, people are always saying, ‘I wish I could eat like you. You stay so thin. You must work out a ton.’ I don’t. My son and daughter are the same way. I’ve always figured it was genetic.” As it turns out, Geredes may be right. Scientists now say they have discovered the “skinny” gene. And they’ve found this lucky batch of DNA in a variety of animals, according to a report published Tuesday in the journal Cell Metabolism. "This gene is in every organism from worms to humans," says the study’s senior author, Dr. Jonathan Graff, an associate professor of developmental biology and internal medicine at the University of Texas Southwestern Medical Center. "We all have it. It's very striking." © 2007 MSNBC.com © 2007 Microsoft

Keyword: Obesity; Genes & Behavior
Link ID: 10687 - Posted: 06.24.2010

How do people become expert musicians? And why is it that, of the millions who take lessons as children, relatively few continue to play music as adults? Many people tell me they love listening to music, but their music lessons “didn’t take”. I think they are being too hard on themselves. The chasm between musical experts and everyday musicians that has grown so wide in our culture makes people feel discouraged, and for some reason this is uniquely so with music. But, although many people say their music lessons didn’t take, cognitive neuroscientists have found otherwise. Even just a small exposure to music lessons as a child creates neural circuits for music-processing that are enhanced and more efficient than in those who lack training. Lessons teach us to listen better and accelerate our ability to discern structure and form in music, making it easier for us to tell what music we like and what we don’t like. But what about that class of people we all acknowledge are true musical experts – the Alfred Brendels, Sarah Changs, Wynton Marsalises and Tori Amoses? Do they have a set of abilities – or neural structures – that are a totally different sort from those the rest of us have (a difference of kind), or do they just have more of the same basic stuff all of us are endowed with (a difference of degree)? And do composers and songwriters have a fundamentally different set of skills from players? © Copyright 2007 Times Newspapers Ltd.

Keyword: Hearing
Link ID: 10686 - Posted: 06.24.2010

Michael Hopkin The genes that underpin schizophrenia may have been favoured by natural selection, according to a survey of human and primate genetic sequences. The discovery suggests that genes linked to the debilitating brain condition conferred some advantage that allowed them to persist in the population — although it is far from clear what this advantage might have been. Researchers led by Bernard Crespi of Simon Fraser University in Burnaby, Canada, examined 76 DNA sequences linked to schizophrenia. They compared these human sequences with one another and with those of primates such as chimps and macaques, as well as with some from mice, rats, cows and dogs. Of the 76 genes studied, 28 showed evidence of being favoured by natural selection. They showed less variation than other control sequences from elsewhere in the genome, and had less evidence of having been jumbled up by the random mixing of genes that occurs during sexual reproduction. These findings suggest that these schizophrenia-linked sequences may have conferred an evolutionary advantage, the researchers explain in Proceedings of the Royal Society B1. The genetic data provide no clues as to the kind of advantage that schizophrenia-linked genes might have offered. "That is the big question and we don't really have a good answer to that," admits Crespi's colleague Steve Dorus of the University of Bath, UK. ©2007 Nature Publishing Group

Keyword: Schizophrenia; Genes & Behavior
Link ID: 10685 - Posted: 06.24.2010

By Constance Holden Scientists are excited over what they see as a possible breakthrough in the treatment of schizophrenia: the first human trials showing efficacy for a completely new class of antipsychotic drugs. The study represents the "leading edge of a new generation of medications" for schizophrenia, says Yale University drug researcher John Krystal. Over the past half-century, many drugs have been introduced to treat schizophrenia, which afflicts about 1% of the population. But all of them have activity at the same target: the D2 dopamine receptor. The "dopamine hypothesis" is based on the fact that excess dopamine causes psychosis. In recent years, however, scientists have been probing another theory, the "glutamate hypothesis." Glutamate is the brain's main excitatory neurotransmitter and activates other neurochemicals. The theory is that low activity in a certain type of glutamate receptor (NMDA) paradoxically leads to excess glutamate elsewhere, damaging brain connections. This results in psychosis, thought disorder, and the dulling of emotions associated with schizophrenia. In animal studies, compounds that act on glutamate receptors seem to block the effects of psychosis-mimicking amphetamines better than do most conventional drugs. In a paper published online Sunday in Nature Medicine, researchers from Eli Lilly and Co. in Indianapolis, Indiana, have shown that these compounds work in humans as well. © 2007 American Association for the Advancement of Science

Keyword: Schizophrenia
Link ID: 10684 - Posted: 06.24.2010

Mary Muers Eating as much as you like but never getting fat sounds like a dieter's dream. But it's a reality for mice missing a key gene, researchers have found. These mice set up a futile cycle of making and breaking unnecessary proteins, burning fat along the way. As a result they eat more food but weigh less than normal mice. The discovery has raised hopes of novel ways to tackle obesity and diabetes. The missing gene in this case codes for an enzyme needed to chemically digest some amino acids — the building blocks of proteins. This results in the build-up of an amino acid called leucine, which in turn tricks cells into making new, unnecessary proteins and then destroying them. This pointless cycle burns up excess calories so the mice stay trim, regardless of the extra food they munch. Obesity results from an imbalance in the simple equation of energy input versus energy output, because excess fuel is turned into fat. The notion that making and breaking down biological molecules can waste spare calories is not new to scientists; it has been posited as an explanation for why some lucky people can naturally eat more but stay slim. But this study, published in Cell Metabolism1 today, is the first time wasteful protein turnover has been shown in practice. ©2007 Nature Publishing Group

Keyword: Obesity
Link ID: 10683 - Posted: 06.24.2010

Men look for beauty, while women go for wealth when it comes to assessing future partners, researchers say. An Indiana University team looked at the behaviour of 46 people taking part in a speed-dating session. They found that the men were more likely to go for the more attractive women, while women opted for those who could give the best financial security. Men were also likely to want to date more women, the Proceedings of the National Academy of Sciences reported. Speed-dating is becoming an increasingly popular way for singles to meet, involving scores of mini-dates whereby couples get a few minutes to get to know each other. Researchers said speed-dating offered a good model to analyse the factors people take into account when choosing partners as it offered a "microcosm" of daily life. During the research, participants were asked what they were looking for. The most common response was to find someone who was like themselves. But once the speed-dating sessions began, participants began conforming to set patterns, according to the analysis of questionnaires filled in. The report said men sought the more attractive women and the women were drawn to material wealth and security. Furthermore, while men on average wanted to see every second woman again, the women wanted to meet only a third of men. Lead researcher Peter Todd said the study showed the public reverted to type when choosing a mate. "While humans may pride themselves on being highly evolved, most still behave like the stereotypical Neanderthals when it comes to choosing a mate. " (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 10682 - Posted: 09.04.2007