Michael Marshall, environment reporter This boa constrictor has no father. She was born in 2009 by parthenogenesis, otherwise known as "virgin birth". This makes her one of the first parthenogenetic vertebrate animals who have made it to adulthood. The mother snake responsible had two litters, one in 2009 and another in 2010, producing a total of 22 offspring. All were female, and all had the same rare "caramel" body colour. Genetic analysis has confirmed that they are not related to any of the males the female had mated with (Biology Letters, DOI: 10.1098/rsbl.2010.0793). In another first, the young snakes have two W chromosomes. Snakes determine their sex differently to humans: males have two Z chromosomes and females have a Z and a W. So in theory, the mother snake's parthenogenetic offspring should have been either ZZ or WW. But WW animals have never been found, and have only been produced in the lab with great difficulty. It's not clear how these WW snakes are able to survive, or indeed why the mother would have produced so many of them. Parthenogenesis is often used as a last-resort technique so that females can reproduce when there are no males around. So you would expect that the mother would produce some male offspring as well as females. Long thought to be vanishingly rare, parthenogenesis is becoming more common the more scientists look for it. For instance, in 2003 a Burmese python in an Amsterdam zoo produced embryos parthenogenetically, but they were not allowed to develop so we do not know if they were truly viable. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 14624 - Posted: 11.04.2010

by Michael Marshall Picture the frustration. You spend weeks assembling the perfect home for your mate, dragging heavy objects around until they are just so. You see off any other males who take an interest in her by showing off your impressive size and musculature. You are king of your domain. Then, just as your girl is laying her eggs in the snug little nursery you've prepared, some weedy little cheat slips in ahead of you and fertilises the lot. This is the infuriating fate that befalls many male Lamprologus callipterus, which are regularly cuckolded by so-called dwarf males. Despite their occasional success, however, dwarf males struggle to father many children. Lamprologus is a cichlid, one of the most diverse animal groups in existence, despite being mostly confined to three large lakes in Africa. The Lake Victoria cichlids are particularly diverse, with over 300 species sharing the water. Male Lamprologus weigh 12 times as much as the females. This is the largest male-female size difference among species where the males are larger, far exceeding the factor-of-three difference in great bustards, which show the greatest difference among birds. The male fish have no grounds for smugness, though: in other species giant females take things much further, with female blanket octopuses reaching almost 200 times the length of the male. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 14623 - Posted: 11.04.2010

by Andy Coghlan A little thing called methylation means that parental neglect, or eating a poor diet, could lead to depression or schizophrenia two generations later WHAT if your bad habits mean that your children and even their children end up with a psychiatric disorder? That is one of the implications of a study in rodents that suggests poor diet and parental neglect can leave their mark on the genes of your children and your children's children. A cryptic epigenetic code added to the DNA of mice shows for the first time that changes in gene activity can pass down three generations. It is likely that the same mechanisms are at work in humans. Epigenetics deals with the regulation of gene activity within a cell - which genes are switched on or off, and when it happens (see diagram). Every cell in the body contains the same DNA but epigenetic settings on cells in the bone and blood, for example, mean the tissues do very different jobs. The epigenetic consequences of a huge range of environmental factors are under investigation, from exposure to drugs, chemicals and hormones, to the impact of poor maternal care in infancy, and the likelihood that they are as heritable as DNA. So far, most epigenetic research has focused on cancer because epigenetic marks unique to cancer cells may set them apart from healthy tissue. Now it's the turn of psychiatric illness. The latest results will be presented this week in Washington DC at the annual meeting of the American Society for Human Genetics (ASHG). © Copyright Reed Business Information Ltd.

Keyword: Stress; Genes & Behavior
Link ID: 14622 - Posted: 11.04.2010

David Perlman, Chronicle Science Editor The tiny zebrafish is fascinating to scientists who study them for insights into genetics and evolution, and as models of human behavior. And they're equally charming for hobbyists who appreciate their ability as swift swimmers in their aquariums. Now two UC researchers in San Francisco and Berkeley have discovered how the nerves and brains of the boldly striped, inch-long fish can distinguish between the sight of small, quick-moving prey and larger objects looming before their eyes that might be hungry predators. And one nerve scientist leading the group likened the fish's ability to make that distinction in its nervous system to a baseball batter's instant ability to grab a hit at a pitcher's oncoming fastball. Filippo Del Bene at UCSF and Claire Wyart of UC Berkeley, both post-doctoral fellows, experimented with nerve cells in the brains of zebrafish larvae and found how the larvae's specialized cells are structured to receive different kinds of signals from the optic nerves in the retinas of their eyes. The larval brains of these fish are transparent. So when the two researchers labeled specific neurons with a newly developed fluorescent protein, they could watch as those nerve cells flashed brightly when they were activated by small and fast-moving objects seen by their eyes while electrical signals were transmitted by their optic nerves to their brains. © 2010 Hearst Communications Inc.

Keyword: Vision; Development of the Brain
Link ID: 14621 - Posted: 11.04.2010

Nicole Baute Living Reporter Stroke victims are 12 per cent more likely to die within seven days if they arrive at the hospital on the weekend, according to a study of more than 20,000 Ontario patients. The study, published today in Neurology, found that patients received the same major interventions — brain scans, clot-busting medications and admission to stroke units — regardless of when they were admitted. Dr. Moira Kapral, a researcher at the Institute for Clinical Evaluative Sciences and one of the study’s authors, says it is possible that the weekend effect is caused by “an accumulation of small deficiencies in care” — including secondary treatment that is nonetheless crucial for recovery. For example, she says, there might be fewer or less-experienced staff working on the weekends. Or patients might experience delays in access to rehabilitation experts, such as physiotherapists who help stroke patients regain mobility or speech pathologists who do swallowing assessments to determine whether or not it’s safe to eat. Further research is necessary to examine these possibilities. In the meantime, says Kapral, health-care administrators should try to determine what is causing the increased mortality gap. “I think hospitals should really look at their weekend practices in terms of staffing and resources to see if there are things that can be done to improve care on weekends.” © Copyright Toronto Star 1996-2010

Keyword: Stroke
Link ID: 14620 - Posted: 11.04.2010

By Steve Connor Can science shed some light on Stephen Fry's comments about female sexuality? Do women really find sex disgusting and only partake of the gruesome act in order to get their man to "commit", as he suggested in an interview with Attitude magazine? The deep frying of Fry for his ill-chosen words, which he insists were made in jest and taken out of context, is perhaps unjustified. The science suggests that he may have a point, but only if the long view of human sexuality is taken into account – in other words, the reason why sex has evolved in the first place. Biologically, sex is a way of mixing the genes between two individuals in order to produce a genetic variety in the offspring that would not exist with asexual reproduction, such as cloning. Many animals and plants engage in sexual reproduction because it confers an advantage, and the fact that sex has been practised for many hundreds of millions of years by a vast plethora of lifeforms attests to its biological importance. But explaining the reasons for sexual reproduction does not explain why we have just two sexes, and why males and females are so different to one another. To understand that we need to understand the two competing and mutually exclusive "strategies" employed by each sex in order to reproduce. Females produce egg cells, which are relatively large structures representing a sizeable investment in the future compared to sperm cells. This investment gets magnified substantially in female mammals, including humans, who get pregnant, lactate and are involved in years of strenuous childcare. ©independent.co.uk

Keyword: Sexual Behavior; Evolution
Link ID: 14619 - Posted: 11.02.2010

A molecular pathway within the brain’s reward circuitry appears to contribute to alcohol abuse, according to laboratory mouse research supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). The findings, published online today in Proceedings of the National Academy of Sciences, also provide evidence that the pathway may be a promising new target for the treatment of alcohol problems. The mammalian target of rapamycin complex 1, or mTORC1, is a group of proteins found in cells throughout the body. An important part of the cellular machinery, mTORC1 sends signals that help regulate the size and number of cells. Scientists have also found that it is involved in other cellular processes. For example, in the central nervous system, mTORC1 has been linked to processes related to learning and memory. Because problems in the cellular mechanisms that underlie learning and memory can contribute to alcohol abuse disorders, NIAAA-supported researchers at the Ernest Gallo Clinic and Research Center of the University of California, San Francisco (UCSF) hypothesized that mTORC1 might be involved in alcohol problems. In laboratory studies conducted with mice, researchers led by Dorit Ron, Ph.D., a Gallo Center principal investigator and a professor of neurology at UCSF, measured an increase in mTORC1 cellular products in the nucleus accumbens of mice that had consumed alcohol — an indication that alcohol activates the mTORC1 pathway. The nucleus accumbens is a brain region that in rodents and humans is part of the reward system that affects craving for alcohol and other addictive substances. They then showed that rapamycin, an immunosuppressant drug that blocks the mTORC1 pathway, decreased excessive alcohol consumption, binge drinking, and alcohol-seeking behavior in the rodents. Rapamycin is currently used to prevent the rejection of transplanted organs.

Keyword: Drug Abuse
Link ID: 14618 - Posted: 11.02.2010

Ben Goldacre When the BBC tells you, in a headline, that libido problems are in the brain and not in the mind, you might find yourself wondering what the difference between the two is supposed to be, and whether a science article can really be assuming – in 2010 – that its readers buy into a strange Cartesian dualism in which the self is contained by a funny little spirit entity in constant and elaborate pneumatic connection with the corporeal realm. But first let's consider the experiment they're reporting on. As far as we know (because this experiment has not yet been published, only presented at a conference), some researchers took seven women with a "normal" sex drive, and 19 women diagnosed with "hypoactive sexual desire disorder". Participants watched a series of erotic films in a scanner while an MRI machine took images of blood flow in their brains: the women with a normal sex drive had an increased flow of blood to some parts of their brain associated with emotion, while those with low libido did not. Dr Michael Diamond, one of the researchers, tells the Mail: "Being able to identify physiological changes, to me provides significant evidence that it's a true disorder as opposed to a societal construct". In the Metro, he goes further: "Researcher Dr Michael Diamond said the findings offer 'significant evidence' that persistent low sex drive – known as hypoactive sexual desire disorder (HSDD) – is a genuine physiological disorder and not made up." © Guardian News and Media Limited 2010

Keyword: Brain imaging; Sexual Behavior
Link ID: 14617 - Posted: 11.02.2010

by Nathan Collins Could a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other aspects of consciousness are fully formed in newborn babies. Resting state networks (RSNs), sometimes called the "dark energy of the brain", are patterns of low-frequency brain activity that are constantly active, even when a person is asleep. Activity in one RSN, the default mode network, drops when someone is engaged in a task, and it may be involved in introspective activities like envisioning the future – what some would call a facet of consciousness. Previous studies suggest that this network only fully develops during childhood, but David Edwards and colleagues at Imperial College London have now shown it is fully formed at birth. The finding came as the team investigated the relationship between RSNs and cognitive functions. They scanned the brains of 70 babies born up to three months early, whose development served as a proxy for fetal development. While rates of progression varied, RSNs for vision, touch, movement and decision-making were largely complete by 40 weeks, as was the default mode network. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Attention
Link ID: 14616 - Posted: 11.02.2010

By APRIL DEMBOSKY SACRAMENTO — In the three years since her son Diego was given a diagnosis of autism at age 2, Carmen Aguilar has made countless contributions to research on this perplexing disorder. She has donated all manner of biological samples and agreed to keep journals of everything she’s eaten, inhaled or rubbed on her skin. Researchers attended the birth of her second son, Emilio, looking on as she pushed, leaving with Tupperware containers full of tissue samples, the placenta and the baby’s first stool. Now the family is in yet another study, part of an effort by a network of scientists across North America to look for signs of autism as early as 6 months. (Now, the condition cannot be diagnosed reliably before age 2.) And here at the MIND Institute at the University of California Davis Medical Center, researchers are watching babies like Emilio in a pioneering effort to determine whether they can benefit from specific treatments. So when Emilio did show signs of autism risk at his 6-month evaluation — not making eye contact, not smiling at people, not babbling, showing unusual interest in objects — his parents eagerly accepted an offer to enroll him in a treatment program called Infant Start. The treatment is based on a daily therapy, the Early Start Denver Model, that is based on games and pretend play. It has been shown in randomized trials to significantly improve I.Q., language and social skills in toddlers with autism, and researchers say it has even greater potential if it can be started earlier. Copyright 2010 The New York Times Company

Keyword: Autism
Link ID: 14615 - Posted: 11.02.2010

By PAM BELLUCK About half of adolescents who recovered from major depression became depressed again within five years, regardless of what treatment or therapy they received to get over their initial depression, a new study shows. The study, published Monday in Archives of General Psychiatry, also found that girls were more likely to have another major depression, which surprised researchers because, as adults, women have not been considered more likely to have a recurrence than men. In the study, nearly 200 adolescents, 12 to 17, received 12 weeks of fluoxetine (Prozac), cognitive behavioral therapy, both, or a placebo pill. (Those not receiving cognitive therapy met with a psychiatrist for basic support.) Placebo-takers who did not improve after 12 weeks could choose any of the other treatments. Researchers had previously found that those receiving the Prozac-and-cognitive-therapy combination recovered faster from the first depression. So they expected those youths to be less prone to another depression. But that did not happen. After 36 weeks, improvement for everyone was similar, researchers said, and by two years most completely recovered. But by five years, 47 percent suffered another major depression, no matter what treatment had helped them recover. Copyright 2010 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 14614 - Posted: 11.02.2010

People who take regular exercise during their free time are less likely to have symptoms of depression and anxiety, a study of 40,000 Norwegians has found. But physical activity which is part and parcel of the working day does not have the same effect, it suggests. Writing in the British Journal of Psychiatry, the researchers said it was probably because there was not the same level of social interaction. The charity Mind said that exercise and interaction aids our mental health. Higher levels of social interaction during leisure time were found to be part of the reason for the link. Researchers from the Institute of Psychiatry at King's College London teamed up with academics from the Norwegian Institute of Public Health and the University of Bergen in Norway to conduct the study. Participants were asked how often, and to what degree, they undertook physical activity in their leisure time and during the course of their work. Researchers also measured participants' depression and anxiety using the Hospital Anxiety and Depression Scale. BBC © MMX

Keyword: Depression
Link ID: 14613 - Posted: 11.01.2010

Alcohol is more harmful than heroin or crack, according to a study published in medical journal the Lancet. The report is co-authored by Professor David Nutt, the former UK chief drugs adviser who was sacked by the government in October 2009. It ranks 20 drugs on 16 measures of harm to users and to wider society. Tobacco and cocaine are judged to be equally harmful, while ecstasy and LSD are among the least damaging. Prof Nutt refused to leave the drugs debate when he was sacked from his official post by the former Labour Home Secretary, Alan Johnson. He went on to form the Independent Scientific Committee on Drugs, a body which aims to investigate the drug issue without any political interference. One of its other members is Dr Les King, another former government adviser who quit over Prof Nutt's treatment. Members of the group, joined by two other experts, scored each drug for harms including mental and physical damage, addiction, crime and costs to the economy and communities. BBC © MMX

Keyword: Drug Abuse
Link ID: 14612 - Posted: 11.01.2010

By SINDYA N. BHANOO The ancestors of humans and other primates like apes and monkeys may have originated in Asia, not Africa, a new study in the journal Nature reports. There has long been debate about the matter, but a recent discovery of anthropoid fossils including two previously unidentified species and one known species provides new clues. The fossils are about 38 million years old and were uncovered in a rock formation in southern Libya. The anthropoids were small, rodent-size creatures that looked similar to larger, modern-day primates, but weighed just 4 to 17 ounces. “At least one of these anthropoids appears to be clearly related to the older Asian form described in Myanmar,” said Jean-Jacques Jaeger, a paleontologist at the University of Poitiers in France and the study’s lead author. “This indicates that there was migration from Asia.” But there is another possibility: that the anthropoids originated in Africa and migrated to Asia, and that they have even older ancestors in Africa that have not yet been discovered. Copyright 2010 The New York Times Company

Keyword: Evolution
Link ID: 14611 - Posted: 11.01.2010

by Liz Day Dating advice, guys: Looking "masculine" may not get you anywhere with the ladies. Skin tone is what really makes a difference. Or so say researchers from University of Bristol and Brunel University, who published in a recent issue of online science journal PLoS ONE. They found that color information is more influential than shape information, upending prior thought on masculinity's link to attractiveness. Previous research studies had suggested that female animals prefer males with exaggerated male traits, such as large antlers and eye-catching peacock tails. Souped-up levels of testosterone are thought to contribute to the very masculine features, while also stressing the immune system. Thus, only high quality males can "afford" exposure to immune stress. Succinctly put, males with masculine shaped faces would appear to be more attractive, healthier partners for mating. Instead, this study found that skin color trumped masculine facial features. To clarify, skin color was measured in tones of lightness, redness and yellowness, and did not involve race or ethnicity. The authors believe that color matters because it fluctuates and is condition-dependent. Thus, skin color could better signal the health of a male partner at that moment, instead of an evolutionary facial structure that has been inherited over generations. © 2010 Discovery Communications, LLC

Keyword: Sexual Behavior; Evolution
Link ID: 14610 - Posted: 11.01.2010

By Wynne Parry, A group of scientists has genetically altered mice so they could "smell" light. That is their neurons responded to light in the same way they would to an odor. This allowed them to study the brain's response without having to deal with the complications associated with smelling. The approach the scientists used to help the mice "smell" the light is called optogenetics. The method uses light to control actions within other specific cells and is broadly applicable. The noses of mice (and humans) are chock-full of sensory neurons that respond to scent molecules that waft by. That odor information gets sent to the olfactory bulb, a part of the brain above the nasal cavities, where the sensory neurons meet up with relay neurons. These two types of neurons then meet within structures called glomeruli. "If you look at two cells receiving input from the same glomerulus, are they just passing it on [in] the same way, or is there something more to it?" said study researcher Venkatesh Murthy from Harvard University, who collaborated with others at Harvard, Cold Spring Harbor Laboratory and in India. A mouse has about 200,000 relay cells, with between 60 and 100 connected to each glomerulus, or hub. Identifying pairs of relay cells that connect to the same glomerulus is difficult, because when a rodent catches a whiff of something, multiple glomeruli go into action, according to Graeme Lowe, a neuroscientist at the independent Monell Chemical Senses Center who was not involved in the research. © The Christian Science Monitor

Keyword: Chemical Senses (Smell & Taste); Vision
Link ID: 14609 - Posted: 11.01.2010

A new stroke prevention clinic in Ottawa is helping patients treated for mini-strokes from developing the full-blown version, doctors report. A transient ischemic attack, or TIA, is a mild stroke that causes stroke symptoms such as sudden numbness of the face, arm or leg. The symptoms last for less than 24 hours and then resolve on their own without disabling neurological effects, but it is a marker for early risk of stroke. At the Ottawa Hospital Stroke Clinic, patients with TIA symptoms are quickly assessed in the emergency department (ED) and referred to the stroke clinic for brain imaging, medication adjustment, counselling about stroke risk factors and surgery in some cases. Dr. Mukul Sharma, deputy director of the Canadian Stroke Network, and his co-authors found that 3.2 per cent of people who experienced TIA at the stroke prevention clinic developed a full-blown stroke within 90 days, compared with about 10 per cent at other centres. "The beauty of this is that we added very few staff," said Sharma, lead author of the study in the November issue of the journal Stroke, and director of The Ottawa Hospital Stroke Clinic. A booking clerk was one of the few staff that was added as part of the program. "It really is that ability to juggle bookings and the acuity of the visit that I think make this process work. I've likened it to getting an orchestra playing the same tune." © CBC 2010

Keyword: Stroke
Link ID: 14608 - Posted: 10.30.2010

By MATTHEW PERRONE WASHINGTON -- Federal health regulators have decided not to approve an experimental diet pill called Qnexa, which had been touted by many experts as the most promising weight-loss drug in more than a decade. The drug's maker, Vivus Inc., said in a statement Thursday that the Food and Drug Administration declined to approve the drug in its present form. The agency asked for more study results and additional information on its possible health risks, including major cardiovascular events and risks for women of childbearing potential. The FDA did not ask for any new clinical studies, but more may be required if the agency's concerns aren't addressed, Vivus said. The company plans to respond to the FDA in about six weeks. "We remain confident in the efficacy and safety profile of Qnexa demonstrated in the clinical development program and look forward to continue working with the FDA towards the approval for the treatment of obesity," Vivus CEO Leland Wilson said in a statement. Vivus, based in Mountain View, Calif., is one of three small drugmakers racing to win approval for their weight-loss drugs. Many analysts picked Qnexa as the most promising contender because of the high level of weight loss reported in company studies: On average, patients lost more than 10 percent total body mass. That compared to weight loss of under 5 percent with drugs currently on the market, like Roche's Xenical. © 2010 The Associated Press

Keyword: Obesity
Link ID: 14607 - Posted: 10.30.2010

By Christof Koch If you have seen the recent Holly­wood blockbuster Inception, a movie that does to dreaming what The Matrix did for virtual reality, you may have been holding your breath as Ariadne, an architecture student, folded the streets of Paris over herself like a blanket. This stunning sequence, an homage to M. C. Escher, is testimony to the bizarre nature of dreams. Watching it made the neuroscientist in me reflect on what dreams are and how they relate to the brain. The first question is easy to answer. Dreams are vivid, sensorimotor hallucinations with a narrative structure. We experience them consciously—seeing, hearing and touching within environments that appear completely real (though curiously, we do not smell in our dreams). Nor are we mere passive observers: we speak, fight, love and run. Dream consciousness is not the same as wakeful consciousness. We are for the most part unable to introspect—to wonder about our uncanny ability to fly or to meet somebody long dead. Only rarely do we control our dreams; rather things happen, and we go along for the ride. Everyone dreams, including dogs, cats and other mammals. But sleep lab data reveal that people consistently underreport how often and how much. The reason is that dreams are ephemeral. Memory for dreams is very limited and largely restricted to the period before awakening. The only way to remember a dream is to immediately recall it on waking and then write it down or describe it to another person. Only then does its content become encoded in memory. © 2010 Scientific American,

Keyword: Sleep; Attention
Link ID: 14606 - Posted: 10.30.2010

By Laura Sanders The brain uses two different checks to guard against sloppy copy, a new study finds. By using a doctored word processor to sneak errors into typed words and surreptitiously fix typists’ real errors, researchers teased apart the various ways people catch their own mistakes. The study, published in the Oct. 29 Science, highlights the complexity of performance monitoring. Psychologist Gordon Logan and his colleague Matthew Crump of Vanderbilt University in Nashville recruited skilled typists — people who typed more than 40 words a minute using all of their fingers. These subjects were able to type a paragraph about the merits of border collies with over 90 percent accuracy. As the typists pecked away, researchers introduced common typing errors into about 6 percent of the words that appeared on a screen (changing sweat to swaet, swerat or swet, for instance). The program also corrected about 45 percent of the typists’ true errors. In questionnaires after the typing test, subjects by and large took the blame for the introduced errors and took credit for the researchers’ corrections. No matter what he actually typed, when the typist saw that the word on the screen matched the word he had intended to type, he assessed his own performance as accurate. © Society for Science & the Public 2000 - 2010

Keyword: Attention
Link ID: 14605 - Posted: 10.30.2010