By Victoria Gill Science reporter, BBC Nature, Ottawa, Canada Male fireflies, known for attracting mates with a flash of light, also seduce with a gift, say scientists. This gifts comes in the form of a spermatophore: a package containing sperm and nourishment for the female. Researchers from Tufts University in Boston, US, found that females preferred males that had the largest, most nourishing gift. The team presented their findings at the First Joint Congress on Evolutionary Biology in Ottawa, Canada. With supervision from his colleague Sara Lewis, who has been studying fireflies for 20 years, Dr Adam South used LED lights to mimic the flashes of amorous male fireflies. They showed one group of females artificial male flashes in patterns and durations that had been proven attractive in previous studies. Another group of females saw "unattractive" flashes. In the wild, females are very picky about what males they reveal themselves to during this part of the courtship routine. Females will only "flash back" to males they are attracted to. But in this experimental set-up, after several minutes of the courtship flashing, males and females were paired together in miniature chambers. The Tufts biologists filmed the encounters under infrared illumination to see what was happening when the lights went out. BBC © 2012

Keyword: Sexual Behavior; Evolution
Link ID: 17013 - Posted: 07.09.2012

By Laura Hambleton, Maureen Michael likes food. Most days, she has three or four meals, and on occasion she eats yet another in the middle of the night. But she rarely worries about her weight, and at 5-foot-8 and 155 pounds, she looks quite trim. “I eat anything, and I eat a lot,” the 51-year-old District resident said. “I like large portions. I have one of those metabolisms, I guess.” Just the other day, Michael ate a salad and two large helpings of spaghetti and meatballs for dinner — after having a hearty bowl of ice cream. For breakfast the next morning, she ate two scrambled eggs, half a package of Polish sausage, English muffins and orange juice. For lunch, she consumed a 12-inch seafood sub and some Doritos, and that night’s dinner featured two pork chops, potatoes and broccoli. That Michael’s weight remains steady even though she eats whatever she wants and does not exercise interests scientists studying the nation’s obesity epidemic. By looking at people who are near their ideal body weight, these reseachers at the National Institutes of Health’s Metabolic Clinical Research Unit in Bethesda hope to figure out what causes so many others to be overweight or uncontrollably fat. Michael is among the one-third of American adults who are at a good weight relative to their height and build. Another third are overweight, and the rest are obese. Unlike Michael, very few people keep their weight in check without paying attention to what they eat and being conscientious about physical activity. © 1996-2012 The Washington Post

Keyword: Obesity; Genes & Behavior
Link ID: 17012 - Posted: 07.09.2012

Scientists have identified why a once-promising class of drugs do not help people with multiple sclerosis. An Oxford University team say an genetic variant linked to MS means the drugs which work for patients with other autoimmune diseases will not work for them. The team, writing in Nature, say the drugs can actually make symptoms worse. Experts say the work shows how a person's genetic make-up could affect how they responded to treatment. The drugs, called anti-TNFs, work for patients with rheumatoid arthritis and inflammatory bowel disease, but they have not done so for patients with MS and researchers were unsure why. The Oxford University team looked at one particular genetic variant, found in a gene called TNFRSF1A, which has previously been associated with the risk of developing MS. The normal, long version of the protein sits on the surface of cells and binds the TNF signalling molecule, which is important for a number of processes in the body. But the team discovered the variant caused the production of an altered, shortened version which "mops up" TNF, preventing it from triggering signals - essentially the same thing that TNF blocking drugs do. BBC © 2012

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 17011 - Posted: 07.09.2012

Meredith Wadman Loretta, Ricky, Tiffany and Torian lead increasingly quiet lives, munching peppers and plums, perching and swinging in their 16-cubic-metre glass enclosures. They are the last four chimpanzees at Bioqual, a contract firm in Rockville, Maryland, that since 1986 has housed young chimpanzees for use by the nearby National Institutes of Health (NIH). Now an animal-advocacy group is demanding that the animals' roles as research subjects is brought to an end. Researchers at the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and the Food and Drug Administration have used the juvenile chimpanzees to study hepatitis C and malaria, as well as other causes of human infection, such as respiratory syncytial virus and norovirus. But now the NIH’s demand for ready access to chimpanzees is on the wane as the scientists who relied on them retire and social and political pressures against their use grow. The four remaining chimps are set to be returned soon to their owner, the New Iberia Research Center (NIRC) near Lafayette, Louisiana. “Much of what I have done over the past years has been research in chimps,” says Robert Purcell, 76, who heads the hepatitis viruses section at the NIAID’s Laboratory of Infectious Diseases. “It’s just a good time now [to retire] as the chimps are essentially no longer available.” Last December, a report from the US Institute of Medicine concluded that most chimpanzee research was scientifically unnecessary and recommended that the NIH sharply curtail its support. © 2012 Nature Publishing Group,

Keyword: Animal Rights
Link ID: 17010 - Posted: 07.09.2012

Mo Costandi It is often assumed that processes such as visual perception work in the same ways in all people, but research now suggests that how we see things may be influenced by our expectations and opinions. Yair Pinto, a cognitive neuroscientist at the University of Amsterdam, and his colleagues asked 45 white Dutch people to perform a binocular rivalry task — a standard tool in visual perception studies. The researchers presented low-contrast images of white, Moroccan and black faces to one eye and high-contrast changing patterns to the other. At first, the study participants were aware of seeing only the patterns. But when the contrast of the patterns was reduced and that of the faces was increased, the patterns became invisible and the faces broke through into the participants' awareness. The researchers asked the participants to indicate when they became aware of seeing the faces by pressing a button on a computer keyboard. It took the participants an average of one-hundredth of a second longer to become aware of the Moroccan and black faces than the white ones. The team also measured participants’ racial biases using the implicit association test, in which participants pair concepts such as 'black' and 'white' with qualities such as 'good' and 'bad'. The participants who exhibited greatest implicit bias in the association test took longest to become aware of the black and Moroccan faces. © 2012 Nature Publishing Group

Keyword: Emotions; Vision
Link ID: 17009 - Posted: 07.07.2012

By Jesse Bering We all know the stereotypes: an unusually light, delicate, effeminate air in a little boy's step, an interest in dolls, makeup, princesses and dresses, and a strong distaste for rough play with other boys. In little girls, there is the outwardly boyish stance, perhaps a penchant for tools, a square-jawed readiness for physical tussles with boys, and an aversion to all the perfumed, delicate trappings of femininity. These behavioral patterns are feared, loathed and often spoken of directly as harbingers of adult homosexuality. It is only relatively recently, however, that developmental scientists have conducted controlled studies to identify the earliest and most reliable signs of adult homosexuality. In looking carefully at the childhoods of gay adults, researchers are finding an intriguing set of behavioral indicators that homosexuals seem to have in common. Curiously enough, the age-old homophobic fears of many parents reflect some genuine predictive currency. J. Michael Bailey and Kenneth J. Zucker, both psychologists, published a seminal paper on childhood markers of homosexuality in 1995. Bailey and Zucker examined sex-typed behavior—that long, now scientifically canonical list of innate sex differences in the behaviors of young males versus young females. In innumerable studies, scientists have documented that these sex differences are largely impervious to learning. They are also found in every culture examined. Of course, there are exceptions to the rule; it is only when comparing the aggregate data that sex differences leap into the stratosphere of statistical significance. © 2012 Scientific American

Keyword: Sexual Behavior; Development of the Brain
Link ID: 17008 - Posted: 07.07.2012

by Michael Slezak Evolutionary biologists have a problem with sex in difficult places. Earth's complex and varied environments should, in theory, offer asexual species advantages over their sexual counterparts, says Matthew Goddard at the University of Auckland in New Zealand. An asexual species should adapt more quickly to a specific niche in the environment than a sexual species, because gene mixing between sexual individuals from different niches will produce maladapted hybrids that will not reliably pass on useful adaptations. "All else being equal, the sexual populations should be outcompeted by asexual populations," says Goddard. But the evidence around us suggests that this doesn't actually happen: environmental niches are almost always far more complex than the simple set-ups used in most lab experiments, and yet sexual species abound. To get a clearer idea of what is going on, Goddard and his Auckland colleague, Jeremy Gray, turned to yeast, single-celled organisms that can reproduce sexually or asexually. Goddard and Gray created two environments for the yeast in their lab – one containing relatively little carbon at an uncomfortably hot 37 °C, the other limited for nitrogen instead, at a less stressful 30 °C but with an "osmotic stress" caused by an unusual balance of salts. The researchers then placed sexual and asexual populations in both environments. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 17007 - Posted: 07.07.2012

by Michael Marshall The male fish, a Phallostethus cuulong just 2 centimetres long, weaves between drifting vegetation in the sluggish waters of a canal. He closes in on a female, swims alongside her and tries to mate with her. But to an outside observer, he seems to be doing it wrong. His head is right next to the female's, but he's at a 45-degree angle so his rear end is well below hers. Sounds misguided, but actually he's doing it exactly right – it's just that his gonads are on his head. This is the challenge faced by all priapiumfish, a little-known group of Asian fish that have their reproductive organs on their chins, just behind their mouths. How does this Cronenbergian arrangement work? Phallic fish P. cuulong is only the 22nd known priapiumfish, which are named after the ancient Greek fertility deity, Priapus. They all belong to a family called Phallostethidae and live in south-east Asia. The new species was discovered in July 2009 by Koichi Shibukawa of the Nagao Natural Environment Foundation in Tokyo, Japan. He saw one swimming alone in a canal near the Mekong River in Vietnam, and managed to catch it in a net. Working with colleagues at Can Tho University in Vietnam, he realised it was a new species. Male priapiumfish don't have a penis like humans and other mammals. Instead they have a unique organ called a priapium, which faces backwards and looks like a muscular nozzle. It's actually a modification of the fish's pectoral and pelvic fins. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 17006 - Posted: 07.07.2012

By Mahir Ozdemir Hardly a week passes without some sensational news about brain scans unleashing yet another secret of our cognitive faculties. Very recently I stumbled upon the news that according to recent research neuroscientists can tell, depending on your brain responses, whether you and your significant one will still be together in a few years: “You might hide it from friends and family. But you can’t hide it from neuroscientists”. The technique at the bottom of the study, just like the majority of studies making a big splash, is functional magnetic resonance imaging, fMRI. Researchers have been struggling to unfold ‘what’s under the hood’ through the lens of Neuroscience and they have been finding all sorts of insights into human behavior. They have been looking at everything from how multitasking is harder for seniors to how people love talking about themselves. Neural basis of love and hatred, compassion and admiration have all been studied with fMRI, yielding colored blobs representing the corresponding love or hatred centers in our brains. First a brief background: The fMRI technique measures brain activity indirectly via changes in blood oxygen levels in different parts of the brain as subjects participate in various activities. While lying down with head immobilized in a small confined chamber of the notoriously noisy MR scanner, subjects are shown experimental stimuli. They wear earplugs to reduce at least some part of the noise while performing these cognitive tasks. © 2012 Scientific American

Keyword: Brain imaging
Link ID: 17005 - Posted: 07.07.2012

by Sarah C. P. Williams Talk about showing your feminine side. On one flank, a courting male cuttlefish looks like a normal male of his species, with tigerlike stripes extending horizontally down his skin. But on the other, he resembles a female, displaying marbled browns and whites. He needs the male pattern to attract the female, while the female motif keeps competing males from fighting him. That’s scientists’ best guess for now, at least, to explain the devious cuttlefish behavior that they’ve observed and reported for the first time. “Cuttlefish are a very smart group of fish,” says lead researcher and ecologist Culum Brown of Macquarie University in Sydney, Australia. “And it’s pretty obvious that they are specifically using this display in a tactical way.” Researchers knew that cuttlefish (Sepia plangon) could camouflage their skin to match their surroundings, and that they could show different patterns on each side. Their skin contains a highly concentrated layer of chromatophores—various colored pigment-containing cells—that can be moved closer or further from the surface to change the pattern on the fish. But scientists had never seen a male fish mimicking a female on only one side as a trick of courtship. Brown and his colleagues first observed the behavior in a large aquarium in their lab. They wondered whether males in the wild did the same thing, and if so, when and why. So they combed through photos of 108 distinct groups of cuttlefish taken on previous dives of Sydney Harbour. They found that when a male was in a group with one female and one other male, he displayed the dual patterns—a male side facing the female and a female side facing the male—39% of the time. In other situations, such as an all-male group or a male matched with two females, the dual display was never seen. © 2010 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 17004 - Posted: 07.05.2012

By James Gallagher Health and Science reporter, BBC News, Istanbul Time-lapse photography has shown that embryos of smoking women develop more slowly. French academics in an IVF clinic took regular pictures of an egg from the moment it was fertilised until it was ready to be implanted into the mother. At all stages of development, embryos from smokers were consistently a couple of hours behind, a study showed. The lead researcher, from Nantes University Hospital, said: "You want a baby, quit smoking". Smoking is known to reduce the chances of having a child. It is why some hospitals in the UK ask couples to give up smoking before they are given fertility treatment. As eggs fertilised through IVF initially develop in the laboratory before being implanted, it gave doctors a unique opportunity to film the embryos as they divide into more and more cells. Researchers watched 868 embryos develop - 139 from smokers. In the clinic the embryos of non-smokers reached the five-cell stage after 49 hours. In the smokers it took 50 hours. The eight-cell stage took 62 hours in smokers' embryos, while non-smokers' embryos reached that point after 58 hours. Senior embryologist and lead researcher, Dr Thomas Freour, told the BBC: "Embryos from smoking women, they behave slower, there is a delay in their development. BBC © 2012

Keyword: Drug Abuse; Development of the Brain
Link ID: 17003 - Posted: 07.05.2012

Jon Bardin Growing up in the suburbs of New York City, Takao Hensch learned German from his father, Japanese from his mother and English from the community around him. “I was always wondering,” he says, “what is it that makes it so easy to learn languages when you're young, and so hard once you begin to get older?” Today, as a neuroscientist at Boston Children's Hospital in Massachusetts, Hensch is at the forefront of efforts to answer that question in full molecular detail. Language acquisition is just one of many processes that go through a 'sensitive' or 'critical' period — an interval during development when the neural circuits responsible for that process can be sculpted, and radically changed, by experience (see 'Open and shut'). During critical periods, children can make rapid progress at discerning facial features that look like their own, recognizing spoken language and locating objects in space. But within a few months or years, each window of opportunity slams shut, and learning anything new in that realm becomes difficult, if not impossible. Or maybe not. What Hensch and others in the small, but rapidly advancing, field of critical-period research are finding is that those windows can be prised back open. “For the first time, we are beginning to understand the biology that underlies critical periods,” says Hensch. And that understanding is suggesting ways to intervene in various neural disorders, including intractable conditions such as adult amblyopia, in which information from one eye is not correctly processed by the brain, and possibly even autism. The work could even lead to 'plasticity pills' that enhance learning or help to wipe out traumatic memories. © 2012 Nature Publishing Group,

Keyword: Development of the Brain; Language
Link ID: 17002 - Posted: 07.05.2012

By Scott O. Lilienfeld and Hal Arkowitz Imagine an eight-year-old boy whom we will call Eric. He is irritable and talks incessantly. Unable to sit still and concentrate, he does poorly at school. Nevertheless, he claims to be one of the smartest kids in the world and blames his poor academic performance on his “horrible” teachers. There are periods when his mood changes abruptly from euphoria to depression and then swings back again. Eric's symptoms qualify him for a diagnosis of bipolar disorder, which is characterized by episodes of full-blown mania or a less severe form called hypomania. These moods usually alternate with periods of depression [see box on opposite page]. Until about 1980 most mental health professionals believed that bipolar disorder did not occur in children. Although a few still hold this view, the general opinion of the psychiatric community has drastically shifted over the past 30 years, a period in which diagnoses of the disorder in kids have skyrocketed. In a study published in 2007 psychiatrist Carmen Moreno, then at Gregorio Marañón University General Hospital in Madrid, and her colleagues found a 40-fold increase between 1994 and 2003 in the number of visits to a psychiatrist in which a patient younger than 19 was given this diagnosis. By 2003, the researchers reported, the number of office visits resulting in a bipolar diagnosis in these youths had risen from 25 per 100,000 people to 1,003 per 100,000 people, a rate almost as high as that for adults. Such data have sparked widespread concern that the condition is egregiously overdiagnosed, perhaps contributing to the use of ineffective and even harmful medical treatments. In this column, we discuss controversies regarding the overdiagnosis of bipolar disorder in children and recent attempts to remedy this situation. © 2012 Scientific American

Keyword: Schizophrenia; Development of the Brain
Link ID: 17001 - Posted: 07.05.2012

An Ontario study of two drugs — one approved to treat wet age-related macular degeneration, and the other used off-label to fight the eye disease —suggests neither increases the risk of stroke or heart attack, adding to the debate over why both treatments from the same company aren't covered under provincial drug plans when used for AMD. AMD, which affects about one million Canadians mostly over age 65, is a progressive condition that damages the macula in the eye, and is a leading cause of blindness. Researchers from Toronto, Hamilton and Kingston, Ont., followed 91,378 older adults with a history of retinal disease between April 1, 2006 and March 31, 2011, to determine if injections of bevacizumab (trade name Avastin) or ranibizumab (Lucentis) could be linked to increased vascular risks including stroke, heart attack or congestive heart failure. Avastin and Lucentis, both manufactured by Roche, are vascular endothelial growth factor (VEGF) inhibiting drugs, and both have the potential to cause vascular side-effects. However, the research done at Ontario's Institute for Clinical Evaluative Sciences (ICES), and published in Wednesday's edition of BMJ (British Medical Joural) concludes injections of these drugs into the eyes of patients with retinal disease did not increase such risks. © CBC 2012

Keyword: Vision
Link ID: 17000 - Posted: 07.05.2012

By Helen Shen, Globe Correspondent The International Olympic Committee has issued new rules for the 2012 London Games that would require checking testosterone levels in athletes whose eligibility as females is called into question. Several elite female athletes have previously been accused of secretly being males, including South African runner Caster Semenya , who was investigated and later cleared after her 2009 world championship victory in the 800-meter event drew accusations from competitors. The IOC says its intent is to identify athletes who would be ineligible “by reason of hormonal characteristics” -- not to determine gender, but the policy has drawn criticism. Stanford University bioethicist Katrina Karkazis said the inclusion of a gynecologist and geneticist on the IOC examining panel contradicts this message. “It’s way more than a blood test or a series of blood tests. There will be genital exams, there will be genetic testing,” she said. Athletes will be disqualified to compete as females if they are found with testosterone levels typical of males, and if they possess cellular receptors that respond to the hormone’s effects, which include boosting muscle mass and strength. “They chose something that really does discriminate between males and females,” said Dr. Joshua Safer, an endocrinologist at Boston Medical Center and expert in transgender care. Testosterone levels vary from one individual to another and, for a given individual, can vary widely by time of day. But the overall ranges of testosterone are about 10 times higher in men than in women, he said. © 2012 NY Times Co.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 16999 - Posted: 07.03.2012

By NICHOLAS BAKALAR Premature birth may increase the risk for serious mental illness in adolescence and young adulthood, a recent study reports. Researchers reviewed birth and hospital admissions records of more than 1.3 million Swedes born from 1973 to 1985. They found that compared with those born at term, young adults born very premature — at less than 32 weeks’ gestation — were more than twice as likely to be hospitalized for schizophrenia or delusional disorders, almost three times as likely for major depression, and more than seven times as likely for bipolar illness. The lead author, Chiara Nosarti, a senior lecturer in neuroimaging at Kings College London, emphasized that while the increase in relative risk is substantial, the absolute increase in numbers of people with the illnesses is not. “Despite these findings,” she said, “the majority of people born preterm have no psychiatric problems, and the number of people hospitalized with psychiatric disease is very low.” Still, she added, “routine screening may help to detect early signs of illness.” The risk also increased for people born late preterm, or 32 to 36 weeks’ gestation, but not as sharply. They were 60 percent more likely to be admitted for schizophrenia or delusional disorders, 34 percent more likely for depressive disorder, and about twice as likely to be hospitalized for bipolar illness. © 2012 The New York Times Company

Keyword: Development of the Brain; Schizophrenia
Link ID: 16998 - Posted: 07.03.2012

By Linda Searing, THE QUESTION Might fear of childbirth contribute to a longer labor? THIS STUDY involved 2,206 women who were pregnant with one child and had planned to have a vaginal birth. Based on their answers to questions about childbirth that they gave when they were 32 weeks pregnant, 165 women (about 8 percent) were classified as fearful. Those women spent more time in labor than did those who were not fearful: eight hours, on average, compared with 6 hours 28 minutes. Also, emergency Caesarean deliveries and births that involved the use of forceps or other instruments were more common among fearful women. Overall, 25 percent of women who feared childbirth delivered vaginally without intervention, compared with 44 percent of those who were not afraid. WHO MAY BE AFFECTED? Pregnant women. Worries related to childbirth generally focus on pain and how to cope with it. Medical experts say the pain varies from woman to woman and depends in part on a woman’s anatomy, the size and position of her baby and the strength of contractions as well as her emotional state and attitude. CAVEATS Some data in the study came from the women’s responses on questionnaires. FIND THIS STUDY June 27 online issue of BJOG: an International Journal of Obstetrics and Gynaecology (www.bjog.org). © 1996-2012 The Washington Post

Keyword: Stress; Emotions
Link ID: 16997 - Posted: 07.03.2012

By Scicurious When I saw all the headlines going around focused on this paper, I KNEW I had to check it out. Heck, sometimes Twitter is faster than my Pubmed alerts! “Chronic Stress, Mood Disorders Linked In New Research On Rats“, “Stress Blocks Gene That Guards Brain Against Depression” The link between stress, dysregulations of the hypothalamic pituitary adrenal axis, and depressive-like symptoms in animals and depression in humans is actually really well known. We can put down our “stress linked to depression” headlines, now. In fact, other papers from the same lab as this paper have shown the link between stress and depression many, many times. We know stress correlates with depression and that stress can produce depressive like symptoms in animals. But this paper? This paper is very new, and very cool! Not because it shows a link between stress and depression. This new finding, the gene neuritin, joins a group of things linking stress and depression, including BDNF, glucocorticoid receptors, serotonin 1A receptors, and many more. This is not the first link between stress and depression and it won’t be the last. But it IS a cool finding. Because it presents us with a new antidepressant target, and we can always use one of those. All of the clinical antidepressants that are currently on the market work through one specific mechanism: they increase the levels of certain neurotransmitters in your brain. © 2012 Scientific American,

Keyword: Stress; Depression
Link ID: 16996 - Posted: 07.03.2012

By Sandra G. Boodman, Of course Diane O’Leary was seriously tired — who wouldn’t be? A doctoral candidate in philosophy with a demanding academic schedule and a 3-year-old son, O’Leary had flown home to Sydney after her family’s annual visit to relatives in Upstate New York. A few days after that 1994 flight, when O’Leary had to stop in the middle of a dance class because she was too exhausted to continue, she chalked it up to bad jet lag. And a week or so later, when she couldn’t walk up a small hill with her son without stopping to rest on a bench, the 33-year-old wasn’t alarmed. “I managed to get myself through it,” she recalled, adding that she was accustomed to being somewhat tired. But a few weeks later, when the exhaustion didn’t recede, O’Leary consulted her general practitioner. He sent her to a specialist, who made a worrisome diagnosis that would prove to be the first of many wrong answers: chronic fatigue syndrome, an illness that is not relieved by rest. Several months later, after she developed joint pain along with the fatigue, doctors decided she had rheumatoid arthritis, a serious inflammatory disorder that can cause joint destruction. The following year, that diagnosis was jettisoned in favor of a severe form of lupus, an autoimmune disease in which the body attacks its own tissues. But after medications that are the mainstay of treating lupus had no effect — and she developed strange new symptoms — O’Leary’s doctors shifted focus, suggesting that she was also suffering from an underlying psychological disorder. She said she remembers one doctor telling her, “You’re just nervous, honey.” © 1996-2012 The Washington Post

Keyword: Stroke; Depression
Link ID: 16995 - Posted: 07.03.2012

Stephanie Pappas Women infected with the cat parasite Toxoplasma gondii are more likely to attempt suicide than non-infected women, new research finds. The reason for this connection, however, remains mysterious. T. gondii is a protozoa that prefers to infect cats, but can make its home in any warm-blooded animal. Humans can pick up the parasite from contact with cat feces, or by eating undercooked meat or unwashed vegetables. Once ingested, T. gondii can make a home for itself inside the brain and muscle tissues, protected inside cysts that are resistant to attacks by the host's immune system. Some studies have linked infection by this parasite with a variety of mental health and brain problems, including schizophrenia, neurosis and brain cancer. But scientists aren't clear on whether the parasite contributes to these problems or is a mere side effect. Someone with schizophrenia, for example, might struggle to keep up good hygiene, meaning the mental disorder could increase the risk for infection. The new study linking suicide and T. gondii has the same limitation. Researchers can't say for sure whether the parasite somehow drives people to suicide. But in women with infections, they found, the risk of an attempt is 1.5 times greater than in women without. "We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that warrants additional studies," lead researcher Teodor Postolache, a psychiatrist at the University of Maryland School of Medicine, said in a statement. "We plan to continue our research into this possible connection." © 2012 msnbc.com

Keyword: Depression
Link ID: 16994 - Posted: 07.03.2012