A previously unrecognised trigger for autism may have been found, in the form of mutations that affects neuron development in a brain region important for learning and social interaction. Autism is around four times more common in boys than girls, which suggests that mutations on the X chromosome play a role, as boys lack a second X chromosome that could compensate for any genetic abnormality. Studies have identified several hundred gene candidates, but no conclusive links to a specific mutation. Now a 15-year-long international screening effort has identified two different mutations of the same X chromosome gene, which seem to be linked to autism in two unrelated families (Molecular Psychiatry, DOI: 10.1038/sj.mp.4001883). The gene encodes a protein called L10, a vital component of ribosomes - the structures that build proteins. L10 is most actively manufactured in the hippocampus, a brain region important in learning and memory as well as some social and emotional functions. Lead author Sabine Klauck of the Division of Molecular Genome Analysis at the German Cancer Research Centre in Heidelberg says the mutations are rare, and not present in their other patients. But they do reveal an important pathway by which different genetic defects could lead to different types of autism. © Copyright Reed Business Information Ltd.

Keyword: Autism; Genes & Behavior
Link ID: 9311 - Posted: 06.24.2010

Helen Thomson The part of the brain responsible for the way we understand words, meanings and concepts has been revealed as the anterior temporal lobe – a region just in front of the ears. In a novel experiment, neuroscientists pinpointed the exact region of the brain that is responsible for encoding semantic memory, which is disrupted in certain forms of dementia. Semantic dementia is the second most common form of dementia in under-65s and is associated with significant loss of brain tissue in the temporal lobe. Patients are able to generate speech fluently but lose their knowledge of objects, people and abstract concepts. For example, when shown a picture of a camel, they may understand that it is an animal but will not be able to give its name, and they lose the idea of associated concepts, such as deserts and palm trees. Matthew Lambon-Ralph and colleagues at the University of Manchester in the UK used transcranial magnetic stimulation (TMS) on 12 healthy volunteers in an attempt to detect which area of the brain is responsible for encoding this type of memory. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 9310 - Posted: 06.24.2010

Women using some hormone replacement therapies may be putting their hearing at risk, US researchers have claimed. A study found women using HRT with oestrogen and progestogen had worse hearing than those using oestrogen-only HRT or no HRT at all. The University of Rochester team gave hearing tests to 124 post-menopausal women aged 60 to 84. But experts said the link, reported by Proceedings of the National Academy of Sciences, was "far from established". HRT is used by about one million middle-aged women in the UK to treat the symptoms of menopause, including mood swings and hot flushes. The majority of women use HRT containing both hormones, as oestrogen-only HRT is usually reserved for women who have had hysterectomies, as it increases womb cancer risk. HRT has come under close scrutiny in recent years. Research has suggested that HRT using a combination of the hormones oestrogen and progestogen may increase the risk of breast cancer. And some studies have also suggested a similar risk is associated with the oestrogen-only form. The treatment has also been linked to heart and dementia problems. The latest study found the group taking HRT with both hormones had poorer speech perception compared with the other groups. This problem was also present with background noise and in quiet surroundings, suggesting that problems occurred both in the inner ear and portions of the brain used for hearing. The report said it was not clear why the effect was found, but it did suggest progestogen may alter the levels of an acid known as GABA in the brainstem and ear auditory system. Researchers recommended more stringent testing of HRT medications to ensure they do not accelerate sensory losses that may impact upon quality of life and professional abilities. (C)BBC

Keyword: Hormones & Behavior; Hearing
Link ID: 9309 - Posted: 09.06.2006

By Dan Whipple Several cultures believe that the mind can be harnessed to control aspects of our physiology, such as ramping up the immune system to fight off a cold. Now, this belief has gotten a dose of scientific support from a study that suggests that the central nervous system can regulate pain and even reduce joint damage in arthritic rats. A team of researchers led by arthritis specialist Gary Firestein of the University of California, San Diego, investigated the influence of the central nervous system in rats with rheumatoid arthritis by blocking a compound made by the spinal cord. The compound, an enzyme called p38 MAP kinase, signals pain and inflammation in rheumatoid arthritis. When the researchers injected a drug into the rats' spines that blocks p38 MAP kinase, swelling in the animals' paws decreased markedly. In addition, rats injected with the drug didn’t respond to ankle pressure, demonstrating reduced pain. Damage to the joints from arthritis was decreased by 60% after spinal injection, compared to untreated animals, the researchers report online 4 September in PLoS Medicine. Firestein says the findings suggest that the central nervous system senses peripheral tissue inflammation, then activates the p38 pathway. Researchers have previously injected p38 MAP kinase inhibitors into arthritic tissues to control pain and inflammation in animals with some success, but the new work indicates that injecting it into the central nervous system may be more effective, he says. © 2006 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 9308 - Posted: 06.24.2010

A type of protein crucial for the growth of brain cells during development appears to be equally important for the formation of long-term memories, according to researchers at UC Irvine. The findings could lead to a better understanding of, and treatments for, cognitive decline associated with normal aging and diseases such as Alzheimer’s. The findings appear in the early online edition of the Proceedings of the National Academy of Sciences. “This study presents strong evidence that a molecular process fundamental during development is retained in the adult and recycled in the service of memory formation,” said Thomas J. Carew, Donald Bren Professor and chair of UCI’s Department of Neurobiology and Behavior. “It is a striking example of how molecular rules employed in building a brain are often reused for different purposes throughout a lifetime.” The researchers have shown that proteins known as growth factors are as essential for the induction of long-term memory as they are for the development of the central nervous system. These growth factors, such as brain derived neurotrophic factor (BDNF), bind onto the brain cell through a specific type of receptor known as TrkB, much the same way a key fits into a lock. As an experimental strategy to determine the importance of BDNF-like growth factors in forming memories, the researchers used a “molecular trick” to keep the proteins from binding with the appropriate TrkB receptors. © Copyright 2002-2006 UC Regents

Keyword: Learning & Memory; Trophic Factors
Link ID: 9307 - Posted: 06.24.2010

UCLA scientists have discovered that infants who possess a specific immune gene that too closely resembles their mothers' are more likely to develop schizophrenia later in life. Reported in the October issue of the American Journal of Human Genetics, the study suggests that the genetic match may increase fetal susceptibility to schizophrenia, particularly in females. HLA-B is one of a family of genes called the human leukocyte antigen (HLA) complex, which helps the immune system distinguish the body's own proteins from those made by foreign invaders, such as viruses and bacteria. The developing fetus inherits one copy of the HLA-B gene from each parent. "Our findings clearly suggest that schizophrenia risk rises, especially in daughters, when the child's HLA-B gene too closely matches its mother's," explained Christina Palmer, Ph.D, UCLA associate professor of psychiatry and human genetics and a researcher at the Semel Institute for Neuroscience and Human Behavior. "We don't know whether sons who match are not affected -- or are more affected and less likely to come to term." In 2002, Palmer and her colleagues discovered that infants are twice as likely to develop schizophrenia later in life when they possess a cell protein called Rhesus (Rh) factor that their mothers lack. Later studies found that male babies were more vulnerable to the consequences of Rh incompatibility than female infants.

Keyword: Schizophrenia; Neuroimmunology
Link ID: 9306 - Posted: 09.06.2006

Michael Hopkin Eating a high-protein diet can boost the release of a hunger-suppressing hormone, according to new study on mice. The research suggests that a diet rich in protein may be a good way to lose weight and keep it off. Mice fed a protein-heavy diet produced higher levels of an appetite-regulating protein called peptide YY (PYY), which has been linked to reduced appetite in human studies. What's more, the high-protein mice put on less fat than mice on a low-protein regime. The discovery boosts the theory that eating more protein might help to reduce appetite and lead to sustained weight loss, says Rachel Batterham of University College London, who led the research, published in the journal Cell Metabolism1. "All the evidence suggests that it will be beneficial," she says. The discovery may also shed light on how the notorious Atkins diet, which ditches carbohydrates in favour of protein and saturated fats, might work. Studies have shown that people on this diet can loose weight, though it is unclear why. Batterham thinks she may have the answer: "People on the Atkins diet don't feel as hungry — that's how it works." But, she cautions, that doesn't mean the Atkins diet is a good idea: "No medical person is going to tell you to have all that saturated fat in your diet and no carbohydrates." ©2006 Nature Publishing Group

Keyword: Obesity
Link ID: 9305 - Posted: 06.24.2010

Lucy Heady Teachers everywhere can be heard shouting "look at me when I'm talking to you". But research presented today at the British Association's Festival of Science in Norwich, UK, suggests that they should be doing exactly the opposite. When posed with a conundrum, it is normal for adults and older children to look away, staring in an unfocused way out of the window or at a patch of the carpet. This aimless gaze isn't necessarily thanks to an attitude of indifference or indolence, but instead might be helping the brain to concentrate. Researchers at the University of Stirling in Scotland took a group of 25 five-year-olds and trained them to look away when they were being asked a question. The effect was a significant increase in correct answers to mental arithmetic questions, says Gwyneth Doherty-Sneddon, who led the research. She declined to give details as the work is in press with the British Journal of Developmental Psychology. Further experiments by the same group showed that the difficulty of both looking at a face and thinking about maths is so extreme it can cause a physiological response. In one study, around 30 adults were asked to perform a task requiring concentration, such as counting backwards from 100 in increments of 7, while staring at a human face. The combination of mental effort and emotional confusion caused the subjects to break out in a sweat. The sweatiest subjects, Doherty-Sneddon adds, were men being tested by a female researcher. ©2006 Nature Publishing Group

Keyword: Attention; Learning & Memory
Link ID: 9304 - Posted: 06.24.2010

By Shankar Vedantam Children born to fathers of advancing age are at significantly higher risk of developing autism compared with children born to younger fathers, according a comprehensive study published yesterday that offers surprising new insight into one of the most feared disorders of the brain. The finding comes at a time of great controversy over autism in the United States, as a recent surge in diagnoses has fueled speculations about various possible causes of the disorder. For scientists, both the origins of and potential treatments for the disorder remain a mystery. With every decade of advancing age starting with men in their teens and twenties, the new study found, older fathers pose a growing risk to their children when it comes to autism -- unhappy evidence that the medical risks associated with late parenthood are not just the province of older mothers, as much previous research has suggested. Of special concern is the finding that the risk for autism not only increases with paternal age but also appears to accelerate. When fathers are in their thirties, children have about 1 1/2 times the risk of developing autism of children of fathers in their teens and twenties. Compared with the offspring of the youngest fathers, children of fathers in their forties have more than five times the risk of developing autism, and children of fathers in their fifties have more than nine times the risk. © 2006 The Washington Post Company

Keyword: Autism
Link ID: 9303 - Posted: 06.24.2010

By ELISSA ELY, M.D. I’m waiting by the nursing station with a million things to do when an elderly woman on the unit wanders by. I’ve noticed her before; she’s implacable, incontinent and undistressed by the noise and smells of dementia. She doesn’t fight her pills and is no troublemaker to the nursing staff. They paint her nails. She never wanders alone. There’s a rubber baby doll in her arms. Someone in China was not paid to paint an expression on the face; it wears an inscrutable little smile. This type of doll is always naked and, through the blessed powers of invention, loved by girls in spite of its unfriendly skin. Little girls grow up believing babies are made of rubber and then are pleasantly surprised later in life. The woman strolls by serenely. A diaper peeks over the back of her pants. She’s not headed anywhere, just taking the little one for some air. No sling or Baby Björn for her — transportation occurs the old-fashioned way. She’s rocking the doll and walking and gazing deeply into its face, all without losing her balance. It’s like watching tai chi. In the corner, a woman in a different stage of dementia shakes in her wheelchair. “I’m nervous, I’m nervous!” she yells, slapping an aide trying to take a blood pressure reading. She was just as nervous five minutes ago in her room, before the aide wheeled her outside for relief. She is unendingly nervous. When you ask what upsets her, she can’t tell you, of course. It may be physical discomfort from a treatable source — tests will tell — or it may be some deeper distress of the soul she cannot escape. She is never happy. Copyright 2006 The New York Times Company

Keyword: Alzheimers
Link ID: 9302 - Posted: 06.24.2010

By CARL ZIMMER Across the eastern United States, a gruesome ritual is in full swing. The praying mantis and its relative, the Chinese mantis, are in their courtship season. A male mantis approaches a female, flapping his wings and swaying his abdomen. Leaping on her back, he begins to mate. And quite often, she tears off his head. The female mantis devours the head of the still-mating male and then moves on to the rest of his body. “If you put a pair together and come back later, you’ll just find the wings of the male and no other evidence he was ever there,” said William Brown, an evolutionary biologist at the State University of New York in Fredonia. Sexual cannibalism has fascinated biologists ever since Darwin. It is not limited to mantises, but is also found in other invertebrates, including spiders, midges and perhaps horned nudibranchs. Biologists have debated how this behavior has evolved in these species. Some have suggested that sexual cannibalism is just a result of a voracious female appetite. But experiments have also suggested that it is a strategy that females use to select the best fathers for their offspring. Other scientists have found evidence that males may have had a role in the evolution of cannibalism. By surrendering themselves to their mates, males increase their reproductive success. Still other scientists have proposed that males actually go to great lengths to minimize their risk of being eaten. Copyright 2006 The New York Times Company

Keyword: Sexual Behavior
Link ID: 9301 - Posted: 06.24.2010

MADISON -- Psychologists have long known that memories of disturbing emotional events - such as an act of violence or the unexpected death of a loved one - are more vivid and deeply imprinted in the brain than mundane recollections of everyday matters. Probing deeper into how such memories form, researchers at the University of Wisconsin-Madison have found that the mere anticipation of a fearful situation can fire up two memory-forming regions of the brain - even before the event has occurred. That means the simple act of anticipation may play a surprisingly important role in how fresh the memory of a tough experience remains. The findings of the brain-imaging study, which appear in the current issue of the Proceedings of the National Academy of Sciences, have important implications for the treatment of psychological conditions such as post-traumatic stress disorder (PTSD) and social anxiety, which are often characterized by flashbacks and intrusive memories of upsetting events. "The main motivation for this study was a clinical one, in terms of understanding and applying knowledge about memory so that we can better inform the treatment of disorders that have a large memory component, like PTSD," says lead author Kristen Mackiewicz, a graduate student at the University of Colorado who worked on the anticipation study while a student at UW-Madison.

Keyword: Learning & Memory
Link ID: 9300 - Posted: 09.05.2006

Adam Feinstein As many as one in 166 people today may be diagnosed with an autistic spectrum disorder. These five books offer timely insights into a condition which, while remaining enigmatic, is slowly yielding up some of its secrets. All of the books have a strong autobiographical element, although two are presented as novels. Kamran Nazeer, the author of Send in the Idiots, is a remarkable character. In 1982, at the age of four, he entered a small private special school in New York, joining a dozen other children diagnosed, as he was, with autism. At the time, he could not speak a word. He is now a high-powered policy adviser in Whitehall. This book records his travels around the United States more than 20 years after his schooldays, to see what has become of some of his former classmates. These turn out to be fascinating encounters. The first is with André, a bright man who is working on a project developing artificial vision for computers and robots. He has overcome his difficulties with conversation by speaking through puppets. He was once turned away from a speed-dating evening because he arrived with a puppet he had just made called Sylvie. Randall is very different. He is in a relationship with Mike, a budding novelist. Nazeer points out that this is unusual, because many people with autism shrink from being touched by others. (In contrast, Temple Grandin, probably the world's best-known person with high-functioning autism, actually preferred to be squeezed tightly, and, based on her observation of cattle in chutes, pioneered the so-called "hug box" to provide deep pressure stimulation evenly. Her device has been used in a number of schools for autistic children.) © Guardian Newspapers Limited 2006

Keyword: Autism
Link ID: 9299 - Posted: 06.24.2010

Gaia Vince Men over 40 are almost six times more likely to father a child with autism than younger men, according to a new study. Israeli researchers looked at birth data of more than 130,000 people born in the 1980s, where the paternal and maternal ages had been recorded. Of these 110 – or just over 1 in 1000 – had an "autism spectrum disorder". ASD can include autism, Asperger syndrome and Rett syndrome. “Men who were over 40 at the time of the child’s birth were 5.75 times as likely to have a child with ASD compared with men under 30,” says Abraham Reichenberg at Mount Sinai School of Medicine in New York, US. “The risk was slightly higher for men in their 30s – they were 1.6 times as likely to produce a child with ASD.” Older maternal age was not found to be a risk factor for ASD. “There might be a maternal age effect, but there were so few women in our study that gave birth after the age of 40 that it was not statistically significant,” explains Reichenberg, who carried out the study with colleagues. As people age, their cells' DNA repair mechanisms lose some functionality. As a result, more of the randomly occurring genetic mutations occurring in sperm-producing cells may be passed from father to offspring, suggests Reichenberg, who now works at the Institute of Psychiatry at Kings College London, UK. © Copyright Reed Business Information Ltd.

Keyword: Autism
Link ID: 9298 - Posted: 06.24.2010

Gaia Vince Monkeys “imitate with a purpose”, matching their behaviour to others’ as a form of social learning, researchers report. Such mimicry has previously been seen only in great apes – including humans and chimps – but now Italian researchers have recorded wonderful footage of the phenomenon in newborn rhesus macaques. Human newborns have a known capacity to mimic certain specific adult facial expressions, including mouth opening and tongue protrusion. The so-called imitation period lasts up to three months in human infants and two months in chimps. Since newborns cannot see their own faces, they rely on watching adults to learn facial expressions, and mimicry is thought to be crucial to the development of a mother-infant relationship. Particular brain cells – called “mirror neurons” – fire in a human infant when it watches an adult expression and copies it. Similar mirror neurons "light up" when rhesus monkeys watch another animal perform an action and when they copy that action. This similarity suggests a common brain pathway for imitation in humans and monkeys. Pier Ferrari at the University of Parma, Italy, and colleagues tested 21 newborn macaques by holding each in front of a researcher who made various facial expressions. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Emotions
Link ID: 9297 - Posted: 06.24.2010

By LYNNE A. ISBELL SNAKES hit a nerve in people. How else to explain why the movie “Snakes on a Plane” became an Internet sensation months before it was released in theaters? The very idea was all it took to rouse attention. That humans have been afraid of snakes for a long time is not a fresh observation; that this fear may be entwined with our development as a species is. New anthropological evidence suggests that snakes, as predators, may have figured prominently in the evolution of primate vision — the ability, shared by humans, apes and monkeys, to see the world in crisp, three-dimensional living color. The snake-detection hypothesis has grown, as scientific theories so often do, out of attempts to grapple with the flaws in earlier ideas about why primates have better vision than any other mammals. (Cats, dogs and horses can see objects well enough, but they lack the depth perception it takes to, say, perform brain surgery, or the visual acuity we humans use to read the fine print on a legal contract.) Back in the early 1900’s, scientists thought that natural selection may have favored sharp eyes in ancestral primates because these animals were presumed to have lived in the canopies of tropical trees, and would have needed excellent vision to negotiate that environment without falling. Copyright 2006 The New York Times Company

Keyword: Vision; Evolution
Link ID: 9296 - Posted: 06.24.2010

In a new study from The American Naturalist, researchers from the University of Zurich studied vocal communication between fallow deer mothers and their offspring. They found that only adult females have individually distinctive calls, meaning that fawns are able to distinguish their mother's calls from those of other females, but mothers are not able to distinguish between the calls of their own offspring and other fawns. This is in contrast to previous studies and provides a novel insight into parent-offspring recognition mechanisms. "Newborn fawns lie concealed and silent in vegetation away from their mothers to avoid detection by predators, and mothers return intermittently to feed them," write Marco Torriani, Elisabetta Vannoni, and Alan McElligott. "Vocal communication is very important for ungulate hider species because mothers and offspring rely on contact calls for reunions to occur." The researchers tested vocal recognition on Swiss fallow deer farms using recordings and playback experiments. Similar research on domestic sheep and reindeer has shown that both mothers and offspring are able to recognize each other based on individually distinctive contact calls. However, reindeer and sheep tend to populate open habitats lacking cover, and the researchers argue that the recognition system employed by deer evolved in habitats providing abundant cover for newborns. While sheep and reindeer are mobile soon after birth – and thus remain in constant close contact with the mother – mother-offspring contact for deer is limited during the first few weeks of life to when nursing occurs.

Keyword: Animal Communication
Link ID: 9295 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Genes shape our health and appearance more than they shape our personality, suggests a new study of thousands of people in a genetically isolated part of the world. According to the study, published in the August issue of PLoS Genetics, genetics account for roughly 51 percent of a person’s height, weight and overall body shape, 25 percent of cardiovascular function, and about 40 percent of certain blood characteristics, such as sugar and cholesterol levels. But genes only account for about 19 percent of many documented personality traits, such as neuroticism, extraversion, agreeableness and conscientiousness. "My personal view is that we have evolved to have very diverse personalities and that, compared to other traits, personality may be much less deterministic than other human characteristics," said Gonçalo Abecasis, one of the study’s authors. "My view is that both genes and environment will play smaller roles than random factors." Abecasis, a scientist at the Center for Statistical Genetics at the University of Michigan, and his colleagues examined 6,148 people from the Mediterranean island of Sardinia, where many residents are related. Roughly 95 percent of all test subjects’ grandparents were Sardinian, and the test group included 5,000 pairs of siblings. © 2006 Discovery Communications Inc.

Keyword: Genes & Behavior; Neuroimmunology
Link ID: 9294 - Posted: 06.24.2010

Eric Jaffe At the opening of Stanley Kubrick's 1968 film 2001: A Space Odyssey, a group of apes hovers around an object that has suddenly appeared in the desert. The sleek, black, rectangular object is five times as tall as the apes and clearly crafted by intelligent beings. The apes approach it with caution, and one animal runs a timid hand along the clean edges that glimmer in the sunlight. Suddenly, something clicks in the ape's mind. The sight of a sophisticated innovation has launched dormant aptitudes, and the ape has realized that a large bone can be used as a weapon to advance its kind. Standing more erect than before and brandishing the weapon, the ape attacks another group. The film then fast-forwards through the remainder of cognitive evolution in a flash: The bone, tossed into the air, becomes a space station floating through the cosmos. Too bad the camera didn't cut instead to a laboratory at the Max Planck Institute in Leipzig, Germany, where scientists are discovering details about apes' brains that could fill in some of the movie's multimillion-year gap. Researchers at the institute, Josep Call and Nicholas Mulcahy, recently demonstrated that apes possess a surprising understanding of tools and even make plans to use them. In fact, the study suggests that planning skills go back 14 million years to ancestors of apes and people. ©2006 Science Service.

Keyword: Evolution
Link ID: 9293 - Posted: 06.24.2010

Molecular geneticists Mario Capecchi and Petr Tvrdik stand over a mouse cage, lightly spraying compressed air over a mouse. But instead of flinching, the mouse doesn't close its eyes or wiggle its little whiskers. Capecchi says that's due to its genetics. It's lost the ability to control its facial muscles, similar to a human condition called Moebius Syndrome. Capecchi and Tvrdik created this condition in the mouse by turning off one of its many Hox genes, which are key in development of the embryo. This pioneering technique developed by Capecchi and others earned them the Albert Lasker Award in 2003. "We developed a technology which allowed us to change any gene we want to in the mouse," he says. "It allows us to inactivate a particular gene and see what effect it has on the mouse." In this study, they turned off the Hox gene that directs facial muscle development. "These muscles allow you, for example, to smile or to frown or to open and close your eyelids, even to shed tears. All of the things that you normally would do with your face," Capecchi says. This gene comes from a big family that was once a single gene. Almost like splitting up work in a factory, genes evolve by splitting up and specializing over time, a process called subfunctionalization. "A common theme during evolution is that you start out with a single gene and then you duplicate it," he says. "Then sometimes those genes are duplicated so that now we have a whole family of genes. The genes acquire new functions, and thereby greater complexity." © ScienCentral, 2000-2006

Keyword: Evolution; Emotions
Link ID: 9292 - Posted: 06.24.2010