Chapter 7. Life-Span Development of the Brain and Behavior
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By Tina Hesman Saey COLD SPRING HARBOR, N.Y. – Taming foxes changes not only the animals’ behavior but also their brain chemistry, a new study shows. The finding could shed light on how the foxes’ genetic cousins, wolves, morphed into man’s best friend. Lenore Pipes of Cornell University presented the results May 10 at the Biology of Genomes conference. The foxes she worked with come from a long line started in 1959 when a Russian scientist named Dmitry Belyaev attempted to recreate dog domestication, but using foxes instead of wolves. He bred silver foxes (Vulpes vulpes), which are actually a type of red fox with white-tipped black fur. Belyaev and his colleagues selected the least aggressive animals they could find at local fox farms and bred them. Each generation, the scientists picked the tamest animals to mate, creating ever friendlier foxes. Now, more than 50 years later, the foxes act like dogs, wagging their tails, jumping with excitement and leaping into the arms of caregivers for caresses. At the same time, the scientists also bred the most aggressive foxes on the farms. The descendents of those foxes crouch, flatten their ears, growl, bare their teeth and lunge at people who approach their cages. The foxes’ tame and aggressive behaviors are rooted in genetics, but scientists have not found DNA changes that account for the differences. Rather than search for changes in genes themselves, Pipes and her colleagues took an indirect approach, looking for differences in the activity of genes in the foxes’ brains. © Society for Science & the Public 2000 - 2013
Keyword: Genes & Behavior
Link ID: 18164 - Posted: 05.16.2013
By David Brown, A team of researchers said Wednesday that it had produced embryonic stem cells — a possible source of disease-fighting spare parts — from a cloned human embryo. Scientists at the Oregon Health and Science University accomplished in humans what has been done over the past 15 years in sheep, mice, cattle and several other species. The achievement is likely to, at least temporarily, reawaken worries about “reproductive cloning” — the production of one-parent duplicate humans. But few experts think that production of stem cells through cloning is likely to be medically useful soon, or possibly ever. “An outstanding issue of whether it would work in humans has been resolved,” said Rudolf Jaenisch, a biologist at MIT’s Whitehead Institute in Cambridge, Mass., who added that he thinks the feat “has no clinical relevance.” “I think part of the significance is technical and part of the significance is historical,” said John Gearhart, head of the Institute for Regenerative Medicine at the University of Pennsylvania. “Many labs attempted it, and no one had ever been able to achieve it.” A far less controversial way to get stem cells is now available. It involves reprogramming mature cells (often ones taken from the skin) so that they return to what amounts to a second childhood from which they can grow into a new and different adulthood. Learning how to make and manipulate those “induced pluripotent stem” (IPS) cells is one of biology’s hottest fields. © 1996-2013 The Washington Post
Ed Yong The US adolescents who signed up for the Study of Mathematically Precocious Youth (SMPY) in the 1970s were the smartest of the smart, with mathematical and verbal-reasoning skills within the top 1% of the population. Now, researchers at BGI (formerly the Beijing Genomics Institute) in Shenzhen, China, the largest gene-sequencing facility in the world, are searching for the quirks of DNA that may contribute to such gifts. Plunging into an area that is littered with failures and riven with controversy, the researchers are scouring the genomes of 1,600 of these high-fliers in an ambitious project to find the first common genetic variants associated with human intelligence. The project, which was launched in August 2012 and is slated to begin data analysis in the next few months, has spawned wild accusations of eugenics plots, as well as more measured objections by social scientists who view such research as a distraction from pressing societal issues. Some geneticists, however, take issue with the study for a different reason. They say that it is highly unlikely to find anything of interest — because the sample size is too small and intelligence is too complex. Earlier large studies with the same goal have failed. But scientists from BGI’s Cognitive Genomics group hope that their super-smart sample will give them an edge, because it should be enriched with bits of DNA that confer effects on intelligence. “An exceptional person gets you an order of magnitude more statistical power than if you took random people from the population — I’d say we have a fighting chance,” says Stephen Hsu, a theoretical physicist from Michigan State University in East Lansing, who acts as a scientific adviser to BGI and is one of the project’s leaders. © 2013 Nature Publishing Group,
Pregnant mothers’ exposure to the flu was associated with a nearly fourfold increased risk that their child would develop bipolar disorder in adulthood, in a study funded by the National Institutes of Health. The findings add to mounting evidence of possible shared underlying causes and illness processes with schizophrenia, which some studies have also linked to prenatal exposure to influenza. “Prospective mothers should take common sense preventive measures, such as getting flu shots prior to and in the early stages of pregnancy and avoiding contact with people who are symptomatic,” said Alan Brown, M.D., M.P.H, of Columbia University and New York State Psychiatric Institute, a grantee of the NIH’s National Institute of Mental Health (NIMH). “In spite of public health recommendations, only a relatively small fraction of such women get immunized. The weight of evidence now suggests that benefits of the vaccine likely outweigh any possible risk to the mother or newborn.” Brown and colleagues reported their findings online May 8, 2013 in JAMA Psychiatry. Although there have been hints of a maternal influenza/bipolar disorder connection, the new study is the first to prospectively follow families in the same HMO, using physician-based diagnoses and structured standardized psychiatric measures. Access to unique Kaiser-Permanente, county and Child Health and Development Study External Web Site Policy databases made it possible to include more cases with detailed maternal flu exposure information than in previous studies.
By Scicurious Aging happens. As you get older, your body slows down, eventually your brain slows down, too. Some things go gradually, and some go suddenly. To many people, this might seem like a pretty random process. We used to think of aging this way, as just…well cells get old, which means we get old, too. DNA replication after a while starts making errors in repair, the errors build up, and on the whole body scale the whole thing just kind of goes downhill. It seems random. But in fact, it’s not. There are specific proteins which can help control this process. And one of these, NF-kB, in one particular brain region, may have a very important role indeed. NF-kB (which stands for nuclear factor kappa-light-chain-enhancer of activated B cells, which is why we use NF-kB) is a protein complex that has a lot of roles to play. It’s an important starting player in the immune system, where it helps to stimulate antibodies. It’s important in memory and stress responses. NF-kB is something called a transcription factor, which helps to control what DNA is transcribed to RNA, and therefore what proteins will eventually be produced. Transcription factors, as you can see, can have a very large number of functions. But in the hypothalamus, NF-kB may have the added function of helping to control aging. The hypothalamus is an area of many small nuclei (further sub areas of neurons) located at the base of the brain. It’s been coming more and more into vogue lately among neuroscientists. In the past, we were interested in the hypothalamus mostly for its role in controlling hormone release from the dangling pituitary gland before it, but now we are learning that the hypothalamus can play roles in fear, mood, food intake, reproduction, and now…aging. © 2013 Scientific American
By DAVID DOBBS In the autistic person, it seems, hums a vital and distinctive essence — but one whose nature is obscured by thick layers of behavior and perception. Or, as Temple Grandin puts it, “two panes of glass.” For a quarter century, Dr. Grandin — the brainy, straight-speaking, cowboy-shirt-wearing animal scientist and slaughterhouse designer who at 62 is perhaps the world’s most famous autistic person — has been helping people break through the barriers separating autistic from nonautistic experience. Like Dr. Sacks, who made her famous as the title figure in his 1995 collection “An Anthropologist on Mars,” Dr. Grandin has helped us understand autism not just as a phenomenon, but as a different but coherent mode of existence that otherwise confounds us. In her own books and public appearances, she excels at finding concrete examples that reveal the perceptual and social limitations of autistic and “neurotypical” people alike. In “The Autistic Brain,” her latest book, written with the science author Richard Panek, she shows this talent most vividly in a middle chapter that looks at the sensory world of autism. It is a world filled with anomalies, in which everyday sensations can be overwhelming: A school bell can feel like a dentist’s drill, a scratchy shirt like a swarm of fire ants. In other cases the autistic person may feel so little sensation that she’ll try to fill the vacuum and create some sort of order — hence the rocking, twirling, hand-flapping, noisemaking behaviors that can discomfit and alienate onlookers. © 2013 The New York Times Company
Link ID: 18149 - Posted: 05.14.2013
By Melanie Tannenbaum Imagine that you’re an infant monkey, and you’ve just been thrown into a cage after several hours in isolation. You’ve been deprived of food, so you’re starving. Facing you are two adult-looking (fake) monkeys, designed to look like each one could potentially be your mother. On the left is a “wire mother,” equipped with a bottle and feeding tube so you can cling to her and fill your belly with milk. On the right is a “cloth mother,” with no bottle, but with a fuzzy terrycloth exterior that will allow for hours of soft, warm snuggles. You can only run to one of the monkeys. Which one will you choose? Six or seven decades ago, many psychologists would have claimed that any affection that we experience towards our parental figures is a purely behaviorist response. After many instances of conditioning a sense of “positive affect” after receiving life-sustaining food from mothers, children associate that positive emotion with these caregivers, an association that serves as the sole explanation for why people “love” their mothers. But that’s not what Harry Harlow thought. Harlow, a psychologist working at the University of Wisconsin – Madison during the 1960s, believed that there was something more important underlying our affection for Mom and Dad than our primal need to eat and survive. He believed that there was an additional factor: Comfort. What Harlow did to test this hypothesis was arguably ingenious, though inarguably cruel.1 Harlow deprived monkeys of food, making them desperately hungry, and then stuck them into a cage where they had a choice of two “mother figures” to run towards. On the left was a wire mother – cold and uncomfortable, yet equipped with a bottle that would feed the baby with life-sustaining nutrients. On the right was a cloth mother – warm, soft, and comfortable, yet unable to provide the infant with any food. If the only reason why we “love” our mothers (and fathers) is based on a conditioned response to our need for food, then the infant monkeys should run to the wire mothers who can feed them every time. © 2013 Scientific American
By Puneet Kollipara Identical twin mice sharing the same mazelike environment develop distinct personalities based on how much they explore their surroundings, researchers report in the May 10 Science. After death, those differences were reflected in the animals’ brains. The study “highlights something for which we had some intuition before, but actually quantifies it,” says Fred Gage, a neuroscientist at the Salk Institute for Biological Studies in La Jolla, Calif. Some character and biological differences between identical twins may originate as early as pregnancy. But twins become more and more different as life goes on, even when they grow up together. Scientists have recognized that having distinct experiences within the same environment might boost such personality differences, but that’s difficult to test in humans. Studying it in animals has multiple benefits. “You can keep the genes constant and also keep the environment constant,” says Gerd Kempermann of the Center for Regenerative Therapies Dresden in Germany. “It’s much more controlled than in a human situation.” Researchers led by Kempermann put 40 genetically identical female mice in an elaborate cage and observed their behavior. The cage had multiple levels linked together by tubes and contained toys and other features that the animals could explore. The researchers equipped each mouse with a microchip that tracked its location, using the animals’ movements as a measure of exploratory behavior. Initially, the mice differed only slightly in their tendency to roam. As they grew older, all tended to explore more often, but the differences among the mice grew more pronounced. © Society for Science & the Public 2000 - 2013
By James Gallagher Health and science reporter, BBC News Flu during pregnancy may increase the risk of the unborn child developing bipolar disorder later in life, research suggests. A study of 814 expectant women, published in JAMA Psychiatry, showed that infection made bipolar four times more likely. The overall risk remained low, but it echoes similar findings linking flu and schizophrenia. Experts said the risks were small and women should not worry. Bipolar leads to intense mood swings, which can last months, ranging from depression and despair to manic feelings of joy, overactivity and loss of inhibitions. Researchers at the Columbia University Medical Center identified a link between the condition, often diagnosed during late teens and twenties, and experiences in the womb. In their study looking at people born in the early 1960s, bipolar disorder was nearly four times as common in people whose mothers caught flu during pregnancy. The condition affects about one in 100 people. The lead researcher, Prof Alan Brown, estimated that influenza infection during pregnancy could lead to a 3-4% chance of bipolar disorder in the resulting children. However, in the vast majority of cases of bipolar disorder there would no history of flu. BBC © 2013
By MARILYNN MARCHIONE DEERFIELD, Ill. (AP) — Baxter International Inc. says that a blood product it was testing failed to slow mental decline or to preserve physical function in a major study of 390 patients with mild to moderate Alzheimer’s disease. The company says that people who received 18 months of infusions with its drug, Gammagard, fared no better than others given infusions of a dummy solution. Gammagard is immune globulin, natural antibodies culled from donated blood. Researchers thought these antibodies might help remove amyloid, the sticky plaque that clogs patients’ brains, sapping memory and ability to think. Patients with moderate disease and those with a gene that raises risk of Alzheimer’s who were taking the higher of two doses in the study seemed to benefit, although the study was not big enough to say for sure. ‘‘The study missed its primary endpoints, however we remain interested by the prespecified sub-group analyses’’ in groups that seemed to benefit, Ludwig Hantson, president of Baxter’s BioScience business, said in a statement. Gammagard is already sold to treat some blood disorders, and the results of the Alzheimer’s study do not affect those uses. About 35 million people worldwide have dementia, and Alzheimer’s is the most common type. In the U.S., about 5 million have Alzheimer's. Current medicines such as Aricept and Namenda just temporarily ease symptoms. There is no known cure. © 2013 NY Times Co.
Link ID: 18131 - Posted: 05.08.2013
By Gisela Telis, I’ve seen friends fret over the purported link between aluminum and Alzheimer’s disease and have often wondered if their fears are founded on fact. Should they give up aluminum pans or aluminum-containing antiperspirants? I’ve always heard that aluminum’s health dangers are just hype. So what’s the real deal? The connection between aluminum and Alzheimer’s disease is less a myth than a longstanding scientific controversy. It began in 1965, when researchers discovered that injecting rabbits’ brains with aluminum caused them to develop neurofibrillary tangles, the twisted proteins found in brain cells of patients with Alzheimer’s disease, a degenerative brain disorder that destroys memory and cognition. The finding spurred a rush of research. Just eight years later, a Canadian group studying brain tissue from deceased Alzheimer’s patients found that certain parts of their brains had two to three times more aluminum than a normal brain. By 1980, Daniel Perl and Arnold Brody had managed to actually peer inside human tangle-bearing brain cells — and found aluminum there, too. “That really changed the whole complexion of the thing,” recalls Perl, now a professor of pathology in the Uniformed Services University of the Health Sciences in Bethesda. “I was getting called all the time, because there was so much public interest.” Despite the rise in interest, no one could figure out what this meant for human health. Part of the problem was that scientific techniques were — and still are — too imperfect to provide an answer. Whether they were studying brain cells or conducting population-wide epidemiological studies that tracked aluminum exposure and Alzheimer’s risk, researchers lacked the tools to get very precise or conclusive results. © 1996-2013 The Washington Post
By Dina Fine Maron Almost a decade after manufacturers stopped using certain chemical flame retardants in furniture foam and carpet padding, many of the compounds still lurk in homes. New work to be presented today reaffirms that the chemicals may also still be hurting young children who were exposed before they were born. Researchers investigating the health impacts of prenatal exposure to flame retardants collected blood samples from 309 pregnant women early in their second trimester. Spikes in the levels of one class of flame retardant, polybrominated diphenyl ethers (PBDEs) correlated with behavior and cognition difficulties during early childhood. The researchers tracked children through the first five years of their lives, looking at a battery of tests for IQ and behavior. They found that children of mothers who had high PBDE levels during their second trimester showed cognition deficits when the children were five years old as well as higher rates of hyperactivity at ages two to five. If the mother’s blood had a 10-fold increase in PBDEs, the average five-year-old had about a four-point IQ deficit. “A four-point IQ difference in an individual child may not be perceivable in…ordinary life. However, in a population, if many children are affected, the social and economic impact can be huge due to the shift of IQ distribution and productivity,” says lead author Aimin Chen, an assistant professor of environmental health at the University of Cincinnati College of Medicine. The findings, based on women and children from Cincinnati, will be presented May 6 at the annual meeting of the Pediatric Academic Societies in Washington, D.C. The unpublished results have been submitted to a peer-reviewed journal, but the paper has not yet been accepted. © 2013 Scientific American
By BILL PENNINGTON BOSTON — The drumbeat of alarming stories linking concussions among football players and other athletes to brain disease has led to a new and mushrooming American phenomenon: the specialized youth sports concussion clinic, which one day may be as common as a mall at the edge of town. In the last three years, dozens of youth concussion clinics have opened in nearly 35 states — outpatient centers often connected to large hospitals that are now filled with young athletes complaining of headaches, amnesia, dizziness or problems concentrating. The proliferation of clinics, however, comes at a time when there is still no agreed-upon, established formula for treating the injuries. “It is inexact, a science in its infancy,” said Dr. Michael O’Brien of the sports concussion clinic at Boston Children’s Hospital. “We know much more than we once did, but there are lots of layers we still need to figure out.” Deep concern among parents about the effects of concussions is colliding with the imprecise understanding of the injury. To families whose anxiety has been stoked by reports of former N.F.L. players with degenerative brain disease, the new facilities are seen as the most expert care available. That has parents parading to the clinic waiting rooms. The trend is playing out vividly in Boston, where the phone hardly stops ringing at the youth sports concussion clinic at Massachusetts General Hospital. “Parents call saying, ‘I saw a scary report about concussions on Oprah or on the ‘Doctors’ show or Katie Couric’s show,’ ” Dr. Barbara Semakula said, describing a typical day at the clinic. “Their child just hurt his head, and they’ve already leapt to the worst possible scenarios. It’s a little bit of a frenzy out there.” © 2013 The New York Times Company
By John Horgan What is mental illness? Schizophrenia? Autism? Bipolar disorder? Depression? Since the 1950s, the profession of psychiatry has attempted to provide definitive answers to these questions in the Diagnostic and Statistical Manual of Mental Disorders. Often called The Bible of psychiatry, the DSM serves as the ultimate authority for diagnosis, treatment and insurance coverage of mental illness. Now, in a move sure to rock psychiatry, psychology and other fields that address mental illness, the director of the National Institutes of Mental Health has announced that the federal agency–which provides grants for research on mental illness–will be “re-orienting its research away from DSM categories.” Thomas Insel’s statement comes just weeks before the scheduled publication of the DSM-V, the fifth edition of the Diagnostic and Statistical Manual. Insel writes: “While DSM has been described as a ‘Bible’ for the field, it is, at best, a dictionary, creating a set of labels and defining each. The strength of each of the editions of DSM has been ‘reliability’–each edition has ensured that clinicians use the same terms in the same ways. The weakness is its lack of validity. Unlike our definitions of ischemic heart disease, lymphoma, or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure. In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain or the quality of fever. Indeed, symptom-based diagnosis, once common in other areas of medicine, has been largely replaced in the past half century as we have understood that symptoms alone rarely indicate the best choice of treatment. Patients with mental disorders deserve better.” © 2013 Scientific American
Alla Katsnelson People who use a ‘brain-workout’ program for just 10 hours have a mental edge over their peers even a year later, researchers report today in PLoS ONE1. The search for a regimen of mental callisthenics to stave off age-related cognitive decline is a booming area of research — and a multimillion-dollar business. But critics argue that even though such computer programs can improve performance on specific mental tasks, there is scant proof that they have broader cognitive benefits. For the study, adults aged 50 and older played a computer game designed to boost the speed at which players process visual stimuli. Processing speed is thought to be “the first domino that falls in cognitive decline”, says Fredric Wolinsky, a public-health researcher at the University of Iowa in Iowa City, who led the research. The game was developed by academic researchers but is now sold under the name Double Decision by Posit Science, based in San Francisco, California. (Posit did not fund the study.) Players are timed on how fast they click on an image in the centre of the screen and on others that appear around the periphery. The program ratchets up the difficulty as a player’s performance improves. Participants played the training game for 10 hours on site, some with an extra 4-hour ‘booster’ session later, or for 10 hours at home. A control group worked on computerized crossword puzzles for 10 hours on site. Researchers measured the mental agility of all 621 subjects before the brain training began, and again one year later, using eight well-established tests of cognitive performance. © 2013 Nature Publishing Group
Chris Palmer NF-kB activation in neurons in the hypothalamus increases with age (left column), while the total number of neurons (middle column) and the total number of all cell types in the hypothalamus (right column) is maintained at a relatively steady rate across age groups. The area of the brain that controls growth, reproduction and metabolism also kick-starts ageing, according to a study published today in Nature1. The finding could lead to new treatments for age-related illnesses, helping people to live longer. Dongsheng Cai, a physiologist at Albert Einstein College of Medicine in New York, and his colleagues tracked the activity of NF-κB — a molecule that controls DNA transcription and is involved in inflammation and the body's response to stress — in the brains of mice. They found that the molecule becomes more active in the brain area called the hypothalamus as a mouse grows older. Further tests suggested that NF-κB activity helps to determine when mice display signs of ageing. Animals lived longer than normal when they were injected with a substance that inhibited the activity of NF-κB in immune cells called microglia in the hypothalamus. Mice that received a substance to stimulate the activity of NF-κB died earlier. “We have provided scientific evidence for the concept that systemic ageing is influenced by a particular tissue in the body,” says Cai. Health and well-being © 2013 Nature Publishing Group
By NICHOLAS BAKALAR A large new study confirms that sticking to the Mediterranean diet — fish, poultry, vegetables and fruit, with minimal dairy foods and meat — may be good for the brain. Researchers prospectively followed 17,478 mentally healthy men and women 45 and older, gathering data on diet from food questionnaires, and testing mental function with a well-validated six-item screening tool. They ranked their adherence to the Mediterranean diet on a 10-point scale, dividing the group into low adherence and high adherence. The study was published April 30 in the journal Neurology. During a four-year follow-up, 1,248 people became cognitively impaired. But those with high adherence to the diet were 19 percent less likely to be among them. This association persisted even after controlling for almost two dozen demographic, environmental and vascular risk factors, and held true for both African-Americans and whites. The study included 2,913 people with Type 2 diabetes, but for them adherence to the diet had no effect on the likelihood of becoming impaired. The lead author, Dr. Georgios Tsivgoulis, an assistant professor of neurology at the University of Athens, said that this is the largest study of its kind. The Mediterranean diet, he added, “has many benefits — cardiovascular, cancer risk, anti-inflammatory, central nervous system. We’re on the tip of the iceberg, and trying to understand what is below.” Copyright 2013 The New York Times Company
By Russell Foster "Making teens start school in the morning is ‘cruel,’ brain doctor claims." So declared a British newspaper headline in 2007 after a talk I gave at an academic conference. One disbelieving reader responded: "This man sounds brain-dead." That was a typical reaction to work I was reporting at the time on teenage sleep patterns and their effect on performance at school. Six years on, there is growing acceptance that the structure of the academic day needs to take account of adolescent sleep patterns. The latest school to adopt a later start time is the UCL Academy in London; others are considering following suit. So what are the facts about teenage slumber, and how should society adjust to these needs? The biology of human sleep timing, like that of other mammals, changes as we age. This has been shown in many studies. As puberty begins, bedtimes and waking times get later. This trend continues until 19.5 years in women and 21 in men. Then it reverses. At 55 we wake at about the time we woke prior to puberty. On average this is two hours earlier than adolescents. This means that for a teenager, a 7 a.m. alarm call is the equivalent of a 5 a.m. start for people in their 50s. Precisely why this is so is unclear, but the shifts correlate with hormonal changes at puberty and the decline in those hormones as we age. However, biology is only part of the problem. Additional factors include a more relaxed attitude to bedtimes by parents, a general disregard for the importance of sleep, and access to TVs, DVDs, PCs, gaming devices, cellphones, and so on, all of which promote alertness and eat into time available for sleep. © 2013 The Slate Group, LLC.
by Emily Underwood In the cartoon series named after them, Pinky and the Brain, two laboratory mice genetically enhanced to increase their intelligence plot to take over the world—and fail each time. Perhaps their creators hadn't tweaked the correct gene. Researchers have now found a genetic mutation that causes mammalian neural tissue to expand and fold. The discovery may help explain why humans evolved more elaborate brains than mice, and it could suggest ways to treat disorders such as autism and epilepsy that arise from abnormal neural development. In mice and humans alike, the cerebral cortex—the outermost layer of brain tissue associated with high-level functions such as memory and decision-making—starts out as a spherical sheet of tissue made up of only neural stem cells. As these stem cells divide, the cortex increases its surface area, expanding like an inflating balloon, says neuroscientist Victor Borrell of the Institute of Neurosciences of Alicante in Spain. Unlike the small, smooth mouse brain, however, the uppermost layers of tissue in the human brain cram millions of neurons into specialized folds and furrows responsible for complex tasks such as language and thought. Because the human cerebral cortex is generally considered "special," some scientists have hypothesized that the genes that govern its development of cortical folds and furrows are also unique to humans, Borrell says. In studies of neural development in mice, Stahl found that TRNP1 produces a protein that determines whether neural stem cells self-replicate, leading to a balloonlike expansion of cortical surface area, or whether they differentiate into a plethora of intermediate stem cell types and neurons, thickening the cortex and forming more complex brain structures. Based on that discovery, the team hypothesized that varying levels of the gene's expression in mice and humans might account for the varying levels of cortical thickness and different shapes between the two species. © 2010 American Association for the Advancement of Science
by Dr. Claire McCarthy April is Autism Awareness Month--and if there's anything that we need when it comes to autism, it's awareness. We need people to be aware of this condition that affects a staggering 1 in 50 children, so that we can understand what causes it, and find ways to prevent it. And we need people to be aware of the signs of autism--because getting help early can make a real difference. Many children aren't diagnosed with autism until they get to preschool, or sometimes even later--and that means important time is lost. The signs of autism can be present in toddlers--and when we find it then, we can get help to those children and their families right away. The trick is in asking the right questions--and acting on the answers. In the practice where I work, as in many other practices, we ask parents to fill out questionnaires about the behavior and development of their children. At the 18 month and 24 month visits, we ask parents to fill out one called the MCHAT (Modified Checklist for Autism in Toddlers)--that's the tool we've chosen to help us look for autism. It's a list of questions that parents answer yes or no to, questions about how their child acts, plays and interacts with other people. While all the questions on the MCHAT are important, there are six that are most important: Does your child take an interest in other children? Does your child ever use his finger to point at or ask for something? Does your child ever bring objects over to you to show you something? Does your child imitate you? Does your child respond to his name when you call? If you point at a toy across the room, does your child look at it? © 2013 NY Times Co.
Link ID: 18081 - Posted: 04.27.2013