Chapter 7. Life-Span Development of the Brain and Behavior
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By Michelle Roberts Health editor, BBC News online Brain training - playing online games that give memory and reasoning skills a workout - is beneficial for older people, a large-scale study has concluded. Researchers at King's College London found the mental exercises kept minds sharp and helped people with everyday skills such as shopping and cooking. Nearly 7,000 people aged 50 and over signed up for the six-month experiment, launched by BBC TV's Bang Goes The Theory. Longer studies are now beginning. The volunteers were recruited from the general population by a partnership between the BBC, the Alzheimer's Society and the Medical Research Council. As far as the investigators were aware, none had any problems with memory or cognition when they signed up to the experiment. Some of the volunteers were encouraged to play online brain training games for 10 minutes at a time, as often as they wished. The others - the control group - were asked to do simple internet searches. The researchers tested the subjects on a series of medically recognised cognitive tests at baseline and then again at three months and six months to see if there was any detectable difference between the groups. The researchers found after six months, those who played "brain training" games for reasoning and problem-solving kept their broader cognitive skills better than those who did not. The benefit appeared to kick in when people played the games at least five times a week. And people over 60 who played these games reported better scores for carrying out essential everyday tasks, the Journal of Post-acute and Long Term Care Medicine reports. © 2015 BBC
By Jennie Baird Last week’s news that Sesame Street was introducing the first autistic Muppet was met in my house with a resounding, “Huh?” “But there already is an autistic Muppet,” my high-functioning 14-year-old said. “Fozzie Bear.” I had never thought of Fozzie that way, but my son had a point. Fozzie is not good at taking social cues; he doesn’t read a room well and he tends to monologue and perseverate (to repeat himself long after the need has passed). He interprets figurative language as literal — remember that fork in the road in “The Muppet Movie?” He has a verbal tic he falls back on, “wokka-wokka.” And he hates to be separated from his hat for no obvious reason. I’ve tested this theory on friends and have seen the light bulb of recognition go off every time. Of course Fozzie has autism! One friend, a mother whose son is also on the spectrum even told me her family had the exact same conversation. Sesame Street hopes children will identify with their new character Julia, described as a “friend who has autism,” and appearing, for now, only in the book “We’re Amazing 1-2-3!” There is no question, the mere presence of Julia is a positive development. But she also introduces a rarely discussed complication of autism. Let’s call it the Fozzie Conundrum. I’m particularly sensitive to the Fozzie Conundrum now that my son attends regular honors classes in a regular public high school. Naturally sociable and charismatic — and with eight years of support and interventions from a team of terrific teachers and therapists at specialized schools — he can easily “pass” as a regular, funny, quirky teenager. © 2015 The New York Times Company
Link ID: 21590 - Posted: 11.02.2015
By Nicholas Bakalar Certain personality traits are often attributed to oldest, middle and youngest children. But a new study found that birth order itself had no effect on character, though it may slightly affect intelligence. Researchers analyzed three large ongoing collections of data including more than 20,000 people: a British study that follows the lives of people who were born in one particular week in 1958, a German study of private households started in 1984 and a continuing study of Americans born between 1980 and 1984. They searched for differences in extroversion, emotional stability, agreeableness, conscientiousness, self-reported intellect, IQ, imagination and openness to experience. They analyzed families with sisters and brothers, large and small age gaps and different numbers of siblings. They even looked to see if being a middle child correlated with any particular trait. But no matter how they spliced the data, they could find no association of birth order with any personality characteristic. The study, in Proceedings of the National Academy of Sciences, did find evidence that older children have a slight advantage in IQ scores, but the difference was apparent only in a large sample, with little significance for any individual. The lead author, Julia M. Rohrer, a graduate student at the University of Leipzig, said that birth order can have an effect — if your older brother bullied you, for example. “But these effects are highly idiosyncratic,” she said. “There is no such thing as a typical older, middle or younger sibling. It’s important to stop believing that you are the way you are because of birth order.” © 2015 The New York Times Company
A drug for Alzheimer’s seems to delay the point at which a person with the condition needs to be moved into a nursing home. Donepezil is usually given to people with moderate forms of the disease, but continuing to take the drug once the disease becomes more severe seems to prolong the period of time a person can remain in their own home. Previously, the drug was not thought to benefit people once they had developed more severe forms of Alzheimer’s. But a study that followed 295 people with moderate to severe Alzheimer’s disease found that those who continued to take donepezil were nearly half as likely to end up in a care home within the next year. “It could mean thousands of patients per year not going into care homes,” says Robert Howard of University College London, who led the study. His team found that those who continued to take donepezil had a 20 per cent chance of being moved into a care home within the first year of the trial, compared to 37 per cent in those who stopped taking the drug. However the effect didn’t last. The trial lasted for three years, and after the first year, those who taking donepezil were just as likely to be moved into a home than those who weren’t, suggesting that the drug does not have a longer-term effect on the care needs of those with Alzheimer’s. “For every six patients treated with donepezil for 12 months, you would prevent one moving into a nursing home,” says Howard. “It’s a modest effect, but it’s important if it’s your mother or your wife.” © Copyright Reed Business Information Ltd.
Link ID: 21577 - Posted: 10.28.2015
By Jessica Schmerler Young brains are plastic, meaning their circuitry can be easily rewired to promote learning. By adulthood, however, the brain has lost much of its plasticity and can no longer readily recover lost function after, say, a stroke. Now scientists have successfully restored full youthful plasticity in adult mice by transplanting young neurons into their brain—curing their severe visual impairments in the process. In a groundbreaking study published in May in Neuron, a team of neuroscientists led by Sunil Gandhi of the University of California, Irvine, transplanted embryonic mouse stem cells into the brains of other mice. The cells were primed to become inhibitory neurons, which tamp down brain activity. Prior to this study, “it was widely doubted that the adult brain would allow these cells to disperse, integrate and reactivate plasticity,” says Melissa Davis, first author of the study. Scientists have been attempting such a feat for years, refining their methods along the way, and the Irvine team finally saw success: the cells were integrated in the brain and caused large-scale rewiring, restoring the high-level plasticity of early development. In visually impaired mice, the transplant allowed for the restoration of normal vision, as demonstrated by tests of visual nerve signals and a swimming maze test. The scientists have not yet tested the transplanting technique for other neurological disorders, but they believe the technique has potential for many conditions and injuries depending on how, exactly, the new neurons restore plasticity. It is not yet known whether the proliferation of the transplanted cells accounts for the restored plasticity or if the new cells trigger plasticity in existing neurons. If the latter, the treatment could spur the rewiring and healing of the brain following traumatic brain injury or stroke. © 2015 Scientific American
By GINA KOLATA Three diseases, leading killers of Americans, often involve long periods of decline before death. Two of them — heart disease and cancer — usually require expensive drugs, surgeries and hospitalizations. The third, dementia, has no effective treatments to slow its course. So when a group of researchers asked which of these diseases involved the greatest health care costs in the last five years of life, the answer they found might seem surprising. The most expensive, by far, was dementia. The study looked at patients on Medicare. The average total cost of care for a person with dementia over those five years was $287,038. For a patient who died of heart disease it was $175,136. For a cancer patient it was $173,383. Medicare paid almost the same amount for patients with each of those diseases — close to $100,000 — but dementia patients had many more expenses that were not covered. On average, the out-of-pocket cost for a patient with dementia was $61,522 — more than 80 percent higher than the cost for someone with heart disease or cancer. The reason is that dementia patients need caregivers to watch them, help with basic activities like eating, dressing and bathing, and provide constant supervision to make sure they do not wander off or harm themselves. None of those costs were covered by Medicare. For many families, the cost of caring for a dementia patient often “consumed almost their entire household wealth,” said Dr. Amy S. Kelley, a geriatrician at Icahn School of Medicine at Mt. Sinai in New York and the lead author of the paper published on Monday in the Annals of Internal Medicine. © 2015 The New York Times Company
Link ID: 21571 - Posted: 10.27.2015
By Dina Fine Maron Early-life exposure to anesthesia does not appear to lead to long-term cognitive problems, researchers announced today. New evidence from the first, randomized anesthesia trial in kids provides the strongest indication yet that exposing young children to anesthesia—at least for a brief time—will not saddle them with developmental deficits. The news comes just a couple of weeks after a medical advisory group reiterated its concerns about such exposures among children younger than four years. Previously, multiple animal and human studies have linked such exposure with cognitive impairment, but none of the information on humans came from a gold-standard, randomized study design that could help eliminate other reasons to explain such a connection. This is a “reassuring finding, but it is not the final answer,” says Dean Andropoulos, anesthesiologist in chief at Texas Children’s Hospital and an expert who was not involved in the work. The new study assesses only what happens to youngsters after a relatively brief bout with anesthetics, so it is possible that longer or repeated exposures to such chemicals may still cause neurodevelopmental issues. There may also be deficits in anesthesia-exposed children that are not measurable until later in life. The study followed more than 500 infants undergoing hernia repair across the U.S., Australia, the U.K., Canada, the Netherlands, New Zealand and Italy. The surgeries lasted an average of roughly an hour. About half of the children were randomly selected to be put under with general anesthesia, and the other half stayed awake during the surgery and received targeted anesthesic in a specific body region. The kids in the study were all younger than 60 weeks and were matched by where they had the surgery and whether they were born prematurely. © 2015 Scientific American
As we get older, most of us will experience some kind of brain degeneration. Typically, we lose the ability to make new neurons. Another problem is chronic, low-grade inflammation in the brain, which is implicated in many age-related brain disorders. To tackle both problems in one go, Ludwig Aigner at Paracelsus Medical University Salzburg in Austria and his colleagues targeted a set of receptors in the brain that, when activated, trigger inflammation. High numbers of these receptors are found in areas of the brain where neurons are born, suggesting they might also be involved in this process, too. A drug called montelukast (Singulair), regularly prescribed for asthma and allergic rhinitis, blocks these receptors, so Aigner and his colleagues tried it on young and old rats. The team used oral doses equivalent to those taken by people with asthma. The older animals were 20 months old – roughly equivalent to between 65 and 75 in human years. The younger rats were 4 months old – about 17 in human years. The animals were fed the drug daily for six weeks, while another set of young and old rats were left untreated. There were 20 young and 14 old rats in total. The rats took part in a range of learning and memory tests. One of these, for example, involved the rats being placed in a pool of water with a hidden escape platform. At the start of the study, untreated young rats learned to recognise landmarks and quickly find their way to the platform, while the untreated older animals struggled at the task. © Copyright Reed Business Information Ltd.
Elizabeth Blair The muppet Julia has not yet made her TV debut, but the wide-eyed little girl with a big smile is the star of her own "digital storybook" called "We're Amazing, 1,2,3." For over a year now, Sesame Street has been working with organizations such as Autism Speaks and Autism Self Advocacy to help reduce the stigma associated with autism spectrum disorder. As part of the campaign "See Amazing in All Children," the adorable muppet Abby Cadabby explains in one YouTube video, "Lots of kids have autism and that just means their brains work a little differently." Julia is not the first fictional media character with autism. But Michael Robb, Director of Research for Common Sense Media, an organization that rates and reviews media aimed at children, says Sesame Street's move is "pretty groundbreaking." "It can be difficult to start a conversation about children with disabilities. It's even harder when that difference isn't visible," he says. After looking through "We're Amazing, 1,2,3," Robb says the story could help children be more understanding of how Julia is different. "It's very real in terms of talking in simple language. It spells out these things in concrete ways that kids can understand. It shows ways she's just like other kids. It shows how making simple accommodations can help Julia." According to Dr. Jeanette Betancourt, Senior Vice President of U.S. Social Impact at Sesame Workshop, says Sesame Street producers are waiting to hear back from the autism community before introducing Julia to the show on TV. © 2015 npr
Link ID: 21557 - Posted: 10.24.2015
Alzheimer's disease can be detected decades before onset, using a virtual reality test, a study suggests. People aged 18 to 30 were asked to navigate through a virtual maze to test the function of certain brain cells. Those with a high genetic risk of Alzheimer's could be identified by their performance, according to German neuroscientists. The findings could help future research, diagnosis and treatment, they report in the journal Science. The scientists, led by Lukas Kunz of the German Centre for Neurodegenerative Diseases in Bonn, say the high risk group navigated the maze differently and had reduced functioning of a type of brain cell involved in spatial navigation. The findings could give an insight into why people with dementia can find navigating the world around them challenging, they say. "Our results could provide a new basic framework for preclinical research on Alzheimer's disease and may provide a neurocognitive explanation of spatial disorientation in Alzheimer's disease," they report in Science. Although genes play a role in dementia, their effects are complex with many unknowns. Dr Laura Phipps of Alzheimer's Research, said the latest study focused on healthy younger people at higher genetic risk of Alzheimer's, suggesting they may already show alterations in spatial navigation several decades before the disease could start. © 2015 BBC.
Link ID: 21555 - Posted: 10.23.2015
By Tara Parker-Pope Children who regularly use antibiotics gain weight faster than those who have never taken the drugs, according to new research that suggests childhood antibiotics may have a lasting effect on body weight well into adulthood. The study, published in the International Journal of Obesity, examined the electronic medical records of 163,820 children ages 3 to 18, counting antibiotic prescriptions, body weight and height. The records, which covered pediatric exams from 2001 through 2012, showed that one in five — over 30,000 children — had been prescribed antibiotics seven or more times. By the time those children reached age 15, they weighed, on average, about 3 pounds more than children who had received no antibiotics. While earlier studies have suggested a link between antibiotics and childhood weight gain, they typically have relied on a mother’s memories of her child’s antibiotic use. The new research is significant because it’s based on documented use of antibiotics in a child’s medical record. “Not only did antibiotics contribute to weight gain at all ages, but the contribution of antibiotics to weight gain gets stronger as you get older,” said Dr. Brian S. Schwartz, the first author and a professor in the department of environmental health sciences at the Johns Hopkins Bloomberg School of Public Health. Scientists have known for years that antibiotic use promotes weight gain in livestock, which is why large food producers include low doses of antibiotics in the diets of their animals. © 2015 The New York Times Company
Jon Hamilton Babies born prematurely are much more likely than other children to develop autism, ADHD and emotional disorders. Now researchers think they may have an idea about how that could happen. There's evidence that preemies are born with weak connections in some critical brain networks, including those involved in focus, social interactions, and emotional processing, researchers reported at the Society for Neuroscience meeting in Chicago. A study comparing MRI scans of the brains of 58 full-term babies with those of 76 babies born at least 10 weeks early found that "preterm infants indeed have abnormal structural brain connections," says Cynthia Rogers, an assistant professor of psychiatry at Washington University School of Medicine in St. Louis. "We were really interested that the tracts that we know connect areas that are involved in attention and emotional networks were heavily affected," Rogers says. That would make it harder for these brain areas to work together to focus on a goal or read social cues or regulate emotions, she says. The team used two different types of MRI to study the nerve fibers that carry signals from one part of the brain to another and measure how well different areas of the brain are communicating. Full-term infants were scanned shortly after they were born, while premature infants were scanned near their expected due date. The researchers are continuing to monitor the brains of the children in their study to see which ones actually develop disorders. © 2015 NPR
By Brook Borel and Spectrum In a lab in Sacramento, California, a wall of plastic boxes lined with corncob bedding holds around 800 mice. Even in this clean and bright room, the smell of so many mice concentrated in one place is overpowering — pungent, and familiar to anyone who has spent time with a pet hamster or gerbil. Most of the boxes hold four adult mice, which flit about, noses twitching as they stare out at the humans staring in. But in one of the boxes, a sleek white mouse is tucked in a corner suckling her litter of half a dozen or so squirmy, dark-furred pups. In most research labs, the fate of these pups would be determined by their sex. The males would spend their lives as test subjects. The females would either be kept for breeding or simply euthanized because they’re not ideal for experiments: They’re supposedly more difficult to work with and generate less consistent data than males do, and it costs too much to maintain both males and females, which must be housed separately. Or so the rationale has gone. But these little female pups are different. The lab where they live is run by Jill Silverman and Mu Yang, researchers at the University of California, Davis (UC Davis) MIND Institute. The two scientists study the behavior of about 15 autism mouse models, and they have always included both males and females in their work. When the pups get older, they will learn to paddle through water mazes or bury black marbles in their bedding, giving researchers insight into how their memory and behavior compare with that of typical mice. Finding the best animal behavioral models of autism is essential because behavior is at the heart of the disorder. In people, autism is diagnosed based on behavioral criteria: abnormal social interactions, difficulties with communication and repetitive actions. © 2015 Scientific American
Mr Tickle can’t bamboozle a baby. Unlike grown-ups, young infants don’t let the positioning of their bodies confuse their sense of touch. If adults who can see are touched on each hand in quick succession while their hands are crossed, they can find it hard to name which hand was touched first. Adults who have been blind from birth don’t have this difficulty, but people who become blind later in life have the same trouble as those who can still see. “That suggests that early on in life, something to do with visual experience is crucial in setting up a typical way of perceiving touch,” says Andrew Bremner at Goldsmiths, University of London. To investigate how this develops in infancy, Bremner and his colleagues compared how babies reacted to having one foot tickled. With their legs crossed over, babies aged 6 months moved the foot being tickled half of the time. But 4-month-olds did better, moving the tickled foot 70 per cent of the time – as often as they did with their legs uncrossed. The team concludes that at 4 months, babies haven’t yet learned to relate what they touch to the physical space that their body occupies. For many adults, the concept might be difficult to envision. “It’s like imagining that you feel a touch on your body, but not really knowing how that’s related to what you’re looking at,” says Bremner. “It’s almost like you have multiple sensory worlds: a visual world, an auditory world and a tactile world, which are separate and not combined in space.” © Copyright Reed Business Information Ltd.
Peter Andrey Smith Nearly a year has passed since Rebecca Knickmeyer first met the participants in her latest study on brain development. Knickmeyer, a neuroscientist at the University of North Carolina School of Medicine in Chapel Hill, expects to see how 30 newborns have grown into crawling, inquisitive one-year-olds, using a battery of behavioural and temperament tests. In one test, a child's mother might disappear from the testing suite and then reappear with a stranger. Another ratchets up the weirdness with some Halloween masks. Then, if all goes well, the kids should nap peacefully as a noisy magnetic resonance imaging machine scans their brains. “We try to be prepared for everything,” Knickmeyer says. “We know exactly what to do if kids make a break for the door.” Knickmeyer is excited to see something else from the children — their faecal microbiota, the array of bacteria, viruses and other microbes that inhabit their guts. Her project (affectionately known as 'the poop study') is part of a small but growing effort by neuroscientists to see whether the microbes that colonize the gut in infancy can alter brain development. The project comes at a crucial juncture. A growing body of data, mostly from animals raised in sterile, germ-free conditions, shows that microbes in the gut influence behaviour and can alter brain physiology and neurochemistry. © 2015 Nature Publishing Group
By Christopher Intagliata
"Babies come prepared to learn any of the world's languages." Alison Bruderer, a cognitive scientist at the University of British Columbia. "Which means no matter where they're growing up in the world, their brains are prepared to pick up the language they're listening to around them."
And listen they do. But another key factor to discerning a language’s particular sounds may be for babies to move their tongues as they listen. Bruderer and her colleagues tested that notion by sitting 24 sixth-month-olds in front of a video screen and displaying a checkerboard pattern, while they played one of two tracks: a single, repeated "D" sound in Hindi, <
Kerri Smith Scientists have discovered two extra neurons in a worm species that — they thought — already had its entire nervous system mapped. “It is a bit of a shock,” says Richard Poole, a developmental biologist at University College London (UCL), and one of the team that found the neurons by accident. The researchers call them mystery cells of the male, or MCMs, because they are found only in male nematode worms. The neurons help the worms learn when to prioritize mating over eating, revealing how a seemingly simple brain can be capable of a complex learned behaviour — and one that differs between the sexes. Caenorhabditis elegans worms are the model animal of choice for many neuroscientists, because their neural circuits are so simple that they can be mapped in full. They have two sexes: hermaphrodite and male. Hermaphrodites, the best studied, have just 302 neurons, but males have more — the MCMs raise their total to 385 neurons1. The two ‘mystery’ cells were discovered when Poole’s colleague at UCL, Arantza Barrios, was looking at the distribution of a peptide often found in neurons, called pdf-1. She saw cells light up where she thought they should not — near the worm’s nose. The neurons develop when male worms reach maturity, the researchers worked out. Their report is published in Nature1. Sex or food? © 2015 Nature Publishing Group,
By SINDYA N. BHANOO Tiny nematode worms called Caenorhabditis elegans have a peculiar reproductive story: Most females are hermaphrodites that make sperm, self-fertilize and produce more hermaphrodites. Males are few, and are known to mate with each other. Now, a new study reports that a variation in a single gene results in male worms with excretory pores that attract the sexual attentions of other males. “Other males copulate with this excretory pore, located on the neck,” said Matthew Rockman, a biologist at New York University. He and his colleagues reported their findings in the journal Current Biology. Although male worms are rare in the wild, they are easily bred in the laboratory. Researchers report that the gene variant, known as plep-1, may somehow be altering the chemical profile of the excretions in a way that makes them more attractive to other males. Copulation often does not work out well for the male that is approached, Dr. Rockman said. Males that mate with the excretory pore of another male usually leave behind a plug that weakens the worm and reduces life expectancy. Hermaphrodites with the variation of the same gene also have a lower life expectancy and do not reproduce as well. Next, the researchers want to learn what it is about a mutation in the plep-1 gene that makes males attractive to other males. © 2015 The New York Times Company
Ed Yong This week, a team from the University of California, Los Angeles claimed to have found several epigenetic marks—chemical modifications of DNA that don’t change the underlying sequence—that are associated with homosexuality in men. Postdoc Tuck Ngun presented the results yesterday at the American Society of Human Genetics 2015 conference. Nature News were among the first to break the story based on a press release issued by the conference organisers. Others quickly followed suit. “Have They Found The Gay Gene?” said the front page of Metro, a London paper, on Friday morning. Meanwhile, the mood at the conference has been decidedly less complimentary, with several geneticists criticizing the methods presented in the talk, the validity of the results, and the coverage in the press. Ngun’s study was based on 37 pairs of identical male twins who were discordant—that is, one twin in each pair was gay, while the other was straight—and 10 pairs who were both gay. He analysed 140,000 regions in the genomes of the twins and looked for methylation marks—chemical Post-It notes that dictate when and where genes are activated. He whittled these down to around 6,000 regions of interest, and then built a computer model that would use data from these regions to classify people based on their sexual orientation. The best model used just five of the methylation marks, and correctly classified the twins 67 percent of the time. “To our knowledge, this is the first example of a biomarker-based predictive model for sexual orientation,” Ngun wrote in his abstract. The problems begin with the size of the study, which is tiny. The field of epigenetics is littered with the corpses of statistically underpowered studies like these, which simply lack the numbers to produce reliable, reproducible results.
By ANDREW SOLOMON INEXPLICABLE violence is the hardest kind to accept. The human wish to insert logic where there is none often drives bystanders to psychic violence of their own. This happened again last week, after it was reported that the shooter at Umpqua Community College in Oregon, Christopher Harper-Mercer, who killed nine people and injured several others, may have been autistic. Although there is no established connection between autism and murder, some eagerly leapt to causality and scapegoating. The killer’s “diagnosis” was based primarily on posts on Yahoo made over the last decade by his mother, Laurel Harper, in which she characterized both herself and her son as having Asperger’s syndrome — a category no longer in medical use that describes autistic people with advanced verbal skills. Mr. Harper-Mercer attended a school that caters to children with special needs, including autism. While Ms. Harper is not a doctor, her descriptions of her son across his childhood are consistent with the syndrome. A Facebook page called “Families Against Autistic Shooters” ranted about “the soulless, dead eyes of autistic children,” and characterized them as “cold, calculating killing machines with no regard for human life!” Its author announced: “What do all shooters over the last few years have in common? A lack of empathy and compassion due to Autism!” If Mr. Harper-Mercer were rumored to have been diabetic or afflicted with male-pattern baldness, no such “explanations” of his behavior would have surfaced. But despite a huge increase in awareness of autism among the public, those with the condition are often subject to this type of disparagement. This was evident in both the Facebook page and the response to it by Facebook’s management, who, despite the site’s anti-bullying policy, initially refused to remove it on grounds that it did not target named individuals. “Families Against Autistic Shooters” remained accessible until last Monday, by which time escalating media attention and a petition on Change.org with nearly 5,000 signatures embarrassed administrators into action. For the time it was viewable, the page stigmatized a population far more likely to be attacked than to attack, far less likely to receive justice when injured, and far more likely to be misunderstood. © 2015 The New York Times Company