Chapter 7. Life-Span Development of the Brain and Behavior
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By Abby Phillip If you're confused about what marijuana use really does to people who use it, you're not alone. For years, the scientific research on health effects of the drug have been all over the map. Earlier this year, one study suggested that even casual marijuana use could cause changes to the brain. Another found that marijuana use was also associated with poor sperm quality, which could lead to infertility in men. But marijuana advocates point to other research indicating that the drug is far less addictive than other drugs, and some studies have found no relationship between IQ and marijuana use in teens. Researchers at the Center for Brain Health at the University of Texas in Dallas sought to clear up some of the confusion with a study that looked at a relatively large group of marijuana users and evaluated their brains for a slew of different indicators. What they found was complex, but the pattern was clear: The brains of marijuana users were different than those of non-marijuana users. The area of the brain responsible for establishing the reward system that helps us survive and also keeps us motivated was smaller in users than in non-marijuana users. But there was also evidence that the brain compensated for this loss of volume by increasing connectivity and the structural integrity of the brain tissue. Those effects were more pronounced for marijuana users who started young. "The orbitofrontal cortex is one of the primary regions in a network of brain areas called the reward system," explained Francesca Filbey, lead author of the study and an associate professor of the neurogenetics of addictive behavior at the University of Texas in Dallas. "
Email David By David Grimm Place a housecat next to its direct ancestor, the Near Eastern wildcat, and it may take you a minute to spot the difference. They’re about the same size and shape, and, well, they both look like cats. But the wildcat is fierce and feral, whereas the housecat, thanks to nearly 10,000 years of domestication, is tame and adaptable enough to have become the world’s most popular pet. Now scientists have begun to pinpoint the genetic changes that drove this remarkable transformation. The findings, based on the first high-quality sequence of the cat genome, could shed light on how other creatures, even humans, become tame. “This is the closest thing to a smoking gun we’ve ever had,” says Greger Larson, an evolutionary biologist at the University of Oxford in the United Kingdom who has studied the domestication of pigs, dogs, and other animals. “We’re much closer to understanding the nitty-gritty of domestication than we were a decade ago.” Cats first entered human society about 9500 years ago, not long after people first took up farming in the Middle East. Drawn to rodents that had invaded grain stores, wildcats slunk out of the deserts and into villages. There, many scientists suspect, they mostly domesticated themselves, with the friendliest ones able to take advantage of human table scraps and protection. Over thousands of years, cats shrank slightly in size, acquired a panoply of coat colors and patterns, and (largely) shed the antisocial tendencies of their past. Domestic animals from cows to dogs have undergone similar transformations, yet scientists know relatively little about the genes involved. Researchers led by Michael Montague, a postdoc at the Washington University School of Medicine in St. Louis, have now pinpointed some of them. The scientists started with the genome of a domestic cat—a female Abyssinian—that had been published in draft form in 2007, then filled in missing sequences and identified genes. They compared the resulting genome with those of cows, tigers, dogs, and humans. © 2014 American Association for the Advancement of Science.
By Dr. Catherine A. Madison “Now why did I walk into this room? Oh, yes, looking for my …” This scenario, familiar to many, is most often a sign of normal aging — or of having too much on our minds. But when these events seem to be happening frequently, is it a more serious problem, such as Alzheimer’s disease or another dementia? Even more importantly, are there good health habits that can help lower the risk of these neurodegenerative conditions? Research continues to demonstrate that healthy lifestyles lower one’s risk of developing cognitive decline later in life. Wise food choices and lots of exercise are a good base, along with learning new material and keeping socially connected. But another key element to brain health is good sleep. We may take sleep for granted, but research suggests this is not a passive process. There is a growing consensus that sleep is linked to learning, memory, nerve cell remodeling and repair. Evidence also suggests lack of sleep can contribute to mood and immune disorders, as well as to a decline in overall health. Most of us have read the dos and don’ts of good sleep hygiene: avoid napping, don’t drink alcohol or caffeine close to bedtime, avoid late-evening exercise and sleep in a room that is quiet, dark and cool. We’ve also been told about sleep cycles, in which we typically progress from light sleep early in the night to slow wave sleep with rapid eye movement, or REM, later on. We need a balance of sleep cycles for optimal health.
By Tracy Jarrett Autism advocates on Friday applauded Jerry Seinfeld's disclosure that he may be autistic, while warning against making him the poster boy for a disorder that is no laughing matter. “I think, on a very drawn-out scale, I think I’m on the spectrum,” Seinfeld told NBC Nightly News’ Brian Williams. "Basic social engagement is really a struggle. I'm very literal, when people talk to me and they use expressions, sometimes I don't know what they're saying," he said. "But I don't see it as dysfunctional, I just think of it as an alternate mindset." Seinfeld's revelation sends a positive message that the autism community is much larger and more diverse than people often understand, Ari Ne’eman, president of the Autistic Advocacy Network, told NBC News. Ne’eman is living with autism and says that there is still a tremendous amount of stigma surrounding autism that hinders the opportunities available to those with the disorder. “Think about what this does for a closeted autistic person who goes into the workplace knowing that their co-workers have just seen somebody they know, respect, and have a positive opinion of, like Jerry Seinfeld, identify in this way — it’s a valuable and important step in building a greater tolerance for autism,” Ne’eman said. Liz Feld, president of Autism Speaks, agreed, pointing out that “there are many people on the autism spectrum who can relate to Jerry’s heartfelt comments about his own experiences.”
Link ID: 20289 - Posted: 11.08.2014
Sara Reardon Delivering medications to the brain could become easier, thanks to molecules that can escort drugs through the notoriously impervious sheath that separates blood vessels from neurons. In a proof-of-concept study in monkeys, biologists used the system to reduce levels of the protein amyloid-β, which accumulates in the brain plaques associated with Alzheimer's disease1. The blood–brain barrier is a layer of cells lining the inner surface of the capillaries that feed the central nervous system. It is nature's way of protecting the delicate brain from infectious agents and toxic compounds, while letting nutrients and oxygen in and waste products out. Because the barrier strictly regulates the passage of larger molecules and often prevents drug molecules from entering the brain, it has long posed one of the most difficult challenges in developing treatments for brain disorders. Several approaches to bypassing the barrier are being tested, including nanoparticles that are small enough to pass through the barrier's cellular membranes and deliver their payload; catheters that carry a drug directly into the brain; and ultrasound pulses that push microbubbles through the barrier. But no approach has yet found broad therapeutic application. Neurobiologist Ryan Watts and his colleagues at the biotechnology company Genentech in South San Francisco have sought to break through the barrier by exploiting transferrin, a protein that sits on the surface of blood vessels and carries iron into the brain. The team created an antibody with two ends. One end binds loosely to transferrin and uses the protein to transport itself into the brain. And once the antibody is inside, its other end targets an enzyme called β-secretase 1 (BACE1), which produces amyloid-β. Crucially, the antibody binds more tightly to BACE1 than to transferrin, and this pulls it off the blood vessel and into the brain. It locks BACE1 shut and prevents it from making amyloid-β. © 2014 Nature Publishing Group,
Link ID: 20286 - Posted: 11.06.2014
|By Lindsey Konkel and Environmental Health News New York City children exposed in the womb to high levels of pollutants in vehicle exhaust had a five times higher risk of attention problems at age 9, according to research by Columbia University scientists published Wednesday. The study adds to earlier evidence that mothers' exposures to polycyclic aromatic hydrocarbons (PAHs), which are emitted by the burning of fossil fuels and other organic materials, are linked to children's behavioral problems associated with Attention Deficit Hyperactivity Disorder (ADHD). “Our research suggests that environmental factors may be contributing to attention problems in a significant way,” said Frederica Perera, an environmental health scientist at Columbia’s Mailman School of Public Health who was the study's lead author. About one in 10 U.S. kids is diagnosed with ADHD, according to the Centers for Disease Control and Prevention. Children with ADHD are at greater risk of poor academic performance, risky behaviors and lower earnings in adulthood, the researchers wrote. “Air pollution has been linked to adverse effects on attention span, behavior and cognitive functioning in research from around the globe. There is little question that air pollutants may pose a variety of potential health risks to children of all ages, possibly beginning in the womb,” said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children’s Medical Center of New York. He did not participate in the new study. © 2014 Scientific American
Kate Baggaley Much of the increase in autism diagnoses in recent decades may be tied to changes in how the condition is reported. Sixty percent of the increase in autism cases in Denmark can be explained by these changes, scientists report November 3 in JAMA Pediatrics. The researchers followed all 677,915 people born in Denmark in 1980 through 1991, monitoring them from birth through the end of 2011. Among children born in this period, diagnoses increased fivefold, until 1 percent of children born in the early 1990s were diagnosed with autism by age 20. During these decades, Denmark experienced two changes in the way autism is reported. In 1994, the criteria physicians rely on to diagnose autism were updated in both the International Classification of Diseases manual used by Denmark and in its American counterpart, the Diagnostic and Statistical Manual of Mental Disorders. Then in 1995, the Danish Psychiatric Register began reporting diagnoses where doctors had only outpatient contact with children, in addition to cases where autism was diagnosed after children had been kept overnight. The researchers estimated Danish children’s likelihood of being diagnosed with autism before and after the two reporting changes. These changes accounted for 60 percent of the increase in diagnoses. © Society for Science & the Public 2000 - 2014.
Link ID: 20280 - Posted: 11.05.2014
By SINDYA N. BHANOO BERKELEY, CALIF. — Lilith Sadil, 12, climbs into an examination chair here at the Myopia Control Center at the University of California. “Do you know why you are here?” asks Dr. Maria Liu, an optometrist. “Because my eyes are changing fast,” Lilith says. “Do you read a lot?” Dr. Liu asks. “Yes.” “Do you use the computer a lot?” “Yes.” Lilith is an active child who practices taekwondo. But like an increasing number of children, she has myopia — she can see close up but not farther away. Her mother, Jinnie Sadil, has brought her to the center because she has heard about a new treatment that could help. Eye specialists are offering young patients special contact lenses worn overnight that correct vision for the next day. Myopia has become something of a minor epidemic: More than 40 percent of Americans are nearsighted, a 16 percent increase since the 1970s. People with so-called high myopia — generally, blurry vision beyond about five inches — face an increased likelihood of developing cataracts and glaucoma, are at higher risk for retinal detachments that can result in blindness. Exactly what is causing the nationwide rise in nearsightedness is not known. “It can’t be entirely genetic, because genes don’t change that fast,” said Susan Vitale, an epidemiologist at the National Institutes of Health who studies myopia. “It’s probably something that’s environmental, or a combination of genetic and environmental factors.” Some research indicates that “near work” — reading, computer work, playing video games, and using tablets and smartphones — is contributing to the increase. A recent study found that the more educated a person is, the more likely he or she will be nearsighted. A number of other studies show that children who spend time outdoors are less likely to develop high myopia. But no one is certain whether the eye benefits from ultraviolet light or whether time outside simply means time away from near work. © 2014 The New York Times Company
Joan Raymond TODAY contributor It’s well established that baby talk plays a huge role in helping the wee widdle babies learn to tawk. And — no surprise — moms talk more to babies than dads do. But it seems that the baby's sex plays a role, too: Moms may be talking more to their infant daughters than their sons during the early weeks and months of a child’s life. In a new study published Monday in the online edition of Pediatrics, researchers looked at the language interactions between 33 late preterm and term infants and their parents by capturing 3,000 hours of recordings. Somewhat surprisingly, the researchers found that moms interacted vocally more with infant daughters rather than sons both at birth and 44 weeks post-menstrual age (equivalent to 1 month old.) Male adults responded more frequently to infant boys than infant girls, but the difference did not reach statistical significance, say the researchers. “We wanted to look more at gender and factors that affect these essentially mini-conversations that parents have with infants,” says lead author and neonatologist Dr. Betty Vohr, director of the Neonatal Follow-Up Program at Women & Infants Hospital of Rhode Island. “Infants are primed to vocalize and have reciprocal interactions.”
By CATHERINE SAINT LOUIS More than 50 children in 23 states have had mysterious episodes of paralysis to their arms or legs, according to data gathered by the Centers for Disease Control and Prevention. The cause is not known, although some doctors suspect the cases may be linked to infection with enterovirus 68, a respiratory virus that has sickened thousands of children in recent months. Concerned by a cluster of cases in Colorado, the C.D.C. last month asked doctors and state health officials nationwide to begin compiling detailed reports about cases of unusual limb weakness in children. Experts convened by the agency plan next week to release interim guidelines on managing the condition. That so many children have had full or partial paralysis in a short period is unusual, but officials said that the cases seemed to be extremely rare. “At the moment, it looks like whatever the chances are of getting this syndrome are less than one in a million,” said Mark A. Pallansch, the director of the division of viral diseases at the C.D.C. Some of the affected children have lost the use of a leg or an arm, and are having physical therapy to keep their muscles conditioned. Others have sustained more extensive damage and require help breathing. Marie, who asked to be identified by her middle name to protect her family’s privacy, said her 4-year-old son used to climb jungle gyms. But in late September, after the whole family had been sick with a respiratory illness, he started having trouble climbing onto the couch. He walked into Boston Children’s Hospital the day he was admitted. But soon his neck grew so weak, it “flopped completely back like he was a newborn,” Marie said. Typically, the time from when weakness begins until it reaches its worst is one to three days. But for her son, eight mornings in a row, he awoke with a "brand new deficit" until he had some degree of weakness in each limb and had trouble breathing. He was eventually transferred to a Spaulding rehabilitation center, where he is now. © 2014 The New York Times Company
By Virginia Morell Human fetuses are clever students, able to distinguish male from female voices and the voices of their mothers from those of strangers between 32 and 39 weeks after conception. Now, researchers have demonstrated that the embryos of the superb fairy-wren (Malurus cyaneus, pictured), an Australian songbird, also learn to discriminate among the calls they hear. The scientists played 1-minute recordings to 43 fairy-wren eggs collected from nests in the wild. The eggs were between days 9 and 13 of a 13- to 14-day incubation period. The sounds included white noise, a contact call of a winter wren, or a female fairy-wren’s incubation call. Those embryos that listened to the fairy-wrens’ incubation calls and the contact calls of the winter wrens lowered their heart rates, a sign that they were learning to discriminate between the calls of a different species and those of their own kind, the researchers report online today in the Proceedings of the Royal Society B. (None showed this response to the white noise.) Thus, even before hatching, these small birds’ brains are engaged in tasks requiring attention, learning, and possibly memory—the first time embryonic learning has been seen outside humans, the scientists say. The behavior is key because fairy-wren embryos must learn a password from their mothers’ incubation calls; otherwise, they’re less successful at soliciting food from their parents after hatching. © 2014 American Association for the Advancement of Science.
By Paula Span First, an acknowledgment: Insomnia bites. S. Bliss, a reader from Albuquerque, comments that even taking Ativan, he or she awakens at 4:30 a.m., can’t get back to sleep and suffers “a state of sleep deprivation and eventually a kind of walking exhaustion.” Molly from San Diego bemoans “confusion, anxiety, exhaustion, depression, loss of appetite, frankly a loss of will to go on,” all consequences of her sleeplessness. She memorably adds, “Give me Ambien or give me death.” Marciacornute reports that she’s turned to vodka (prompting another reader to wonder if Medicare will cover booze). After several rounds of similar laments here (and not only here; insomnia is prevalent among older adults), I found the results of a study by University of Chicago researchers particularly striking. What if people who report sleep problems are actually getting enough hours of sleep, overall? What if they’re not getting significantly less sleep than people who don’t complain of insomnia? Maybe there’s something else going on. It has always been difficult to ascertain how much people sleep; survey questions are unreliable (how can you tell when you’ve dozed off?), and wiring people with electrodes creates such an abnormal situation that the results may bear little resemblance to ordinary nightlife. Enter the actigraph, a wrist-motion monitor. “The machines have gotten better, smaller, less clunky and more reliable,” said Linda Waite, a sociologist and a co-author of the study. By having 727 older adults across the United States (average age: almost 72) wear actigraphs for three full days, Dr. Waite and her colleagues could tell when subjects were asleep and when they weren’t. Then they could compare their reported insomnia to their actual sleep patterns. Overall, in this random sample, taken from an ongoing national study of older adults, people didn’t appear sleep-deprived. They fell asleep at 10:27 p.m. on average, and awakened at 6:22 a.m. After subtracting wakeful periods during the night, they slept an average seven and a quarter hours. But averages don’t tell us much, so let’s look more closely at their reported insomnia. “What was surprising to us is that there’s very little association between people’s specific sleep problems and what the actigraph shows,” Dr. Waite said. © 2014 The New York Times Company
By Neuroskeptic A new paper threatens to turn the world of autism neuroscience upside down. Its title is Anatomical Abnormalities in Autism?, and it claims that, well, there aren’t very many. Published in Cerebral Cortex by Israeli researchers Shlomi Haar and colleagues, the new research reports that there are virtually no differences in brain anatomy between people with autism and those without. What makes Haar et al.’s essentially negative claims so powerful is that their study had a huge sample size: they included structural MRI scans from 539 people diagnosed with high-functioning autism spectrum disorder (ASD) and 573 controls. This makes the paper an order of magnitude bigger than a typical structural MRI anatomy study in this field. The age range was 6 to 35. The scans came from the public Autism Brain Imaging Data Exchange (ABIDE) database, a data sharing initiative which pools scans from 18 different neuroimaging centers. Haar et al. examined the neuroanatomy of the cases and controls using the popular FreeSurfer software package. What did they find? Well… not much. First off, the ASD group had no differences in overall brain size (intracranial volume). Nor were there any group differences in the volumes of most brain areas; the only significant finding here was an increased ventricle volume in the ASD group, but even this had a small effect size (d = 0.34). Enlarged ventricles is not specific to ASD by any means – the same thing has been reported in schizophrenia, dementia, and many other brain disorders.
by Neurobonkers A paper published in Nature Reviews Neuroscience last week addressed the prevalence of neuromyths among educators. The paper has been widely reported, but the lion's share of the coverage glossed over the impact that neuromyths have had in the real world. Your first thought after reading the neuromyths in the table below — which were widely believed by teachers — may well be, "so what?" It is true that some of the false beliefs are relatively harmless. For example, encouraging children to drink a little more water might perhaps result in the consumption of less sugary drinks. This may do little if anything to reduce hyperactivity but could encourage a more nutritious diet which might have impacts on problems such as Type II diabetes. So, what's the harm? The paper addressed a number of areas where neuromyths have had real world impacts on educators and policymakers, which may have resulted negatively on the provision of education. The graph above, reprinted in the Nature Reviews Neuroscience, paper has been included as empirical data in educational policy documents to provide evidence for an "allegedly scientific argument for withdrawing public funding of university education." The problem? The data is made up. The graph is in fact a model that is based on the false assumption that investment before the age of three will have many times the benefit of investment made in education later in life. The myth of three — the belief that there is a critical window to educate children before the age of three, after which point the trajectory is fixed — is one of the most persistent neuromyths. Viewed on another level, while some might say investment in early education can never be a bad thing, how about the implication that the potential of a child is fixed at such an early point in their life, when in reality their journey has just begun. © Copyright 2014, The Big Think, Inc
By CLIVE THOMPSON “You just crashed a little bit,” Adam Gazzaley said. It was true: I’d slammed my rocket-powered surfboard into an icy riverbank. This was at Gazzaley’s San Francisco lab, in a nook cluttered with multicolored skullcaps and wires that hooked up to an E.E.G. machine. The video game I was playing wasn’t the sort typically pitched at kids or even middle-aged, Gen X gamers. Indeed, its intended users include people over 60 — because the game might just help fend off the mental decline that accompanies aging. It was awfully hard to play, even for my Call of Duty-toughened brain. Project: Evo, as the game is called, was designed to tax several mental abilities at once. As I maneuvered the surfboard down winding river pathways, I was supposed to avoid hitting the sides, which required what Gazzaley said was “visual-motor tracking.” But I also had to watch out for targets: I was tasked with tapping the screen whenever a red fish jumped out of the water. The game increased in difficulty as I improved, making the river twistier and obliging me to remember turns I’d taken. (These were “working-memory challenges.”) Soon the targets became more confusing — I was trying to tap blue birds and green fish, but the game faked me out by mixing in green birds and blue fish. This was testing my “selective attention,” or how quickly I could assess a situation and react to it. The company behind Project: Evo is now seeking approval from the Food and Drug Administration for the game. If it gets that government stamp, it might become a sort of cognitive Lipitor or Viagra, a game that your doctor can prescribe for your aging mind. After only two minutes of play, I was making all manner of mistakes, stabbing frantically at the wrong fish as the game sped up. “It’s hard,” Gazzaley said, smiling broadly as he took back the iPad I was playing on. “It’s meant to really push it.” “Brain training” games like Project: Evo have become big business, with Americans spending an estimated $1.3 billion a year on them. They are also a source of controversy. © 2014 The New York Times Company
By Emily Underwood Aging baby boomers and seniors would be better off going for a hike than sitting down in front of one of the many video games designed to aid the brain, a group of nearly 70 researchers asserted this week in a critique of some of the claims made by the brain-training industry. With yearly subscriptions running as much as $120, an expanding panoply of commercial brain games promises to improve memory, processing speed, and problem-solving, and even, in some cases, to stave off Alzheimer’s disease. Many companies, such as Lumosity and Cogmed, describe their games as backed by solid scientific evidence and prominently note that neuroscientists at top universities and research centers helped design the programs. But the cited research is often “only tangentially related to the scientific claims of the company, and to the games they sell,” according to the statement released Monday by the Stanford Center on Longevity in Palo Alto, California, and the Max Planck Institute for Human Development in Berlin. Although the letter, whose signatories include many researchers outside those two organizations, doesn’t point to specific bad actors, it concludes that there is “little evidence that playing brain games improves underlying broad cognitive abilities, or that it enables one to better navigate a complex realm of everyday life.” A similar statement of concern was published in 2008 with a smaller number of signatories, says Ulman Lindenberger of the Max Planck Institute for Human Development, who helped organize both letters. Although Lindenberger says there was no particular trigger for the current statement, he calls it the “expression of a growing collective concern among a large number of cognitive psychologists and neuroscientists who study human cognitive aging.” © 2014 American Association for the Advancement of Science
By PAUL VITELLO Most adults do not remember anything before the age of 3 or 4, a gap that researchers had chalked up to the vagaries of the still-developing infant brain. By some accounts, the infant brain was just not equipped to remember much. Textbooks referred to the deficiency as infant amnesia. Carolyn Rovee-Collier, a developmental psychologist at Rutgers University who died on Oct. 2 at 72, challenged the theory, showing in a series of papers in the early 1980s that babies remember plenty. A 3-month-old can recall what he or she learned yesterday, she found, and a 9-month-old can remember a game for as long as a month and a half. She cited experiments suggesting that memory processes in adults and infants are virtually the same, and argued that infant memories were never lost. They just become increasingly harder to retrieve as the child grows, learns language and loses touch with the visual triggers that had kept those memories sharp — a view from between the bars of a crib, say, or the view of the floor as a crawler, not a toddler, sees it. Not all of Dr. Rovee-Collier’s theories won over the psychology establishment, which still uses the infant amnesia concept to explain why people do not remember life as a baby. But her insights about an infant’s short-term memory and ability to learn have been widely accepted, and have helped recast scientific thinking about the infant mind over the past 30 years. Since the first of her 200 papers was published, infant cognitive studies has undergone a boom in university programs around the country. It was a field that had been largely unexplored in any systematic way by the giants of psychological theory. Freud and Jean Piaget never directly addressed the subject of infant memory. William James, considered the father of American psychology, once hazarded a guess that the human baby’s mind was a place of “blooming, buzzing confusion.” © 2014 The New York Times Company
By Fergus Walsh Medical correspondent A paralysed man has been able to walk again after a pioneering therapy that involved transplanting cells from his nasal cavity into his spinal cord. Darek Fidyka, who was paralysed from the chest down in a knife attack in 2010, can now walk using a frame. The treatment, a world first, was carried out by surgeons in Poland in collaboration with scientists in London. Prof Wagih El Masri Consultant spinal injuries surgeon Details of the research are published in the journal Cell Transplantation. BBC One's Panorama programme had unique access to the project and spent a year charting the patient's rehabilitation. Darek Fidyka, 40, from Poland, was paralysed after being stabbed repeatedly in the back in the 2010 attack. He said walking again - with the support of a frame - was "an incredible feeling", adding: "When you can't feel almost half your body, you are helpless, but when it starts coming back it's like you were born again." He said what had been achieved was "more impressive than man walking on the moon". UK research team leader Prof Geoff Raisman: Paralysis treatment "has vast potential" The treatment used olfactory ensheathing cells (OECs) - specialist cells that form part of the sense of smell. OECs act as pathway cells that enable nerve fibres in the olfactory system to be continually renewed. In the first of two operations, surgeons removed one of the patient's olfactory bulbs and grew the cells in culture. Two weeks later they transplanted the OECs into the spinal cord, which had been cut through in the knife attack apart from a thin strip of scar tissue on the right. They had just a drop of material to work with - about 500,000 cells. About 100 micro-injections of OECs were made above and below the injury. BBC © 2014
By Paula Span Maybe it’s something else. That’s what you tell yourself, isn’t it, when an older person begins to lose her memory, repeat herself, see things that aren’t there, lose her way on streets she’s traveled for decades? Maybe it’s not dementia. And sometimes, thankfully, it is indeed some other problem, something that mimics the cognitive destruction of Alzheimer’s disease or another dementia — but, unlike them, is fixable. “It probably happens more often than people realize,” said Dr. P. Murali Doraiswamy, a neuroscientist at Duke University Medical Center. But, he added, it doesn’t happen nearly as often as family members hope. Several confounding cases have appeared at Duke: A woman who appeared to have Alzheimer’s actually was suffering the effects of alcoholism. Another patient’s symptoms resulted not from dementia but from chronic depression. Dr. Doraiswamy estimates that when doctors suspect Alzheimer’s, they’re right 50 to 60 percent of the time. (The accuracy of Alzheimer’s diagnoses, even in specialized medical centers, is more haphazard than you would hope.) Perhaps another 25 percent of patients actually have other types of dementia, like Lewy body or frontotemporal — scarcely happy news, but because these diseases have different trajectories and can be exacerbated by the wrong drugs, the distinction matters. The remaining 15 to 25 percent “usually have conditions that can be reversed or at least improved,” Dr. Doraiswamy said. © 2014 The New York Times Company
Link ID: 20227 - Posted: 10.22.2014
By Jane E. Brody Within a week of my grandsons’ first year in high school, getting enough sleep had already become an issue. Their concerned mother questioned whether lights out at midnight or 1 a.m. and awakening at 7 or 7:30 a.m. to get to school on time provided enough sleep for 14-year-olds to navigate a demanding school day. The boys, of course, said “yes,” especially since they could “catch up” by sleeping late on weekends. But the professional literature on the sleep needs of adolescents says otherwise. Few Americans these days get the hours of sleep optimal for their age, but experts agree that teenagers are more likely to fall short than anyone else. Researchers report that the average adolescent needs eight and a half to nine and a half hours of sleep each night. But in a poll taken in 2006 by the National Sleep Foundation, less than 20 percent reported getting that much rest on school nights. With the profusion of personal electronics, the current percentage is believed to be even worse. A study in Fairfax, Va., found that only 6 percent of children in the 10th grade and only 3 percent in the 12th grade get the recommended amount of sleep. Two in three teens were found to be severely sleep-deprived, losing two or more hours of sleep every night. The causes can be biological, behavioral or environmental. And the effect on the well-being of adolescents — on their health and academic potential — can be profound, according to a policy statement issued in August by the American Academy of Pediatrics. “Sleep is not optional. It’s a health imperative, like eating, breathing and physical activity,” Dr. Judith A. Owens, the statement’s lead author, said in an interview. “This is a huge issue for adolescents.” © 2014 The New York Times Company