Chapter 7. Life-Span Development of the Brain and Behavior
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by Sarah Schwartz Brainlike cell bundles grown in a lab may expose some of the biological differences of autistic brains. Researchers chemically reprogrammed human stem cells into small bundles of functional brain cells that mimic the developing brain. These “organoids” appear to be different when built with cells from autistic patients compared with when they are built with cells from the patients’ non-autistic family members, researchers report July 16 in Cell. The brainlike structures created from cells taken from autistic children showed increased activity in genes that control brain-cell growth and development. Too much activity in one of these genes led to an overproduction of a certain type of brain cell that suppresses the activity of other brain cells. At an early stage of development, the miniature organs grown from autistic patients’ stem cells also showed faster cell division rates than those grown from the cells of non-autistic relatives. Though the study was small, using cells from only four autistic patients and eight family members, the results may indicate common factors underlying autism, the scientists say. © Society for Science & the Public 2000 - 2015.
Link ID: 21186 - Posted: 07.18.2015
By Fredrick Kunkle A new study suggests that Alzheimer’s disease may affect the brain differently in black people compared with whites. The research, conducted by Lisa L. Barnes at the Rush University Medical Center, suggests that African Americans are less likely than Caucasians to have Alzheimer’s disease alone and more likely to have other pathologies associated with dementia. These include the presence of Lewy bodies, which are abnormal proteins found in the brain, and lesions arising from the hardening of tiny arteries in the brain, which is caused mainly by high blood pressure and other vascular conditions. The findings suggest that researchers should seek different strategies to prevent and treat Alzheimer’s disease in blacks. While many therapeutic strategies focus on removing or modifying beta amyloid – a key ingredient whose accumulation leads to the chain of event triggering the neurodegenerative disease – the study suggests that possible treatments should pursue additional targets, particularly for African Americans. But the study also points up the critical need to enroll more black people in clinical trials. Although Barnes said the research was the largest sample of its kind, she also acknowledged that the sample is still small. And that’s at least partially because blacks, for a variety of cultural and historical reasons, are less likely to participate in scientific research.
Link ID: 21176 - Posted: 07.16.2015
Nikki Stevenson Autism may represent the last great prejudice we, as a society, must overcome. History is riddled with examples of intolerance directed at the atypical. We can sometime fear that which diverges from the “norm”, and sometimes that fear leads us to frame those who are different as being in some way lesser beings than ourselves. Intolerances take generations to overcome. Racism is an obvious, ugly example. Other horrifying examples are easy to find: take, for instance the intolerance faced by the gay community. Countless gay people were diagnosed with “sociopathic personality disturbance” based upon their natural sexuality. Many were criminalised and forced into institutions, the “treatments” to which they were subject akin to torture. How many believed they were sociopathic and hated themselves, wishing to be free from the label they had been given? How many wished to be “cured” so that they could live their lives in peace? The greatest crime was the damage perpetuated by the image projected upon them by those claiming to be professionals. Autism is framed as a disability, with mainstream theories presenting autism via deficit models. Popular theory is often passed off as fact with no mention of the morphic nature of research and scientific process. Most mainstream theory is silent regarding autistic strengths and atypical ability; indeed, what is in print often presents a damning image of autism as an “epidemic”. Hurtful words such as risk, disease, disorder, impairment, deficit, pedantic, obsession are frequently utilised. © 2015 Guardian News and Media Limited
Link ID: 21175 - Posted: 07.16.2015
By Lauran Neergaard, New research suggests it may be possible to predict which preschoolers will struggle to read — and it has to do with how the brain deciphers speech when it's noisy. Scientists are looking for ways to tell, as young as possible, when children are at risk for later learning difficulties so they can get early interventions. There are some simple pre-reading assessments for preschoolers. But Northwestern University researchers went further and analyzed brain waves of children as young as three. How well youngsters' brains recognize specific sounds — consonants — amid background noise can help identify who is more likely to have trouble with reading development, the team reported Tuesday in the journal PLOS Biology. If the approach pans out, it may provide "a biological looking glass," said study senior author Nina Kraus, director of Northwestern's Auditory Neuroscience Laboratory. "If you know you have a three-year-old at risk, you can as soon as possible begin to enrich their life in sound so that you don't lose those crucial early developmental years." Connecting sound to meaning is a key foundation for reading. For example, preschoolers who can match sounds to letters earlier go on to read more easily. Auditory processing is part of that pre-reading development: If your brain is slower to distinguish a "D" from a "B" sound, for example, then recognizing words and piecing together sentences could be affected, too. What does noise have to do with it? It stresses the system, as the brain has to tune out competing sounds to selectively focus, in just fractions of milliseconds. And consonants are more vulnerable to noise than vowels, which tend to be louder and longer, Kraus explained. ©2015 CBC/Radio-Canada
By Ferris Jabr Newborns are hardly blank slates devoid of knowledge and experience, contrary to historical notions about the infant mind. Sensory awareness and learning start in the womb, as the recently reinvigorated study of fetal perception has made clearer than ever. In the past few years lifelike images and videos created by 3-D and 4-D ultrasound have divulged much more about physiology and behavior than the blurry 2-D silhouettes of typical ultrasound. And noninvasive devices can now measure electrical activity in the developing brain of a fetus or newborn. Recent insights gleaned from such tools provide a rich portrait of how a fetus uses its budding brain and senses to learn about itself and the outside world well before birth. Such research has improved care for preterm babies, suggesting the benefits of dim lights, familiar and quiet voices, and lots of comforting skin contact between mother and child. © 2015 Scientific American
Keyword: Development of the Brain
Link ID: 21161 - Posted: 07.13.2015
Patricia Neighmond Some antidepressants may increase the risk of birth defects if taken early in pregnancy, while others don't seem to pose the same risks, a study finds. The question of whether antidepressants can cause birth defects has been debated for years, and studies have been all over the map. That makes it hard for women and their doctors to make decisions on managing depression during pregnancy. To try to untangle the question, researchers at the Centers for Disease Control and Prevention analyzed federal data on more than 38,000 women who gave birth between 1997 and 2009. They looked at the number of birth defects among babies and asked women whether they took any antidepressants in the month before getting pregnant or during the first three months of pregnancy. The study, published Wednesday in The BMJ, found no association between the most commonly used antidepressant, sertraline (Zoloft), and birth defects. Forty percent of the women who took antidepressants took sertraline. They also found no increased risk of birth defects with the antidepressants citalopram (Celexa) and escitalopram (Lexapro). But the analysis did find an association between birth defects and the antidepressants fluoxetine (Prozac) or paroxetine (Paxil). That included heart defects, abdominal wall defects, and missing brain and skull defects with paroxetine, and heart wall defects and irregular skull shape with fluoxetine. The relative risk increased 2 to 3.5 times, depending on the defect and the medication. That may sound like a lot, but Jennita Reefhuis, an epidemiologist and lead researcher in the study, says "the overall risk is still small." © 2015 NPR
By Sarah C. P. Williams The next time you forget where you left your car keys, you might be able blame an immune protein that builds up in your blood as you age. The protein impairs the formation of new brain cells and contributes to age-related memory loss—at least in mice, according to a new study. Blocking it could help prevent run-of-the-mill memory decline or treat cognitive disorders, the researchers say. “The findings are really exciting,” says neurologist Dena Dubal of the University of California, San Francisco (UCSF), who was not involved in the study. “The importance of this work cannot be underestimated as the world’s population is aging rapidly.” Multiple groups of scientists have shown that adding the blood of older mice to younger animals’ bodies makes them sluggish, weaker, and more forgetful. Likewise, young blood can restore the memory and energy of older mice. Neuroscientist Saul Villeda of UCSF homed in on one actor he thought might be responsible for some of that effect: β2 microglobulin (B2M), an immune protein normally involved in distinguishing one’s own cells from invading pathogens. B2M has also been found at increased levels in patients with Alzheimer’s disease and other cognitive disorders. Villeda and his colleagues first measured B2M levels in the blood of both people and mice of different ages; they found that those levels increased with age. When the researchers injected B2M into 3-month-old mice, the young animals suddenly had trouble remembering how to complete a water maze, making more than twice as many errors after they’d already been trained to navigate the maze. Moreover, their brains had fewer new neurons than other mice. Thirty days later, however, when the protein had been cleared from their bodies, the animals' memory troubles were gone as well, and the number of newly formed brain cells was back to normal. © 2015 American Association for the Advancement of Science
By Adrian Cho Whether they're from humans, whales, or elephants, the brains of many mammals are covered with elaborate folds. Now, a new study shows that the degree of this folding follows a simple mathematical relationship—called a scaling law—that also explains the crumpling of paper. That observation suggests that the myriad forms of mammalian brains arise not from subtle developmental processes that vary from species to species, but rather from the same simple physical process. In biology, it rare to find a mathematical relationship that so tightly fits all the data, say Georg Striedter, a neuroscientist at the University of California, Irvine. "They've captured something," he says. Still, Striedter argues that the scaling law describes a pattern among fully developed brains and doesn't explain how the folding in a developing brain happens. The folding in the mammalian brain serves to increase the total area of the cortex, the outer layer of gray matter where the neurons reside. Not all mammals have folded cortices. For example, mice and rats have smooth-surfaced brains and are "lissencephalic." In contrast, primates, whales, dogs, and cats have folded brains and are "gyrencephalic." For decades, scientists have struggled to relate the amount of folding in a species' brain to some other characteristic. For example, although animals with tiny brains tend to have smooth ones, there is no clean relationship between the amount of folding—measured by the ratio of the total area of the cortex to the exposed outer surface of the brain—and brain mass. Make a plot of folding versus brain mass for various species and the data points fall all over and not on a unified curve. Similarly, there is no clean relationship between the amount of folding and the number of neurons, the total area of the cortex, or the thickness of the cortex. © 2015 American Association for the Advancement of Science
By SINDYA N. BHANOO It may be possible to diagnose autism by giving children a sniff test, a new study suggests. Most people instinctively take a big whiff when they encounter a pleasant smell and limit their breathing when they encounter a foul smell. Children with autism spectrum disorder don’t make this natural adjustment, said Liron Rozenkrantz, a neuroscientist at the Weizmann Institute of Science in Israel and one of the researchers involved with the study. She and her colleagues report their findings in the journal Current Biology. They presented 18 children who had an autism diagnosis and 18 typically developing children with pleasant and unpleasant odors and measured their sniff responses. The pleasant smells were rose and soap, and the unpleasant smells were sour milk and rotten fish. Typically developing children adjusted their sniffing almost immediately — within about 305 milliseconds. Children with autism did not respond as rapidly. As they were exposed to the smells, the children were watching a cartoon or playing a video game. “It’s a semi-automated response,” Ms. Rozenkrantz said. “It does not require the subject’s attention.” Using the sniff test alone, the researchers, who had not been told which children had autism, were able to correctly identify those with autism 81 percent of the time. They also found that the farther removed an autistic child’s sniff response was from the average for typically developing children, the more severe the child’s social impairments were. © 2015 The New York Times Company
Nancy Shute Powerful antipsychotic medications are being used to treat children and teenagers with ADHD, aggression and behavior problems, a study finds, even though safer treatments are available and should be used first. "There's been concern that these medications have been overused, particularly in young children," says Mark Olfson, a professor of psychiatry at Columbia University who led the study. It was published Wednesday in JAMA Psychiatry. "Guidelines and clinical wisdom suggest that you really should be using a high degree of caution and only using them when other treatments have failed, as a last resort." Olfson and his colleagues looked at prescription data from about 60 percent of the retail pharmacies in the United States in 2006, 2008 and 2010. That included almost 852,000 children, teenagers and young adults. Teens were most likely to be prescribed antipsychotics, with 1.19 percent getting the drugs in 2010, compared to 0.11 percent in younger children. Boys were more likely to be given the medications. Antipsychotic medications like clozapine and olanzapine are used to treat schizophrenia, bipolar disorder and some symptoms of autism. They have not been approved by the Food and Drug Administration to treat aggression and ADHD, but are prescribed off label to reduce disruptive behavior. FDA Debates Safety Of Antipsychotic Drugs In Kids Use of antipsychotics in children has been questioned because the drugs can have serious side effects, including tremors, weight gain, increased diabetes risk and elevated cholesterol. © 2015 NPR
Boys are more likely than girls to receive a prescription for antipsychotic medication regardless of age, researchers have found. Approximately 1.5 percent of boys ages 10-18 received an antipsychotic prescription in 2010, although the percentage falls by nearly half after age 19. Among antipsychotic users with mental disorder diagnoses, attention deficit hyperactivity disorder (ADHD) was the most common among youth ages 1-18, while depression was the most common diagnosis among young adults ages 19-24 receiving antipsychotics. Despite concerns over the rising use of antipsychotic drugs to treat young people, little has been known about trends and usage patterns in the United States before this latest research, which was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health. Mark OlfsonExternal Web Site Policy, M.D., M.P.H., of the Department of Psychiatry, College of Physicians and Surgeons and Columbia University and New York State Psychiatric Institute, New York City, and colleagues Marissa King, Ph.D., Yale, New Haven, Connecticut, and Michael Schoenbaum, Ph.D., NIMH, report their findings on July 1 in JAMA Psychiatry. “No prior study has had the data to look at age patterns in antipsychotic use among children the way we do here,” said co-author Michael Schoenbaum, Ph.D., senior advisor for mental health services, epidemiology and economics at NIMH. “What’s especially important is the finding that around 1.5 percent of boys aged 10-18 are on antipsychotics, and then this rate abruptly falls by half, as adolescents become young adults.” “Antipsychotics should be prescribed with care,” says Schoenbaum. “They can adversely affect both physical and neurological function and some of their adverse effects can persist even after the medication is stopped.”
By Dina Fine Maron The game is a contemporary of the original Nintendo but it still appeals to today’s teens and lab monkeys alike—which is a boon for neuroscientists. It offers no lifelike graphics. Nor does it boast a screen. Primate players—whether human or not—are simply required to pull levers and replicate patterns of flashing lights. Monkeys get a banana-flavored treat as a reward for good performance whereas kids get nickels. But the game's creators are not really in it for fun. It was created by toxicologists at the U.S. Food and Drug Administration in the 1980s to study how chronic exposure to marijuana smoke affects the brain. Players with trouble responding quickly and correctly to the game’s commands may have problems with short-term memory, attention or other cognitive issues. The game has since been adapted to address a different question: whether anesthetics used to knock pediatric patients unconscious during surgery and diagnostic tests could affect a youngster's long-term neural development and cognition. Despite 20 years’ worth of experiments in young rodents and monkeys, there have been few definitive answers. To date, numerous studies suggest that being put under with anesthesia early in life seems somehow related to future cognitive problems. But whether this association is causal or merely coincidence is unclear. Researchers do know that the young human brain is exceptionally sensitive. When kids are exposed to certain harmful chemicals in their formative years, that experience can fundamentally alter the brain’s architecture by misdirecting the physical connections between neurons or causing cell deaths. But unraveling whether anesthetics may fuel such long-term damage in humans remains a challenge. © 2015 Scientific American
Hannah Devlin Science correspondent Two licensed drugs have been shown to halt brain degeneration in mice, raising the prospect of a rapid acceleration in the search for a medicine to beat Alzheimer’s disease. The results, presented on Tuesday at the Alzheimer’s Society annual research conference in Manchester, have been hailed as “hugely promising” because they involve medicines that are already known to be safe and well-tolerated in people – potentially cutting years from the timeline for drugs to reach patients. Speaking ahead of her presentation, Giovanna Mallucci, professor of clinical neuroscience at the University of Cambridge, said: “It’s really exciting. They’re licensed drugs. This means you’d do a straightforward basic clinical trial on a small group of patients because these are not new compounds, they’re known drugs.” The scientists have chosen not to name the two drugs, which are currently used for conditions unrelated to dementia, to avoid the possibility of patients seeking to use them ahead of any clinical trial to prove their efficacy. The findings build on a landmark study two years ago, showing that brain cell death could be halted in mice by switching off a faulty signal in the brain that stops new proteins being produced. However, the breakthrough relied on a compound that had severe physical side-effects including weight loss and diabetes, making it unsuitable for use in humans. The two drugs were identified after Mallucci’s team screened hundreds of licensed compounds in search for something safe that had the same protective effects on the brain. Clare Walton, research manager at the Alzheimer’s Society, said: “The new results are hugely promising because the drugs are already given to people and we know they’re safe.” © 2015 Guardian News and Media Limited
Link ID: 21114 - Posted: 07.01.2015
By Jan Hoffman Guinea pigs do not judge. They do not bully. They are characteristically amiable, social and oh-so-tactile. They tuck comfortably into child-size laps and err on the side of the seriously cute. When playing with guinea pigs at school, children with autism spectrum disorders are more eager to attend, display more interactive social behavior and become less anxious, according to a series of studies, the most recent of which was just published in Developmental Psychobiology. In previous studies, researchers in Australia captured these results by surveying parents and teachers or asking independent observers to analyze videotapes of the children playing. In the new report, however, the researchers analyzed physiological data pointing to the animals’ calming effect on the children. The children played with two guinea pigs in groups of three — one child who was on the spectrum and two typically developing peers. All 99 children in the study, ages 5 to 12, wore wrist bands that monitored their arousal levels, measuring electric charges that race through the skin. Arousal levels can suggest whether a subject is feeling anxious or excited. The first time that typically developing children played with the guinea pigs, they reported feeling happy and registered higher levels of arousal. The researchers speculate that the children were excited by the novelty of the animals. Children with autism spectrum disorders also reported feeling elated, but the wrist band measurements suggested their arousal levels had declined. The animals seem to have lowered the children’s stress, the researchers concluded. © 2015 The New York Times Company
Link ID: 21111 - Posted: 06.30.2015
By Ariana Eunjung Cha One of the most heartbreaking things about Alzheimer's is that it has been impossible for doctors to predict who will get it before symptoms begin. And without early detection, researchers say, a treatment or cure may be impossible. Governments, drug companies and private foundations have poured huge amounts of money into trying to come up with novel ways to detect risk through cutting-edge technologies ranging from brain imaging, protein analysis of cerebrospinal fluid and DNA profiling. Now a new study, published in the journal Neurology, shows that perhaps something more old-fashioned could be the answer: a memory test. The researchers tracked 2,125 participants in four Chicago neighborhoods for 18 years, giving them tests of memory and thinking every three years. They found that those who scored lowest on the tests during the first year were 10 times more likely to be diagnosed with Alzheimer's down the road -- indicating that cognitive impairment may be affecting the brain "substantially earlier than previously established," the researchers wrote.
Amy Standen A doctor I interviewed for this story told me something that stuck with me. He said for every person with dementia he treats, he finds himself caring for two patients. That's how hard it can be to be a caregiver for someone with dementia. The doctor is Bruce Miller. He directs the Memory and Aging Center at the University of California, San Francisco. According to Miller, 50 percent of caregivers develop a major depressive illness because of the caregiving. "The caregiver is so overburdened that they don't know what to do next," he says. "This adds a huge burden to the medical system." This burden is going increase dramatically in the coming decade. By 2025, 7 million Americans will have Alzheimer's disease, according to one recent estimate. Millions more will suffer from other types of dementia. Together these diseases may become the most expensive segment of the so-called "silver tsunami" — 80 million baby boomers who are getting older and needing more medical care. The cost of caring for Alzheimer's patients alone is expected to triple by 2050, to more than $1 trillion a year. So UCSF, along with the University of Nebraska Medical Center, is beginning a $10 million study funded by the federal Centers for Medicare & Medicaid Innovation. Researchers plan to develop a dementia "ecosystem," which aims to reduce the cost of caring for the growing number of dementia patients and to ease the strain on caregivers. © 2015 NPR
Link ID: 21104 - Posted: 06.29.2015
Sharon Darwish Bottlenose dolphins have an average brain mass of 1.6 kg, slightly greater than that of humans, and about four times the size of chimpanzee brains. Although you couldn’t really imagine a dolphin writing poetry, dolphins demonstrate high levels of intelligence and social behaviour. For example, they display mirror self-recognition, as well as an understanding of symbol-based communication systems. Research into the differing brain sizes and intellectual capabilities within the animal kingdom is fascinating. Why have some species evolved to be more intelligent than others? Does brain size affect cognitive ability? Some studies say yes, but some insist otherwise. It really depends which species we are talking about. In humans, for example, larger brains do not indicate higher intelligence – otherwise Einstein, who had an average-sized brain, may have not been quite as successful in his career. (Yes, that link was to a 23-pager on the analysis of Einstein’s brain. It makes for great bedtime reading.) Most neuroscientists now believe that it is the structure of the brain on a cellular and molecular level that determines its computational capacity. Within certain animal species however, a larger brain offers evolutionary advantage. For example, large-brained female guppies are better survivors and demonstrate greater cognitive strengths than their smaller-brained counterparts. © 2015 Guardian News and Media Limited
By Nicholas Bakalar Exposure to air pollution may hasten brain aging, a new study has found. Researchers studied 1,403 women without dementia who were initially enrolled in a large health study from 1996 to 1998. They measured their brain volume with M.R.I. scans in 2005 and 2006, when the women were 71 to 89 years old. Using residential histories and air pollution data, they estimated their exposure to air pollution from 1999 to 2006. They used data recorded at monitoring sites on exposure to PM 2.5 — tiny particulate matter that easily penetrates the lungs. Each increase of 3.49 micrograms per cubic centimeter cumulative exposure to pollutants was associated with a 6.23 cubic centimeter decrease in white matter, the equivalent of one to two years of brain aging. The association remained after adjusting for many variables, including age, smoking, physical activity, blood pressure, body mass index, education and income. Previous studies have shown that air pollution can cause inflammation and damage to the vascular system, but this study, in The Annals of Neurology, showed damage to the brain itself. “This tells us that the damage air pollution can impart goes beyond the circulatory system,” said the lead author, Dr. Jiu-Chiuan Chen, an associate professor of preventive medicine at the Keck School of Medicine at the University of Southern California. “Particles in the ambient air are an environmental neurotoxin to the aging brain.” © 2015 The New York Times Company
Children who have a good memory are better at telling lies, say child psychology researchers. They tested six and seven-year-olds who were given an opportunity to cheat in a trivia game and then lie about their actions. Children who were good liars performed better in tests of verbal memory - the number of words they could remember. This means they are good at juggling lots of information, even if they do tell the odd fib. Writing in the Journal of Experimental Child Psychology, researchers from the Universities of North Florida, Sheffield and Stirling, recruited 114 children from four British schools for their experiment. Using hidden cameras during a question-and-answer game, they were able to identify the children who peeked at the answer to a fictitious question, even though they were told not to. A potentially surprising finding (for parents) is that only a quarter of the children cheated by looking at the answer. Further questioning allowed the researchers to work out who was a good liar or a bad liar. They were particularly interested in children's ability to maintain a good cover story for their lie. In separate memory tests, the good liars showed they had a better working memory for words - but they didn't show any evidence of being better at remembering pictures (visuo-spatial memory). The researchers said this was because lying involves keeping track of lots of verbal information, whereas keeping track of images is less important. © 2015 BBC
Maanvi Singh Teenagers aren't exactly known for their responsible decision making. But some young people are especially prone to making rash, risky decisions about sex, drugs and alcohol. Individual differences in the brain's working memory — which allows people to draw on and use information to make decisions — could help explain why some adolescents are especially impulsive when it comes to sex, according to a study published Wednesday in Child Development. "Working memory is the ability to keep different things in mind when you're making decisions or problem solving," explains Atika Khurana, an assistant professor of counseling psychology at the University of Oregon who led the study. Khurana and her colleagues rounded up 360 adolescents, ages 12 to 15, and assessed their working memory using a series of tests. For example, the researchers told the participants a string of random numbers and asked them to repeat what they heard in reverse order. "We basically tested their ability to keep information in mind while making decisions," Khurana says. The researchers then tracked all the participants for two years, and asked about the teens' sexual activity. And through another series of tests and surveys, the researcher tried to gauge how likely each teen was to act without thinking, to make rash decisions and take risks. There was a correlation between weaker working memory and the likelihood that a teen would have sex — including unprotected sex — at a younger age. And they were more likely to act without much deliberation. That trend held true even after the researchers accounted for the teenagers' age, socioeconomic status and gender. © 2015 NPR