Links for Keyword: Development of the Brain

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Lida Katsimpardi Could the elixir of youth be as simple as a protein found in young blood? In recent years, researchers studying mice found that giving old animals blood from young ones can reverse some signs of aging, and last year one team identified a growth factor in the blood that they think is partly responsible for the anti-aging effect on a specific tissue--the heart. Now that group has shown this same factor can also rejuvenate muscle and the brain. "This is the first demonstration of a rejuvenation factor" that is naturally produced, declines with age, and reverses aging in multiple tissues, says Harvard stem cell researcher Amy Wagers, who led efforts to isolate and study the protein. Independently, another team has found that simply injecting plasma from young mice into old mice can boost learning. The results build on a wave of studies in the last decade in which investigators sewed together the skins of two mice, joining their circulation systems, and studied the effects on various tissues. “It’s still a bit creepy for many people. At meetings, people talk about vampires,” says Stanford University neuroscientist Tony Wyss-Coray, who led the study of learning. But he, Wagers, and others think unease will give way to excitement. The new work, he says, “opens the possibility that we can try to isolate additional factors” from blood, “and they have effects on the whole body.” Hope and hype are high in the anti-aging research arena, and other researchers caution that the work is preliminary. “These are exciting papers,” but “it’s a starting point,” says neuroscientist Sally Temple of the Neural Stem Cell Institute in Rensselaer, NY. Adds Matthew Kaeberlein, a biologist who studies aging at the University of Washington, Seattle, “The therapeutic implications are profound if this mechanism holds true in people.” But that “is the million dollar question here, and that may take some time to figure out.” © 2014 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 8: Hormones and Sex
Link ID: 19575 - Posted: 05.05.2014

By Julie Steenhuysen CHICAGO (Reuters) - International teams of researchers using advanced gene sequencing technology have uncovered a single genetic mutation responsible for a rare brain disorder that may have stricken families in Turkey for some 400 years. The discovery of this genetic disorder, reported in two papers in the journal Cell, demonstrates the growing power of new tools to uncover the causes of diseases that previously stumped doctors. Besides bringing relief to affected families, who can now go through prenatal genetic testing in order to have children without the disorder, the discovery helps lend insight into more common neurodegenerative disorders, such as ALS, also known as Lou Gehrig's disease, the researchers said. The reports come from two independent teams of scientists, one led by researchers at Baylor College of Medicine and the Austrian Academy of Sciences, and the other by Yale University, the University of California, San Diego, and the Academic Medical Center in the Netherlands. Both focused on families in Eastern Turkey where marriage between close relatives, such as first cousins, is common. Geneticists call these consanguineous marriages. In this population, the researchers focused specifically on families whose children had unexplained neurological disorders that likely resulted from genetic defects. Both teams identified a new neurological disorder arising from a single genetic variant called CLP1. Children born with this disorder inherit two defective copies of this gene, which plays a critical role in the health of nerve cells. Babies with the disorder have small and malformed brains, they develop progressive muscle weakness, they do not speak and they are increasingly prone to seizures.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 5: The Sensorimotor System
Link ID: 19542 - Posted: 04.28.2014

|By Simon Makin Scientists have observed that reading ability scales with socioeconomic status. Yet music might help close the gap, according to Nina Kraus and her colleagues at Northwestern University. Kraus's team tested the auditory abilities of teenagers aged 14 or 15, grouped by socioeconomic status (as indexed by their mother's level of education, a commonly used surrogate measure). The researchers recorded the kids' brain waves with EEG as they listened to a repeated syllable against soft background sound and when they heard nothing. They found that children of mothers with a lower education had noisier, weaker and more variable neural activity in response to sound and greater activity in the absence of sound. The children also scored lower on tests of reading and working memory. Kraus thinks music training is worth investigating as a possible intervention for such auditory deficits. The brains of trained musicians differ from nonmusicians, and they also enjoy a range of auditory advantages, including better speech perception in noise, according to research from Kraus's laboratory. The researchers admit that this finding could be the result of preexisting differences that predispose some people to choose music as a career or hobby, but they point out that some experimental studies show that musical training, whether via one-on-one lessons or in group sessions, enhances people's response to speech. Most recently Kraus's group has shown that these effects may last. Kraus surveyed 44 adults aged 55 to 76 and found that four or more years of musical training in childhood was linked to faster neural responses to speech, even for the older adults who had not picked up an instrument for more than 40 years. © 2014 Scientific American

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 19480 - Posted: 04.14.2014

by Aviva Rutkin Don't blame baby for trying to eat that Lego piece. Humans may have a brain circuit dedicated to grabbing stuff and putting it in our mouths, and it probably develops in the womb. Researchers and parents alike have long known that babies stick all manner of things in their mouths from very early on. Some fetuses even suck their thumbs. As putting something in the mouth seems advanced compared to the other, limited actions of newborns, Angela Sirigu of the Institute of Cognitive Sciences in Bron, France, and colleagues wondered whether the behaviour is encoded in the brain from birth. To investigate, they studied 26 people of different ages while they were undergoing brain surgery. The researchers found that they were able to make nine of the unconscious patients bring their hands up and open their mouths, just by stimulating a part of the brain we know is linked to those actions in non-human primates. Brain pudding Because this behaviour is encoded in the same region as in other primates, it may be there from birth or earlier, the researchers say. If it was learned, you would expect it to involve multiple brain areas, and those could vary between individuals. Newborn kangaroos are able to climb into their mother's pouch and baby wildebeests can run away from lions, but our babies appear helpless and have to learn most complex actions. The new work suggests that the way our brain develops is more like what happens in other animals than previously thought. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19431 - Posted: 04.01.2014

By SABRINA TAVERNISE In 1972, researchers in North Carolina started following two groups of babies from poor families. In the first group, the children were given full-time day care up to age 5 that included most of their daily meals, talking, games and other stimulating activities. The other group, aside from baby formula, got nothing. The scientists were testing whether the special treatment would lead to better cognitive abilities in the long run. Forty-two years later, the researchers found something that they had not expected to see: The group that got care was far healthier, with sharply lower rates of high blood pressure and obesity, and higher levels of so-called good cholesterol. The study, which was published in the journal Science on Thursday, is part of a growing body of scientific evidence that hardship in early childhood has lifelong health implications. But it goes further than outlining the problem, offering evidence that a particular policy might prevent it. “This tells us that adversity matters and it does affect adult health,” said James Heckman, a professor of economics at the University of Chicago who led the data analysis. “But it also shows us that we can do something about it, that poverty is not just a hopeless condition.” The findings come amid a political push by the Obama administration for government-funded preschool for 4-year-olds. But a growing number of experts, Professor Heckman among them, say they believe that more effective public programs would start far earlier — in infancy, for example, because that is when many of the skills needed to take control of one’s life and become a successful adult are acquired. © 2014 The New York Times Company

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 13: Memory, Learning, and Development
Link ID: 19425 - Posted: 03.29.2014

The cancer gene BRCA1, which keeps tumors in the breast and ovaries at bay by producing proteins that repair damaged DNA, may also regulate brain size. Mice carrying a mutated copy of the gene have 10-fold fewer neurons and other brain abnormalities, a new study suggests. Such dramatic effects on brain size and function are unlikely in human carriers of BRCA1 mutations, the authors of the study note, but they propose the findings could shed light on the gene's role in brain evolution. Scientists have known for a long time that the BRCA1 gene is an important sentinel against DNA damage that can lead to ovarian and breast cancers. More than half of women with a mutated copy of the BRCA1 gene will develop breast cancer, a statistic that has led some who carry the mutation to get preventative mastectomies. But its roles outside the breast and ovaries are less clear, says Inder Verma, a geneticist and molecular biologist at the Salk Institute for Biological Studies in San Diego, California, who headed the new study. Mice bred without BRCA1 die soon after birth, so it’s clear that the gene is necessary to sustain life, but scientists are just starting to unravel its many functions, he says. Several years ago, one of the students in Verma’s lab noticed that BRCA1 is very active in the neuroectoderm, a sliver of embryonic tissue containing neural stem cells that divide and differentiate into the brain’s vast assortment of cell types and structures. Verma and his colleagues wondered why the gene was expressed at such high levels in that region, and what would happen if it were eliminated. They created a strain of mice in which BRCA1 was knocked out only in neural stem cells. As the mice developed, Verma’s team found that the rodents’ brains were only a third of their normal size, with particularly striking reductions in brain areas involved in learning and memory. The grown mice also had a wobbly, drunken gait—a telltale symptom of ataxia, a neurological disorder that affects muscle control and balance, the researchers report online today in the Proceedings of the National Academy of Sciences. © 2014 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19378 - Posted: 03.18.2014

by Laura Sanders Candy and sweets make your kid hyper, the common lore goes. But science says that's not true. 1. Sugar makes kids hyper. Lots of parents swear that a single hit of birthday cake holds the power to morph their well-behaved, polite youngster into a sticky hot mess that careens around a room while emitting eardrum-piercing shrieks. Anyone who has had the pleasure to attend a 5-year-old’s birthday party knows that the hypothesis sounds reasonable, except that science has found that it’s not true. Sugar doesn’t change kids’ behavior, a double-blind research study found way back in 1994. A sugary diet didn’t affect behavior or cognitive skills, the researchers report. Sugar does change one important thing, though: parents’ expectations. After hearing that their children had just consumed a big sugar fix, parents were more likely to say their child was hyperactive, even when the big sugar fix was a placebo, another study found. Of course, there are plenty of good reasons not to feed your kids a bunch of sugar, but fear of a little crazed sugar monster isn’t one of them. © Society for Science & the Public 2000 - 2013.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 19376 - Posted: 03.18.2014

|By Roni Jacobson Modern antipsychotic drugs are increasingly prescribed to children and adolescents diagnosed with a broad variety of ailments. The drugs help to alleviate symptoms in some disorders, such as schizophrenia and bipolar disorder, but in others their effectiveness is questionable. Yet off-label prescribing is on the rise, especially in children receiving public assistance and Medicaid. Psychotic disorders typically arise in adulthood and affect only a small proportion of children and adolescents. Off-label prescriptions, however, most often target aggressive and disruptive behaviors associated with attention-deficit hyperactivity disorder (ADHD). “What's really concerning now is that a lot of this prescription is occurring in the face of emerging evidence that there are significant adverse effects that may be worse in youth than in adults,” says David Rubin, a general pediatrician and co-director of PolicyLab at Children's Hospital of Philadelphia. Here we review the evidence for the effectiveness of antipsychotic medications commonly prescribed for five childhood conditions. But do the benefits outweigh the risks? Schizophrenia Evidence from several randomized controlled trials conducted in the past 10 years strongly suggests that antipsychotics are an effective treatment for youths with schizophrenia. Indeed, the FDA has approved five medications—risperidone, aripiprazole, olanzapine, quetiapine and paliperidone—for use in adolescents aged 13 to 17. Bipolar Disorder Recent research indicates that antipsychotics may hasten the resolution of manic and mixed episodes in children with bipolar disorder and increase the likelihood that the illness will go into remission. The FDA has approved the same set of drugs for 10- to 17-year-olds with bipolar disorder as it has for youths with schizophrenia, with the exception of paliperidone. © 2014 Scientific American

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders; Chapter 13: Memory, Learning, and Development
Link ID: 19321 - Posted: 03.04.2014

by Emily Sohn Immediately after birth on many dairy farms, baby cows are separated from their mothers and housed in their own pens to protect them from getting sick. Two months later, they join the herd. But early-life isolation may be depriving baby cows of the opportunity to reach their full potential, found a new study. Compared to calves raised in pairs, isolated calves were much slower to learn new things and had a harder time adapting to changes in their environment. Aside from animal welfare concerns, the new findings suggest that dairy farmers have long been overlooking the brain development of their cows by depriving them of social interaction in their early weeks. “Imagine I said that instead of sending your child to kindergarten, I could put him in the classroom one-on-one with the teacher and all the same resources,” said Daniel Weary, a professor of animal welfare and dairy science at the University of British Columbia in Vancouver. “But at the end of the day, if we found that individuals in this system were showing cognitive deficits in relation to other individuals, we would feel bad about that.” For cows, he said, “it means we’re not keeping these animals in an environment that allows them to be what they can be and should be.” © 2014 Discovery Communications, LLC

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19298 - Posted: 02.27.2014

|By Jenni Laidman People born with Down syndrome have always been considered to be incurably developmentally delayed—until now. In the past few years a number of laboratories have uncovered critical drug targets within disabled chemical pathways in the brain that might be restored with medication. At least two clinical trials are currently studying the effects of such treatments on people with Down syndrome. Now geneticist Roger Reeves of Johns Hopkins University may have stumbled on another drug target—this one with the potential to correct the learning and memory deficits so central to the condition. Down syndrome occurs in about one in 1,000 births annually worldwide. It arises from an extra copy of chromosome 21 and the overexpression of each of the 300 to 500 genes the chromosome carries. “If you go back even as recently as 2004, researchers didn't have much of a clue about the mechanisms involved in this developmental disability,” says Michael Harpold, chief scientific officer with the Down Syndrome Research and Treatment Foundation. But all that has changed. “In the past six or seven years there have been several breakthroughs—and ‘breakthroughs’ is not by any means too big a word—in understanding the neurochemistry in Down syndrome,” Reeves says. This improved knowledge base has led to a series of discoveries with therapeutic promise, including the latest by Reeves. He and his team were attempting to restore the size of the cerebellum in mice engineered to show the hallmarks of Down syndrome. The cerebellum lies at the base of the brain and controls motor functions, motor learning and balance. In people with Down syndrome and in the Down mouse model the cerebellum is about 40 percent smaller than normal. By restoring its size, Reeves hoped to gain a clearer picture of the developmental processes that lead to anomalies in a brain with Down syndrome. © 2014 Scientific American

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19288 - Posted: 02.25.2014

Ian Sample, science correspondent, in Chicago A woman's diet in early life has more impact on her baby's birth weight than the food she eats as an adult, researchers say. The surprise finding suggests that you are what your mother ate, and that a woman's diet in her adult life has less influence on her baby's health than previously thought. Prof Christopher Kuzawa at Northwestern University in Illinois said that women's bodies seemed to "buffer" the supply of nutrients to their unborn babies, meaning that foetuses were partly protected from changes in women's diets. Kuzawa advised pregnant women to follow a healthy diet, but said they need not worry about every calorie because their health and diet as a toddler could be more important for their baby. "There is some good news here for expectant mothers. Although there certainly are some harmful things to avoid during pregnancy, and some supplements to take to make sure some important bases are covered, the mother's body seems to do a good job of buffering overall nutritional supply to her growing baby," he said. "Within the bounds of a healthy balanced diet, the overall quantity of food that a mother eats is unlikely to have large effects on her baby's birth weight," he added. The findings emerged from a 30-year study that followed more than 3,000 pregnant women in the Philippines whose children have now begun to have babies of their own. Kuzawa said that while there was good evidence that unborn children benefit from their mothers taking extra folate and that they are harmed by toxins such as lead, mercury, excessive alcohol and bisphenol A, which is used to make some plastics, the picture was less clear on the roles of calories, protein, fat and carbohydrates. © 2014 Guardian News and Media Limited

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 19257 - Posted: 02.17.2014

CHICAGO, ILLINOIS—Chances are, your baby won’t respond to questions like, “How was your day, honey?” Or, “What do you want to be when you grow up?” But just because infants can’t form sentences until toddlerhood doesn’t mean that they don’t benefit from early conversations with their parents. It’s long been observed that the better children perform in school and the more successful their careers, the higher the socioeconomic status (SES) of their family—and, according to Stanford University’s Anne Fernald, this has a lot to do with how parents of different SES speak to their babies. Those babies that are spoken to frequently in an engaging and nurturing way—generally from a higher SES—tend to develop faster word-processing skills, or the ability to follow a sentence from one object or setting to another. This word processing speed, in turn, directly relates to the development not just of vocabulary and language skills, but also memory and nonverbal cognitive abilities. In a new study, Fernald and colleagues measured parent-baby banter from round-the-clock recordings in babies’ homes, then tested those babies’ word-processing speed using retinal-following experiments that tracked how long it took them to follow a prompt to an image like a dog or juice. The researchers found that the differences in word-processing speed between high and low SES were stark: By 2 years of age, high SES children were 6 months ahead of their low SES counterparts; and by age 3, the differences in processing abilities were highly predictive of later performance in and out of school, the team reported here today at the annual meeting of AAAS, which publishes Science. Fernald hopes that this research will lead to interventions that help to shrink the language gap between kids on either side of the income gap. © 2014 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 15: Language and Our Divided Brain
Link ID: 19249 - Posted: 02.15.2014

by Laura Sanders Some of the human brain’s wrinkles are forged by the behavior of a single gene, scientists report in the Feb. 14 Science. By scanning more than 1,000 people’s brains, researchers identified five with malformed wrinkles in a specific region. The abnormalities — numerous shallow dips surrounding an unusually wide brain furrow called the Sylvian fissure — were linked with intellectual and language disabilities and seizures in these people. All five people had mutations that dampened the behavior of a gene named GPR56. Curbing this gene’s behavior results in diminished production of cells that eventually become neurons in the affected brain region, mouse experiments revealed. Boosting the gene’s behavior had the opposite effect. The results might clarify how wrinkles allow human brains to cram lots of neurons into a small space, Christopher Walsh of Boston Children’s Hospital and colleagues suggest. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19248 - Posted: 02.15.2014

By NICHOLAS BAKALAR There are many well established risk factors for cardiovascular death, but researchers may have found one more: slower reaction time. In the late 1980s and early ’90s, researchers measured the reaction times of 5,134 adults ages 20 to 59, having them press a button as quickly as possible after a light flashed on a computer screen. Then they followed them to see how many would still be alive after 15 years. The study is in the January issue of PLOS One. Unsurprisingly, men, smokers, heavy drinkers and the physically inactive were more likely to die. But after controlling for these and other factors, they found that those with slower reaction times were 25 percent more likely to die of any cause, and 36 percent more likely to die of cardiovascular disease, than those with faster reactions. Reaction time made no difference in cancer mortality. The reasons for the connection are unclear, but the lead author, Gareth Hagger-Johnson, a senior research associate at University College London, said it may reflect problems with the brain or nervous system. He stressed, though, that “a single test of reaction time is not going to tell you when you’re going to die. There’s a link at a population level. We didn’t look at individual people.” © 2014 The New York Times Company

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19210 - Posted: 02.06.2014

by Laura Sanders Despite seeming like a bystander, your baby is attuned to your social life (assuming you have one, which, with a baby, would be amazing). Every time you interact with someone, your wee babe is watching, eagerly slurping up social conventions. Scientists already know that babies expect some social graces: They expect people in a conversation to look at each other and talk to other people, not objects, and are eager to see good guys rewarded and bad guys punished, scientists have found. Now, a new study shows that babies are also attuned to other people’s relationships, even when those relationships have nothing to do with them. Babies are pretty good at figuring out who they want to interact with. The answer in most cases: Nice people. And that makes sense. The helpless wailers need someone reliable around to feed, change and entertain them. So to find out how good babies are at reading other people’s social relationships, University of Chicago psychologists showed 64 9-month-old babies a video of two women eating. Sometimes the women ate from the same bowl and agreed that the food was delicious, or agreed that it was gross. Sometimes the women disagreed. Later, the women interacted again, either warmly greeting each other and smiling, or giving each other the cold shoulder, arms crossed with a “hmph.” Researchers then timed how long the babies spent looking at this last scene, with the idea that the longer the baby spent looking, the more surprising the scene was. © Society for Science & the Public 2000 - 2014.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 19195 - Posted: 02.01.2014

Madhusree Mukerjee By displaying images on an iPad, researchers tested patients' ability to detect contrast after their vision was restored by cataract surgery. In a study of congenitally blind children who underwent surgery to restore vision, researchers have found that the brain can still learn to use the newly acquired sense much later in life than previously thought. Healthy infants start learning to discern objects, typically by their form and colour, from the moment they open their eyes. By the time a baby is a year old vision development is more or less complete, although refinements continue through childhood. But as the brain grows older, it becomes less adaptable, neuroscientists generally believe. "The dogma is that after a certain age the brain is unable to process visual inputs it has never received before," explains cognitive scientist Amy Kalia of the Massachusetts Institute of Technology (MIT) in Cambridge. Consequently, eye surgeons in India often refuse to treat children blinded by cataracts since infancy if they are over the age of seven. Such children are not usually found in wealthier countries such as the United States — where cataracts are treated as early as possible — but are tragically plentiful in India. In the study, which was published last week in Proceedings of the National Academy of Sciences1, Kalia and her collaborators followed 11 children enrolled in Project Prakash2, a humanitarian and scientific effort in India that provides corrective surgery to children with treatable cataracts and subsequently studies their visual abilities. ('Prakash' is Sanskrit for light.) © 2014 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 7: Vision: From Eye to Brain
Link ID: 19190 - Posted: 01.30.2014

by Helen Thomson A drug for perfect pitch is just the start: mastering new skills could become easy if we can restore the brain's youthful ability to create new circuits WANNABE maestros, listen up. A mood-stabilising drug can help you achieve perfect pitch – the ability to identify any note you hear without inferring it from a reference note. Since this is a skill that is usually acquired only early in life, the discovery is the first evidence that it may be possible to revert the human brain to a childlike state, enabling us to treat disorders and unlock skills that are difficult, if not impossible, to acquire beyond a certain age. From bilingualism to sporting prowess, many abilities rely on neural circuits that are laid down by our early experiences. Until the age of 7 or so, the brain goes through several "critical periods" during which it can be radically changed by the environment. During these times, the brain is said to have increased plasticity. In order to take advantage of these critical periods, the brain needs to be stimulated appropriately so it lays down the neuronal circuitry needed for a particular ability. For example, young children with poor sight in one eye may develop lazy eye, or amblyopia. It can be treated by covering the better eye, forcing the child to use the lazy eye – but this strategy only works during the critical period. These windows of opportunity are fleeting, but now researchers are beginning to understand what closes them and how they might be reopened. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 17: Learning and Memory; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 19115 - Posted: 01.09.2014

By CARL ZIMMER There are many things that make humans a unique species, but a couple stand out. One is our mind, the other our brain. The human mind can carry out cognitive tasks that other animals cannot, like using language, envisioning the distant future and inferring what other people are thinking. The human brain is exceptional, too. At three pounds, it is gigantic relative to our body size. Our closest living relatives, chimpanzees, have brains that are only a third as big. Scientists have long suspected that our big brain and powerful mind are intimately connected. Starting about three million years ago, fossils of our ancient relatives record a huge increase in brain size. Once that cranial growth was underway, our forerunners started leaving behind signs of increasingly sophisticated minds, like stone tools and cave paintings. But scientists have long struggled to understand how a simple increase in size could lead to the evolution of those faculties. Now, two Harvard neuroscientists, Randy L. Buckner and Fenna M. Krienen, have offered a powerful yet simple explanation. In our smaller-brained ancestors, the researchers argue, neurons were tightly tethered in a relatively simple pattern of connections. When our ancestors’ brains expanded, those tethers ripped apart, enabling our neurons to form new circuits. Dr. Buckner and Dr. Krienen call their idea the tether hypothesis, and present it in a paper in the December issue of the journal Trends in Cognitive Sciences. “I think it presents some pretty exciting ideas,” said Chet C. Sherwood, an expert on human brain evolution at George Washington University who was not involved in the research. Dr. Buckner and Dr. Krienen developed their hypothesis after making detailed maps of the connections in the human brain using f.M.R.I. scanners. When they compared their maps with those of other species’ brains, they saw some striking differences. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 19072 - Posted: 12.27.2013

By Alexandra Sifferlin It’s always been conventional wisdom that girls reach maturity more quickly than boys, but now scientists have provided some proof. In new research published in the journal Cerebral Cortex, an international group of researchers led by a team from Newcastle University in England found that girls’ brains march through the reorganization and pruning typical of normal brain development earlier than boys’ brains. In the study, in which 121 people between ages 4 to 40 were scanned using MRIs, the scientists documented the ebb and flow of new neural connections, and found that some brain fibers that bridged far-flung regions of the brain tended to remain stable, while shorter connections, many of which were redundant, were edited away. And the entire reorganization seemed to occur sooner in girls’ brains than in boys’ brains. Females also tended to have more connections across the two hemispheres of the brain. The researchers believe that the earlier reorganization in girls makes the brain work more efficiently, and therefore reach a more mature state for processing the environment. What drives the gender-based difference in timing isn’t clear from the current study, but the results suggest that may be a question worth investigating. © 2013 Time Inc.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 8: Hormones and Sex
Link ID: 19062 - Posted: 12.23.2013

Smoking tobacco or marijuana, taking prescription painkillers, or using illegal drugs during pregnancy is associated with double or even triple the risk of stillbirth, according to research funded by the National Institutes of Health. Researchers based their findings on measurements of the chemical byproducts of nicotine in maternal blood samples; and cannabis, prescription painkillers and other drugs in umbilical cords. Taking direct measurements provided more precise information than did previous studies of stillbirth and substance use that relied only on women’s self-reporting. The study findings appear in the journal Obstetrics & Gynecology. “Smoking is a known risk factor for stillbirth, but this analysis gives us a much clearer picture of the risks than before,” said senior author Uma M. Reddy, M.D., MPH, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH institute that supported the study. “Additionally, results from the latest findings also showed that likely exposure to secondhand smoke can elevate the risk of stillbirth.” Dr. Reddy added, “With the legalization of marijuana in some states, it is especially important for pregnant women and health care providers to be aware that cannabis use can increase stillbirth risk.” The study enrolled women between March 2006 and September 2008 in five geographically defined areas delivering at 59 hospitals participating in the Stillbirth Collaborative Research Network External Web Site Policy. Women who experienced a stillbirth and those who gave birth to a live infant participated in the study. The researchers tested blood samples at delivery from the two groups of women and the umbilical cords from their deliveries to measure the exposure to the fetus. They also asked participants to self-report smoking and drug use during pregnancy.

Related chapters from BP7e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 13: Memory, Learning, and Development
Link ID: 19030 - Posted: 12.12.2013