Links for Keyword: Development of the Brain

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Gene therapy could treat rare brain disorder in unborn babies

Ian Sample Science editor Scientists are developing a radical form of gene therapy that could cure a devastating medical disorder by mending mutations in the brains of foetuses in the womb. The treatment, which has never been attempted before, would involve doctors injecting the feotus’s brain with a harmless virus that infects the neurons and delivers a suite of molecules that correct the genetic faults. Tests suggest that the therapy will be most effective around the second trimester, when their brains are in the early stages of development. “We believe that this could provide a treatment, if not a cure, depending on when it’s injected,” said Mark Zylka, a a neurobiologist at the University of North Carolina. The therapy is aimed at a rare brain disorder known as Angelman syndrome, which affects one in 15,000 births. Children with the condition have small brains and often experience seizures and problems with walking and sleeping. They can live their whole lives without speaking a word. Zylka said children with Angelman syndrome can have such severe sleeping difficulties that parents can feel they must lock them in their rooms at night to prevent them from getting up and having accidents around the house. Healthy people tend to have two copies of every gene in the genetic code, one inherited from their mother and the other from their father. But both copies are not always switched on. For normal brain development, the mother’s copy of a gene called UBE3A is switched on, while the father’s copy is silenced. © 2019 Guardian News & Media Limited

Related chapters from BN8e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 25975 - Posted: 02.19.2019

Having Anesthesia Once as a Baby Does Not Cause Learning Disabilities

By Perri Klass, M.D. A major international study provides new reassurance around the question of whether young children who have anesthesia are more likely to develop learning disabilities The issue has troubled pediatric anesthesiologists and parents for well over a decade, after research on animals suggested that there was a connection. Do the drugs that make it possible to perform vital surgical procedures without pain cause lasting damage to the developing human brain? Several large studies have found ways to tease out the effects of actual surgeries and anesthetic exposures on children. The new study, in the British journal The Lancet, is a randomized controlled trial involving more than 700 infants who needed hernia repairs. The babies, at 28 hospitals in seven countries, were randomly assigned to receive either general anesthesia or regional (spinal) anesthesia for these short operations — the mean duration of general anesthesia was 54 minutes. The study, called the GAS study — for general anesthesia compared to spinal — compared neurodevelopmental outcomes at 5 years of age, and found no significant difference in the children’s performance in the two groups. Dr. Andrew Davidson, a professor in the department of anesthesia at the Royal Children’s Hospital of Melbourne and one of the two lead investigators on the trial, said that this prospective, randomized design allows researchers to avoid many confounding factors that have complicated previous studies, and answer a very specific question. Preliminary data from testing the children at age 2 had shown no significant differences between the groups, and the children were then evaluated at the age of school entry. “If you have an hour of anesthesia as a child, then you are at no greater risk of deficits of cognition at the age of 5,” Dr. Davidson said. “It doesn’t increase the risk of poor neurodevelopmental outcome.” © 2019 The New York Times Company

Related chapters from BN8e: 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: 25972 - Posted: 02.18.2019

Why it’s key to identify preschoolers with anxiety and depression

Sujata Gupta The task was designed to scare the kids. One by one, adults guided children, ranging in age from 3 to 7, into a dimly lit room containing a mysterious covered mound. To build anticipation, the adults intoned, “I have something in here to show you,” or “Let’s be quiet so it doesn’t wake up.” The adult then uncovered the mound — revealed to be a terrarium — and pulled out a realistic looking plastic snake. Throughout the 90-second setup, each child wore a small motion sensor affixed to his or her belt. Those sensors measured the child’s movements, such as when they sped up or twisted around, at 100 times per second. Researchers wanted to see if the movements during a scary situation differed between children diagnosed with depression or anxiety and children without such a diagnosis. It turns out they did. Children with a diagnosis turned further away from the perceived threat — the covered terrarium — than those without a diagnosis. In fact, the sensors could identify very young children who have depression or anxiety about 80 percent of the time, researchers report January 16 in PLOS One. Such a tool could be useful because, even as it’s become widely accepted that children as young as age 3 can suffer from mental health disorders, diagnosis remains difficult. Such children often escape notice because they hold their emotions inside. It’s increasingly clear, though, that these children are at risk of mental and physical health problems later in life, says Lisabeth DiLalla, a developmental psychologist at Southern Illinois University School of Medicine in Carbondale. “The question is: ‘Can we turn that around?’” |© Society for Science & the Public 2000 - 2019

Related chapters from BN8e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 25936 - Posted: 02.06.2019

Drinking While Pregnant: An Inconvenient Truth

By Jen Gunter Pregnant women are given a long list of medical recommendations that can come across as patriarchal don’ts: Don’t eat raw fish. Don’t consume deli meats. Don’t do hot yoga! Don’t drink. There’s scientific evidence that these activities can have negative impacts on the health of the fetus, but the one that seems to be the source of most debate is alcohol. After all, the French do it, don’t they? And many people born in the 1960s or earlier had mothers who drank. And we’re fine, right? My mother had a fairly regular glass of rye and ginger ale when she was pregnant with me. And she smoked. And I graduated from medical school at the age of 23. So my opinion, especially as someone who believes strongly in a woman’s right to make decisions about her own body, may come as a surprise: It’s medically best not to drink alcohol in pregnancy. Not even a little. The source of that viewpoint? My training and practice as an OB/GYN. Some attribute this abstinence approach to the patriarchy: Clearly we doctors know that moderate alcohol is safe (we don’t!), and we just don’t trust women with that knowledge. According to this theory, we think a woman who hears that an occasional drink is O.K. will blithely go on a bender. (We don’t think that.) Some also say that, in an effort to avoid frivolous lawsuits, doctors advise against alcohol while using a nudge-nudge-wink-wink to insinuate that a glass or two is fine. But this isn’t about sexism (not this time) or dodging litigation. This is about facts. How women use those facts is, of course, their choice. The truth is that fetal alcohol syndrome is far more common than people think, and we have no ability to say accurately what level of alcohol consumption is risk free. © 2019 The New York Times Company

Prenatal Exposure to Cannabis Affects the Developing Brain

Andrew Scheyer We live in a medicated era. Recent data indicate that more than half of Americans are currently taking prescription drugs. Among pregnant women this number skyrockets to more than 80 percent. One of these women was a 24-year-old from California named Carol, whom I met and befriended through an online drug research forum. After weeks of debilitating morning sickness, persistent pain in her back and hips, and chronic anxiety about becoming a mother, Carol was taking a tranquilizer called alprazolam as needed, plus daily doses of acetaminophen and an anti-nausea drug called metoclopramide. Carol felt uneasy using the medications. Like many Americans and an even greater proportion of Europeans, Carol (who asked that I not use her surname) favors home remedies over pharmaceutical treatments. “I’ll always choose a tea over a pill,” she says. And so, as she sought relief during her pregnancy, she turned to marijuana. In the summer of 2007, Carol was surrounded by people touting the wonders of cannabis as a panacea for diseases from depression to glaucoma and myriad ailments in between—including nausea, pain, and anxiety. Worried that her suboptimal diet and poor sleep could be affecting the development of her child, she considered using small amounts of cannabis instead of the multiple prescription medications suggested by her doctor. Seventy percent of women in the United States believe that there is “slight or no risk of harm” in using cannabis during pregnancy. © 1986 - 2019 The Scientist

In the Nature–Nurture War, Robert Plomin Is Fighting a Losing Battle

By Scott Barry Kaufman Robert Plomin is a legend. For over 40 years he has been on the forefront of our understanding of the genetic and environmental influences on human behavior. Based on his groundbreaking work on twins, he showed that genes really do have a substantial influence on our psychological traits-- we are not born a lump of clay. Plomin coined the phrase "non-shared environment," and he was ranked as the 71st most "eminent psychologists of the 20th century." When I taught a course on human intelligence at NYU, I repeatedly cited his research and quoted his measured language and caution surrounding the interpretation of his findings. All of this makes it rather bewildering that, ever since his book Blueprint: How DNA Makes Us Who We Are came out, he has been spreading a lot of outdated misinformation in the media that is not supported by the latest science of genetics, including his own work. Also, many of his statements have been riddled with contradictions and logical non sequiturs, and some of his more exaggerated rhetoric is even potentially dangerous if actually applied to educational selection. Don't get me wrong: I am excited about the rapid progress scientists are making in using information about DNA to predict individual differences in intellectual functioning and personality. But I firmly believe we need to be more thoughtful in determining what relevance these rapidly emerging findings have for the actual individual human beings who are inhabited by the DNA.

The Games Animals Play

By C. Claiborne Ray Many immature mammals practice hunting and fighting skills in preparation for the real thing. Anyone who has raised a litter of kittens has observed their almost continuous cycles of pursuit and evasion, capture and attempted evisceration, and sometimes even a mock version of the killing bite. Fortunately, the rules of the game seem to stop a killer kitten short of committing real bodily harm to a littermate. To the human observer, it looks like fun, but there is an underlying evolutionary utility to such romps. At least one researcher has suggested that such games, if games they are, are not just physical practice, but a way of preparing animals for mental and emotional reaction to unexpected perils. The avian world also includes examples of what appears to be play. Absent the more detailed brain research done in mammals, this is a hard hypothesis to test conclusively. But some scientists believe that birds do things for pure pleasure, not just to practice useful skills, and that birds have the necessary brain receptors for reward and pleasure, as do mammals. As for other animals, there is at least anecdotal evidence that some turtles and octopuses engage in play-like activities. © 2019 The New York Times Company

Is Screen Time Bad for Kids’ Brains?

By Benedict Carey A generation ago, parents worried about the effects of TV; before that, it was radio. Now, the concern is “screen time,” a catchall term for the amount of time that children, especially preteens and teenagers, spend interacting with TVs, computers, smartphones, digital pads, and video games. This age group draws particular attention because screen immersion rises sharply during adolescence, and because brain development accelerates then, too, as neural networks are pruned and consolidated in the transition to adulthood. On Sunday evening, CBS’s “60 Minutes” reported on early results from the A.B.C.D. Study (for Adolescent Brain Cognitive Development), a $300 million project financed by the National Institutes of Health. The study aims to reveal how brain development is affected by a range of experiences, including substance use, concussions, and screen time. As part of an exposé on screen time, “60 Minutes” reported that heavy screen use was associated with lower scores on some aptitude tests, and to accelerated “cortical thinning" — a natural process — in some children. But the data is preliminary, and it’s unclear whether the effects are lasting or even meaningful. Does screen addiction change the brain? Yes, but so does every other activity that children engage in: sleep, homework, playing soccer, arguing, growing up in poverty, reading, vaping behind the school. The adolescent brain continually changes, or “rewires” itself, in response to daily experience, and that adaptation continues into the early to mid 20s. What scientists want to learn is whether screen time, at some threshold, causes any measurable differences in adolescent brain structure or function, and whether those differences are meaningful. Do they cause attention deficits, mood problems, or delays in reading or problem-solving ability? © 2018 The New York Times Company

Infections May Raise The Risk Of Mental Illness In Children

Rhitu Chatterjee Researchers have traced a connection between some infections and mental illnesses like schizophrenia, depression and bipolar disorder. New research from Denmark bolsters that connection. The study, published Thursday in JAMA Psychiatry, shows that a wide variety of infections, even common ones like bronchitis, are linked to a higher risk of many mental illnesses in children and adolescents. The findings support the idea that infections affect mental health, possibly by influencing the immune system. "This idea that activation of the body's immune inflammatory system as a causative factor in ... select mental illnesses is one that has really caught on," says Dr. Roger McIntyre, a professor of psychology and pharmacology at the University of Toronto, who wasn't involved in the study. "This study adds to that generally, but builds the case further in a compelling way." In the new study, the researchers gathered data on hospitalizations and prescription medications for the 1.1 million children born in Denmark between Jan. 1, 1995, and June 30, 2012. "We could follow individuals from birth, so there was no missing information during the study period," says Dr. Ole Köhler-Forsberg of Aarhus University Hospital, a neuroscientist and one of the authors of the study. Köhler-Forsberg and his colleagues used two national registries — one to get data on hospitalizations because of severe infections like pneumonia and another for data on antimicrobial or antiparasitic medications prescribed to children for less severe infections. "Most of them are those infections that you and I and all others have experienced," says Köhler-Forsberg. © 2018 npr

Lab-grown ‘mini brains’ produce electrical patterns that resemble those of premature babies

Sara Reardon ‘Mini brains’ grown in a dish have spontaneously produced human-like brain waves for the first time — and the electrical patterns look similar to those seen in premature babies. The advancement could help scientists to study early brain development. Research in this area has been slow, partly because it is difficult to obtain fetal-tissue samples for analysis and nearly impossible to examine a fetus in utero. Many researchers are excited about the promise of these ‘organoids’, which, when grown as 3D cultures, can develop some of the complex structures seen in brains. But the technology also raises questions about the ethics of creating miniature organs that could develop consciousness. A team of researchers led by neuroscientist Alysson Muotri of the University of California, San Diego, coaxed human stem cells to form tissue from the cortex — a brain region that controls cognition and interprets sensory information. They grew hundreds of brain organoids in culture for 10 months, and tested individual cells to confirm that they expressed the same collection of genes seen in typical developing human brains1. The group presented the work at the Society for Neuroscience meeting in San Diego this month. Muotri and his colleagues continuously recorded electrical patterns, or electroencephalogram (EEG) activity, across the surface of the mini brains. By six months, the organoids were firing at a higher rate than other brain organoids previously created, which surprised the team. © 2018 Springer Nature Limited.

What makes us? Nature or nurture? The DNA debate comes back to life

by Robin McKie Robert Shafran’s first inkling that his life would soon be turned on its head occurred on his first day at college in upstate New York in 1980. His fellow students greeted him like a long-lost friend. “Guys slapped me on the back, girls hugged and kissed me,” he recalls. Yet Robert had never set foot inside Sullivan County Community College until that day. Another student, Eddy Galland, who had studied at the college the previous year, was the cause of the confusion, it transpired. Eddy was his spitting image, said classmates. Robert was intrigued and went to Eddy’s home to confront him. Sign up for Lab Notes - the Guardian's weekly science update Read more “As I reached out to knock on the door, it opened – and there I am,” says Robert, recalling his first meeting with Eddy in the forthcoming documentary Three Identical Strangers. The two young men had the same facial features, the same heavy build, the same dark complexions, the same mops of black curly hair – and the same birthday: 12 July 1961. They were identical twins, a fact swiftly confirmed from hospital records. Each knew he had been adopted but neither was aware he had a twin. Their story made headlines across the US. One reader – David Kellman, a student at a different college – was particularly interested. Robert and Eddy also looked astonishingly like him. So he contacted Eddy’s adoptive mother, who was stunned to come across, in only a few weeks, two young men who were identical in appearance to her son. “My God, they are coming out of the woodwork,” she complained. © 2018 Guardian News and Media Limited

Fetal Marijuana Exposure Stunts Rat Cognitive Performance

Jef Akst When presented with two levers, laboratory rats that were exposed to cannabis in utero were able to learn to push the one below the lightbulb that lit up. But the animals struggled to adjust their strategy when the rules of the game changed, for example, when they received a sugar reward when they pushed only the left or right lever regardless of the lightbulb. Rats born to mothers who had not inhaled cannabis were better able to learn the new strategy. The results, presented yesterday (November 4) at the annual Society for Neuroscience conference, are “indicative of an inability to acquire and maintain a new strategy” following fetal cannabis exposure, says Hayden Wright, a PhD student in Ryan McLaughlin’s lab at Washington State University. Understanding such effects is critical as marijuana becomes legalized across the US, he adds. “As states allow more access, there has been an increase in self-reported cannabis use during pregnancy.” Most studies of cannabis exposure in rodents have used injections of purified THC, the psychoactive ingredient in the drug, and the results are therefore hard to translate to humans who smoke marijuana, which contains more than 100 other active cannabinoids, Wright says. So the McLaughlin lab developed an experimental system that vaporizes cannabis extract into a glass enclosure where rats can be kept for variable periods of time. For the current study, the researchers placed female rats in the chamber for two one-hour sessions per day throughout mating and gestation. During these sessions, the animals were exposed to cannabis-free vapor or vapor that contained high or low levels of the drug. The offspring of these rats were then tested for their ability to learn a simple lever-pressing task at two-months old. © 1986 - 2018 The Scientist

A ‘don’t eat me’ immune signal protects neuronal connections

Serge Rivest The signals transmitted between neurons through synaptic connections are responsible for most, if not all, brain functions, from learning to decision-making. During brain development, synapses that are stimulated less often than others are eliminated through a process called pruning, whereas those that are highly stimulated are retained. This refines the brain’s ability to respond to stimuli and environmental cues. Microglia, the brain’s innate immune cells, have a key role in pruning — they engulf and digest synapses through a process called phagocytosis. But the mechanism that determines which synapses they avoid has been unclear. Writing in Neuron, Lehrman et al.1 describe a ‘don’t eat me’ signal, involving a protein called cluster of differentiation 47 (CD47), that prevents inappropriate synaptic pruning by microglia. About a decade ago, it was shown that synapses requiring elimination send an ‘eat me’ signal to microglia2 (Fig. 1a). This signal involves the proteins C1q and CR3, which are part of the complement cascade — a complex series of interactions that is best known for activating cells of the innate immune system to eliminate disease-causing organisms and damaged cells. ‘Don’t eat me’ signals act to limit the effects of ‘eat me’ signals in the immune system, but it was not known whether the same process occurs during synaptic pruning in the developing brain. CD47 is a cell-surface protein that has many immune functions, including acting as a ‘don’t eat me’ signal for macrophages3, microglia’s sister cells, which exist outside the brain. Lehrman et al. analysed whether CD47 is expressed in the dorsal lateral geniculate nucleus (dLGN), a region of the brain involved in vision. This region receives inputs from neurons called retinal ganglion cells (RGCs) that originate in the retina. The authors demonstrated in mice that, at five days after birth, synapses from RGCs to other neurons in the dLGN are being pruned at high levels. © 2018 Springer Nature Limited

Related chapters from BN8e: 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: 25629 - Posted: 10.31.2018

Surgeons repair babies' spinal cords in the womb in UK first

Weeks before they took their first breaths, two babies had their spinal cords delicately repaired by surgeons in the first operations of their kind in the UK. The spina bifida surgeries were successfully performed by a team at University College hospital in London this summer on two babies while they were still in the womb. Spina bifida is usually treated after birth, but research shows repairing the spine earlier can stop the loss of spinal fluid and lead to better long-term health and mobility outcomes. A 30-strong team carried out the two operations, coordinated by the UCL professor Anna David, who had worked for three years to bring the procedure to patients in the UK. She said mothers previously had to travel to the US, Belgium or Switzerland. “It’s fantastic. Women now don’t have to travel out of the UK,” David said. “They can have their family with them. There are less expenses. So all good things.” Advertisement The surgery team from University College London hospitals (UCLH) and Great Ormond Street hospital travelled to Belgium to train at a facility in Leuven, where more than 40 of the operations have been carried out. Spina bifida is a condition that develops during pregnancy when the bones of the spine do not form properly, creating a gap that leaves the spinal cord unprotected. It can cause a baby’s spinal fluid to leak and affect brain development, potentially leading to long-term health and mobility problems. © 2018 Guardian News and Media Limited

Leaping from specialists to ERs fails to solve this young boy’s odd ailments

By Sandra G. Boodman Ever since he was a toddler, Michael had been beset by an array of medical problems that doctors couldn’t explain. Severe leg pain came first. That was followed a few years later by recurrent, sometimes severe, stomachaches. Later, the little boy developed a wracking cough, followed by trouble breathing. In fifth grade, after he fell and smacked his tailbone, he was in so much pain he wound up in a wheelchair. His worried parents took him to four emergency rooms and an array of Washington-area specialists, among them orthopedists, neurologists, pediatricians and a gastroenterologist. Yet virtually every test failed to uncover a problem. It would take a seasoned pediatrician to pull together the disparate elements of the 10-year-old’s medical history and make an unexpected diagnosis that would prove to be a turning point for the boy and his family. Three years later, Michael, now 14 and a freshman in high school, seems to have moved beyond the disorder that dominated his first decade. His father said he believes his son’s illness resulted from “a perfect storm” of factors. He would have preferred that the doctors who saw Michael had spoken “a little more freely about their guesses” and had provided more guidance. To protect Michael’s privacy, his parents requested that he and they be identified by their middle names. When he was nearly 2, Michael, who had been previously healthy, began limping and then stopped walking. His pediatrician found no obvious explanation and sent him to a pediatric neurologist, who ordered an extensive work-up, including scans and blood tests. © 1996-2018 The Washington Post

Related chapters from BN8e: 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: The Biology of Behavioral Disorders; Chapter 13: Memory, Learning, and Development
Link ID: 25598 - Posted: 10.22.2018

A tailormade drug developed in record time may save girl from fatal brain disease

By Jocelyn KaiserO For years, a Colorado couple searched for an explanation for why their bright, active little girl was having increasing trouble walking, speaking, and seeing. In December 2016, Julia Vitarello and Alek Makovec learned that 6-year-old Mila Makovec almost certainly had Batten disease, an inherited and fatal neurodegenerative disorder. Now, in a stunning illustration of personalized genomic medicine, Mila is receiving a drug tailored to her particular disease-causing DNA mutation—and it appears to have halted the condition’s progression. Today at the annual meeting of The American Society of Human Genetics in San Diego, California, researchers told the story of how in less than a year, they went from sequencing Mila’s genome to giving her a synthetic RNA molecule that helps her cells ignore her genetic flaw and make a needed protein. The same steps could help some other patients with diseases caused by unique mutations in a single gene, they said. “It’s very exciting,” says gene therapy researcher Steven Gray of the University of Texas Southwestern Medical Center in Houston, who wasn’t involved in the research. “There couldn’t be a stronger example of how personalized medicine might work in practice.” Batten disease afflicts an estimated two to four in 100,000 births in the United States. Patients have problems with lysosomes, enzyme-filled sacs within cells that clear waste molecules. Without properly working lysosomes, waste builds up and kills neural cells, causing brain damage and death by adolescence. © 2018 American Association for the Advancement of Science

Why is a remote Colombian town a hot spot of an inherited intellectual disability?

By Hannah Furfaro, RICAURTE, COLOMBIA—It's late afternoon in this tiny town tucked into the Colombian Andes, when Mercedes Triviño, 82, lights the wood stove to start to prepare dinner. Smoke fills the two-bedroom home she shares with six of her adult children. Francia, 38, one of the youngest, is the family's primary breadwinner. She brings home 28,000 Colombian pesos (roughly $10) a day harvesting papayas in the fields just outside town. "Really, what I earn is just enough for eating and nothing else," she says. Four of her siblings have fragile X syndrome, a genetic condition that causes intellectual disability, physical abnormalities, and often autism. Jair, 57, works alongside Francia when he can. Hector, 45, is also somewhat able to care for himself. Victor, 55, and Joanna, 35—who has both fragile X and Down syndrome—are less independent. As Mercedes serves coffee on this July afternoon, sweetening it with a hefty dose of sugar and offering her best cups to her guests, she talks about the condition that dominates the lives of her family and many others here. Her niece, Patricia, 48, who lives a few blocks away, cares for two adult sons and a nephew with fragile X. More distant kin in town, the Quinteros, also have grown children with the condition. Other neighbors are adults with fragile X who have no caretaker and look after one another. © 2018 American Association for the Advancement of Science

See these dazzling images of a growing mouse embryo

Cassie Martin A new microscope is giving researchers an unprecedented view of how mammals are built, cell by cell. Light sheet microscopes use ultrathin laser beams to illuminate sections of a specimen while cameras record those lit-up sections. Previous iterations of the device have captured detailed portraits of living zebra fish and fruit fly embryos as they develop. Kate McDole, a developmental biologist at Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va., and colleagues used a new-and-improved version to monitor the development of a larger, more complex organism: the mouse. Algorithms in the microscope tracked six-day-old mouse embryos in real time over roughly two days, keeping the device focused on the cell clusters as they grew. A suite of computer programs used the data — about a million images per embryo — to map the life history of each embryo’s every cell, the team reports October 11 in Cell. The result: dazzling views of mouse organs taking shape. As an embryo rapidly expands in size, the gut starts to form when part of the embryo collapses into a craterlike hole. And a structure that eventually forms the brain and spinal cord, called a neural tube, appears like a comet shooting across the night sky. Researchers also captured the first beats of heart cells. “These are processes no one has been able to watch before,” McDole says. Seeing the gut form in minutes was stunning. “We never expected it to be that fast or that dramatic. It’s not like you can Google these things.” |© Society for Science & the Public 2000 - 2018

Survey raises worries about how screen time affects kids’ brains

Laura Sanders Nearly two out of three U.S. kids spend more than two hours a day looking at screens, a new analysis of activity levels finds. And those children perform worse on memory, language and thinking tests than kids who spend less time in front of a device, the study of over 4,500 8- to 11-year-olds shows. The finding, published online September 26 in Lancet Child & Adolescent Health, bolsters concerns that heavy use of smartphones, tablets or televisions can hurt growing minds. But because the study captures a single snapshot in time, it’s still not known whether too much screen time can actually harm brain development, experts caution. Researchers used data gleaned from child and parent surveys on daily screen time, exercise and sleep, collected as part of a larger effort called the Adolescent Brain Cognitive Development Study. Cognitive abilities were also tested in that bigger study. As a benchmark for the new study, the researchers used expert guidelines set in 2016 that recommend no more than two hours of recreational screen time a day, an hour of exercise and between nine and 11 hours of nighttime sleep. Overall, the results are concerning, says study coauthor Jeremy Walsh, an exercise physiologist who at the time of the study was at the Children’s Hospital of Eastern Ontario Research Institute in Ottawa, Canada. Only 5 percent of the children met all three guidelines on screen time, exercise and sleep, the survey revealed. Twenty-nine percent of the children didn’t meet any of the guidelines, meaning that “they’re getting less than nine hours of sleep, they’re on their screens for longer than two hours and they’re not being physically active,” Walsh says. “This raises a flag.” |© Society for Science & the Public 2000 - 2018.

Growing Brains in Lab

By Sam Rose Imagine the following transformation. A pea-sized chunk of your skin breaks apart in a dish of salts and serums. The mixture is infected with viruses that make some cells smaller, more circular, and clump together. They’ve turned into stem cells. Then, a bath of other salts, serums, and factors coax them into becoming mature neurons. The neurons divide and organize themselves into three dimensional spheres. Inside the spheres, the neurons layer themselves like the neurons in your cerebral cortex. There’s not just one ball, but an army of tiny spheres. Each sphere contains thousands of neurons; each neuron with a copy of your DNA. The neurons communicate with each other with pulses of electricity. The spheres start to organize structures that look a lot like the different lobes and substructures of your brain. Some of the spheres may even form an optic cup, an early version of your retina. This may seem like a perverse form of human cloning carried out by a neuroscientist turned witch-doctor. But it’s real: an emerging laboratory model system that might one day help treat you or a loved one’s debilitating neurological disorder. They are called brain spheroids (or three-dimensional brain cultures or cerebral organoids) and are a relatively new creation. They were first described in a splashy study published in Nature in 2013 and are one of the most technically impressive forms of tissue culture. What brain spheroids are not, however, is as important as what they are. They’re not ‘mini-brains’. They’re not generating thoughts and emotions. Without any sensory input they lack grounding in the physical world. Brain spheroids are also very small. At 4 mm in diameter, they’re much smaller than a mouse’s brain. They’re this small because real developing brains need massive amounts of nutrients throughout the depth of their structure. Brain spheroids get their nutrients from a bath of serums. But without a network of blood vessels to deliver the serum to deeper parts of the spheroid, these parts starve. Attaching a functioning circulatory system to the spheroids isn’t feasible with current techniques, so making bigger, more developed spheroids seems unlikely at this point. © 2018 Scientific American

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