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Nature Versus Nurture? Add ‘Noise’ to the Debate

Jordana Cepelewicz In the 1990s, an army of clones invaded Germany. Within a decade, they had spread to Italy, Croatia, Slovakia, Hungary, Sweden, France, Japan and Madagascar — wreaking havoc in rivers and lakes, rice paddies and swamps; in waters warm and cold, acidic and basic. The culprits: six-inch-long, lobster-like creatures called marbled crayfish. Scientists suspect that sometime around 1995, a genetic mutation allowed a pet crayfish to reproduce asexually, giving rise to a new, all-female species that could make clones of itself from its unfertilized eggs. Deliberately or accidentally, some of these mutants were released from aquariums into the wild, where they rapidly multiplied into the millions, threatening native waterways species and ecosystems. But their success is strange. “All marbled crayfish which exist today derive from a single animal,” said Günter Vogt, a biologist at Heidelberg University. “They are all genetically identical.” Ordinarily, the absence of genetic diversity makes a population exceedingly vulnerable to the vagaries of its environment. Yet the marbled crayfish have managed to thrive around the globe. A closer look reveals that the crayfishes’ uniformity is only genome-deep. According to studies conducted by Vogt and others in the mid-2000s, these aquatic clones actually vary quite a bit in their color, size, behavior and longevity. Which means that something other than their genes is inspiring that diversity. Common sense tells us that if it’s not nature, it’s nurture: environmental influences that interact with an animal’s genome to generate different outcomes for various traits. But that’s not the whole story. New research on crayfish and scores of other organisms is revealing an important role for a third, often-overlooked source of variation and diversity — a surprising foundation for what makes us unique that begins in the first days of an embryo’s development: random, intrinsic noise. All Rights Reserved © 2020

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: 27139 - Posted: 03.24.2020

How Siblings’ Gender Can Affect a Child’s Development

By Perri Klass, M.D. When you talk about sibling issues, everyone takes it personally. Whether it’s birth order and the supposed advantages of being the oldest (or youngest, or middle), or the question of having (or being) the favorite child, people tend to respond immediately with their own sometimes very individual and emotional stories. What I want to talk about today are sibling sex ratios — having a sibling of the other sex versus growing up in all-boy or all-girl sibling configurations. The most evocative phrase I’ve seen for this is “family constellations,” which I like because it suggests that there are lots of interesting — and even beautiful — arrangements, but that differences are real. But let’s take one step further back: Are there actually parents, or parent pairs, who are more likely to conceive boys or girls? Does the five-daughter family (from “Pride and Prejudice” or “Fiddler on the Roof”) or the seven-son setup (“Seven Brides for Seven Brothers”) just reflect five (or seven) random rolls of the dice, or is there actually something going on from an evolutionary point of view? The evolutionary theory, which has been advanced to explain sex ratio, goes back to Darwin, but was fully formulated in 1930 by a British scientist named Ronald Fisher, who made the argument that if individuals vary in the sex ratio among their offspring (that is, some are more likely to produce more males or more females), the reproductive advantage in a population will always lie with the rarer sex, and thus the sex ratio will equilibrate toward 1:1. After all, Fisher argued, half of the genetic material of the next generation must come by way of those who tend to produce males, and half from those who tend to produce females. But are there such tendencies? I’ve heard people say that having boys “runs in the family,” or that their cousins are almost all girls, that’s the “family pattern.” But a very large study of 4.7 million births in Sweden published in February in the journal Proceedings of the Royal Society argues that there is no evidence of a genetic tendency toward one sex or the other, or a family tendency. © 2020 The New York Times Company

Related chapters from BN8e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory, Learning, and Development
Link ID: 27108 - Posted: 03.10.2020

Born Ready: Babies Are Prewired to Perceive the World

By Simon Makin Neuroscientists understand much about how the human brain is organized into systems specialized for recognizing faces or scenes or for other specific cognitive functions. The questions that remain relate to how such capabilities arise. Are these networks—and the regions comprising them—already specialized at birth? Or do they develop these sensitivities over time? And how might structure influence the development of function? “This is an age-old philosophical question of how knowledge is organized,” says psychologist Daniel Dilks of Emory University. “And where does it come from? What are we born with, and what requires experience?” Dilks and his colleagues addressed these questions in an investigation of neural connectivity in the youngest humans studied in this context to date: 30 infants ranging from six to 57 days old (with an average age of 27 days). Their findings suggest that circuit wiring precedes, and thus may guide, regional specialization, shedding light on how knowledge systems emerge in the brain. Further work along these lines may provide insight into neurodevelopmental disorders such as autism. In the study, published Monday in Proceedings of the National Academy of Sciences USA, the researchers looked at two of the best-studied brain networks dedicated to a particular visual function—one that underlies face recognition and another that processes scenes. The occipital face area and fusiform face area selectively respond to faces and are highly connected in adults, suggesting they constitute a face-recognition network. The same description applies to the parahippocampal place area and retrosplenial complex but for scenes. All four of these areas are in the inferior temporal cortex, which is behind the ear in humans. © 2020 Scientific American,

Related chapters from BN8e: 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: 27088 - Posted: 03.03.2020

Bumblebees Solve a 17th-Century Psychological Puzzle

By Viviane Callier In 1688 Irish philosopher William Molyneux wrote to his colleague John Locke with a puzzle that continues to draw the interest of philosophers and scientists to this day. The idea was simple: Would a person born blind, who has learned to distinguish objects by touch, be able to recognize them purely by sight if he or she regained the ability to see? The question, known as Molyneux’s problem, probes whether the human mind has a built-in concept of shapes that is so innate that such a blind person could immediately recognize an object with restored vision. The alternative is that the concepts of shapes are not innate but have to be learned by exploring an object through sight, touch and other senses, a process that could take a long time when starting from scratch. An attempt was made to resolve this puzzle a few years ago by testing Molyneux's problem in children who were congenitally blind but then regained their sight, thanks to cataract surgery. Although the children were not immediately able to recognize objects, they quickly learned to do so. The results were equivocal. Some learning was needed to identify an object, but it appeared that the study participants were not starting completely from scratch. Lars Chittka of Queen Mary University of London and his colleagues have taken another stab at finding an answer, this time using another species. To test whether bumblebees can form an internal representation of objects, Chittka and his team first trained the insects to discriminate spheres and cubes using a sugar reward. The bees were trained in the light, where they could see but not touch the objects that were isolated inside a closed petri dish. Then they were tested in the dark, where they could touch but not see the spheres or cubes. The researchers found that the invertebrates spent more time in contact with the shape they had been trained to associate with the sugar reward, even though they had to rely on touch rather than sight to discriminate the objects. © 2020 Scientific American

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 13: Memory, Learning, and Development
Link ID: 27061 - Posted: 02.21.2020

He worried about headaches and fainting spells, only to learn a tapeworm was living in his brain for

Timothy Bella The headaches had become so splitting for Gerardo Moctezuma that the pain caused him to vomit violently. The drowsiness that came with it had intensified for months. But it wasn’t until Moctezuma, 40, fainted without explanation at a soccer match in Central Texas last year that he decided to figure out what was going on. When Jordan Amadio looked down at his MRI results, the neurosurgeon recognized — but almost couldn’t believe — what looked to be lodged in Moctezuma’s brain. As he opened up Moctezuma’s skull during an emergency surgery in May 2019, he was able to confirm what it was that had uncomfortably set up shop next to the man’s brain stem: a tapeworm measuring about an inch-and-a-half. “It’s very intense, very strong, because it made me sweat too, sweat from the pain,” Moctezuma said to KXAN. The clear and white parasite came from tapeworm larva that Amadio believes Moctezuma, who moved from Mexico to the U.S. 14 years before his diagnosis, might have had in his brain for more than a decade undetected. His neurological symptoms had intensified due to his neurocysticercosis, which was the direct result of the tapeworm living in his brain. The cyst would trigger hydrocephalus, an accumulation of cerebrospinal fluid that increased pressure to the skull to the point that the blockage and pain had become life-threatening. “It’s a remarkable case where a patient came in and, if he had not been treated urgently, he would have died from tremendous pressure in the brain,” Amadio, attending neurosurgeon at the Ascension Seton Brain and Spine Institute in Austin, told The Washington Post on Thursday night.

Related chapters from BN8e: Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 27013 - Posted: 02.01.2020

Brain organoids help neuroscientists understand brain development, but aren’t perfect matches for

Madeline Andrews, Aparna Bhaduri, Arnold Kriegstein What was going on with our brain organoids? As neuroscientists, we use these three-dimensional clusters of cells grown in petri dishes to learn more about how the human brain works. Researchers culture various kinds of organoids from stem cells – cells that have the potential to become one of many different cell types found throughout the body. We use chemical signals to direct stem cells to produce brain-like cells that together resemble certain structural aspects of a real brain. While they are not “brains in a dish” – organoids cannot function or think independently – the idea is that organoid models let scientists see developmental processes that may yield insights into how the human brain works. If researchers better understand normal development, we may be able to understand when and how things go wrong in diseases. When we recently compared our lab’s organoid cells to normal brain cells, we were surprised to find that they didn’t look as similar as we’d expected. Our brain organoids, each the size of a few millimeters, were stressed out. Our investigation into why has important implications for this popular new method since many labs are using it to study brain function and neurological disease. Without accurate models of the brain, scientists will not be able to work toward disease treatments. Our lab is particularly interested in the human cerebral cortex – the brain’s bumpy exterior – because it is so different in human beings than it is in any other species. The human cortex is proportionally bigger than in our closest living relatives, the great apes, containing more and different types of cells. It’s the source of many unique human abilities, including our cognitive capacity. © 2010–2020, The Conversation US, Inc.

A Rat With No Brain?

By Neuroskeptic A new neuroscience paper bears the remarkable title of Life without a brain. Although the title is somewhat misleading, this is still a rather interesting report about a unique rat who functioned extremely well despite having a highly abnormal brain. This case sheds new light on a number of famous examples of humans born with similar abnormalities. According to the authors of the new paper, Ferris et al., the rat in question was called R222 and it was discovered unexpectedly during testing as part of a batch of rats taking part in an experiment. R222 didn't actually have no brain, but it had a highly abnormal brain anatomy. Its brain was actually twice the size of a normal rat's, but much of it consisted of empty, fluid-filled space. The cerebral cortex was limited to a thin sheet surrounding the fluid spaces, although the total cortical volume was - surprisingly given the images shown above - only slightly less than normal - 575 μL vs. the normal ~615 μL. Despite the grossly abnormal appearance of R222's brain, the rat seemed to suffer no major impairments. Ferris et al. say that "R222’s general health, appearance and body weight were no different from the other rats in the cohort." The rodent's motor skills and memory function were within the normal range, although it did seem to be highly anxious. © 2020 Kalmbach Media Co.

An Ethical Future for Brain Organoids Takes Shape

Jordana Cepelewicz Part of the brain’s allure for scientists is that it is so deeply personal — arguably the core of who we are and what makes us human. But that fact also renders a large share of imaginable experiments on it monstrous, no matter how well intended. Neuroscientists have often had to swallow their frustration and settle for studying the brains of experimental animals or isolated human neurons kept alive in flat dishes — substitutes that come with their own ethical, practical and conceptual limitations. A new world of possibilities opened in 2008, however, when researchers learned how to create cerebral organoids — tiny blobs grown from human stem cells that self-organize into brainlike structures with electrically active neurons. Though no bigger than a pea, organoids hold enormous promise for improving our understanding of the brain: They can replicate aspects of human development and disease once thought impossible to observe in the laboratory. Scientists have already used organoids to make discoveries about schizophrenia, autism spectrum disorders and the microcephaly caused by the Zika virus. Yet the study of brain organoids can also be fraught with ethical dilemmas. “In order for it to be a good model, you want it to be as human as possible,” said Hank Greely, a law professor at Stanford University who specializes in ethical and legal issues in the biosciences. “But the more human it gets, the more you’re backing into the same sorts of ethics questions that are the reasons why you can’t just use living humans.” In the popular imagination, fueled by over-the-top descriptions of organoids as “mini-brains,” these questions often center on whether the tissue might become conscious and experience its unnatural existence as torture. The more immediate, realistic concerns that trouble experts are less sensational but still significant. It also doesn’t help that the study of organoids falls into an odd gap between other areas of research, complicating formal ethical oversight. Still, no one wants to see brain organoids’ potential discarded lightly. All Rights Reserved © 2020

Related chapters from BN8e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 1: Introduction: Scope and Outlook
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 1: An Introduction to Brain and Behavior
Link ID: 27007 - Posted: 01.29.2020

This Rat Had 'No Brain' and It Somehow Lived a Normal Life

One day, a scientist in Craig Ferris’s lab was scanning the brains of very old rats when he found that one could see, hear, smell, and feel just like the other rats, but it was walking around with basically no brain—and likely had been since birth. This rat, named R222, did have a brain. But its brain, affected by a condition called hydrocephalus, had compressed and collapsed as it filled with fluid, and many of the functions that would ordinarily be carried out in the brain had relocalized to areas that weren’t taken over by fluid. This provided the tools for Ferris, a psychology professor at Northeastern, to investigate how powerful the brain remains, even when tight on space. This, he says, might even influence the ever-present goal of machine learning: How small can you be and still get the job done? Pretty small, it turns out, at least in R222’s case, but this efficient use of space is dependent on the brain’s capacity to reorganize. This ability, known as neuroplasticity, is a widely documented phenomenon, but such an extreme example was rare, says Ferris. In R222’s case, he says, the processing of visual input “was distributed over much of the remaining brain, and the same thing with smell and touch.” What at first the scans suggested to be a brainless rat was actually a rat with a brain that had been pushed out of the way and flattened like a pancake—and kept working. ©2020 Technology Networks

Benefits of fetal surgery to repair spina bifida persist through school age

Children as young as 6 years old who underwent fetal surgery to repair a common birth defect of the spine are more likely to walk independently and have fewer follow-up surgeries, compared to those who had traditional corrective surgery after birth, according to researchers funded by the National Institutes of Health. The study appears in Pediatrics. The procedure corrects myelomeningocele, the most serious form of spina bifida, a condition in which the spinal column fails to close around the spinal cord. With myelomeningocele, the spinal cord protrudes through an opening in the spine and may block the flow of spinal fluid and pull the brain into the base of the skull, a condition known as hindbrain herniation. In 2011, the Management of Myelomeningocele study, funded by NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), found that by 12 months of age, children who had fetal surgery required fewer surgical procedures to divert, or shunt, fluid away from the brain. By 30 months, the fetal surgery group was more likely to walk without crutches or other devices. For the current study, NICHD-funded researchers re-evaluated children from the original trial when they were 6 to 10 years old. Of the 161 children who took part in the follow-up study, 79 had been assigned to prenatal surgery and 82 had been assigned to traditional surgery. Children in the prenatal surgery group walked independently more often than those in the traditional surgery group (93% vs. 80%). Those in the prenatal surgery group also had fewer shunt placements for hydrocephalus, or fluid buildup in the brain (49% vs. 85%), and fewer shunt replacements (47% vs. 70%). The group also scored higher on a measure of motor skills. The two groups did not differ significantly in a test measuring communication ability, daily living skills, and social interaction skills.

“Organoids” Reveal How Human Forebrain Develops

By Simon Makin Knowing how the human brain develops is critical to understanding how things can go awry in neurodevelopmental disorders, from intellectual disability and epilepsy to schizophrenia and autism. But between the fact that researchers cannot poke around inside growing human brains and the inadequacies of animal models, scientists currently do not fully understand the process. “We know a bit about the early stages because [the situation is] very similar to what happens in rodents,” says psychiatrist Sergiu Paşca of Stanford University. “But everything beyond the second trimester [of pregnancy] and soon after birth is poorly understood.” Enter the invention of brain “organoids”: cells grown in 3-D clusters in the lab and designed to mimic the composition of the organ’s tissue. The technology recently reached the point where specific brain regions can be modelled for sufficiently long periods to allow researchers to study their development. Paşca and his colleagues have now used organoid models of parts of the human forebrain—the seat of higher cognitive abilities such as complex thought, perception and voluntary movement—to peer into how gene activity drives brain development. “The work brings new understanding of how, as the brain is formed, distinct regulatory regions of the genome are used to execute specific tasks—for example, the generation of specific types of neurons,” says neuroscientist Paola Arlotta of Harvard University, who was not involved in the new study. The researchers used their findings to map genes associated with certain disorders to specific cell types at specific stages, giving insight into the origins of conditions such as autism and schizophrenia. © 2020 Scientific American,

Build a Better Brain Model

Kayt Sukel Since its inception, the field of neuroscience has relied on animal models, from fruit flies to macaque monkeys, to better understand the behavior and inner workings of neurons. But while these models have led to remarkable insights about the brain in both health and in disease, they do have limitations. The very genetic differences that place us in different species also make the translation of neurobiological findings in animals to humans challenging—if not outright impossible. “We’ve now cured Alzheimer’s disease a dozen times over in mice, but we haven’t cured it in human patients,” said Matthew Blurton-James, Ph.D., a neurobiologist at the University of California, Irvine. “There’s clearly a big species difference in how this disease develops, which means our current animal models can’t get us the answers we’re searching for.” In the past few years, however, advances in technology have led to the development of innovative models to study the activity of human neurons—and how they communicate with one another. Such models, which include ex vivo tissue harvested from living human donors, organoids, and chimeric models (animal tissue modified with human genes or cells), are enabling scientists to investigate processes in ways that were previously unthinkable. “These new technologies, including those that use induced pluripotent stem cells (iPSCs), are really quite striking,” said Walter Koroshetz, M.D., director of the National Institute of Neurological Disorders and Stroke. “And the real advantage of these is that they offer us a new way to study human brain cells, particularly when it comes to developmental processes, that is incredibly valuable.” © 2020 The Dana Foundation

Neglected children end up with 'smaller brains'

By James Gallagher Health and science correspondent An early life full of neglect, deprivation and adversity leads to people growing up with smaller brains, a study suggests. The researchers at King's College London were following adopted children who spent time in "hellhole" Romanian orphanages. They grew up with brains 8.6% smaller than other adoptees. The researchers said it was the "most compelling" evidence of the impact on the adult brain. The appalling care at the orphanages came to light after the fall of Romania's communist dictator Nicolae Ceausescu in 1989. "I remember TV pictures of those institutions, they were shocking," Prof Edmund Sonuga-Barke, who now leads the study following those children, told the BBC. He described the institutions as "hellholes" where children were "chained into their cots, rocking, filthy and emaciated". The children were physically and psychologically deprived with little social contact, no toys and often ravaged by disease. The children studied had spent between two weeks and nearly four years in such institutions. Previous studies on children who were later adopted by loving families in the UK showed they were still experiencing mental health problems in adulthood. Higher levels of traits including autism, attention deficit hyperactivity disorder (ADHD) and a lack of fear of strangers (disinhibited social engagement disorder) have all been documented. The latest study, published in Proceedings of the National Academy of Sciences, is the first to scan the brains for answers. There were 67 Romanian adoptees in the study and their brains were compared to 21 adoptees who did not suffer early life deprivation. "What we found is really quite striking," Prof Sonuga-Barke told the BBC. First the total brain volume - the size of the brain - was 8.6% smaller in the Romanian adoptees on average. And the longer they spent in the Romanian orphanages, the greater the reduction in brain size. © 2020 BBC.

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: 26935 - Posted: 01.07.2020

Extending ‘Healthspan’: Brain Scientists Tap Into The Secrets Of Living Well Longer

By Sharon Jayson AUSTIN, Texas — Retired state employees Vickey Benford, 63, and Joan Caldwell, 61, are Golden Rollers, a group of the over-50 set that gets out on assorted bikes — including trikes for adults they call “three wheels of awesome” — for an hour of trail riding and camaraderie. “I love to exercise, and I like to stay fit,” said Caldwell, who tried out a recumbent bike, a low-impact option that can be easier on the back. “It keeps me young.” Benford encouraged Caldwell to join the organized rides, which have attracted more than 225 riders at city rec centers and senior activity centers. The cyclists can choose from a small, donated fleet of recumbent bikes, tandem recumbents and tricycles. “With seniors, it’s less about transportation and more about access to the outdoors, social engagement and quality of life,” said Christopher Stanton, whose idea for Golden Rollers grew out of the Ghisallo Cycling Initiative, a youth biking nonprofit he founded in 2011. But that’s not all, according to brain scientists. They point to another important benefit: Exercising both body and brain can help people stay healthier longer. The new thinking about aging considers not just how long one lives, but how vibrant one stays later in life. “If you’re living, you want to be living well,” said Tim Peterson, an assistant professor of internal medicine at the Washington University School of Medicine in St. Louis. “Most people who were interested in life span and were studying genes — which control life span — switched to ‘healthspan.’” “Healthspan,” a coinage now gaining traction, refers to the years that a person can expect to live in generally good health — free of chronic illnesses and cognitive decline that can emerge near life’s end. Although there’s only so much a person can do to delay the onset of disease, there’s plenty that scientists are learning to improve your chances of a better healthspan. © 2020 Kaiser Family Foundation

Related chapters from BN8e: 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: 26932 - Posted: 01.04.2020

Could adding folic acid to salt curb Ethiopia’s sky-high rate of spinal cord deformities?

By Meredith Wadman Tony Magana, chief of neurosurgery at Mekelle University School of Medicine in Ethiopia’s Tigray province, confronts his country’s high prevalence of neural tube defects nearly every day. His team operates on more than 400 babies annually to repair these severe, often lethal birth malformations, in which babies can be born without brains or with their spinal cords protruding from their backs. “Probably every other day we see a child that is so bad we can’t help them,” Magana says. The holes where the spinal cord protrudes “are so big that you can’t close them.” This month, a team of nutrition experts converged in Addis Ababa to lay groundwork for an unproven but possibly highly effective intervention: fortifying Ethiopia’s salt supply with folic acid, a synthetic form of the B vitamin folate. In the first 4 weeks of pregnancy, folate is essential to proper closure of the neural tube, which gives rise to the brain and spinal cord, and since the mid-1990s, more than 80 countries have mandated flour fortification with folic acid. Ethiopia, where fewer than one-third of people eat flour, is not among them. Last year, a pair of studies that surveyed births at 11 public hospitals there shook the global health community. The studies—one co-authored by Magana—found that among every 10,000 births, between 126 and 131 babies suffered from neural tube defects (NTDs). That’s seven times their global prevalence and 26 times the prevalence in high-income, flour-fortifying countries such as the United States. According to Ethiopian government data, 84% of Ethiopian women of reproductive age have folate levels in their red blood cells that put them at risk of giving birth to a child with an NTD. © 2019 American Association for the Advancement of Science

Prenatal exposure to opioids may alter brain development

A disturbing aspect of Canada's opioid crisis is that more babies are being born to mothers who use fentanyl and other opioid drugs. The Canadian Institute for Health Information says more than 1,800 infants per year are born with symptoms of opioid withdrawal. A study presented Monday at the 105th Scientific Assembly and Annual Meeting of the Radiological Society of North America suggests that prenatal exposure to opioids may have a significant impact on the brain development of unborn children. A team of obstetricians, neonatologists, psychologists and radiologists led by Dr. Rupa Radhakrishnan, a radiologist at Indiana University School of Medicine, did functional MRI brain scans on 16 full-term infants. Eight of the infants had mothers who used opioids during pregnancy and eight had mothers who did not use opioids. The brain imaging technique used by the researchers is called resting state functional MRI (fMRI). The technique enabled researchers to measure brain activity by detecting changes in blood flow. The technique permits researchers to measure how well different regions of the brain talk to one another. The researchers found abnormal connections to and from a part of the brain called the amygdala. It's a region that is responsible for the perception and regulation of emotions such as anger, fear, sadness and aggression. This is one of the first studies to suggest that the brain function of infants may be affected by prenatal exposure to opioids. Abnormal function in the amygdala could make it difficult for children exposed to opioids to regulate their emotions. That could have serious implications on their social development and on their behaviour. The researchers say the study is small. They say they aren't certain as to the clinical implications of this study. A long-term outcome study is underway to understand better the functional brain changes caused by prenatal opioid exposure and their associated long-term developmental outcomes. How newborns face opioid withdrawal This research may become even more important should current trends continue, and we see an increase in the number of infants exposed to opioids prenatally. ©2019 CBC/Radio-Canada

How the Brain Can Rewire Itself After Half of It Is Removed

By Knvul Sheikh Shortly after the birth of her first son, Monika Jones learned that he had a rare neurological condition that made one side of his brain abnormally large. Her son, Henry, endured hundreds of seizures a day. Despite receiving high doses of medication, his little body seemed like a rag doll as one episode blended into another. He required several surgeries, starting when he was 3 1/2 months old, eventually leading to a complete anatomical hemispherectomy, or the removal of half of his brain, when he turned 3. The procedure was first developed in the 1920s to treat malignant brain tumors. But its success in children who have brain malformations, intractable seizures or diseases where damage is confined to half the brain, has astonished even seasoned scientists. After the procedure, many of the children are able to walk, talk, read and do everyday tasks. Roughly 20 percent of patients who have the procedure go on to find gainful employment as adults. Now, research published Tuesday in the journal Cell Reports suggests that some individuals recover so well from the surgery because of a reorganization in the remaining half of the brain. Scientists identified the variety of networks that pick up the slack for the removed tissue, with some of the brain’s specialists learning to operate like generalists. “The brain is remarkably plastic,” said Dorit Kliemann, a cognitive neuroscientist at the California Institute of Technology, and the first author of the study. “It can compensate for dramatic loss of brain structure, and in some cases the remaining networks can support almost typical cognition.” The study was partially funded by a nonprofit organization that Mrs. Jones and her husband set up to advocate for others who need surgery to stop seizures. The study’s findings could provide encouragement for those seeking hemispherectomies beyond early childhood. © 2019 The New York Times Company

Related chapters from BN8e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 26837 - Posted: 11.20.2019

The Hidden Cost of Gold: Birth Defects and Brain Damage

By Richard C. Paddock CIDAHU, Indonesia — Thousands of children with crippling birth defects. Half a million people poisoned. A toxic chemical found in the food supply. Accusations of a government cover-up and police officers on the take. This is the legacy of Indonesia’s mercury trade, a business intertwined with the lucrative and illegal production of gold. More than a hundred nations have joined a global campaign to reduce the international trade in mercury, an element so toxic there is “no known safe level of exposure,” according to health experts. But that effort has backfired in Indonesia, where illicit backyard manufacturers have sprung up to supply wildcat miners and replace mercury that was previously imported from abroad. Now, Indonesia produces so much black-market mercury that it has become a major global supplier, surreptitiously shipping thousands of tons to other parts of the world. Much of the mercury is destined for use in gold mining in Africa and Asia, passing through hubs such as Dubai and Singapore, according to court records — and the trade has deadly consequences. “It is a public health crisis,” said Yuyun Ismawati, a co-founder of an Indonesian environmental group, Nexus3 Foundation, and a recipient of the 2009 Goldman Environmental Prize. She has called for a worldwide ban on using mercury in gold mining. Mercury can be highly dangerous as it accumulates up the food chain, causing a wide range of disorders, including birth defects, neurological problems and even death. ImageA small mine on Sumbawa. Miners often dig for ore on land without permission or government permits. Today, despite the risks, small-scale miners using mercury operate in about 80 countries in Asia, Africa and the Americas. They produce up to 25 percent of all gold sold. © 2019 The New York Times Company

Using both marijuana and alcohol during early pregnancy may increase the likelihood of disrupting fe

New preclinical research reported in animal models shows that exposure to compounds found in marijuana called cannabinoids (CBs), which includes cannabidiol (CBD) and tetrahydrocannabinol (THC), during early pregnancy can cause malformations in the developing embryo. The research also demonstrated that co-exposure to CBs and alcohol increased the likelihood of birth defects involving the face and brain. The study, funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health, was published in Scientific Reports. “Prenatal alcohol exposure is a leading preventable cause of birth defects and neurodevelopmental abnormalities in the United States,” said NIAAA Director, George F. Koob, Ph.D. “Since marijuana and alcohol are frequently used simultaneously, the combined effects of cannabinoids and alcohol are worrisome as well as the dangers of either substance alone.” The detrimental effects of prenatal alcohol exposure on human development are well known and include an array of lifelong physical, cognitive, and behavioral problems collectively called fetal alcohol spectrum disorders (FASD). Alcohol can disrupt fetal development at any stage during pregnancy, even the earliest stages before a woman knows she is pregnant. The effects of marijuana exposure during pregnancy and the combined effect of alcohol and marijuana are less known. In the study, scientists led by Scott Parnell, Ph.D., at the Bowles Center for Alcohol Studies at the University of North Carolina in Chapel Hill, administered a variety of CBs alone and in combination with alcohol in varying amounts to mice on day eight of pregnancy, which is similar to the third and fourth weeks of pregnancy in humans. The CBD amounts administered were within what is considered a therapeutic range for several medical conditions in humans. The THC concentration administered was similar to levels reached by a person smoking marijuana.

Study offers fresh hope to premature babies with brain injuries

Nicola Davis A potential route to reducing brain injury in premature babies has been found, say researchers who have discovered a way to tackle overactive immune cells in the brain. Microglia are a type of immune cell that play an important part in the building of a baby’s brain. However, if these cells go into overdrive as a result of inflammation – often because of a bacterial infection of the foetal membranes, a maternal infection or even sepsis after delivery of the baby – they can cause harm to the child’s brain. In particular, they can damage white matter, reducing the degree to which neurons are insulated and thereby affecting connectivity in the brain. It is thought that of the 15 million infants born before 37 weeks every year, up to 9 million are left with lifelong harm to the brain, sometimes resulting in conditions such as epilepsy or cerebral palsy. Now researchers say they have found a signalling pathway in these immune cells that is behind their transformation. “We have actually identified the immune switch that turns these immune cells in the developing brain from being helpful in building a brain and taking care of the brain to causing damage,” said Dr Bobbi Fleiss from RMIT University in Melbourne, Australia, a co-author of the study. What is more, the researchers say, it might even be possible to intervene and turn rogue microglia back into helpful workhorses. Writing in the journal Brain, Fleiss and colleagues reported how they took mouse pups just after birth and injected them with proteins that mimic an infection in the mother or foetus, inducing the transformation of microglia from helpful to harmful. © 2019 Guardian News & Media Limited

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