Links for Keyword: Development of the Brain

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.


Links 1 - 20 of 1033

By Claudia López Lloreda By squirting cells from a 3D printer, researchers have created tissue that looks—and acts—like a chunk of brain. In recent years, scientists have learned how to load up 3D printers with cells and other scaffolding ingredients to create living tissues, but making realistic brainlike constructs has been a challenge. Now, one team has shown that, by modifying its printing techniques, it can print and combine multiple subtypes of cells that better mimic signaling in the human brain. “It’s remarkable that [the researchers] can replicate” how brain cells work, says Riccardo Levato, a regenerative medicine researcher at Utrecht University who was not involved with the study. “It’s the first demonstration that, with some simple organization [of cells], you can start getting some interesting functional [responses].” The new technology, described last week in Cell Stem Cell, could offer advantages over existing techniques that neuroscientists use to create 3D brain tissues in the lab. One common approach involves using stem cells to grow miniature brainlike blobs called organoids. But researchers can’t control the types of cells or their precise location in these constructs. Each organoid “is unique,” making it difficult to reproduce research results, says neuroscientist Su-Chun Zhang of the University of Wisconsin–Madison, an author of the new study. With the right kind of 3D printing, however, “you can control where different cell types are placed,” says developmental biologist Francis Szele of the University of Oxford. Past studies have used 3D printers to construct brain tissues that allowed researchers to study how the cells matured and made connections, and even integrate printed tissue into mouse brains. But those constructs had limited functionality. And efforts that produced more functional printed tissue used rat cells, not human cells. © 2024 American Association for the Advancement of Science.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 5: The Sensorimotor System
Link ID: 29145 - Posted: 02.10.2024

By Viviane Callier Aging can seem like an unregulated process: As time marches along, our cells and bodies inevitably accumulate dings and dents that cause dysfunctions, failures and ultimately death. However, in 1993 a discovery upended that interpretation of events. Researchers found a mutation in a single gene that doubled a worm’s life span; subsequent work showed that related genes, all involved in the response to insulin, are key regulators of aging in a host of animals, from worms and flies to humans. The discovery suggested that aging is not a random process — indeed, specific genes regulate it — and opened the door to further research into how aging proceeds at a molecular level. Recently, a set of papers documented a new biochemical pathway that regulates aging, one based on signals passed between mitochondria, the organelles best known as the powerhouse of the cell. Working with worms, the researchers found that damage to mitochondria in brain cells triggered a repair response that was then amplified, setting off similar reactions in mitochondria throughout the worm’s body. The effect of this repair activity was to extend the organism’s life span: The worms with repaired mitochondrial damage lived 50% longer. What’s more, cells in the germline — the cells that produce eggs and sperm — were central to this anti-aging communication system. It’s a finding that adds new dimensions to the fertility concerns implied when people talk about aging and their “biological clock.” Some of the findings were reported in Science Advances and others were posted on the scientific preprint server biorxiv.org in the fall. All Rights Reserved © 2024

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29092 - Posted: 01.11.2024

By Sara Reardon At birth, a human baby’s brain contains the most neurons it will ever have. How this complex brain develops in the womb has been hard to study in humans. But a new and potentially controversial method, growing tiny, brainlike structures called organoids in a dish from human fetal brain tissue, could provide a realistic model and improve the study of developmental disorders or brain cancers. The team that achieved this first, reported yesterday in Cell, has also shown it can genetically engineer the blobs of tissue, which could help the fetal brain organoids (FeBOs) mimic certain diseases. The researchers have “demonstrated some interesting and creative uses,” for the new organoids, says Arnold Kriegstein, a neurologist at the University of California (UC), San Francisco. He thinks FeBOs might help researchers tackle previously unexplored questions about how neurons take on specific identities in the maturing brain, for example. Researchers have already created organoids that mimic multiple parts of the brain and nervous system using stem cells that have the capacity to turn into many or all known cell types with the right stimulation and environment. To study genetic conditions that affect brain development, scientists can also “reprogram” mature cells from affected patients into stem cells to make organoids. Some stem cell–derived brain organoids, which are usually about the size of a grain of rice, have even produced electrical activity reminiscent of that in the brain of a fetus. But although these organoids can be useful representations of the brain, the starting stem cells must be “pushed” into a brainlike state through an introduced cocktail of signaling molecules—a complex process that may not fully replicate normal development, says stem cell biologist Benedetta Artegiani of the Princess Máxima Center for Pediatric Oncology. Using natural fetal brain tissue might reveal more about what the human brain really looks like at this stage of development. (Previous studies have made organoids from human fetal intestine, liver, and lung tissue, but not brain.) © 2024 American Association for the Advancement of Science.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29090 - Posted: 01.11.2024

By Yasemin Saplakoglu In the 16th century, the Belgian cartographer Abraham Ortelius created the world’s first modern atlas — a collection of maps that he called “The Theater of the World.” The maps, drawn by Ortelius and others, detailed what was at the time the best knowledge of the world’s continents, cities, mountains, rivers, lakes and oceans and helped usher in a new understanding of global geography. Similarly, the creation of cell atlases — maps of organs and bodies constructed cell by cell — is heralding a new era in our understanding of biology. Powerful sequencing and imaging technologies invented in the last decade are revealing with unprecedented detail the composition of human organs and tissues, from the pancreas and liver to the placenta, as well as those of other animals like the mouse and fruit fly. With these new tools, researchers can fingerprint individual cells based on which genes they are expressing. That information has revealed subtle and unsuspected distinctions among cells and has begun to illuminate how the diversity of cell types can be essential to the healthy functioning of organs. “We’re at this amazing point in time in science where we’re now able to understand the composition of these cell types,” said Steve Quake, a bioengineer and biophysicist at Stanford University who helped develop the technologies that make cell atlases possible. “It’s changed the way we understand how human biology works.” Two cell atlas efforts, part of the National Institutes of Health’s $250 million brain cell census, that just released their findings illustrate the excitement bubbling up in the field. Today in Nature, a coalition of laboratories published nine studies that collectively form a detailed atlas of the mouse brain — the most comprehensive mammalian brain atlas to date. It describes more than 5,300 types of cells found throughout the organ. How these cells are distributed and are related to one another suggests many intriguing ideas about the evolution of the mammalian brain. All Rights Reserved © 2023

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 29053 - Posted: 12.16.2023

By Carl Zimmer Why do we grow old and die? In the 19th century, the German biologist August Weismann argued that the machinery of life inevitably wore out with time. Death had evolved “for the need of the species,” he declared. It cleared away weak, old individuals so they wouldn’t compete with young ones. That explanation never made sense to George Williams, an American evolutionary biologist. Natural selection acts only on the genes that are passed down from one generation to the next. What happens at the end of an animal’s life can have no effect on the course of evolution. It occurred to Williams that growing old might instead be an inescapable side effect of natural selection. In 1957, he proposed a new theory: Genetic mutations that increased an animal’s fertility could also cause harm late in life. Over many generations, those mutations would create a burden that would lead eventually to death. A new study, published on Friday in the journal Science Advances, bolsters Williams’s theory using a trove of human DNA. Researchers found hundreds of mutations that could boost a young person’s fertility and that were linked to bodily damage later in life. Smaller studies in the past had already offered some support for Williams’s theory. In 2007, for example, a team of researchers studying a tiny worm found a pair of mutations that lengthened the creature’s life while cutting down its average number of offspring. But Jianzhi Zhang, an evolutionary biologist at the University of Michigan, was not satisfied with these experiments. “These are case studies,” he said. “We don’t know if in the entire genome there are lots of such mutations.” Dr. Zhang tapped into the UK Biobank, a database containing genetic material from half a million volunteers in Britain, along with information on their health and life experiences. The biobank has permitted scientists to uncover subtle links between genetic variations and thousands of traits such as high blood pressure, schizophrenia and a habit of smoking. Working with Dr. Erping Long, a medical researcher now at the Chinese Academy of Sciences, Dr. Zhang pored over the database for information about reproduction and longevity. The scientists found that the genetic variations linked to fertility, such as the number of children a volunteer had, were also linked to a shorter life span. © 2023 The New York Times Company

Related chapters from BN: 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 and Learning; Chapter 8: Hormones and Sex
Link ID: 29048 - Posted: 12.16.2023

By Laura Sanders WASHINGTON — Brain scans could be used to predict how teenagers’ mental health will fare during a stressful time, an analysis that spanned the COVID-19 pandemic suggests. The findings, presented November 13 in a news briefing at the annual meeting of the Society for Neuroscience, may help explain why some people succumb to stress while others are more resilient. For a lot of research, “the study happens, and you report on the results, and that’s about it,” says Margot Wagner, a bioengineer at the University of California, San Diego who was not involved in the new work. But this research followed hundreds of teenagers over time, a study design that “means you can intervene and help way sooner than otherwise,” Wagner says. The pandemic was particularly tough for many teenagers, as isolation, worry and upheaval of daily routines affected them in ways that scientists are just now starting to see (SN: 1/3/23). A record number of young people are struggling with depression and anxiety, a mental health crisis that some scientists are calling “the second pandemic” (SN: 6/30/23). While many teenagers struggled during the pandemic, others did OK. Computational neuroscientist Caterina Stamoulis of Harvard Medical School and Boston Children’s Hospital investigated why responses differed using data collected as part of the Adolescent Brain Cognitive Development, or ABCD, study. That larger study — involving scientists at 21 research sites across the United States — aims to figure out how teenagers’ brains grow over the years. “This is the first time in history we’re looking at thousands of participants and getting these measures over time,” Wagner says. “It’s truly remarkable.” The ABCD study, begun in 2015, was well under way when COVID hit, so researchers possessed brain scans from before the pandemic. “Without the pandemic, we would not have been able to understand the impact of a long-lasting adverse event” that deeply affected the participants’ lives, changing their interactions with their family and friends, Stamoulis says. © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 29012 - Posted: 11.18.2023

By Laura Sanders A new look at the human brain is beginning to reveal the inner lives of its cellular residents. The human brain holds a dizzying collection of diverse cells, and no two brains are the same, cellularly speaking. Those are the prevailing conclusions of an onslaught of 21 papers published online October 12 in Science, Science Advances and Science Translational Medicine. The results just start to scratch the surface of understanding the mysteries of the brain. Still, they provide the most intimate look yet at the cells that build the brain, and offer clues about how the brain enables thoughts, actions and memories. The collection of data may also guide researchers in their hunt for the causes of brain disorders such as schizophrenia, Alzheimer’s disease and depression. The new brain map is a result of a coordinated international research effort called the National Institutes of Health’s Brain Initiative Cell Census Network, or BICCN, which ramped up in 2017. Many of the studies in the collection are based on a powerful technology called single-cell genomics. The method reveals which genes are active inside of a single cell, information that provides clues about the cell’s identity and job. As part of the BICCN, researchers examined all sorts of brains. One project detailed the cells in small pieces of live brain tissue taken from 75 people undergoing surgery for tumors or epilepsy, an approach that’s been used on smaller scales before (SN: 8/7/19). Another looked at samples taken from the brains of 17 deceased children. Still another looked at brain tissue from seven people, seven chimpanzees, four gorillas, three rhesus macaques and three marmosets. © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 28962 - Posted: 10.14.2023

Saima May Sidik A protein involved in wound healing can improve learning and memory in ageing mice1. Platelet factor 4 (PF4) has long been known for its role in promoting blood clotting and sealing broken blood vessels. Now, researchers are wondering whether this signalling molecule could be used to treat age-related cognitive disorders such as Alzheimer’s disease. “The therapeutic possibilities are very exciting,” says geneticist and anti-ageing scientist David Sinclair at Harvard University in Boston, Massachusetts, who was not involved in the research. The study was published on 16 August in Nature. Young blood, old brains About a decade ago, scientists discovered that blood from young mice could restore youthful properties, including learning abilities, in older mice2,3. The idea captivated Saul Villeda, a neuroscientist at the University of California, San Francisco, and a co-author of the new study. He and his colleagues have since been trying to identify the components of blood that cause this rejuvenation. Several lines of evidence suggested that PF4 might be one of these components, including the fact that young mice have higher levels of this molecule in their blood than do older mice. Villeda and his colleagues tried injecting PF4 into aged mice without including other blood components. The researchers found that the ratios of various types of immune cell shifted to become more similar to what is typically seen in younger mice. Some immune cells also reverted to a more youthful pattern of gene expression. Although PF4 was not able to cross the blood–brain barrier, its effects on the immune system also led to changes in the brain, probably through indirect mechanisms. Old mice that received doses of PF4 showed decreases in damaging inflammation in the hippocampus — a part of the brain that’s particularly vulnerable to the effects of ageing. They also showed increases in the levels of molecules that promote synaptic plasticity (the capacity to alter the strength of connections between nerve cells). © 2023 Springer Nature Limited

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28874 - Posted: 08.19.2023

By Claudia Lopez Lloreda There are plenty of reasons to get off your duff and exercise—but is improving your brain one of them? The U.S. Centers for Disease Control and Prevention touts exercise as a way to “boost brain health,” while the World Health Organization suggests that about 2 hours of moderate activity or 75 minutes of vigorous activity per week can help improve thinking and memory skills. But new research reveals a more complex picture. One recent review of the literature suggests the studies tying exercise to brain health may have important limitations, including small sample sizes. Other studies suggest there is no one-size-fits-all approach to exercising as a way to boost cognition or prevent age-related cognitive decline. Still others indicate exercise may actually be harmful in people with certain medical conditions. Here’s the latest on what we know. What is the science linking exercise and improved brain function? Many studies correlate participants’ self-reported exercise with scores on cognitive tests, or track the effects of randomizing participants into groups that either exercise or remain sedentary. They typically find that the more physical activity a person does, the better their cognition. This result holds for healthy people, stroke survivors, and those with other neurological conditions such as Alzheimer’s disease. A study published earlier this year relied on genetic data to explore the effects of exercise. A team led by sports scientist Boris Cheval at the University of Geneva grouped about 350,000 people in the United Kingdom according to genetic variants associated with more or less physical activity. Those with an apparent genetic predisposition to be more active also tended to perform better on a set of cognitive tests, the researchers concluded in Scientific Reports. Other studies have focused on age-related cognitive decline. Research published in February in the Journal of Neurology, Neurosurgery & Psychiatry tracked more than 1400 people for 30 years, showing that more physical activity was associated with better cognitive performance at age 69.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 5: The Sensorimotor System
Link ID: 28838 - Posted: 07.01.2023

By Claudia Lopez Lloreda A baby born through the vaginal canal picks up critical microbes along the way that help it stay healthy later in life. But babies delivered via cesarean section miss out on those useful, gut-colonizing bacteria, which may put them at greater risk of developing certain health conditions and developmental disorders. Now, researchers at Southern Medical University say that by exposing C-section babies to the microbes they’ve missed—an intervention called vaginal seeding—doctors can partially restore these missing gut bacteria. The procedure may even aid in their early development. Newborns delivered via C-section who received their mother’s vaginal microbes had more advanced motor and communication skills than other C-section babies months later, the team reports today in Cell Host & Microbe. But some clinicians argue these benefits for infants have not yet been proved, nor has the procedure’s safety. “This study establishes a link showing that there is a possible benefit in a select group of infants and mothers,” says Mehreen Zaigham, an obstetrician at Lund University who was not involved in the study. “But it has to be proven with larger longitudinal studies.” The microbiomes of C-section babies look a lot different from those of babies born vaginally. In particular, they have lower numbers of Lactobacillus, Escherichia, and Bacteroides bacteria in their guts. These microbes are believed to be critical for growth and are thought to help protect against asthma, allergies, obesity, and autoimmune disorders—all conditions that are more common among C-section babies. A few highly controversial studies have suggested some babies delivered by C-section may be at a greater risk of developing neurodevelopmental conditions such as autism spectrum disorder, which some researchers attribute to their disrupted microbiome. Other researchers have roundly criticized that suggestion, however. To restore the microbiomes of infants delivered by C-section, researchers have come up with a simple solution: Swab them with bacteria from their mother’s vagina shortly after they are born. This method, called vaginal seeding, was first clinically tested 7 years ago by Jose Clemente, a geneticist at the Icahn School of Medicine at Mount Sinai, and Maria Gloria Dominguez Bello, a microbial ecologist at Rutgers University, who found the procedure indeed restored microbes that C-section babies lacked. However, these results were based on a small group of just 11 babies.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28824 - Posted: 06.17.2023

By Kate Laskowski In the age-old debate about nature versus nurture — whether our characteristics are forged by our genes or our upbringing — I have an answer for you. It is both. And it is neither. I’m a behavioral ecologist who seeks to answer this question by studying a particular kind of fish. The Amazon molly (Poecilia formosa) is an experimental goldmine for these types of questions. She naturally clones herself by giving birth to offspring with identical genomes to her own and to each other’s. A second quirk of this little fish is that her offspring are born live and are completely independent from birth. This means I can control their experiences from the earliest possible age. Essentially, this fish gives me and my colleagues the opportunity to perform “twin studies” to understand how and why individuality develops. And what we’ve found may surprise you. As humans, we know the critical importance of our personalities. These persistent differences among us shape how we navigate our worlds and respond to major life events; whether we are bold or shy; whether we ask someone on a second date or not. Given the obvious importance of personality, it’s perhaps a bit surprising that scientists generally overlooked these kinds of differences in other species for a long time. Up until about 30 years ago, these differences (what I prefer to call “individuality,” as it avoids the human connotation of “personality”) were typically viewed as cute anecdotes with little evolutionary importance. Instead, researchers focused on the typical behavior of a given population. With guppies, for example — a classic workhorse of behavioral ecology research — researchers found that fish will, on average, swim more tightly together if they live among lots of predatory fish, whereas fish from areas with fewer predators spend less time schooling and more time fighting one another, as they don’t have to worry so much about being eaten. © 2023 Annual Reviews

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28815 - Posted: 06.07.2023

By Cordula Hölig, Brigitte Röder, Ramesh Kekunnaya Growing up in poverty or experiencing any adversity, such as abuse or neglect, during early childhood can put a person at risk for poor health, including mental disorders, later in life. Although the underlying mechanisms are poorly understood, some studies have shown that adverse early childhood experience leaves persisting (and possibly irreversible) traces in brain structure. As neuroscientists who are investigating sensitive periods of human brain development, we agree: safe and nurturing environments are a prerequisite for healthy brain development and lifelong well-being. Thus, preventing early childhood adversity undoubtedly leads to healthier lives. Poverty and adversity can cause changes in brain development. Harms can come from exposure to violence or toxins or a lack of nutrition, caregiving, perceptual and cognitive stimulation or language interaction. Neuroscientists have demonstrated that these factors crucially influence human brain development. Advertisement We don’t know whether these changes are reversed by more favorable circumstances later in life, however. Investigating this question in humans is extremely difficult. For one, multiple biological and psychological factors through which poverty and adversity affect brain development are hard to disentangle. That’s because they often occur together: a neglected child often experiences a lack of caregiving simultaneously with malnutrition and exposure to physical violence. Secondly, a clear beginning and end of an adverse experience is hard to define. Finally, it is almost impossible to fully reverse harsh environments in natural settings because most of the time it is impossible to move children out of their families or communities.. © 2023 Scientific American

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 13: Memory and Learning
Link ID: 28783 - Posted: 05.13.2023

By Sofia Quaglia With a large blade resembling a bread knife—but without the jagged edges—Stephanie Forkel slices through the human brain lying in front of her on the dissection table. A first-year university student, Forkel is clad in an apron and protective gear. It’s her first day working in the morgue at a university hospital in Munich, Germany, where the brains of people who’ve donated their bodies to science are examined for research. Her contact lenses feel dry because of the dense formaldehyde hanging in the air. But that’s not the only reason she squints a little harder. When she looks down at the annotated brain diagram in the textbook she’s supposed to use for reference, the real human brain in front of her looks nothing like the illustrated one. That was Forkel’s first eureka moment: The standard reference shape of the brain and real brains were actually vastly divergent. As she continued her studies, she confirmed that, indeed, “every individual brain looked very different,” she recounts decades later. A growing body of research now confirms there are plenty of physical dissimilarities between individual brains, particularly when it comes to white matter—the material nestled beneath the much-prized gray matter. And it’s not just anatomical. White matter hosts connections between the brain’s sections, like a city’s streets and avenues. So behavioral patterns can arise from even small physical differences in white matter, according to a late 2022 Science paper penned by Forkel and a colleague.1 Forkel is now one of a host of researchers probing subtle differences in white matter to better understand the extent of its role in making us who we are—including how much white matter dictates variations between people’s everyday behavior, and whether it’s implicated in how some patients recover better than others from life-threatening brain injuries. © 2023 NautilusNext Inc.,

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28762 - Posted: 05.03.2023

By Emily Underwood The ability to set a goal and pursue it without getting derailed by temptations or distractions is essential to nearly everything we do in life, from finishing homework to driving safely in traffic. It also places complex demands on the brain, requiring skills like working memory — the ability to keep small amounts of information in mind to perform a task — as well as impulse control and being able to rapidly adapt when rules or circumstances change. Taken together, these elements add up to something researchers call executive function. We all struggle with executive function sometimes, for example when we’re stressed or don’t get enough sleep. But in teenagers, these powers are still a work in progress, contributing to some of the contradictory behaviors and lapses in judgment — “My honor roll student did what on TikTok?” — that baffle many parents. This erratic control can be dangerous, especially when teens make impulsive choices. But that doesn’t mean the teen brain is broken, says Beatriz Luna, a developmental cognitive neuroscientist at the University of Pittsburgh and coauthor of a review on the maturation of one aspect of executive function, called cognitive control, in the 2015 Annual Review of Neuroscience. Adolescents have all the basic neural circuitry needed for executive function and cognitive control, Luna says. In fact, they have more than they need — what’s lacking is experience, which over time will strengthen some neural pathways and weaken or eliminate others. This winnowing serves an important purpose: It tailors the brain to help teens handle the demands of their unique, ever-changing environments and to navigate situations their parents may never have encountered. Luna’s research suggests that teens’ inconsistent cognitive control is key to becoming independent, because it encourages them to seek out and learn from experiences that go beyond what they’ve been actively taught. © 2023 Annual Reviews

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 13: Memory and Learning
Link ID: 28751 - Posted: 04.26.2023

Jon Hamilton Boys born to mothers who got COVID-19 while pregnant appear nearly twice as likely as other boys to be diagnosed with subtle delays in brain development. That's the conclusion of a study of more than 18,000 children born at eight hospitals in Eastern Massachusetts. Nearly 900 of the children were born to mothers who had COVID during their pregnancy. In the study, boys, but not girls, were more likely to be diagnosed with a range of developmental disorders in the first 18 months of life. These included delays in speech and language, psychological development and motor function, as well as intellectual disabilities. In older children, these differences are often associated with autism spectrum disorder, says Dr. Roy Perlis, a co-author of the study and a psychiatrist at Massachusetts General Hospital. But for the young children in this study, "it's way too soon to reliably diagnose autism," Perlis says. "All we can hope to detect at this point are more subtle sorts of things like delays in language and speech, and delays in motor milestones." The study, which relied on an analysis of electronic health records, was published in March in the journal JAMA Network Open. The finding is just the latest to suggest that a range of maternal infections can alter fetal brain development, especially in male offspring. For example, studies have found links between infections like influenza and cytomegalovirus, and disorders like autism and schizophrenia. "Male fetuses are known to be more vulnerable to maternal infectious exposures during pregnancy," says Dr. Andrea Edlow, the study's lead author and a maternal-fetal medicine specialist at Massachusetts General Hospital. © 2023 npr

Related chapters from BN: 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 and Learning; Chapter 8: Hormones and Sex
Link ID: 28743 - Posted: 04.18.2023

By Emily Underwood Many of our defining traits — including the languages we speak and how we connect with others — can be traced back at least in part to our earliest experiences. Although our brains remain malleable throughout our lives, most neuroscientists agree that the changes that occur in the womb and in the first few years of life are among the most consequential, with an outsize effect on our risk of developmental and psychiatric conditions. “Early on in life, the brain is still forming itself,” says Claudia Lugo-Candelas, a clinical psychologist at Columbia University and coauthor of an overview of the prenatal origins of psychiatric illness in the Annual Review of Clinical Psychology. Starting from a tiny cluster of stem cells, the brain develops into a complex organ of roughly 100 billion neurons and trillions of connections in just nine months. Compared to the more subtle brain changes that occur later in life, Lugo-Candelas says, what happens in utero and shortly after birth “is like building the house, versus finishing the deck.” But just how this process unfolds, and why it sometimes goes awry, has been a hard mystery to crack, largely because so many of the key events are difficult to observe. The first magnetic resonance imaging (MRI) scans of baby and fetal brains were taken back in the early 1980s, and doctors seized on the tool to diagnose major malformations in brain structure. But neuroimaging tools that can capture the baby brain’s inner workings in detail and spy on fetal brain activity in pregnant moms are much newer developments. Today, this research, coupled with long-term studies that follow thousands of individual children for years, is giving scientists new insights into how the brain develops. These advances have propelled researchers to a different stage than they were in even five years ago, says Damien Fair, a neuroscientist at the University of Minnesota who studies developmental conditions like autism and attention deficit hyperactivity disorder (ADHD). © 2023 Annual Reviews

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28718 - Posted: 03.25.2023

Jon Hamilton Mora Leeb places some pieces into a puzzle during a local puzzle tournament. The 15-year-old has grown up without the left side of her brain after it was removed when she was very young. Seth Leeb In most people, speech and language live in the brain's left hemisphere. Mora Leeb is not most people. When she was 9 months old, surgeons removed the left side of her brain. Yet at 15, Mora plays soccer, tells jokes, gets her nails done, and, in many ways, lives the life of a typical teenager. "I can be described as a glass-half-full girl," she says, pronouncing each word carefully and without inflection. Her slow, cadence-free speech is one sign of a brain that has had to reorganize its language circuits. Yet to a remarkable degree, Mora's right hemisphere has taken on jobs usually done on the left side. It's an extreme version of brain plasticity, the process that allows a brain to modify its connections to adapt to new circumstances. Brain plasticity is thought to underlie learning, memory, and early childhood development. It's also how the brain revises its circuitry to help recover from a brain injury — or, in Mora's case, the loss of an entire hemisphere. Scientists hope that by understanding the brains of people like Mora, they can find ways to help others recover from a stroke or traumatic brain injury. They also hope to gain a better understanding of why very young brains are so plastic. Sometime in the third trimester of Ann Leeb's pregnancy, the child she was carrying had a massive stroke on the left side of her brain. No one knew it at the time. © 2023 npr

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 28714 - Posted: 03.23.2023

Heidi Ledford A mouse’s brain (red and blue) hosts a human astrocyte (green) that arose from transplanted neural stem cells.Credit: Liu et al./Cell (2023) In a technical “tour de force”, researchers have analysed multiple traits of individual cells to pinpoint those that give rise to crucial components of the human brain. The analysis, published on 16 March in Cell1, uses a combination of protein and RNA analysis to painstakingly purify and classify individual stem cells and their close relatives isolated from human brains. Researchers then injected different types of cell into mice and monitored the cells as they divided and their progeny took on specialized roles in the brain. The hope is that this study, and others like it, will illuminate how such developmental programmes go awry in neurological diseases — and how they can be harnessed to create new therapies. “The census of stem and progenitor cells in the developing human brain is really just beginning,” says Arnold Kriegstein, a developmental neuroscientist at the University of California, San Francisco, who was not involved in the research. “This work offers a nice window into some of that complexity.” The brain is an intricate symphony of different cells, each of which performs essential functions. Star-shaped cells known as astrocytes, for example, are important for supporting metabolism in neurons, and loss of astrocyte function is linked to neurodegenerative conditions such as Alzheimer’s disease. Oligodendrocytes are cells that create a protective, insulating sheath around the connections between neurons. When they are damaged — as in diseases such as multiple sclerosis — communication between neurons slows or stops altogether. © 2023 Springer Nature Limited

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28707 - Posted: 03.18.2023

By Jacob Beck, Sam Clarke Imagine hosting a party. You arrange snacks, curate a playlist and place a variety of beers in the refrigerator. Your first guest shows up, adding a six-pack before taking one bottle for himself. You watch your next guest arrive and contribute a few more beers, minus one for herself. Ready for a drink, you open the fridge and are surprised to find only eight beers remaining. You haven't been consciously counting the beers, but you know there should be more, so you start poking around. Sure enough, in the crisper drawer, behind a rotting head of romaine, are several bottles. How did you know to look for the missing beer? It's not like you were standing guard at the refrigerator, tallying how many bottles went in and out. Rather you were using what cognitive scientists call your number sense, a part of the mind that unconsciously solves simple math problems. While you were immersed in conversation with guests, your number sense was keeping tabs on how many beers were in the fridge. For a long time scientists, mathematicians and philosophers have debated whether this number sense comes preinstalled or is learned over time. Plato was among the first in the Western tradition to propose that humans have innate mathematical abilities. In Plato's dialogue Meno, Socrates coaxes the Pythagorean theorem out of an uneducated boy by asking him a series of simple questions. Socrates's takeaway is that the boy had innate knowledge of the Pythagorean theorem all along; the questioning just helped him express it. In the 17th century John Locke rejected this idea, insisting that the human mind begins as a tabula rasa, or blank slate, with almost all knowledge acquired through experience. This view, known as empiricism, in contrast to Plato's nativism, was later further developed by John Stuart Mill, who argued that we learn two plus three is five by seeing many examples where it holds true: two apples and three apples make five apples, two beers and three beers make five beers, and so on.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 13: Memory and Learning
Link ID: 28693 - Posted: 03.08.2023

by Laura Dattaro Neurons deep in the prefrontal cortex of fragile X model mice have trouble generating the electrical spikes needed to transmit information, according to a new study. The difficulty originates from faulty sodium channels. Fragile X syndrome, one of the leading genetic causes of autism, results from mutations in the gene FMR1. People with the condition often have difficulty with executive-function skills, such as working memory and planning. The new study may explain why, says Randi Hagerman, medical director of the MIND Institute at the University of California, Davis: The disruption to signals propagating through the prefrontal cortex may impede the region’s role in coordinating communication among other parts of the brain. Some drugs that regulate sodium channels, such as the diabetes drug metformin, are already approved for use in people. “This is a great animal model to look at the effects of medication,” says Hagerman, who was not involved in the new work. Mutations in the autism-linked gene SCN2A, which encodes a protein for the sodium channel Nav1.2, also suppress dendritic spikes, researchers previously showed in mice. The cellular mechanism for channel disruption is different between the models, but it’s possible that multiple genetic causes of autism “coalesce around sodium channel disfunction,” says Darrin Brager, research associate professor of neuroscience at the University of Texas at Austin and lead investigator on the FMR1 study. “The same channel is altered, and that’s changing the way the cells are able to integrate information and transmit it.” © 2023 Simons Foundation

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 28677 - Posted: 02.22.2023