Chapter 13. Memory and Learning

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By Lisa L. Lewis To any observers, the electrodes were the most visible sign that the Stanford Summer Sleep Camp was a bit out of the ordinary. Joe Oliveira, one of the original campers, recalls that right after check-in, four electrodes were glued to his hair, two taped next to his eyes, and several more by his chin. The electrodes remained in place the whole time. Long cords came out of them that were, “very small, like an iPhone charger,” he told me. During the day, the cords were often tied back and taped together into a compact bundle at the back of his head. The “trodes” (as the campers were called because of their electrode ponytails) attracted their fair share of weird looks on their outings around the university campus. And there was something else peculiar: Like clockwork, every two hours, they all returned to the dorm for “nap tests,” according to Mary Carskadon, who was pursuing her doctorate in neuro- and biobehavioral sciences at Stanford University. In their darkened dorm rooms, all the campers — a mix of kids and teens — would lie quietly for 20 minutes and attempt to fall asleep. Meanwhile, technicians in a nearby control room monitored their brainwaves, eye movements, and chin-muscle activity being transmitted from their electrodes via the cords, which had been plugged into a box near the headboard that had cables linked to a polysomnograph machine in the other room. There, a continuous paper trail issued forth mapping the campers’ data. When the time was up, the campers were roused and unplugged. The counselors recorded their vital signs, then plugged their wires into a second box closer to the dorm room desk and ran the campers through a short series of tests to measure their recall, attention span, and other aspects of alertness and cognitive functioning. Tom Harvey, who worked as a counselor/technician at the camp for several years, recalled a mix of “math tests and memory tests and ‘can you suffer through boredom’ tests.”

Keyword: Sleep; Development of the Brain
Link ID: 28381 - Posted: 06.25.2022

By Rachel Yehuda Rachel Yehuda is a professor of psychiatry and neuroscience and director of the Center for Psychedelic Psychotherapy and Trauma Research at the Icahn School of Medicine at Mount Sinai. She is also director of mental health at the James J. Peters Veterans Affairs Medical Center. Credit: Nick Higgins After the twin towers of the World Trade Center collapsed on September 11, 2001, in a haze of horror and smoke, clinicians at the Icahn School of Medicine at Mount Sinai in Manhattan offered to check anyone who'd been in the area for exposure to toxins. Among those who came in for evaluation were 187 pregnant women. Many were in shock, and a colleague asked if I could help diagnose and monitor them. They were at risk of developing post-traumatic stress disorder, or PTSD—experiencing flashbacks, nightmares, emotional numbness or other psychiatric symptoms for years afterward. And were the fetuses at risk? My trauma research team quickly trained health professionals to evaluate and, if needed, treat the women. We monitored them through their pregnancies and beyond. When the babies were born, they were smaller than usual—the first sign that the trauma of the World Trade Center attack had reached the womb. Nine months later we examined 38 women and their infants when they came in for a wellness visit. Psychological evaluations revealed that many of the mothers had developed PTSD. And those with PTSD had unusually low levels of the stress-related hormone cortisol, a feature that researchers were coming to associate with the disorder. Surprisingly and disturbingly, the saliva of the nine-month-old babies of the women with PTSD also showed low cortisol. The effect was most prominent in babies whose mothers had been in their third trimester on that fateful day. Just a year earlier a team I led had reported low cortisol levels in adult children of Holocaust survivors, but we'd assumed that it had something to do with being raised by parents who were suffering from the long-term emotional consequences of severe trauma. Now it looked like trauma leaves a trace in offspring even before they are born. © 2022 Scientific American

Keyword: Epigenetics; Stress
Link ID: 28378 - Posted: 06.25.2022

By Emily Bazelon Scott Leibowitz is a pioneer in the field of transgender health care. He has directed or worked at three gender clinics on the East Coast and the Midwest, where he provides gender-affirming care, the approach the medical community has largely adopted for embracing children and teenagers who come out as transgender. He also helps shape policy on L.G.B.T. issues for the American Academy of Child and Adolescent Psychiatry. As a child and adolescent psychiatrist who is gay, he found it felt natural to work under the L.G.B.T. “umbrella,” as he put it, aware of the overlap as well as the differences between gay and trans identity. It was for all these reasons that Leibowitz was selected, in 2017, to be a leader of a working group of seven clinicians and researchers drafting a chapter on adolescents for a new version of guidelines called the Standards of Care to be issued by the World Professional Association for Transgender Health (WPATH). The guidelines are meant to set a gold standard for the field of transgender health care, and this would be the first update since 2012. What Leibowitz and his co-authors didn’t foresee, when they began, was that their work would be engulfed by two intersecting forces: a significant rise in the number of teenagers openly identifying as transgender and seeking gender care, and a right-wing backlash in the United States against allowing them to medically transition, including state-by-state efforts to ban it. During the last decade, the field of transgender care for youth has greatly shifted. A decade ago, there were a handful of pediatric gender clinics in the United States and a dozen or so more in other countries. The few doctors and therapists who worked in them knew one another, and the big debate was whether kids in preschool or elementary school should be allowed to live fully as the gender they identified as when they strongly and consistently asserted their wishes. Now there are more than 60 comprehensive gender clinics in the United States, along with countless therapists and doctors in private practice who are also seeing young patients with gender-identity issues. The number of young people who identify as transgender nationally is about 300,000, according to a new report by the Williams Institute, a research center at U.C.L.A.’s law school, which is much higher than previous estimates. In countries that collect national data, like the Netherlands and Britain, the number of 13-to-17-year-olds seeking treatment for gender-identity issues has also increased, from dozens to hundreds or thousands a year. © 2022 The New York Times Company

Keyword: Sexual Behavior; Development of the Brain
Link ID: 28375 - Posted: 06.15.2022

Philip Ball How do you spot an optimistic pig? This isn’t the setup for a punchline; the question is genuine, and in the answer lies much that is revealing about our attitudes to other minds – to minds, that is, that are not human. If the notion of an optimistic (or for that matter a pessimistic) pig sounds vaguely comical, it is because we scarcely know how to think about other minds except in relation to our own. Here is how you spot an optimistic pig: you train the pig to associate a particular sound – a note played on a glockenspiel, say – with a treat, such as an apple. When the note sounds, an apple falls through a hatch so the pig can eat it. But another sound – a dog-clicker, say – signals nothing so nice. If the pig approaches the hatch on hearing the clicker, all it gets is a plastic bag rustled in its face. What happens now if the pig hears neither of these sounds, but instead a squeak from a dog toy? An optimistic pig might think there’s a chance that this, too, signals delivery of an apple. A pessimistic pig figures it will just get the plastic bag treatment. But what makes a pig optimistic? In 2010, researchers at Newcastle University showed that pigs reared in a pleasant, stimulating environment, with room to roam, plenty of straw, and “pig toys” to explore, show the optimistic response to the squeak significantly more often than pigs raised in a small, bleak, boring enclosure. In other words, if you want an optimistic pig, you must treat it not as pork but as a being with a mind, deserving the resources for a cognitively rich life. We don’t, and probably never can, know what it feels like to be an optimistic pig. Objectively, there’s no reason to suppose that it feels like anything: that there is “something it is like” to be a pig, whether apparently happy or gloomy. Until rather recently, philosophers and scientists have been reluctant to grant a mind to any nonhuman entity. Feelings and emotions, hope and pain and a sense of self were deemed attributes that separated us from the rest of the living world. To René Descartes in the 17th century, and to behavioural psychologist BF Skinner in the 1950s, other animals were stimulus-response mechanisms that could be trained but lacked an inner life. To grant animals “minds” in any meaningful sense was to indulge a crude anthropomorphism that had no place in science. © 2022 Guardian News & Media Limited

Keyword: Evolution; Intelligence
Link ID: 28367 - Posted: 06.11.2022

William E. Pelham, Jr. For decades, many physicians, parents and teachers have believed that stimulant medications help children with ADHD learn because they are able to focus and behave better when medicated. After all, an estimated 6.1 million children in the U.S. are diagnosed with attention-deficit/hyperactivity disorder, and more than 90% are prescribed stimulant medication as the main form of treatment in school settings. However, in a peer-reviewed study that several colleagues and I published in the Journal of Consulting and Clinical Psychology, we found medication has no detectable effect on how much children with ADHD learn in the classroom. At least that’s the case when learning – defined as the acquisition of performable skills or knowledge through instruction – is measured in terms of tests meant to assess improvements in a student’s current academic knowledge or skills over time. Compared to their peers, children with ADHD exhibit more off-task, disruptive classroom behavior, earn lower grades and score lower on tests. They are more likely to receive special education services and be retained for a grade, and less likely to finish high school and enter college – two educational milestones that are associated with significant increases in earnings. In this study, funded by the National Institute of Mental Health, we evaluated 173 children between the ages of 7 and 12. They were all participants in our Summer Treatment Program, a comprehensive eight-week summer camp for children with ADHD and related behavioral, emotional and learning challenges. Children got grade-level instruction in vocabulary, science and social studies. The classes were led by certified teachers. The children received medication the first half of summer and a placebo during the other half. They were tested at the start of each academic instruction block, which lasted approximately three weeks. They then took the same test at the end to determine how much they learned. © 2010–2022, The Conversation US, Inc.

Keyword: ADHD; Learning & Memory
Link ID: 28366 - Posted: 06.11.2022

by Charles Q. Choi The primordial cells that give rise to most other brain cells do not proliferate in a typical way in autistic people — and that could explain how common traits emerge from a range of genetic origins, according to a new study. The idea that autism disrupts the proliferation of neural precursor cells isn’t new, but until now, few studies had investigated how that difference arises. In the new study, scientists fashioned neural precursor cells out of cord blood cells from five autistic boys ages 4 to 14 and, to serve as controls, either their non-autistic brothers or unrelated non-autistic people. Three of the autistic children have idiopathic cases, in which there is no known genetic cause for their autism; the other two have deletions in 16p11.2, a chromosomal region linked to autism and other neuropsychiatric conditions. Three of the autistic children have macrocephaly, or a large head. Neural precursors from the autistic boys all proliferated in atypical ways, the scientists found. Among children with macrocephaly, this growth was accelerated, leading to 28 to 55 percent more cells than in the non-autistic controls after six days. In contrast, cells from the other two boys, both with idiopathic autism, grew more slowly and more of those cells died, yielding 40 to 65 percent fewer cells than in controls after six days. “Despite the fact that these individuals are genetically distinct, especially the idiopathic individuals, it is amazing they have a common developmental process dysfunction — control of proliferation,” says study co-lead investigator Emanuel DiCicco-Bloom, professor of neuroscience, cell biology and pediatrics at Rutgers University in Piscataway, New Jersey. © 2022 Simons Foundation

Keyword: Autism; Genes & Behavior
Link ID: 28363 - Posted: 06.11.2022

Helena Horton Environment reporter Otters are able to learn from each other – but still prefer to solve some puzzles on their own, scientists have found. The semi-aquatic mammals are known to be very social and intelligent creatures, but a study by the University of Exeter has given new insight into their intellect. Researchers gave otters “puzzle boxes”, some of which contained familiar food, while others held unfamiliar natural prey – shore crab and blue mussels, which are protected by hard outer shells. For the familiar food – meatballs, a favourite with the Asian short-clawed otters in the study – the scientists had five different types of boxes, and the method to extract the food changed in each version, for example pulling a tab or opening a flap. The unfamiliar food presented additional problems because the otters did not know if the crab and mussels were safe to eat and had no experience of getting them out of their shells. In order to decide whether food was safe and desirable to eat, the otters, which live at Newquay zoo and the Tamar Otter and Wildlife Centre, watched intently as their companions inspected what was in the boxes and copied if the other otters sampled the treats. However, they spent more time trying to figure out how to remove the meat from the shells on their own and relied less on the actions of their companions. Of the 20 otters in the study, 11 managed to extract the meat from all three types of natural prey. © 2022 Guardian News & Media Limited

Keyword: Learning & Memory; Evolution
Link ID: 28360 - Posted: 06.09.2022

Daniel Lavelle With ADHD, thoughts and impulses intrude on my focus like burglars trying to break into a house. Sometimes these crooks carefully pick the backdoor lock before they silently enter and pilfer all the silverware. At other times, stealth goes out of the window; they’re kicking through the front door and taking whatever they like. Either way, I was supposed to be reading a book just now, but all I can think about is how great it would be if I waded into a river to save a litter of kittens from tumbling down a waterfall just in the nick of time. I’ve got the kittens in my hand, and the crowd has gone wild; the spectres of Gandhi, Churchill and Obi-Wan Kenobi hover over the riverbank, nodding their approval while fireworks crackle overhead … I snap back and realise I’ve read three pages, only I don’t remember a single line. I reread the same pages, but the same thing happens, only now I’m so hung up on concentrating that another fantasy has hijacked my attention. This time I’m imagining that I’m super-focused, so focused that Manchester United have called and told me they want me to be their special penalty taker. These Walter Mitty, borderline narcissistic episodes persist for a while until I give up and go and be distracted somewhere else. Advertisement Unfortunately, I don’t take Ritalin, a stimulant prescribed to daydreamers like me, so when it comes to focusing I need all the help I can get. Enter Swiss developer and typographic designer Renato Casutt, who has spent six years trying to develop a typographical trick that helps people read more quickly and efficiently. “Bionic reading” is a font people can use on their devices via apps for iPhone and other Apple products. It works by highlighting a limited number of letters in a word in bold, and allowing your brain – or, more specifically, your memory – to fill in the rest. © 2022 Guardian News & Media Limited

Keyword: ADHD; Dyslexia
Link ID: 28358 - Posted: 06.07.2022

by Laura Dattaro Two new studies untangle how various classes of genetic variants underpin the vast differences in traits seen among people diagnosed with autism. The studies were published yesterday in Nature Genetics. “The fundamental question behind this is heterogeneity in autism,” says Varun Warrier, a postdoctoral researcher in Simon Baron-Cohen’s lab at the University of Cambridge in the United Kingdom and an investigator on one of the studies. The presence and intensity of core autism traits and co-occurring conditions vary widely among autistic people. The new studies, from largely independent teams, sought to unravel how different categories of genetic variants — rare, common, inherited and spontaneous — contribute to this heterogeneity. Though the two sets of findings conflict in some ways — potentially because of methodological differences — the papers add to the evidence that common and rare variants contribute to autism’s genetic architecture differently, says Yufeng Shen, associate professor of systems biology at Columbia University, who was not involved in either study. “When we say different, it’s not black and white,” Shen says. “They overlap, but it seems like, qualitatively, they have different contributions.” Warrier and his colleagues analyzed genetic and behavioral data from 12,893 autistic people. The data came from the Autism Genetic Resource Exchange, the Longitudinal European Autism Project, the Simons Simplex Collection and SPARK. (The Simons Simplex Collection and SPARK are funded by the Simons Foundation, Spectrum’s parent organization.) © 2022 Simons Foundation

Keyword: Autism; Genes & Behavior
Link ID: 28356 - Posted: 06.07.2022

Viviane Callier Our human brains can seem like a crowning achievement of evolution, but the roots of that achievement run deep: The modern brain arose from hundreds of millions of years of incremental advances in complexity. Evolutionary biologists have traced that progress back through the branch of the animal family tree that includes all creatures with central nervous systems, the bilaterians, but it is clear that fundamental elements of the nervous system existed much earlier. How much earlier has now been made dramatically clear by a recent discovery by a team of researchers at the University of Exeter in the United Kingdom. They found that the chemical precursors of two important neurotransmitters, or signaling molecules used in nervous systems, appear in all the major animal groups that preceded creatures with central nervous systems. The big surprise, however, is that these molecules are also present in single-celled relatives of animals, called choanoflagellates. This finding shows that animal neuropeptides originated before the evolution of even the very first animals. The discovery “solves a long-standing question about when and how animal neuropeptides evolved,” said Pawel Burkhardt, who studies the evolutionary origin of neurons at the Sars International Center for Marine Molecular Biology in Norway. It also indicates that at least some of the signaling molecules fundamental to the operation of our brains first evolved for an entirely different purpose in organisms that consisted of only a single cell. Animal nervous systems are made of neurons that connect to each other, zipping information across synapses with a variety of small peptide neurotransmitters. These peptides are the language with which neurons speak to each other. All Rights Reserved © 2022

Keyword: Development of the Brain
Link ID: 28354 - Posted: 06.04.2022

Jon Hamilton An HIV drug — known as maraviroc — may have another, unexpected, use. The medication appears to restore a type of memory that allows us to link an event, like a wedding, with the people we saw there, a team reports in this week's issue of the journal Nature. Maraviroc's ability to improve this sort of memory was demonstrated in mice, but the drug acts on a brain system that's also found in humans and plays a role in a range of problems with the brain and nervous system. "You might have an effect in Alzheimer's disease, in stroke, in Parkinson's and also in spinal cord injuries," says Dr. S. Thomas Carmichael, chair of neurology at the University of California, Los Angeles, who was not involved in the study. The ability to link memories that occur around the same time is known as relational memory. It typically declines with age, and may be severely impaired in people with Alzheimer's disease. Problems with relational memory can appear in people who have no difficulty forming new memories, says Alcino Silva, an author of the new study and director of the Integrative Center for Learning and Memory at UCLA. "You learn about something, but you can't remember where you heard it. You can't remember who told you about it," Silva says. "These incidents happen more and more often as we go from middle age into older age." © 2022 npr

Keyword: Learning & Memory
Link ID: 28353 - Posted: 06.04.2022

By Azeen Ghorayshi Marcia Herman-Giddens first realized something was changing in young girls in the late 1980s, while she was serving as the director for the child abuse team at Duke University Medical Center in Durham, N.C. During evaluations of girls who had been abused, Dr. Herman-Giddens noticed that many of them had started developing breasts at ages as young as 6 or 7. “That did not seem right,” said Dr. Herman-Giddens, who is now an adjunct professor at the University of North Carolina Gillings School of Global Public Health. She wondered whether girls with early breast development were more likely to be sexually abused, but she could not find any data keeping track of puberty onset in girls in the United States. So she decided to collect it herself. A decade later, she published a study of more than 17,000 girls who underwent physical examinations at pediatricians’ offices across the country. The numbers revealed that, on average, girls in the mid-1990s had started to develop breasts — typically the first sign of puberty — around age 10, more than a year earlier than previously recorded. The decline was even more striking in Black girls, who had begun developing breasts, on average, at age 9. The medical community was shocked by the findings, and many were doubtful about a dramatic new trend spotted by an unknown physician assistant, Dr. Herman-Giddens recalled. “They were blindsided,” she said. But the study turned out to be a watershed in the medical understanding of puberty. Studies in the decades since have confirmed, in dozens of countries, that the age of puberty in girls has dropped by about three months per decade since the 1970s. A similar pattern, though less extreme, has been observed in boys. Although it is difficult to tease apart cause and effect, earlier puberty may have harmful impacts, especially for girls. Girls who go through puberty early are at a higher risk of depression, anxiety, substance abuse and other psychological problems, compared with peers who hit puberty later. Girls who get their periods earlier may also be at a higher risk of developing breast or uterine cancer in adulthood. © 2022 The New York Times Company

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 28332 - Posted: 05.21.2022

By Benjamin Mueller Five years ago, Tal Iram, a young neuroscientist at Stanford University, approached her supervisor with a daring proposal: She wanted to extract fluid from the brain cavities of young mice and to infuse it into the brains of older mice, testing whether the transfers could rejuvenate the aging rodents. Her supervisor, Tony Wyss-Coray, famously had shown that giving old animals blood from younger ones could counteract and even reverse some of the effects of aging. But the idea of testing that principle with cerebrospinal fluid, the hard-to-reach liquid that bathes the brain and spinal cord, struck him as such a daunting technical feat that trying it bordered on foolhardy. “When we discussed this initially, I said, ‘This is so difficult that I’m not sure this is going to work,’” Dr. Wyss-Coray said. Dr. Iram persevered, working for a year just to figure out how to collect the colorless liquid from mice. On Wednesday, she reported the tantalizing results in the journal Nature: A week of infusions of young cerebrospinal fluid improved the memories of older mice. The finding was the latest indication that making brains resistant to the unrelenting changes of older age might depend less on interfering with specific disease processes and more on trying to restore the brain’s environment to something closer to its youthful state. “It highlights this notion that cerebrospinal fluid could be used as a medium to manipulate the brain,” Dr. Iram said. Turning that insight into a treatment for humans, though, is a more formidable challenge, the authors of the study said. The earlier studies about how young blood can reverse some signs of aging have led to recent clinical trials in which blood donations from younger people were filtered and given to patients with Alzheimer’s or Parkinson’s disease. But exactly how successful those treatments might be, much less how widely they can be used, remains unclear, scientists said. And the difficulties of working with cerebrospinal fluid are steeper than those involved with blood. Infusing the fluid of a young human into an older patient is probably not possible; extracting the liquid generally requires a spinal tap, and scientists say that there are ethical questions about how to collect enough cerebrospinal fluid for infusions. © 2022 The New York Times Company

Keyword: Development of the Brain; Learning & Memory
Link ID: 28327 - Posted: 05.14.2022

Imma Perfetto Have you ever driven past an intersection and registered you should have turned right a street ago, or been in a conversation and, as soon as the words are out of your mouth, realised you really shouldn’t have said that thing you just did? It’s a phenomenon known as performance monitoring; an internal signal produced by the brain that lets you know when you’ve made a mistake. Performance monitoring is a kind of self-generated feedback that’s essential to managing our daily lives. Now, neuroscientists have discovered that signals from neurons in the brain’s medial frontal cortex are responsible for it. A new study published in Science reports that these signals are used to give humans the flexibility to learn new tasks and the focus to develop highly specific skills. “Part of the magic of the human brain is that it is so flexible,” says senior author Ueli Rutishauser, professor of Neurosurgery, Neurology, and Biomedical Sciences at Cedars-Sinai Medical Center, US. “We designed our study to decipher how the brain can generalise and specialise at the same time, both of which are critical for helping us pursue a goal.” They found that the performance monitoring signals help improve future attempts of a particular task by passing information to other areas of the brain. They also help the brain adjust its focus by signalling how much conflict or difficulty was encountered during the task. “An ‘Oops!’ moment might prompt someone to pay closer attention the next time they chat with a friend, or plan to stop at the store on the way home from work,” explains first author Zhongzheng Fu, researcher in the Rutishauser Laboratory at Cedars-Sinai.

Keyword: Attention; Learning & Memory
Link ID: 28322 - Posted: 05.11.2022

Erin Spencer The octopus is one of the coolest animals in the sea. For starters, they are invertebrates. That means they don’t have backbones like humans, lions, turtles and birds. Understand new developments in science, health and technology, each week That may sound unusual, but actually, nearly all animals on Earth are invertebrates – about 97%. Octopuses are a specific type of invertebrate called cephalopods. The name means “head-feet” because the arms of cephalopods surround their heads. Other types of cephalopods include squid, nautiloids and cuttlefish. As marine ecologists, we conduct research on how ocean animals interact with each other and their environments. We’ve mostly studied fish, from lionfish to sharks, but we have to confess we remain captivated by octopuses. What octopuses eat depends on what species they are and where they live. Their prey includes gastropods, like snails and sea slugs; bivalves, like clams and mussels; crustaceans, like lobsters and crabs; and fish. To catch their food, octopuses use lots of strategies and tricks. Some octopuses wrap their arms – not tentacles – around prey to pull them close. Some use their hard beak to drill into the shells of clams. All octopuses are venomous; they inject toxins into their prey to overpower and kill them. There are about 300 species of octopus, and they’re found in every ocean in the world, even in the frigid waters around Antarctica. A special substance in their blood helps those cold-water species get oxygen. It also turns their blood blue. © 2010–2022, The Conversation US, Inc.

Keyword: Evolution; Intelligence
Link ID: 28321 - Posted: 05.11.2022

Neuroscience researchers have found a master gene that controls the development of special sensory cells in the ears – potentially opening the door to reversing hearing loss. A team led by Jaime García-Añoveros of Northwestern University, US, established that a gene called Tbx2 controls the development of ear hair cells in mice. The findings of their study are published today in Nature. What are hair cells? Hair cells are the sensory cells in our ears that detect sound and then transmit a message to our brains. They are so named because they have tiny hairlike structures called stereocilia. “The ear is a beautiful organ,” says García-Añoveros. “There is no other organ in a mammal where the cells are so precisely positioned.” Hair cells are found in a structure called the organ of Corti, in the cochlea in the inner ear. The organ of Corti sits on top of the basilar membrane. Sound waves are funnelled through our ear canal and cause the eardrum (also known as the tympanic membrane) and ossicles (tiny bones called the malleus, incus and stapes) to vibrate. The vibrations, or waves, are transmitted through fluid in the cochlea, causing the basilar membrane to move as well. When the basilar membrane moves, the stereocilia tilt, causing ion channels in the hair cell membrane to open. This stimulates the hair cell to release neurotransmitter chemicals, which will transmit the sound signal to the brain via the auditory nerve.

Keyword: Hearing; Regeneration
Link ID: 28319 - Posted: 05.07.2022

by Rachel Zamzow Inflammation may inflate or thin out brain regions tied to autism and schizophrenia, researchers report in a new study. The findings add nuance to the long-held hypothesis that immune activation elevates the risk for neurodevelopmental conditions. Autism, for example, is associated with prenatal exposure to infection, previous studies show. Taking a different approach, the new work focuses on how a genetic predisposition to inflammation affects brain development in the general population, says John Williams, research fellow at the University of Birmingham in the United Kingdom, who conducted the work with lead researcher Rachel Upthegrove, professor of psychiatry and youth mental health at the university. By pinpointing where inflammation leaves its mark in the brain, the findings serve as a guidepost for future studies of people with neuropsychiatric conditions, he says. “We think that it points to something that’s fairly transdiagnostic.” For their analyses, the team drew on brain imaging and genetic data from 10,828 women and 9,860 men in the general population who participated in the UK Biobank. They explored how 1,436 possible structural changes in the brain track with having single-nucleotide variants previously shown to increase circulating levels of five inflammatory molecules — interleukin 1 (IL-1), IL-2, IL-6, C-reactive protein and brain-derived neurotrophic factor. Three variants thought to boost IL-6 were associated with 33 structural changes, most notably increased volume in the middle temporal gyrus and fusiform gyrus, and decreased cortical thickness in the superior frontal gyrus — all brain areas implicated in autism. Variants associated with other inflammatory molecules did not track with brain changes, the researchers found. © 2022 Simons Foundation

Keyword: Autism; Genes & Behavior
Link ID: 28317 - Posted: 05.07.2022

By James Gorman Don’t judge a book by its cover. Don’t judge a dog by its breed. After conducting owner surveys for 18,385 dogs and sequencing the genomes of 2,155 dogs, a group of researchers reported a variety of findings in the journal Science on Thursday, including that for predicting some dog behaviors, breed is essentially useless, and for most, not very good. For instance, one of the clearest findings in the massive, multifaceted study is that breed has no discernible effect on a dog’s reactions to something it finds new or strange. This behavior is related to what the nonscientist might call aggression and would seem to cast doubt on breed stereotypes of aggressive dogs, like pit bulls. One thing pit bulls did score high on was human sociability, no surprise to anyone who has seen internet videos of lap-loving pit bulls. Labrador retriever ancestry, on the other hand, didn’t seem to have any significant correlation with human sociability. This is not to say that there are no differences among breeds, or that breed can’t predict some things. If you adopt a Border collie, said Elinor Karlsson of the Broad Institute and the University of Massachusetts Chan Medical School, an expert in dog genomics and an author of the report, the probability that it will be easier to train and interested in toys “is going to be higher than if you adopt a Great Pyrenees.” But for any given dog you just don’t know — on average, breed accounts for only about 9 percent of the variations in any given dog’s behavior. And no behaviors were restricted to any one breed, even howling, though the study found that behavior was more strongly associated with breeds like Siberian huskies than with other dogs. And yet, in what might seem paradoxical at first, the researchers also found that behavior patterns are strongly inherited. The behaviors they studied had a 25 percent heritability, a complex measure which indicates the influence of genes, but depends on the group of animals studied. But with enough dogs, heritability is a good measure of what’s inherited. In comparing whole genomes, they found several genes that clearly influence behavior, including one for how friendly dogs are. © 2022 The New York Times Company

Keyword: Genes & Behavior; Aggression
Link ID: 28309 - Posted: 04.30.2022

By Laura Sanders Young kids’ brains are especially tuned to their mothers’ voices. Teenagers’ brains, in their typical rebellious glory, are most decidedly not. That conclusion, described April 28 in the Journal of Neuroscience, may seem laughably obvious to parents of teenagers, including neuroscientist Daniel Abrams of Stanford University School of Medicine. “I have two teenaged boys myself, and it’s a kind of funny result,” he says. But the finding may reflect something much deeper than a punch line. As kids grow up and expand their social connections beyond their family, their brains need to be attuned to that growing world. “Just as an infant is tuned into a mom, adolescents have this whole other class of sounds and voices that they need to tune into,” Abrams says. He and his colleagues scanned the brains of 7- to 16-year-olds as they heard the voices of either their mothers or unfamiliar women. To simplify the experiment down to just the sound of a voice, the words were gibberish: teebudieshawlt, keebudieshawlt and peebudieshawlt. As the children and teenagers listened, certain parts of their brains became active. Previous experiments by Abrams and his colleagues have shown that certain regions of the brains of kids ages 7 to 12 — particularly those parts involved in detecting rewards and paying attention — respond more strongly to mom’s voice than to a voice of an unknown woman. “In adolescence, we show the exact opposite of that,” Abrams says. In these same brain regions in teens, unfamiliar voices elicited greater responses than the voices of their own dear mothers. The shift from mother to other seems to happen between ages 13 and 14. Society for Science & the Public 2000–2022.

Keyword: Language; Development of the Brain
Link ID: 28307 - Posted: 04.30.2022

Carrie Arnold Playing the mating game is risky. Organisms must cope with the existential risk that swiping right on the wrong choice could doom future generations to a lifetime of bad genes. They also have to contend with more immediate burdens and risks: Participants need to gather resources for courting and summon energy to pursue a potential partner. Animals engaged in amorous activities also make easy targets for predators. Small wonder, then, that when times are good, the roundworm Caenorhabditis elegans doesn’t bother with the process. As a mostly hermaphroditic species (with a few males thrown in for variety), a C. elegans worm usually self-fertilizes its eggs until its sperm stash is depleted late in life; only then does it produce a pheromone to attract males and stay in the reproductive game. But when environmental conditions become stressful, the worms become sexually attractive much sooner. For them, sex is the equivalent of a Hail Mary pass — a desperate gamble that if their offspring are more genetically diverse, some will fare better under the new, rougher conditions. Scientists thought this stress-induced shift was purely fleeting. But recently when scientists at Tel Aviv University raised C. elegans in too-warm conditions for more than 10 generations, they discovered that the worms continued to be sexually attractive for several more generations after they were moved to cooler surroundings. It’s an observation that highlights how inheritance does not always reduce to a simple accounting of the genes in organisms, and it may point to a mechanism that works in tandem with traditional natural selection in shaping the evolution of some organisms. As the new paper in Developmental Cell shows, the cause of this trait wasn’t a genetic change to the worm’s DNA but rather an inherited “epigenetic” change that influenced how the DNA was used. The researchers — senior author Oded Rechavi, a biologist at Tel Aviv University, first author Itai Toker (now a postdoctoral fellow at Columbia University) and their colleagues — identified a small RNA molecule that can be passed between generations to signal for production of the pheromone. In effect, this heritable RNA molecule improves the odds that the worms will evolve in stressful times. All Rights Reserved © 2022

Keyword: Sexual Behavior; Epigenetics
Link ID: 28299 - Posted: 04.23.2022