By Gina Kolata Is it possible to predict who will develop Alzheimer’s disease simply by looking at writing patterns years before there are symptoms? According to a new study by IBM researchers, the answer is yes. And, they and others say that Alzheimer’s is just the beginning. People with a wide variety of neurological illnesses have distinctive language patterns that, investigators suspect, may serve as early warning signs of their diseases. For the Alzheimer’s study, the researchers looked at a group of 80 men and women in their 80s — half had Alzheimer’s and the others did not. But, seven and a half years earlier, all had been cognitively normal. The men and women were participants in the Framingham Heart Study, a long-running federal research effort that requires regular physical and cognitive tests. As part of it, they took a writing test before any of them had developed Alzheimer’s that asks subjects to describe a drawing of a boy standing on an unsteady stool and reaching for a cookie jar on a high shelf while a woman, her back to him, is oblivious to an overflowing sink. The researchers examined the subjects’ word usage with an artificial intelligence program that looked for subtle differences in language. It identified one group of subjects who were more repetitive in their word usage at that earlier time when all of them were cognitively normal. These subjects also made errors, such as spelling words wrongly or inappropriately capitalizing them, and they used telegraphic language, meaning language that has a simple grammatical structure and is missing subjects and words like “the,” “is” and “are.” The members of that group turned out to be the people who developed Alzheimer’s disease. The A.I. program predicted, with 75 percent accuracy, who would get Alzheimer’s disease, according to results published recently in The Lancet journal EClinicalMedicine. © 2021 The New York Times Company

Keyword: Alzheimers; Language
Link ID: 27677 - Posted: 02.03.2021

by Laura Dattaro Genetic variants that contribute to autism may also be involved in attention deficit hyperactivity disorder (ADHD) and Tourette syndrome, according to a new study. In 2019, researchers from the Psychiatric Genomics Consortium linked variants associated with autism to seven neuropsychiatric conditions, including anorexia, bipolar disorder and schizophrenia. Despite the genetic overlap, though, some of those conditions, such as anorexia and Tourette syndrome, don’t tend to co-occur. The new work homes in on Tourette syndrome — a motor and tic condition — and three diagnoses that often present with it: More than half of people with Tourette also have obsessive-compulsive disorder (OCD) or ADHD, and up to 20 percent have autism. Because all four conditions can involve impulsive and compulsive behaviors, some scientists have proposed that they exist along a spectrum, with ADHD on one end, OCD on the other, and autism and Tourette in the middle. The goal of looking at all the conditions on this spectrum together is to elucidate the genetics underlying their traits, says lead investigator Peristera Paschou, associate professor of biological sciences at Purdue University in West Lafayette, Indiana. “There is a lot of value in zooming out and trying to think across what would be strict diagnostic categories,” Paschou says. Gene associations: The researchers analyzed data from previous studies that involved a total of 93,294 people with at least one of the four conditions, along with 51,311 controls. They looked at common variants — single-letter changes to DNA that appear in more than 1 percent of the population — shared by any two of the four conditions. © 2021 Simons Foundation

Keyword: Autism; Tourettes
Link ID: 27676 - Posted: 02.03.2021

By Jason Castro Pursued by poets and artists alike, beauty is ever elusive. We seek it in nature, art and philosophy but also in our phones and furniture. We value it beyond reason, look to surround ourselves with it and will even lose ourselves in pursuit of it. Our world is defined by it, and yet we struggle to ever define it. As philosopher George Santayana observed in his 1896 book The Sense of Beauty, there is within us “a very radical and wide-spread tendency to observe beauty, and to value it.” Philosophers such as Santayana have tried for centuries to understand beauty, but perhaps scientists are now ready to try their hand as well. And while science cannot yet tell us what beauty is, perhaps it can tell us where it is—or where it isn’t. In a recent study, a team of researchers from Tsinghua University in Beijing and their colleagues examined the origin of beauty and argued that it is as enigmatic in our brain as it is in the real world. There is no shortage of theories about what makes an object aesthetically pleasing. Ideas about proportion, harmony, symmetry, order, complexity and balance have all been studied by psychologists in great depth. The theories go as far back as 1876—in the early days of experimental psychology—when German psychologist Gustav Fechner provided evidence that people prefer rectangles with sides in proportion to the golden ratio (if you’re curious, that ratio is about 1.6:1). © 2021 Scientific American

Keyword: Emotions; Vision
Link ID: 27675 - Posted: 02.03.2021

The earliest eye damage from prion disease takes place in the cone photoreceptor cells, specifically in the cilia and the ribbon synapses, according to a new study of prion protein accumulation in the eye by National Institutes of Health scientists. Prion diseases originate when normally harmless prion protein molecules become abnormal and gather in clusters and filaments in the human body and brain. Understanding how prion diseases develop, particularly in the eye because of its diagnostic accessibility to clinicians, can help scientists identify ways to slow the spread of prion diseases. The scientists say their findings, published in the journal Acta Neuropathologica Communications, may help inform research on human retinitis pigmentosa, an inherited disease with similar photoreceptor degeneration leading to blindness. Prion diseases are slow, degenerative and usually fatal diseases of the central nervous system that occur in people and some other mammals. Prion diseases primarily involve the brain, but also can affect the eyes and other organs. Within the eye, the main cells infected by prions are the light-detecting photoreceptors known as cones and rods, both located in the retina. In their study, the scientists, from NIH’s National Institute of Allergy and Infectious Diseases at Rocky Mountain Laboratories in Hamilton, Montana, used laboratory mice infected with scrapie, a prion disease common to sheep and goats. Scrapie is closely related to human prion diseases, such as variant, familial and sporadic Creutzfeldt-Jakob disease (CJD). The most common form, sporadic CJD, affects an estimated one in one million people annually worldwide. Other prion diseases include chronic wasting disease in deer, elk and moose, and bovine spongiform encephalopathy in cattle.

Keyword: Prions; Vision
Link ID: 27674 - Posted: 02.03.2021

By Jonathan Lambert When one naked mole-rat encounters another, the accent of their chirps might reveal whether they’re friends or foes. These social rodents are famous for their wrinkly, hairless appearance. But hang around one of their colonies for a while, and you’ll notice something else — they’re a chatty bunch. Their underground burrows resound with near-constant chirps, grunts, squeaks and squeals. Now, computer algorithms have uncovered a hidden order within this cacophony, researchers report in the Jan. 29 Science. These distinctive chirps, which pups learn when they’re young, help the mostly blind, xenophobic rodents discern who belongs, strengthening the bonds that maintain cohesion in these highly cooperative groups. “Language is really important for extreme social behavior, in humans, dolphins, elephants or birds,” says Thomas Park, a biologist at the University of Illinois Chicago who wasn’t involved in the study. This work shows naked mole-rats (Heterocephalus glaber) belong in those ranks as well, Park says. Naked mole-rat groups seem more like ant or termite colonies than mammalian societies. Every colony has a single breeding queen who suppresses the reproduction of tens to hundreds of nonbreeding worker rats that dig elaborate subterranean tunnels in search of tubers in eastern Africa (SN: 10/18/04). Food is scarce, and the rodents vigorously attack intruders from other colonies. While researchers have long noted the rat’s raucous chatter, few actually studied it. “Naked mole-rats are incredibly cooperative and incredibly vocal, and no one has really looked into how these two features influence one another,” says Alison Barker, a neuroscientist at the Max Delbrück Center for Molecular Medicine in Berlin. © Society for Science & the Public 2000–2021.

Keyword: Language; Evolution
Link ID: 27673 - Posted: 01.30.2021

By Brooke Jarvis Danielle Reed stopped counting after the 156th email arrived in a single afternoon. It was late March, and her laboratory at the Monell Chemical Senses Center in Philadelphia had abruptly gone into Covid-19 lockdown. For weeks, there had been little to do. Reed, who is famous in her field for helping to discover a new family of receptors that perceive bitter flavors, had spent years studying the way human genetics affect the way we experience smell and taste. It was important but niche science that seemingly had little to do with a dangerous respiratory virus spreading around the globe. And then one Saturday, she checked her email. Reed watched in amazement as the messages proliferated. It wasn’t how many threads there were, though that was overwhelming, but the way they seemed to grow like Hydras, sprouting in all directions. Recipients copied other people they thought might be interested in the discussion, who added more people, who added still others, across a huge range of countries and disciplines. The cascading emails were all responding to the same rather obscure news alert, meant for ear, nose and throat doctors based in Britain. It was titled: “Loss of smell as marker of Covid-19 infection.” The week before, Claire Hopkins, the president of the British Rhinological Society and an author of the alert, was seeing patients in her clinic in London when she noticed something odd. Hopkins, who specializes in nose and sinus diseases, especially nasal polyps, was accustomed to seeing the occasional patient — usually about one per month — whose sense of smell disappeared after a viral infection. Most of the time, such losses were fairly self-explanatory: A stuffy, inflamed nose keeps odorants from reaching the smell receptors at the top of the airway. Sometimes these receptors are also damaged by inflammation and need time to recover. But patients were now arriving with no blockage or swelling, no trouble breathing, no notable symptoms, other than the sudden and mysterious disappearance of their ability to smell. And there were nine of them. © 2021 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27672 - Posted: 01.30.2021

The Physics arXiv Blog One of the best-studied networks in neuroscience is the brain of a fruit fly, in particular, a part called the mushroom body. This analyzes sensory inputs such as odors, temperature, humidity and visual data so that the fly can learn to distinguish friendly stimuli from dangerous ones. Neuroscientists have long known how this section of the brain is wired. It consists of a set of cells called projection neurons that transmit the sensory information to a population of 2,000 neurons called Kenyon cells. The Kenyon cells are wired together to form a neural network capable of learning. This is how fruit flies learn to avoid potentially hazardous sensory inputs — such as dangerous smells and temperatures — while learning to approach foodstuffs, potential mates, and so on. But the power and flexibility of this relatively small network has long raised a curious question for neuroscientists: could it be re-programmed to tackle other tasks? Now they get an answer thanks to the work of Yuchan Liang at the Rensselaer Polytechnic Institute, the MIT-IBM Watson AI Lab, and colleagues. This team has hacked the fruit fly brain network to perform other tasks, such as natural language processing. It's the first time a naturally occurring network has been commandeered in this way. And this biological brain network is no slouch. Liang and the team says it matches the performance of artificial learning networks while using far fewer computational resources. © 2021 Kalmbach Media Co.

Keyword: Learning & Memory
Link ID: 27671 - Posted: 01.30.2021

Paul Tullis On a sunny day in London in 2015, Kirk Rutter rode the Tube to Hammersmith Hospital in hopes of finally putting an end to his depression. Rutter had lived with the condition off and on for years, but the burden had grown since the death of his mother in 2011, followed by a relationship break-up and a car accident the year after. It felt as if his brain was stuck on what he describes as “an automatic circuit”, repeating the same negative thoughts like a mantra: “‘Everything I do turns to crap.’ I actually believed that,” he recalls. The visit to Hammersmith was a preview. He would be returning the next day to participate in a study, taking a powerful hallucinogen under the guidance of Robin Carhart-Harris, a psychologist and neuroscientist at Imperial College London. Years of talking therapy and a variety of anti-anxiety medications had failed to improve Rutter’s condition, qualifying him for the trial. “Everyone was super nice, like really lovely, and especially Robin,” Rutter recalls. Carhart-Harris led him to a room with a magnetic resonance imaging (MRI) machine, so researchers could acquire a baseline of his brain activity. Then he showed Rutter where he would spend his time while on the drug. Carhart-Harris asked him to lie down and played him some of the music that would accompany the session. He explained that he would have on hand a drug that could neutralize the hallucinogen, if necessary. Then the two practised a grounding technique, to help calm Rutter in the event that he became overwhelmed. Without warning, Rutter burst into tears. “I think I knew this was going to be unpacking a lot — I was carrying a bit of a load at the time,” Rutter says. © 2021 Springer Nature Limited

Keyword: Depression; Drug Abuse
Link ID: 27670 - Posted: 01.30.2021

By Veronique Greenwood Last spring, robins living on an Illinois tree farm sat on some unusual eggs. Alongside the customary brilliant blue ovoids they had laid were some unusually shaped objects. Although they had the same color, some were long and thin, stretched into pills. Others were decidedly pointy — so angular, in fact, that they bore little resemblance to eggs at all. If robins played Dungeons and Dragons, they might have thought, “Why do I have an eight-sided die in my nest?” The answer: Evolutionary biologists were gauging how birds decide what belongs in their nests, and what is an invasive piece of detritus that they need to throw out. Thanks to the results of this study, published Wednesday in Royal Society Open Science, we now know what the robins thought of the eggs, which were made of plastic and had been 3-D printed by the lab of Mark Hauber, a professor of animal behavior at the University of Illinois, Urbana-Champaign and a fellow at Hanse-Wissenschaftskolleg in Delmenhorst, Germany. He and his colleagues reported that the thinner the fake eggs got, the more likely the birds were to remove them from the nest. But curiously, the robins were more cautious about throwing out the pointy objects like that eight-sided die, which were closer in width to their own eggs. Birds, the results suggest, are using rules of thumb that are not intuitive to humans when they decide what is detritus and what is precious cargo. It’s not as uncommon as you’d think for robins to find foreign objects in their nests. They play host to cowbirds, a parasitic species that lays eggs in other birds’ nests, where they hatch and compete with the robins’ own offspring for nourishment. Confronted with a cowbird egg, which is beige and squatter than its blue ovals, parent robins will often push the parasite’s eggs out. That makes the species a good candidate for testing exactly what matters when it comes to telling their own eggs apart from other objects, Dr. Hauber said. © 2021 The New York Times Company

Keyword: Attention; Evolution
Link ID: 27669 - Posted: 01.30.2021

Allyson Chiu Sleep and circadian rhythms have long been associated with the powerful effects of the sun cycle. But in recent years, a growing number of studies have suggested that another familiar celestial body might also be impacting your ability to get a restful night’s sleep: the moon. A paper published this week in the journal Science Advances found that people tend to have a harder time sleeping in the days leading up to a full moon. Researchers reported that sleep patterns among the study’s 98 participants appeared to fluctuate over the course of the 29½ -day lunar cycle, with the latest bedtimes and least amount of rest occurring on nights three to five days before the moon reaches its brightest phase. They found a similar pattern in sleep data from another group of more than 460 people. Ahead of the full moon, it took people, on average, 30 minutes longer to fall asleep and they slept for 50 minutes less, said Leandro Casiraghi, the study’s lead author and a postdoctoral researcher in the Department of Biology at the University of Washington. “What we did is we came up with a set of data that shockingly proves that this is real, that there’s an actual effect of the moon on our sleep,” Casiraghi said. Previous studies examining the moon’s effect on sleep have produced contradictory results. Some research has found minimal or no association between the lunar cycle and sleep, while other studies have demonstrated correlations in controlled settings. The findings of the Jan. 27 paper support existing observations that there is a link, Casiraghi said. But, he noted that the work he and his fellow scientists did is distinct from past research by a critical difference in methodology. © 1996-2021 The Washington Post

Keyword: Sleep
Link ID: 27668 - Posted: 01.30.2021

Research shows that hallucinogens can be highly effective treatments for anxiety, depression, addiction, and trauma. Here's everything you need to know: Aren't psychedelic drugs illegal? Under federal and most states' laws, they are, but a push to legalize or decriminalize the drugs is gaining momentum. On Election Day, Oregon voters made their state the first to legalize the active ingredient in "magic mushrooms" — psilocybin — for mental health therapy in a controlled setting with a therapist. Washington, D.C., voters passed Initiative 81, making the city at least the fifth to decriminalize magic mushrooms. Similar legislation has been proposed in California, Vermont, and Iowa. Last summer, Canada issued four terminally ill patients exemptions to take psilocybin for end-of-life anxiety and depression. British Columbia resident Mona Strelaeff, 67, got an exemption for treatment for trauma, addiction, depression, and anxiety. "All the unresolved trauma," Strelaeff said, "it came back and I was beyond terrified, shaking uncontrollably, and crying." She said that psilocybin therapy helped her conquer "those tough memories" and today she "ain't afraid of jack (s---)." How does psychedelic therapy work? Participants usually take psilocybin or LSD in a relaxing setting, lying down with blindfolds and headphones on, listening to music. Trained supervisors encourage them to "go inward and to kind of experience whatever is going to come up," said Alan Davis, who studies psychedelics at Johns Hopkins University. Bad psilocybin trips are rare — Johns Hopkins and NYU researchers conducted 500 sessions without observing any "serious adverse effects" — but they can occur. Advocates say careful dose control, supervision, and controlled settings are very important. Psilocybin sessions typically last between four and six hours, while LSD sessions go on for 12. Robin Carhart-Harris, who runs the Centre for Psychedelic Research at Imperial College in London, theorized that such sessions can "reboot" the brain in a way similar to a near-death or intense spiritual experience. ® 2021 The Week Publications Inc.,

Keyword: Depression; Drug Abuse
Link ID: 27667 - Posted: 01.27.2021

Jessica Koehler Ph.D. The only true voyage of discovery...would be not to visit strange lands, but to possess other eyes, to behold the universe through the eyes of another, of a hundred others, to behold the hundred universes that each of them beholds, that each of them is. Marcel Proust Perception is everything—and it is flawed. Most of us navigate our daily lives believing we see the world as it is. Our brains are perceiving an objective reality, right? Well, not quite. Everything we bring in through our senses is interpreted through the filter of our past experiences. Sensation is physical energy detection by our sensory organs. Our eyes, mouth, tongue, nose, and skin relay raw data via a process of transduction, which is akin to translation of physical energy—such as sound waves—into the electrochemical energy the brain understands. At this point, the information is the same from person to person—it is unbiased. To understand human perception, you must first understand that all information in and of itself is meaningless. Beau Lotto While Dr. Lotto's statement is bold, from the perspective of neuroscience, it is true. Meaning is applied to everything, from the simplest to the most complex sensory input. Our brain's interpretation of the raw sensory information is known as perception. Everything from our senses is filtered through our unique system of past experiences in the world. Usually, the meaning we apply is functional and adequate—if not fully accurate, but sometimes our inaccurate perceptions create real-world difficulty.

Keyword: Vision; Attention
Link ID: 27666 - Posted: 01.27.2021

by Peter Hess Mice missing a copy of the autism-linked gene MAGEL2 have trouble discerning between a familiar mouse and an unfamiliar one, but treating them with the social hormone vasopressin reverses this deficit, according to a new study. Mutations in or deletions of MAGEL2 are linked to autism and several related conditions, including Prader-Willi syndrome, which is characterized by intellectual disability, poor muscle tone, difficulty feeding and problems with social interactions. The new findings suggest that these social issues in people stem from impairments in vasopressin’s function in a brain region called the lateral septum, which relays signals between the hippocampus and the ventral tegmental area. They also hint that vasopressin treatment could remedy those issues, says Elizabeth Hammock, assistant professor of psychology and neuroscience at Florida State University in Tallahassee, who was not involved with the study. A 2020 study showed that low levels of vasopressin in cerebrospinal fluid can flag many infants who are later diagnosed with autism. But clinical trials have shown that either providing vasopressin or blocking its effects can improve social communication in autistic children. Because of these seemingly contradictory results, “a better understanding of how alterations in the vasopressinergic system leads to social deficits and how vasopressin administration could resolve some of these problems was needed,” says co-lead researcher Freddy Jeanneteau, professor of neuroscience at Montpellier University in Montpellier, France. © 2021 Simons Foundation

Keyword: Autism; Hormones & Behavior
Link ID: 27665 - Posted: 01.27.2021

By Clay Risen In 1978, James R. Flynn, a political philosopher at the University of Otago, in New Zealand, was writing a book about what constituted a “humane” society. He considered “inhumane” societies as well — dictatorships, apartheid states — and, in his reading, came across the work of Arthur R. Jensen, a psychologist at the University of California, Berkeley. Dr. Jensen was best known for an article he published in 1969 claiming that the differences between Black and white Americans on I.Q. tests resulted from genetic differences between the races — and that programs that tried to improve Black educational outcomes, like Head Start, were bound to fail. Dr. Flynn, a committed leftist who had once been a civil rights organizer in Kentucky, felt instinctively that Dr. Jensen was wrong, and he set out to prove it. In 1980 he published a thorough, devastating critique of Dr. Jensen’s work — showing, for example, that many groups of whites scored as low on I.Q. tests as Black Americans. But he didn’t stop there. Like most researchers in his field, Dr. Jensen had assumed that intelligence was constant across generations, pointing to the relative stability of I.Q. tests over time as evidence. But Dr. Flynn noticed something that no one else had: Those tests were recalibrated every decade or so. When he looked at the raw, uncalibrated data over nearly 100 years, he found that I.Q. scores had gone up, dramatically. “If you scored people 100 years ago against our norms, they would score a 70,” or borderline mentally disabled, he said later. “If you scored us against their norms, we would score 130” — borderline gifted. Just as groundbreaking was his explanation for why. The rise was too fast to be genetic, nor could it be that our recent ancestors were less intelligent than we are. Rather, he argued, the last century has seen a revolution in abstract thinking, what he called “scientific spectacles,” brought on by the demands of a technologically robust industrial society. This new order, he maintained, required greater educational attainment and an ability to think in terms of symbols, analogies and complex logic — exactly what many I.Q. tests measure. © 2021 The New York Times Company

Keyword: Learning & Memory; Development of the Brain
Link ID: 27664 - Posted: 01.27.2021

By Linda Searing A surge in the number of U.S. residents who have died of a drug overdose — 81,230 in the 12 months ending last May — set a record for the most such deaths in a one-year span, according to a report issued by the Centers for Disease Control and Prevention. Overall, drug overdose deaths jumped by 18 percent from the previous year, with increases recorded in 46 states (by more than 20 percent in 25 of those states) and just four states recording a decrease. Deaths attributed to synthetic opioids, mainly fentanyl, increased 38 percent nationwide, but 98 percent in 10 western states. Overdose deaths tied to cocaine use, often involving co-use or mixing with fentanyl or heroin, increased about 26 percent, and deaths linked to psychostimulants, such as methamphetamine, increased 35 percent. The CDC noted that the death rate from drug overdoses accelerated as the coronavirus pandemic set in, disrupting daily life and leading to isolation, depression, anxiety and economic distress for many, including people with a substance use disorder. In a health alert, the CDC urged broader distribution and use of naloxone, a medication that can block the effects of an overdose, as well as expanded prevention and treatment for those struggling with drug use. A free and confidential hotline, offering information and treatment referral, can be reached by calling the Substance Abuse and Mental Health Services Administration at 800-662-4357.

Keyword: Drug Abuse
Link ID: 27663 - Posted: 01.27.2021

By Katherine J. Wu For a lesson in euphoria, look no further than a house cat twined around a twig of silver vine. When offered a snipping of the plant, which contains chemicals similar to the ones found in catnip, most domesticated felines will purr, drool and smoosh their faces into its intoxicating leaves and stems, then zonk out in a state of catatonic bliss. But the ecstatic rush might not be the only reason felines flock to these plants, new research suggests. Compounds laced into plants like silver vine and catnip might also help cats ward off mosquitoes, equipping them with a DIY pest repellent that’s far more fun to apply than a greasy coat of DEET. Other papers have pointed to the insect-deterring effects of catnip and similar plants. But the new study, published Wednesday in the journal Science Advances, is the first to draw a direct link between the plants and their protective effects on cats. “It’s a really interesting observation, that such a well-known behavior could be having this unappreciated benefit for cats,” said Laura Duvall, a mosquito researcher at Columbia University in New York who wasn’t involved in the study. Botanically speaking, catnip and silver vine are distant cousins. But both contain iridoids, a suite of chemicals that seem to potently tickle pleasure circuits in cats. To pinpoint the evolutionary roots of this plant-feline connection, a team of researchers led by Masao Miyazaki, a biochemist and veterinary scientist at Iwate University in Japan, corralled a menagerie of cats — some domestic, some wild — and monitored their responses to an iridoid extracted from silver vine, which thrives in many mountainous parts of Asia. Presented with scraps of paper dosed with iridoid, most of the cats initiated a ritualized rolling and rubbing. Some cats were so eager to engage with the compounds that they climbed up the sides of their cages — some of which were nearly four feet tall — to anoint themselves with chemical-soaked paper secured to the ceiling. © 2021 The New York Times Company

Keyword: Drug Abuse
Link ID: 27662 - Posted: 01.23.2021

By Stephani Sutherland Patrick Thornton, a 40-year-old math teacher in Houston, Tex., relies on his voice to clearly communicate with his high school students. So when he began to feel he was recovering from COVID, he was relieved to get his voice back a month after losing it. Thornton got sick in mid-August and had symptoms typical of a moderate case: a sore throat, headaches, trouble breathing. By the end of September, “I was more or less counting myself as on the mend and healing,” Thornton says. “But on September 25, I took a nap, and then my mom called.” As the two spoke, Thornton’s mother remarked that it was great that his voice was returning. Something was wrong, however. “I realized that some of the words didn’t feel right in my mouth, you know?” he says. They felt jumbled, stuck inside. Thornton had suddenly developed a severe stutter for the first time in his life. “I got my voice back, but it broke my mouth,” he says. After relaying the story over several minutes, Thornton sighs heavily with exhaustion. The thought of going back to teaching with his stutter, “that was terrifying,” he says. In November Thornton still struggled with low energy, chest pain and headaches. And “sometimes my heart rate [would] just decide that we’re being chased by a tiger out of nowhere," he adds. His stutter only worsened by that time, Thornton says, and he worried that it reflected some more insidious condition in his brain, despite doctors’ insistence that the speech disruption was simply a product of stress. © 2021 Scientific American,

Keyword: Learning & Memory; Schizophrenia
Link ID: 27661 - Posted: 01.23.2021

by Angie Voyles Askham Mutations that affect a histone called H3.3 can lead to a neurodegenerative condition marked by developmental delay and congenital anomalies, according to a new study. Histones act as spools for DNA, making it possible to pack the strands of genetic material tightly within the nucleus. They also serve as gatekeepers for protein production, physically blocking proteins from interacting with genes, or allowing them access to turn genes on and off. Autism has been tied to mutations in proteins that modify histones and disrupt this gatekeeping process. The new work is among the first to link atypical neurodevelopment and degeneration to mutations that affect a histone itself. It focuses on 46 people with a mutation in either of two genes that code for H3.3. All have a diagnosis of developmental delay. Many also have other medical conditions, such as seizures, heart defects and atypical development of the head and face. “We see this [result] as a Rosetta Stone,” says lead researcher Elizabeth Bhoj, assistant professor of pediatrics and human genetics at the University of Pennsylvania. In addition to providing information about this particular cohort, the findings could help explain the role that histones play in neurodevelopmental conditions in general, she says. Earlier studies have associated H3.3 with cancer, but none of the participants in the new study have tumors. About 21 percent, however, show signs of neurodegeneration, and 26 percent have shrinkage in the cerebral cortex, the brain’s outer layer, suggesting the condition may be progressive. “It’s an impressive collection of novel mutations that seem to be converging on a set of clinical features,” says James Noonan, associate professor of genetics and neuroscience at Yale School of Medicine, who was not involved in the study. © 2021 Simons Foundation

Keyword: Autism; Epigenetics
Link ID: 27660 - Posted: 01.23.2021

By Mitch Leslie Spitting cobras protect themselves by shooting jets of venom into the eyes of their attackers. A new study suggests that over the course of several million years, all three groups of spitters independently tailored the chemistry of their toxins in the same way to cause pain to a would-be predator. The work provides a novel example of convergent evolution that “deepens our understanding of this unique system” for delivering venom, says Timothy Jackson, an evolutionary toxinologist at the University of Melbourne. Like other cobras, spitting cobras will bite attackers in self-defense. Spitting is their signature move, however, and the snakes are crack shots. They can direct a stream of venom into an attacker’s face from more than 2 meters away, aiming for the eyes. The behavior is such a formidable defense that it evolved independently three times: in Asian cobras, African cobras, and a cobra cousin called the rinkhals (Hemachatus haemachatus) that lives in southern Africa. Scientists previously found the venom of some other snakes evolved to better subdue their prey. By analyzing the venoms of 17 spitting and nonspitting species—and measuring their effects—venom biologist Nicholas Casewell of the Liverpool School of Tropical Medicine and colleagues tested whether the makeup of spitting cobra venom had also changed over time to become a more effective defense. © 2021 American Association for the Advancement of Science.

Keyword: Pain & Touch; Evolution
Link ID: 27659 - Posted: 01.23.2021

Bob McDonald Scientists used raw eggs to simulate the damaging effects on the brain from strikes to the head, with surprising results. If someone calls you an egghead, they are not too far off. Think about it: an egg has a hard outer shell; a liquid interior, which is the white of the egg; and liquid yolk surrounded by a membrane suspended in the centre. Your head also has a hard outer skull and liquid, called the cerebrospinal fluid, inside of it — which, among other things, acts as a shock absorber around the squishy brain. In a research paper in the journal Physics of Fluids, scientists from Villanova University in Pennsylvania conducted rather simple kitchen style experiments on raw eggs to simulate strikes to the head that could lead to concussion. They wanted to determine how much shock absorbing protection the egg white would provide the yolk and how much the yolk would be distorted out of shape during an impact. The results were not what they expected. Applying force to monitor yolk deformation In order to see the yolks in action, the egg material was placed in a clear plastic container that was mounted on springs and filmed with high speed cameras. First, they hit it in a straight line by dropping a 1.77 kg weight on it from a height of one metre. representing a direct blow to the head. To their surprise, the yolk remained suspended in the egg white and did not change shape or break as the container suddenly accelerated downwards. This could be because liquids cannot be compressed, and since the two liquids are almost the same density, both of them moved together as one unit. ©2021 CBC/Radio-Canada.

Keyword: Brain Injury/Concussion
Link ID: 27658 - Posted: 01.23.2021