by Jessica Jiménez, Mark Zylka Mice and rats typically give birth to 6 to 12 animals per litter. Some scientists treat this as a benefit, because a large number of animals can be produced with a small number of matings. In reality, though, this is of no benefit at all, especially when you consider a fact that is well known in the toxicology field: Animals within a litter are more similar to one another than animals between litters. Herein lies what is known as the ‘litter effect.’ Anyone who uses multiple animals from a small number of litters to increase sample size is making a serious mistake. The similarities within individual litters will heavily skew the results. Our goal in writing this article, and an accompanying peer-reviewed paper on this topic, is to raise awareness about the litter effect and to encourage researchers who study neurodevelopmental conditions to control for it in future work. Like many scientists who use rodents to study autism and related conditions, we were oblivious to the litter effect and its impact on research. However, we now recognize that it is essential to control for the litter effect whenever a rodent autism model is studied, be it a mouse with a gene mutation or an environmental exposure. It is essential because the litter effect can lead to erroneous conclusions that negatively influence the rigor and reproducibility of scientific research. Indeed, false positives, or the incorrect identification of a significant effect, increase as fewer litters are sampled. Conversely, litter-to-litter variation adds ‘noise’ to the data that can mask true treatment or genetic effects. This is concerning because most phenotypes associated with rodent models of autism are remarkably small, and they are often difficult to reproduce between labs. © 2021 Simons Foundation

Keyword: Development of the Brain; Sexual Behavior
Link ID: 27789 - Posted: 04.28.2021

The government of New Brunswick says there are now 47 cases of a mysterious neurological disease, for which experts are still trying to figure out a source. As of last Thursday, there have been 37 confirmed and 10 suspected cases of "a neurological syndrome of unknown cause," Bruce Macfarlane, spokesperson for the Department of Health, said in an email Monday. That brings the number of cases up from 44. The province last reported a new case in early April. There have been six deaths caused by the disease, with no new deaths reported Monday. Macfarlane said the province is collaborating with local and national subject matter experts and health-care providers to investigate the individuals showing signs and symptoms of the syndrome. "At this time, the investigation is active and ongoing to determine if there are similarities among the reported cases that can identify potential causes for this syndrome, and to help identify possible strategies for prevention. "The investigation team is exploring all potential causes including food, environmental and animal exposures." Macfarlane said most of the cases are in people who were living in areas around Moncton and on the Acadian Peninsula. "However, it is unknown at this stage of our investigation whether geographic area is linked to the neurological condition and related symptoms" he said. The disease cluster was first reported on in March, when Radio-Canada obtained a memo from Public Health to medical professionals. ©2021 CBC/Radio-Canada.

Keyword: Alzheimers; Neurotoxins
Link ID: 27788 - Posted: 04.28.2021

By Kathiann Kowalski On most mornings, Jeremy D. Brown eats an avocado. But first, he gives it a little squeeze. A ripe avocado will yield to that pressure, but not too much. Brown also gauges the fruit’s weight in his hand and feels the waxy skin, with its bumps and ridges. “I can’t imagine not having the sense of touch to be able to do something as simple as judging the ripeness of that avocado,” says Brown, a mechanical engineer who studies haptic feedback — how information is gained or transmitted through touch — at Johns Hopkins University. Many of us have thought about touch more than usual during the COVID-19 pandemic. Hugs and high fives rarely happen outside of the immediate household these days. A surge in online shopping has meant fewer chances to touch things before buying. And many people have skipped travel, such as visits to the beach where they might sift sand through their fingers. A lot goes into each of those actions. “Anytime we touch anything, our perceptual experience is the product of the activity of thousands of nerve fibers and millions of neurons in the brain,” says neuroscientist Sliman Bensmaia of the University of Chicago. The body’s natural sense of touch is remarkably complex. Nerve receptors detect cues about pressure, shape, motion, texture, temperature and more. Those cues cause patterns of neural activity, which the central nervous system interprets so we can tell if something is smooth or rough, wet or dry, moving or still. © Society for Science & the Public 2000–2021.

Keyword: Pain & Touch; Robotics
Link ID: 27787 - Posted: 04.24.2021

By Pam Belluck Could getting too little sleep increase your chances of developing dementia? For years, researchers have pondered this and other questions about how sleep relates to cognitive decline. Answers have been elusive because it is hard to know if insufficient sleep is a symptom of the brain changes that underlie dementia — or if it can actually help cause those changes. Now, a large new study reports some of the most persuasive findings yet to suggest that people who don’t get enough sleep in their 50s and 60s may be more likely to develop dementia when they are older. The research, published Tuesday in the journal Nature Communications, has limitations but also several strengths. It followed nearly 8,000 people in Britain for about 25 years, beginning when they were 50 years old. It found that those who consistently reported sleeping six hours or less on an average weeknight were about 30 percent more likely than people who regularly got seven hours sleep (defined as “normal” sleep in the study) to be diagnosed with dementia nearly three decades later. “It would be really unlikely that almost three decades earlier, this sleep was a symptom of dementia, so it’s a great study in providing strong evidence that sleep is really a risk factor,” said Dr. Kristine Yaffe, a professor of neurology and psychiatry at the University of California, San Francisco, who was not involved in the study. Pre-dementia brain changes like accumulations of proteins associated with Alzheimer’s are known to begin about 15 to 20 years before people exhibit memory and thinking problems, so sleep patterns within that time frame could be considered an emerging effect of the disease. That has posed a “chicken or egg question of which comes first, the sleep problem or the pathology,” said Dr. Erik Musiek, a neurologist and co-director of the Center on Biological Rhythms and Sleep at Washington University in St. Louis, who was not involved in the new research. © 2021 The New York Times Company

Keyword: Sleep; Alzheimers
Link ID: 27786 - Posted: 04.24.2021

By Virginia Morell Like members of a street gang, male dolphins summon their buddies when it comes time to raid and pillage—or, in their case, to capture and defend females in heat. A new study reveals they do this by learning the “names,” or signature whistles, of their closest allies—sometimes more than a dozen animals—and remembering who consistently cooperated with them in the past. The findings indicate dolphins have a concept of team membership—previously seen only in humans—and may help reveal how they maintain such intricate and tight-knit societies. “It is a ground-breaking study,” says Luke Rendell, a behavioral ecologist at the University of St. Andrews who was not involved with the research. The work adds evidence to the idea that dolphins evolved large brains to navigate their complex social environments. Male dolphins typically cooperate as a pair or trio, in what researchers call a “first-order alliance.” These small groups work together to find and corral a fertile female. Males also cooperate in second-order alliances comprised of as many as 14 dolphins; these defend against rival groups attempting to steal the female. Some second-order alliances join together in even larger third-order alliances, providing males in these groups with even better chances of having allies nearby should rivals attack. © 2021 American Association for the Advancement of Science

Keyword: Animal Communication; Language
Link ID: 27785 - Posted: 04.24.2021

Lise Eliot Everyone knows the difference between male and female brains. One is chatty and a little nervous, but never forgets and takes good care of others. The other is calmer, albeit more impulsive, but can tune out gossip to get the job done. These are stereotypes, of course, but they hold surprising sway over the way actual brain science is designed and interpreted. Since the dawn of MRI, neuroscientists have worked ceaselessly to find differences between men’s and women’s brains. This research attracts lots of attention because it’s just so easy to try to link any particular brain finding to some gender difference in behavior. But as a neuroscientist long experienced in the field, I recently completed a painstaking analysis of 30 years of research on human brain sex differences. And what I found, with the help of excellent collaborators, is that virtually none of these claims has proven reliable. Except for the simple difference in size, there are no meaningful differences between men’s and women’s brain structure or activity that hold up across diverse populations. Nor do any of the alleged brain differences actually explain the familiar but modest differences in personality and abilities between men and women. © 2010–2021, The Conversation US, Inc.

Keyword: Sexual Behavior; Brain imaging
Link ID: 27784 - Posted: 04.24.2021

by Angie Voyles Askham A dearth of insulation around neuronal projections may explain why some parts of the cerebral cortex can appear thicker in brain scans of autistic people than in those of non-autistic people, according to a new study. Magnetic resonance imaging (MRI) studies show that some autistic children have bigger brains than their non-autistic peers, with much of the overgrowth occurring in the cerebral cortex. The reason for this difference remains unclear, but it seems to reflect an apparent excess of gray matter, which consists of neuronal cell bodies, relative to white matter, composed of neuronal projections. Newly developed neurons in the brains of autistic people may have trouble migrating to the proper place, some researchers have suggested, which could blur the boundary between gray and white matter in some regions and cause the gray matter to look thicker on an MRI scan. But higher levels of myelin, the insulation that surrounds neuronal projections, in non-autistic people could also skew these measures, says lead researcher of the new work, Mallar Chakravarty, associate professor of psychiatry at McGill University in Montreal. Myelin appears brighter on an MRI scan than other tissue, so an abundance of it near the boundary between gray and white matter could make the gray matter appear thinner, he says. © 2021 Simons Foundation

Keyword: Autism; Glia
Link ID: 27783 - Posted: 04.24.2021

Johnjoe McFadden Some 2,700 years ago in the ancient city of Sam’al, in what is now modern Turkey, an elderly servant of the king sits in a corner of his house and contemplates the nature of his soul. His name is Katumuwa. He stares at a basalt stele made for him, featuring his own graven portrait together with an inscription in ancient Aramaic. It instructs his family, when he dies, to celebrate ‘a feast at this chamber: a bull for Hadad harpatalli and a ram for Nik-arawas of the hunters and a ram for Shamash, and a ram for Hadad of the vineyards, and a ram for Kubaba, and a ram for my soul that is in this stele.’ Katumuwa believed that he had built a durable stone receptacle for his soul after death. This stele might be one of the earliest written records of dualism: the belief that our conscious mind is located in an immaterial soul or spirit, distinct from the matter of the body. More than 2 millennia later, I was also contemplating the nature of the soul, as my son lay propped up on a hospital gurney. He was undertaking an electroencephalogram (EEG), a test that detects electrical activity in the brain, for a condition that fortunately turned out to be benign. As I watched the irregular wavy lines march across the screen, with spikes provoked by his perceptions of events such as the banging of a door, I wondered at the nature of the consciousness that generated those signals. Just how do the atoms and molecules that make up the neurons in our brain – not so different to the bits of matter in Katumwa’s inert stele or the steel barriers on my son’s hospital bed – manage to generate human awareness and the power of thought? In answering that longstanding question, most neurobiologists today would point to the information-processing performed by brain neurons. For both Katumuwa and my son, this would begin as soon as light and sound reached their eyes and ears, stimulating their neurons to fire in response to different aspects of their environment. For Katumuwa, perhaps, this might have been the pinecone or comb that his likeness was holding on the stele; for my son, the beeps from the machine or the movement of the clock on the wall. © Aeon Media Group Ltd. 2012-2021

Keyword: Consciousness; Attention
Link ID: 27782 - Posted: 04.21.2021

By Emily Anthes Male tanagers are meant to be noticed. Many species of the small, tropical bird sport deep black feathers and splashes of eye-catching color — electric yellows, traffic-cone oranges and nearly neon scarlets. To achieve this flashiness, the birds must spend time and energy foraging for, and metabolizing, plants that contain special color pigments, which make their way into the feathers. A vibrantly colored male is thus sending an “honest signal,” many scientists have long theorized: He is alerting nearby females that he has a good diet, is in good health and would make a worthy mate. But some birds may be guilty of false advertising, a new study suggests. Male tanagers have microstructures in their feathers that enhance their colors, researchers reported Wednesday in the journal Scientific Reports. These microstructures, like evolution’s own Instagram filters, may make the males seem as if they are more attractive than they truly are. “Many male birds are colorful not just because they’re honestly signaling their quality, but because they’re trying to get chosen,” said Dakota McCoy, a doctoral student at Harvard University who conducted the research as part of her dissertation. “This is basically experimental evidence that whenever there’s a high-stakes test in life, it’s worth your while to cheat a little bit.” The new study is an important contribution to the longstanding debate over how, and why, brightly colored feathers evolved in birds, said Geoffrey Hill, an ornithologist and evolutionary ecologist at Auburn University. “Scientists have spent the last 150 years since Darwin and Wallace trying to understand ornaments in animals and especially colors in birds,” he said. “And this is the kind of original approach that helps us.” © 2021 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 27781 - Posted: 04.21.2021

David Cox When John Abraham began to lose his mind in late 2019, his family immediately feared the worst. Abraham had enjoyed robust health throughout retirement, but now at 80 he suddenly found himself struggling to finish sentences. “I would be talking to people, and all of a sudden the final word wouldn’t come to mind,” he remembers. “I assumed this was simply a feature of ageing, and I was finding ways of getting around it.” But within weeks, further erratic behaviours started to develop. Abraham’s family recall him often falling asleep mid-conversation, he would sometimes shout out bizarre comments in public, and during the night he would wake up every 15 minutes, sometimes hallucinating. Patients can go from being in a nursing home, unable to communicate, to returning to work To his son Steve, the diagnosis seemed inevitable, one which all families dread. “I was convinced my dad had dementia,” he says. “What I couldn’t believe was the speed at which it was all happening. It was like dementia on steroids.” Dementia is not just one disease – it has more than 200 different subtypes. Over the past decade neurologists have become increasingly interested in one particular subtype, known as autoimmune dementia. In this condition, the symptoms of memory loss and confusion are the result of brain inflammation caused by rogue antibodies – known as autoantibodies – binding to the neuronal tissue, rather than an underlying neurodegenerative disease. Crucially this means that unlike almost all other forms of dementia, in some cases it can be cured, andspecialist neurologists have become increasingly adept at both spotting and treating it. © 2021 Guardian News & Media Limited

Keyword: Alzheimers; Neuroimmunology
Link ID: 27780 - Posted: 04.21.2021

By Nambi Ndugga and Austin Frakt American deaths from misuse of substances, including alcohol, have increased over the past two decades, but not uniformly across various demographic groups. Overall rates of alcohol abuse and related deaths have consistently and significantly increased for white non-Hispanic Americans, while Black Americans have experienced a much slower and less significant incline, and some other groups have had declines. More recently, alcohol use has been up during the pandemic, with one study showing a greater increase in misuse among women than among men. (For men, heavy drinking is considered more than four drinks per day and 14 drinks per week, and for women, more than three drinks per day and seven drinks per week, according to the National Institute on Alcohol Abuse and Alcoholism.) “Alcohol kills many more people than many may realize,” said Yusuf Ransome, an assistant professor at Yale’s School of Public Health. “It is a major contributor to deaths linked to physical injuries, interpersonal violence, motor vehicle crashes, self-harm and other harmful outcomes.” One reason for this might be that alcohol is often viewed as socially acceptable. “Alcohol use has been normalized because it is consumed sometimes at family and communal gatherings, casual outings, and that’s the type of drinking that is typically seen or showed within the media,” he said. “We rarely see the long-term health impacts of excessive alcohol use, nor do we show the acute dangers of alcohol misuse and abuse.” Between 2000 and 2016, according to research published in JAMA, alcohol-related deaths continually increased for white men (2.3 percent per year on average) and white women (4.1 percent), with middle-aged white Americans accounting for the highest increase in deaths. Rapid increases during this period in mortality related to alcohol and drugs like opioids among white Americans — particularly those without a college degree — have been termed “deaths of despair.” Sign up for The Upshot Newsletter: Analysis that explains politics, policy and everyday life, with an emphasis on data and charts. © 2021 The New York Times Company

Keyword: Drug Abuse; Stress
Link ID: 27779 - Posted: 04.21.2021

Jordana Cepelewicz During every waking moment, we humans and other animals have to balance on the edge of our awareness of past and present. We must absorb new sensory information about the world around us while holding on to short-term memories of earlier observations or events. Our ability to make sense of our surroundings, to learn, to act and to think all depend on constant, nimble interactions between perception and memory. But to accomplish this, the brain has to keep the two distinct; otherwise, incoming data streams could interfere with representations of previous stimuli and cause us to overwrite or misinterpret important contextual information. Compounding that challenge, a body of research hints that the brain does not neatly partition short-term memory function exclusively into higher cognitive areas like the prefrontal cortex. Instead, the sensory regions and other lower cortical centers that detect and represent experiences may also encode and store memories of them. And yet those memories can’t be allowed to intrude on our perception of the present, or to be randomly rewritten by new experiences. A paper published recently in Nature Neuroscience may finally explain how the brain’s protective buffer works. A pair of researchers showed that, to represent current and past stimuli simultaneously without mutual interference, the brain essentially “rotates” sensory information to encode it as a memory. The two orthogonal representations can then draw from overlapping neural activity without intruding on each other. The details of this mechanism may help to resolve several long-standing debates about memory processing. To figure out how the brain prevents new information and short-term memories from blurring together, Timothy Buschman, a neuroscientist at Princeton University, and Alexandra Libby, a graduate student in his lab, decided to focus on auditory perception in mice. They had the animals passively listen to sequences of four chords over and over again, in what Buschman dubbed “the worst concert ever.” All Rights Reserved © 2021

Keyword: Learning & Memory
Link ID: 27778 - Posted: 04.17.2021

Mark Shelhamer, Sc.D. A few short months ago, news programs around the globe showed NASA engineers and scientists celebrating as a robot named Perseverance successfully landed on the surface of Mars. The mission: capture and share images and audio that have never been seen or heard before. As impressed as most observers were of this major milestone, many couldn’t help but wonder when we might be ready to someday send humans. While it seems the stuff of science fiction and almost inconceivable, the answer—according to recent NASA planning—is before the end of the 2030s, less than two decades away. There are still many obstacles to accomplishing such a feat, many of which have to do with overcoming cognitive and mental health challenges that would impact a crew: long-term isolation, eyesight impairment, and psychological effects from the stress of danger and what could amount to life-or-death decisions. For a mission to succeed, high mental and cognitive function would be absolutely critical; astronauts would be called on to perform demanding tasks in a demanding environment. Losing 20 IQ points halfway to Mars is not an option. Finding the answers to overcoming those obstacles has not only offered us the opportunity to advance spaceflight, it also allows us to apply what we learn to help people here on Earth. While we haven’t yet seen anything as a dramatic as a clear loss of intellectual capacity in space, there are enough indicators to suggest that we should pay close attention. Stress—an emotional or mental state resulting from tense or overwhelming circumstances—and the body’s response to it, which involves multiple systems, from metabolism to muscles to memory—may be the chief challenge that astronauts face. Spaceflight is full of stressors, many of which can have an impact on brain function, cognitive performance, and mental capacities. Several changes in brain structure and function have been observed [in astronauts after spaceflight]. The full implications of these changes for health and performance are not yet known, but any adverse consequences will be increasingly important as spaceflights become longer and more ambitious (such as a three-year mission to Mars). © 2021 The Dana Foundation.

Keyword: Stress
Link ID: 27777 - Posted: 04.17.2021

by Grace Huckins Autism-linked mutations in the CUL3 gene may alter brain structure by disrupting the ‘skeletons’ of neurons, according to a new study. Like all cells, neurons contain long strands of protein that help them keep their shape. These strands, collectively called a cytoskeleton, also help ferry substances within cells and enable developing cells to migrate through the brain. Mice engineered to have a CUL3 mutation that resembles one seen in an autistic person show atypical expression of a variety of cytoskeleton proteins, the new work shows. These mice exhibit some autism-like social behaviors — for instance, unlike wildtype mice, they display no preference for a novel mouse over a familiar one. In addition, various cortical regions in the CUL3 mice are smaller than in wildtype mice, and their cortices are, on the whole, thinner. The brain and behavioral differences observed in these mice may be linked to cytoskeletal abnormalities, says lead investigator Lilia Iakoucheva, associate professor of psychiatry at the University of California, San Diego. Mutations in CUL3 could lead to cytoskeletal changes via RhoA, an enzyme linked to autism, Iakoucheva says. RhoA carries out some of the effects of mutations in KCTD13, an autism-related gene that works with CUL3, according to past work by her team. The new study represents an important step forward in understanding the link between Rho enzymes and autism, says Froylan Calderón de Anda, research group leader at the Center for Molecular Neurobiology Hamburg in Germany, who was not involved in the work. “Little by little, we are adding to this puzzle.” © 2021 Simons Foundation

Keyword: Development of the Brain
Link ID: 27776 - Posted: 04.17.2021

By Lisa Sanders, M.D. It was dark by the time the 41-year-old woman was able to start the long drive from her father’s apartment in Washington, D.C., to her home in Westchester County, N.Y. She was eager to get back to her husband and three children. Somewhere after she crossed the border into Maryland, the woman suddenly developed a terrible itch all over her body. She’d been a little itchy for the past couple of weeks but attributed that to dry skin from her now-faded summertime tan. This seemed very different: much stronger, much deeper. And absolutely everywhere, all at the same time. The sensation was so intense it was hard for the woman to pay attention to the road. She found herself driving with one hand on the steering wheel and the other working to respond to her skin’s new need. There was no rash — or at least nothing she could feel — just the terrible itch, so deep inside her skin that she felt as if she couldn’t scratch hard enough to really get to it. By the light of the Baltimore Harbor Tunnel she saw that her nails and fingers were dark with blood. That scared her, and she tried to stop scratching, but she couldn’t. It felt as if a million ants were crawling all over her body. Not on her skin, but somehow under it. The woman had gone to Washington to help her elderly father move. His place was a mess. Many of his belongings hadn’t been touched in years. She figured that she was having a reaction to all the dust and dirt and who knows what else she encountered while cleaning. As soon as she got home, she took a long shower; the cool water soothed her excoriated skin. She lathered herself with moisturizer and sank gratefully into her bed. But the reprieve didn’t last, and from that night on she was tormented by an itch that no scratching could satisfy. © 2021 The New York Times Company

Keyword: Pain & Touch; Hormones & Behavior
Link ID: 27775 - Posted: 04.17.2021

: Peter Campochiaro, M.D. A 72-year-old lawyer who is pursuing his passion for photography in retirement was suddenly unable to take sharp, well-focused photographs. An examination of each eye revealed yellow spots in the macula, the central area of the retina responsible for sharp vision. The macula in the right eye was thickened and raised in height, substantially reducing and distorting his vision. A test called a fluorescein angiogram, in which fluorescent dye is injected into an arm vein that travels to blood vessels in the retina for imaging, revealed a spot of intense fluorescence that enlarged over time, indicating the presence of abnormal blood vessels leaking plasma into surrounding tissue. An optical coherence tomography scan provided a two-dimensional optical cross section showing fluid beneath and within the right eye’s macula. The patient had a condition known as age-related macular degeneration (AMD), common to about 200 million individuals globally and referred to as “age-related” because it is rarely seen in individuals younger than 60 years old. With people living longer and longer, it is estimated that by 2040, there will be 300 million individuals with AMD throughout the world. And besides the blurred vision that this patient was experiencing, other patients often complain about difficulty recognizing familiar faces; straight lines that appear wavy; dark, empty areas or blind spots; and a general loss of central vision, which is necessary for driving, reading, and recognizing faces. Besides age, smoking is a universally agreed upon risk factor for AMD; hypertension and high blood lipids have been identified in some studies but not others. © 2021 The Dana Foundation.

Keyword: Vision
Link ID: 27774 - Posted: 04.17.2021

By Pam Belluck Reports about the mysterious Covid-related inflammatory syndrome that afflicts some children and teenagers have mostly focused on physical symptoms: rash, abdominal pain, red eyes and, most seriously, heart problems like low blood pressure, shock and difficulty pumping. Now, a new report shows that a significant number of young people with the syndrome also develop neurological symptoms, including hallucinations, confusion, speech impairments and problems with balance and coordination. The study of 46 children treated at one hospital in London found that just over half — 24 — experienced such neurological symptoms, which they had never had before. Those patients were about twice as likely as those without neurological symptoms to need ventilators because they were “very unwell with systemic shock as part of their hyperinflammatory state,” said an author of the study, Dr. Omar Abdel-Mannan, a clinical research fellow at University College London’s Institute of Neurology. Patients with neurological symptoms were also about twice as likely to require medication to improve the heart’s ability to squeeze, he said. The condition, called Multisystem Inflammatory Syndrome in Children (MIS-C), typically emerges two to six weeks after a Covid infection, often one that produces only mild symptoms or none at all. The syndrome is rare, but can be very serious. The latest data from the Centers for Disease Control and Prevention reports 3,165 cases in 48 states, Puerto Rico and the District of Columbia, including 36 deaths. The new findings strengthen the theory that the syndrome is related to a surge of inflammation triggered by an immune response to the virus, Dr. Abdel-Mannan said. For the children in the report, the neurological symptoms mostly resolved as the physical symptoms were treated. © 2021 The New York Times Company

Keyword: Development of the Brain
Link ID: 27773 - Posted: 04.14.2021

Natalie Grover Few species in the animal kingdom can change the size of their brain. Fewer still can change it back to its original size. Now researchers have found the first insect species with that ability: Indian jumping ants. They are like catnip to researchers in the field. In contrast to their cousins, Indian jumping ants colonies do not perish once their queen dies. Instead, “chosen” workers take her place – with expanded ovaries and shrunken brains – to produce offspring. But, if a worker’s “pseudo-queen” status is somehow revoked, their bodies can bounce back, the research suggests. Typically, whether an ant will be a worker or a queen is decided at the larval stage. If fed generously and given the right hormones, the ant has the chance to become a big queen. If not, then it is stuck with a career as a sterile worker deprived of the opportunity to switch – unless it’s part of a species such as the Indian jumping ant. “They have this ability to completely transform themselves at the adult stage, and that makes them interesting to try to understand,” said lead author Dr Clint Penick from US-based Kennesaw State University. Social insects such as ants typically inhabit a caste-based society – the queen reigns as the sole reproducer by secreting pheromones that thwart female worker ants from laying eggs. The other ants work hard: foraging and hunting for food, cleaning, caring for the young and defending the nest. But unlike typical colonies that wither away on the death of their queen, Indian jumping ant colonies are functionally immortal. © 2021 Guardian News & Media Limited

Keyword: Learning & Memory
Link ID: 27772 - Posted: 04.14.2021

By Anushree Dave Screams of joy appear to be easier for our brains to comprehend than screams of fear, a new study suggests. The results add a surprising new layer to scientists’ long-held notion that our brains are wired to quickly recognize and respond to fearful screams as a survival mechanism (SN: 7/16/15). The study looked at different scream types and how listeners perceive them. For example, the team asked participants to imagine “you are being attacked by an armed stranger in a dark alley” and scream in fear and to imagine “your favorite team wins the World Cup” and scream in joy. Each of the 12 participants produced seven different types of screams: six emotional screams (pain, anger, fear, pleasure, sadness, and joy) and one neutral scream where the volunteer just loudly yelled the ‘a’ vowel. Separate sets of study participants were then tasked with classifying and distinguishing between the different scream types. In one task, 33 volunteers were asked to listen to screams and given three seconds to categorize them into one of the seven different screams. In another task, 35 different volunteers were presented with two screams, one at a time, and were asked to categorize the screams as quickly as possible while still trying to make an accurate decision about what type of scream it was, either alarming screams of pain, anger or fear or non-alarming screams of pleasure, sadness or joy. It took longer for participants to complete the task when it involved fear and other alarming screams, and those screams were not as easily recognizable as non-alarming screams like joy, the researchers report online April 13 in PLOS Biology. © Society for Science & the Public 2000–2021.

Keyword: Emotions
Link ID: 27771 - Posted: 04.14.2021

Sarah DeGenova Ackerman The human brain is made up of billions of neurons that form complex connections with one another. Flexibility at these connections is a major driver of learning and memory, but things can go wrong if it isn’t tightly regulated. For example, in people, too much plasticity at the wrong time is linked to brain disorders such as epilepsy and Alzheimer’s disease. Additionally, reduced levels of the two neuroplasticity-controlling proteins we identified are linked to increased susceptibility to autism and schizophrenia. Similarly, in our fruit flies, removing the cellular brakes on plasticity permanently impaired their crawling behavior. While fruit flies are of course different from humans, their brains work in very similar ways to the human brain and can offer valuable insight. One obvious benefit of discovering the effect of these proteins is the potential to treat some neurological diseases. But since a neuron’s flexibility is closely tied to learning and memory, in theory, researchers might be able to boost plasticity in a controlled way to enhance cognition in adults. This could, for example, allow people to more easily learn a new language or musical instrument. A colorful microscope image of a developing fruit fly brain. In this image showing a developing fruit fly brain on the right and the attached nerve cord on the left, the astrocytes are labeled in different colors showing their wide distribution among neurons. Sarah DeGenova Ackerman, CC BY-ND © 2010–2021, The Conversation US, Inc.

Keyword: Learning & Memory; Glia
Link ID: 27770 - Posted: 04.14.2021