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

Keyword: Development of the Brain; Epilepsy
Link ID: 28714 - Posted: 03.23.2023

By Brian Gallagher One question for Christopher Timmermann, a cognitive neuroscientist at the Centre for Psychedelic Research at Imperial College London, where he leads the DMT Research Group and focuses on the nature of consciousness. What happens to my brain on the psychedelic DMT? The DMT experience is one in which people report going into a different dimension, an alternate reality that feels convincingly real, even more real than this everyday reality. One that has a spiritual significance. In that DMT experience, they sometimes encounter beings. In our latest study we looked at brain scans using fMRI and EEG, and found that this feeling of immersion appears to be underpinned by a dysregulation of the systems in the human brain—in the prefrontal cortex, in the temporal cortices—involved in planning, decision making, and semantics. The way in which we construct meaning, essentially. The brain usually functions in this modular, organized, hierarchical way. You have different networks and systems that crystallize as we grow older. What we see with DMT (specifically N,N-Dimethyltryptamine) is that the systems that generate complex behaviors and tasks stop working in this specialized fashion. They start to work in synchrony with the rest of the brain. The specialization is interrupted. The hierarchy is dysregulated, flattens out. What you have as a result is a more integrated connectivity in the brain. In our day-to-day lives, we have a very good demarcation of what happens inside us versus what happens outside. The sensory areas of the brain that allow us to engage with the external world are very much separated from the reflective areas of the brain that allow us to engage with ourselves. Not on DMT. What we see is that this separation, that usually divides these two poles of organization of the brain, starts to mesh together. The neurons are firing in sync. © 2023 NautilusNext Inc.,

Keyword: Drug Abuse; Depression
Link ID: 28713 - Posted: 03.23.2023

Nicola Davis Science Correspondent If the sound of someone chewing gum or slurping their tea gets on your nerves, you are not alone. Researchers say almost one in five people in the UK has strong negative reactions to such noises. Misophonia is a disorder in which people feel strong emotional responses to certain sounds, feeling angry, distressed or even unable to function in social or work settings as a result. But just how common the condition is has been a matter of debate. Now researchers say they have found 18.4% of the UK population have significant symptoms of misophonia. “This is the very first study where we have a representative sample of the UK population,” said Dr Silia Vitoratou, first author of the study at King’s College London. “Most people with misophonia think they are alone, but they are not. This is something we need to know [about] and make adjustments if we can.” Writing in the journal Plos One, the team report how they gathered responses from 768 people using metrics including the selective sound sensitivity syndrome scale. This included one questionnaire probing the sounds that individuals found triggering, such as chewing or snoring, and another exploring the impact of such sounds – including whether they affected participants’ social life and whether the participant blamed the noise-maker – as well as the type of emotional response participants felt to the sounds and the intensity of their emotions. As a result, each participant was given an overall score. The results reveal more than 80% of participants had no particular feelings towards sounds such as “normal breathing” or “yawning” but this plummeted to less than 25% when it came to sounds including “slurping”, “chewing gum” and “sniffing”. © 2023 Guardian News & Media Limited

Keyword: Hearing; Attention
Link ID: 28712 - Posted: 03.23.2023

By Freda Kreier The only cure to being drunk is to wait it out. But that might not always be the case: Injecting drunk mice with a naturally occurring hormone helped them sober up more quickly than they otherwise would have, a new study shows. Mice that received a shot of FGF21 — a hormone made by the liver — woke up from a drunken stupor roughly twice as fast as those that didn’t, researchers report in the March 7 Cell Metabolism. The find could one day be used to help treat alcohol poisoning, a sometimes-deadly side effect of heavy drinking that lands millions of people in the emergency room every year, says molecular endocrinologist David Mangelsdorf. The sobering effect of FGF21 isn’t the first time the hormone has been linked to drinking. Scientists have previously shown that livers ramp up production of this hormone when alcohol floods the bloodstream. And while FGF21 doesn’t help break down alcohol, researchers have found that the hormone can help protect livers from the toxic effects of liquor while dampening the desire to continue drinking in mice and monkeys. Those findings made Mangelsdorf, of the University of Texas Southwestern Medical Center in Dallas, and his colleagues curious whether FGF21 also plays a role in recovering from too much alcohol. So the team fed mice enough alcohol to knock them out and waited to see how long it took for them to wake up. © Society for Science & the Public 2000–2023.

Keyword: Drug Abuse; Hormones & Behavior
Link ID: 28711 - Posted: 03.23.2023

Miryam Naddaf It is thanks to proteins in the nose called odour receptors that we find the smell of roses pleasant and that of rotting food foul. But little is known about how these receptors detect molecules and translate them into scents. Now, for the first time, researchers have mapped the precise 3D structure of a human odour receptor, taking a step forwards in understanding the most enigmatic of our senses. The study, published in Nature on 15 March1, describes an olfactory receptor called OR51E2 and shows how it ‘recognizes’ the smell of cheese through specific molecular interactions that switch the receptor on. “It’s basically our first picture of any odour molecule interacting with one of our odour receptors,” says study co-author Aashish Manglik, a pharmaceutical chemist at the University of California, San Francisco. Smell mystery The human genome contains genes encoding 400 olfactory receptors that can detect many odours. Mammalian odour-receptor genes were first discovered in rats by molecular biologist Richard Axel and biologist Linda Buck in 19912. Researchers in the 1920s estimated that the human nose could discern around 10,000 smells3, but a 2014 study suggests that we can distinguish more than one trillion scents4. Each olfactory receptor can interact with only a subset of smelly molecules called odorants — and a single odorant can activate multiple receptors. It is “like hitting a chord on a piano”, says Manglik. “Instead of hitting a single note, it’s a combination of keys that are hit that gives rise to the perception of a distinct odour.” Beyond this, little is known about exactly how olfactory receptors recognize specific odorants and encode different smells in the brain. Technical challenges in producing mammalian olfactory-receptor proteins using standard laboratory methods have made it difficult to study how these receptors bind to odorants. © 2023 Springer Nature Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 28710 - Posted: 03.18.2023

By Katherine Harmon Courage We all might wish for minds as retentive as a hard drive. Memory file created. Saved. Ready for access at any time. But don’t yet go wishing for the memory performance of AI. Artificial neural networks are prone to a troublesome glitch known, evocatively, as catastrophic forgetting. These seemingly tireless networks can keep learning tasks day and night. But sometimes, once a new task is learned, any recollection of an old task vanishes. It’s as if you learned to play tennis decently well, but after being taught to play water polo, you suddenly had no recollection of how to swing a racket. This apparent network overload put an idea in the head of Maxim Bazhenov, a professor who studies computational neuroscience and sleep at the University of California San Diego School of Medicine. Perhaps the spiking neural networks he was working with simply needed a rest. In natural sleep, he had seen that the same basic brain processes occur in humans and in honeybees, working over information accumulated during waking moments. “That machinery presumably was doing something useful” in order to be conserved across evolutionary paths, he says. So, he thought, why not try a similar state for the machines. The idea was to simply provide the artificial neural networks with a break from external stimuli, to instruct them to go into a sort of rest state. Like the dozing human brain, the networks were still active, but instead of taking in new information, they were mulling the old stuff, consolidating, surfacing patterns.

Keyword: Sleep; Learning & Memory
Link ID: 28709 - Posted: 03.18.2023

By Allison Parshall Functional magnetic resonance imaging, or fMRI, is one of the most advanced tools for understanding how we think. As a person in an fMRI scanner completes various mental tasks, the machine produces mesmerizing and colorful images of their brain in action. Looking at someone’s brain activity this way can tell neuroscientists which brain areas a person is using but not what that individual is thinking, seeing or feeling. Researchers have been trying to crack that code for decades—and now, using artificial intelligence to crunch the numbers, they’ve been making serious progress. Two scientists in Japan recently combined fMRI data with advanced image-generating AI to translate study participants’ brain activity back into pictures that uncannily resembled the ones they viewed during the scans. The original and re-created images can be seen on the researchers’ website. “We can use these kinds of techniques to build potential brain-machine interfaces,” says Yu Takagi, a neuroscientist at Osaka University in Japan and one of the study’s authors. Such future interfaces could one day help people who currently cannot communicate, such as individuals who outwardly appear unresponsive but may still be conscious. The study was recently accepted to be presented at the 2023 Conference on The study has made waves online since it was posted as a preprint (meaning it has not yet been peer-reviewed or published) in December 2022. Online commentators have even compared the technology to “mind reading.” But that description overstates what this technology is capable of, experts say. “I don’t think we’re mind reading,” says Shailee Jain, a computational neuroscientist at the University of Texas at Austin, who was not involved in the new study. “I don’t think the technology is anywhere near to actually being useful for patients—or to being used for bad things—at the moment. But we are getting better, day by day.”

Keyword: Vision; Brain imaging
Link ID: 28708 - Posted: 03.18.2023

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

Keyword: Development of the Brain
Link ID: 28707 - Posted: 03.18.2023

ByClaudia Lopez Lloreda Peanuts have a dark side. In some people, they can cause a dangerous and sometimes deadly allergic reaction marked by a sharp drop in body temperature and blood pressure, as well as difficulty breathing. This anaphylactic shock has typically been blamed on the immune system going into overdrive. But a new study in mice pegs an additional culprit: the nervous system. The findings, reported today in Science Immunology, “are line with what people thought but no one was actually able to demonstrate,” says Sebastien Talbot, a neuroimmunologist at Queen’s University who was not involved in the study. The work, he says, could open up new targets to treat severe allergic reactions in people. Anaphylaxis strikes about one in 50 individuals in the United States every year. Besides peanuts, bee stings and some medicines are common triggers. These allergens cause the immune system’s mast cells to release a barrage of histamine and other molecules that spread throughout the body, dilating blood vessels and narrowing airways. Body temperature can also drop, making people feel cold and clammy, though why this happens has been less clear. Mice experience anaphylaxis, too. When exposed to an allergen, they lie on their bellies and stretch out. Such behaviors are controlled by the central nervous system, which made Soman Abraham, an immunologist at Duke University, suspect nerves may also play a role in severe allergic reactions. To find out, he and colleagues gave the mice ovalbumin—the main protein found in egg whites and a known trigger of anaphylaxis—and used electrodes and microscopy to record and measure neuron activity. As in humans, the rodents’ body temperature dropped—about 10°C. But the mice’s brains didn’t register this as a sudden freeze; instead, brain areas that typically respond to heat had higher levels of activity. This false feeling of warmth explains why the animals stretch out as if they’re overheating even as their body temperature drops.

Keyword: Neuroimmunology
Link ID: 28706 - Posted: 03.18.2023

By Bethany Brookshire When you’re stressed and anxious, you might feel your heart race. Is your heart racing because you’re afraid? Or does your speeding heart itself contribute to your anxiety? Both could be true, a new study in mice suggests. By artificially increasing the heart rates of mice, scientists were able to increase anxiety-like behaviors — ones that the team then calmed by turning off a particular part of the brain. The study, published in the March 9 Nature, shows that in high-risk contexts, a racing heart could go to your head and increase anxiety. The findings could offer a new angle for studying and, potentially, treating anxiety disorders. The idea that body sensations might contribute to emotions in the brain goes back at least to one of the founders of psychology, William James, says Karl Deisseroth, a neuroscientist at Stanford University. In James’ 1890 book The Principles of Psychology, he put forward the idea that emotion follows what the body experiences. “We feel sorry because we cry, angry because we strike, afraid because we tremble,” James wrote. The brain certainly can sense internal body signals, a phenomenon called interoception. But whether those sensations — like a racing heart — can contribute to emotion is difficult to prove, says Anna Beyeler, a neuroscientist at the French National Institute of Health and Medical Research in Bordeaux. She studies brain circuitry related to emotion and wrote a commentary on the new study but was not involved in the research. “I’m sure a lot of people have thought of doing these experiments, but no one really had the tools,” she says. Deisseroth has spent his career developing those tools. He is one of the scientists who developed optogenetics — a technique that uses viruses to modify the genes of specific cells to respond to bursts of light (SN: 6/18/21; SN: 1/15/10). Scientists can use the flip of a light switch to activate or suppress the activity of those cells. © Society for Science & the Public 2000–2023.

Keyword: Emotions
Link ID: 28705 - Posted: 03.15.2023

By Ellen Barry It is a truism that time seems to expand or contract depending on our circumstances: In a state of terror, seconds can stretch. A day spent in solitude can drag. When we’re trying to meet a deadline, hours race by. A study published this month in the journal Psychophysiology by psychologists at Cornell University found that, when observed at the level of microseconds, some of these distortions could be driven by heartbeats, whose length is variable from moment to moment. The psychologists fitted undergraduates with electrocardiograms to measure the length of each heartbeat precisely, and then asked them to estimate the length of brief audio tones. The psychologists discovered that after a longer heartbeat interval, subjects tended to perceive the tone as longer; shorter intervals led subjects to assess the tone as shorter. Subsequent to each tone, the subjects’ heartbeat intervals lengthened. A lower heart rate appeared to assist with perception, said Saeedeh Sadeghi, a doctoral candidate at Cornell and the study’s lead author. “When we need to perceive things from the outside world, the beats of the heart are noise to the cortex,” she said. “You can sample the world more — it’s easier to get things in — when the heart is silent.” The study provides more evidence, after an era of research focusing on the brain, that “there is no single part of the brain or body that keeps time — it’s all a network,” she said, adding, “The brain controls the heart, and the heart, in turn, impacts the brain.” Interest in the perception of time has exploded since the Covid pandemic, when activity outside the home came to an abrupt halt for many and people around the world found themselves facing stretches of undifferentiated time. A study of time perception conducted during the first year of the lockdown in Britain found that 80 percent of participants reported distortions in time, in different directions. On average, older, more socially isolated people reported that time slowed, and younger, more active people reported that it sped up. © 2023 The New York Times Company

Keyword: Attention
Link ID: 28704 - Posted: 03.15.2023

Hannah Devlin Daniela da Silva is feeling good. Lying cocooned under fleece blankets inside a medical scanner, her eyes are closed and her mind is focused and remarkably unperturbed by negative thoughts. Three hours earlier, the 39-year-old yoga teacher and neuroscience student was given a dose of the stimulant drug dextroamphetamine, which is often used to treat ADHD. “I’m having a serotonin increase. Oh definitely,” she predicts before entering the PET scanner. Da Silva is a healthy volunteer in a trial using a pioneering brain imaging technique designed to measure serotonin changes in the brains of living people. Last year, scientists used the scan to obtain what they claimed to be the first direct evidence that serotonin release is blunted in the brains of people with depression. The findings added fuel to a fiercely fought debate over the role of the brain chemical – if any – in depression. Just months earlier, a high-profile scientific review caused a stir when it reached the opposite conclusion that “after a vast amount of research, conducted over several decades, there is no convincing evidence” for the idea that depression is caused by a chemical imbalance in the brain. To many, it was news that the case for serotonin being implicated in depression was not already watertight. The idea of a chemical imbalance is embedded in public consciousness and has shaped the way we view mental illness. The main class of antidepressant drugs, selective serotonin reuptake inhibitors (SSRIs), are widely assumed to work by boosting serotonin levels. So the suggestion that the way we discuss, and treat, mental illness might be based on shaky foundations was disconcerting. But it also served as a wake-up call that this view of depression has failed to provide effective treatments for a substantial proportion of those affected. Serotonin is sometimes referred to as the “happy hormone”, conjuring up the image of a substance that swooshes through the brain leaving a warm glow of contentment in its wake. In reality, its biological role is complex and extends to basic functions like the regulation of sleep, intestinal activity and the formation of blood clots. In the brain, serotonin acts as a chemical messenger between neurons, but also as a form of volume control that alternately increases or decreases the level of communication between other neurons. “Put another way, serotonin fine-tunes the working of the brain, regulating how different parts of the brain communicate with each other,” says Dr James Rucker, a consultant psychiatrist at South London and Maudsley NHS foundation trust, whose research focuses on developing new treatments for depression. © 2023 Guardian News & Media Limited

Keyword: Depression; Emotions
Link ID: 28703 - Posted: 03.15.2023

By Mark Johnson Archaeologists excavating the ancient city of Megiddo in modern-day Israel have discovered a window into medicine’s ancient past: the 3,500-year-old bones of two brothers, both bearing signs of an infectious disease, and one scarred from cranial surgery that may have been an attempt to treat the illness. A recent paper in the journal PLOS ONE describes the discovery, which is one of the region’s earliest examples of a widely practiced type of surgery that creates an opening in the skull. The work should help scientists and anthropologists understand how surgeries developed and became more effective over time. The procedure, known as cranial trephination, was performed thousands of years ago in different parts of the world, including Europe, Africa, China and South America. A 2020 paper listed trephination as one of “the first three procedures that marked the dawn of surgery,” along with circumcision and bladder stone removal. Versions of the procedure, called either a craniotomy or craniectomy, are still practiced today “as emergency treatment for brain swelling, bleeding, as well as for surgeries to treat epilepsy and to remove some tumors,” said John Verano, a professor of anthropology at Tulane University, who described the new paper as an interesting case report. Although the electric drills used today are a far cry from the handheld flints and metal tools used thousands of years ago, the objective — making a hole in the skull — is the same. However, Verano stressed that trephination was not brain surgery. “They were careful not to cut through the membrane protecting the brain, which would lead to meningitis and death if not done under strictly sterile conditions,” he said. Archaeologists and anthropologists cannot be certain what conditions ancient healers were treating by cutting into the skull, but most speculation centers on serious head injuries. Other possibilities include epilepsy, mental illness and swelling in the brain.

Keyword: Brain Injury/Concussion
Link ID: 28702 - Posted: 03.15.2023

By Christina Jewett The Food and Drug Administration has approved a Pfizer nasal spray for treatment of migraines that uses a different therapy from other nasal products on the market for severe headache pain, the company said on Friday. The fast-acting treatment, which is called zavegepant and will be sold as Zavzpret, performed better than a placebo in relieving pain and patients’ most bothersome symptoms, according to clinical trial results published in the journal Lancet Neurology. Participants in the trial who took the medication were more likely to report returning to normal function 30 minutes to two hours after taking it. The gains, though, were not significant for every patient. A study tracked the experience of 1,269 patients — half on the drug and half on a placebo — focusing on how they reported feeling two hours after using either substance. About 24 percent on the medication reported freedom from pain, compared to about 15 percent who took a placebo, according to the study. Dr. Timothy A. Collins, chief of the headache division at Duke University Medical Center’s neurology department, said the product gave doctors a new option in a nasal spray format that patients with migraines tended to appreciate. He said the condition often comes with nausea, so swallowing a pill can be unpleasant. He also said the drug presented few side effects, like drowsiness, that had been reported with other products. “We’ve been waiting for this medication to come out,” Dr. Collins said. “It’s a really helpful addition to migraine management.” One additional upside of the medication is that it’s safe for patients who have had a heart attack or a stroke, he added. Pfizer said the medication would be available in pharmacies in July, but did not disclose the estimated price of the new spray. The company estimated that nearly 40 million people in the United States suffered from migraines each year. © 2023 The New York Times Company

Keyword: Pain & Touch
Link ID: 28701 - Posted: 03.15.2023

By Elizabeth Preston Several years ago, Christian Rutz started to wonder whether he was giving his crows enough credit. Rutz, a biologist at the University of St. Andrews in Scotland, and his team were capturing wild New Caledonian crows and challenging them with puzzles made from natural materials before releasing them again. In one test, birds faced a log drilled with holes that contained hidden food, and could get the food out by bending a plant stem into a hook. If a bird didn’t try within 90 minutes, the researchers removed it from the dataset. But, Rutz says, he soon began to realize he was not, in fact, studying the skills of New Caledonian crows. He was studying the skills of only a subset of New Caledonian crows that quickly approached a weird log they’d never seen before — maybe because they were especially brave, or reckless. The team changed their protocol. They began giving the more hesitant birds an extra day or two to get used to their surroundings, then trying the puzzle again. “It turns out that many of these retested birds suddenly start engaging,” Rutz says. “They just needed a little bit of extra time.” Scientists are increasingly realizing that animals, like people, are individuals. They have distinct tendencies, habits and life experiences that may affect how they perform in an experiment. That means, some researchers argue, that much published research on animal behavior may be biased. Studies claiming to show something about a species as a whole — that green sea turtles migrate a certain distance, say, or how chaffinches respond to the song of a rival — may say more about individual animals that were captured or housed in a certain way, or that share certain genetic features. That’s a problem for researchers who seek to understand how animals sense their environments, gain new knowledge and live their lives. “The samples we draw are quite often severely biased,” Rutz says. “This is something that has been in the air in the community for quite a long time.” In 2020, Rutz and his colleague Michael Webster, also at the University of St. Andrews, proposed a way to address this problem. They called it STRANGE. © 2023 Annual Reviews

Keyword: Emotions; Evolution
Link ID: 28700 - Posted: 03.11.2023

By Bruce Bower Monkeys in southern Thailand use rocks to pound open oil palm nuts, inadvertently shattering stone pieces off their makeshift nutcrackers. These flakes resemble some sharp-edged stone tools presumed to have been created on purpose by ancient hominids, researchers say. Thailand’s long-tailed macaques (Macaca fascicularis) produce shards that could easily be mistaken for stone flakes previously found at 17 East African hominid sites dating from about 3.3 million to 1.56 million years ago, say archaeologist Tomos Proffitt and colleagues. The finding suggests that ancient hominids may sometimes have created the stone flakes by accident while using rocks to smash nuts, bones or other objects, the scientists report March 10 in Science Advances. Previous research has already shown that rock-wielding capuchin monkeys in Brazil unwittingly produce hominid-like stone flakes (SN: 10/19/16). Observations of rock bashing by these two monkey species undermine a long-standing assumption that hominids must have intentionally made certain ancient stone flakes, including some of the earliest known examples of tools, Proffitt says (SN: 6/3/19). It’s time to reevaluate how such determinations are made, he contends. Proffitt’s group identified 219 complete and fragmented stone flakes at 40 macaque nut-cracking sites on the island where the monkeys live. The team also found rocks showing damage consistent with having been used either as pounding implements or pounding platforms. Some differences do exist between macaque and hominid stone flakes, says Proffitt, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. For instance, many macaque flakes display battering damage on only one side, versus frequent two-sided damage on hominid artifacts. © Society for Science & the Public 2000–2023.

Keyword: Evolution; Intelligence
Link ID: 28699 - Posted: 03.11.2023

By Catherine Offord When you come down with the flu, your body lets you know. You lose your appetite, you feel sluggish, and your mood takes a hit. The infection itself doesn’t cause these symptoms—your brain does. Now, scientists may have figured out a key part of how this happens. Studying mice with influenza, they found a cluster of nerve cells in the back of the throat that detects a virus’ presence and sends signals to the brain, triggering symptoms that respond to the infection. The study is among the first to pin this response on a specific population of nerve cells, says Anoj Ilanges, a biologist at the Howard Hughes Medical Institute’s Janelia Research Campus who was not involved in the work. “They’ve done a really great job of looking at this comprehensively.” Scientists know feeling crummy during an illness is partly the result of chemicals produced by infected tissue. Several of these compounds, such as prostaglandins, are known to trigger sickness behaviors. (Drugs such as ibuprofen work by blocking prostaglandin production.) But it’s often unclear exactly how these chemicals communicate with the brain, says Stephen Liberles, a molecular neuroscientist at Harvard Medical School. “Surprisingly little is understood about how the brain becomes aware that there’s an infection in the body.” In the new study, Liberles, postdoc Na-Ryum Bin, and colleagues focused on influenza, which infects the body’s airways. Previous research hinted that a type of prostaglandin made in response to viral infection called PGE2 could travel via the blood to interact with cells in the brain. But when the researchers infected mice that had been genetically engineered to lack receptors for PGE2 in the central nervous system, the animals still acted sick—avoiding eating and drinking, and moving around less than normal.

Keyword: Neuroimmunology
Link ID: 28698 - Posted: 03.11.2023

By McKenzie Prillaman The wiring of one insect’s brain no longer contains much uncharted territory. All of the nerve cells — and virtually every connection between them — in a larval fruit fly brain have now been mapped, researchers report in the March 10 Science. It’s the most complex whole brain wiring diagram yet created. Previously, just three organisms — a sea squirt and two types of worm — had their brain circuitry fully diagrammed to this resolution. But the brains of those creatures have only a few hundred neurons. The scientists who conducted the new study wanted to understand much more complicated brains. Fruit flies (Drosophila melanogaster) share a wide range of behaviors with humans, including integrating sensory information and learning. Larvae perform nearly all the same actions as adult flies — except for some, like flying and mating — but have smaller brains, making data collection much faster (SN: 7/19/18). The idea for this project came 12 years ago, says neuroscientist Marta Zlatic of the MRC Laboratory of Molecular Biology in Cambridge, England. At that time, she and her colleagues captured electron microscope images of the entire larval fruit fly brain. They then stitched those images together in a computer and manually traced each neuron to create a 3-D rendering of the cells. Finally, the team found the connections where information gets passed between the cells, and even determined the sending and receiving ends. Neurons transmit information to one another in circuits. Exploring the neurons’ connectivity patterns — not just directly linked partners, but also the links of linked cells and so on — revealed 93 different types of neurons. The classes were consistent with preexisting groupings characterized by shape and function. And nearly 75 percent of the most well-connected neurons were tied to the brain’s learning center, indicating the importance of learning in animals. © Society for Science & the Public 2000–2023.

Keyword: Brain imaging; Development of the Brain
Link ID: 28697 - Posted: 03.11.2023

By Lisa Sanders, M.D. “It’s happening,” the 58-year-old man said quietly. Dr. Mark Chelmowski looked over to observe his patient. He was leaning forward, elbows on table, head propped up on his hands. Beads of sweat suddenly appeared on the man’s brow. More popped up on his cheeks, then his jaw. Rivulets ran down the contours of his face, then dripped off his chin onto the table. The man’s eyes were closed. He almost seemed asleep. Chelmowski said his name. “Yes, doctor” was the only response the normally chatty man gave. It was as if he were somehow distracted by the profound sweating. The patient’s vital signs were normal. He didn’t have a fever. His blood pressure and heart rate were normal. Throughout the exam, the patient sat quietly sweating. The collar, front and back of his shirt darkened. Then, as abruptly as it started, it was over. He opened his eyes and looked at Chelmowski. The patient could see the surprise in his doctor’s face. Chelmowski knew about his episodes of sweating — the two of them had been trying to figure them out for the past five months — but he had not yet witnessed one. The first time it happened, the patient was in his car on the way to the gym when suddenly he felt intensely hot. It was a bright July day in the Milwaukee area and seasonably warm. But this heat felt as if it came from inside his body. A vague prickling sensation spread down his face and neck to his chest and back. His heart seemed to speed up and then — pow — he was drenched in sweat. He turned the car around and headed home. He was describing the strange event to his partner when it happened again. And again. Each episode lasted only a couple of minutes, but it was strange. The sweating was so excessive. After a fourth episode, the patient’s partner insisted they go to the emergency room. He had another bout in front of the E.R. doctor, who immediately admitted him to the hospital. He was worried the patient might be having a heart attack. Profuse sweating often accompanies myocardial infarctions, the doctor told him. But it wasn’t his heart. He was discharged the next day and encouraged to follow up with his primary-care doctor. © 2023 The New York Times Company

Keyword: Epilepsy; Hormones & Behavior
Link ID: 28696 - Posted: 03.11.2023

By Susan Milius In a castaway test setup, groups of young honeybees figuring out how to forage on their own start waggle dancing spontaneously — but badly. Waggling matters. A honeybee’s rump-shimmy runs and turning loops encode clues that help her colony mates fly to food she has found, sometimes kilometers away. However, five colonies in the new test had no older sisters or half-sisters around as role models for getting the dance moves right. Still, dances improved in some ways as the youngsters wiggled and looped day after day, reports behavioral ecologist James Nieh of the University of California, San Diego. But when waggling the clues for distance information, Apis mellifera without role models never did match the timing and coding in normal colonies where young bees practiced with older foragers before doing the main waggle themselves. The youngsters-only colonies thus show that social learning, or the lack of it, matters for communicating by dance among honeybees, Nieh and an international team of colleagues say in the March 10 Science. Bee waggle dancing, a sort of language, turns out to be both innate and learned, like songbird or human communication. The dance may appear simple in a diagram, but executing it on expanses of honeycomb cells gets challenging. Bees are “running forward at over one body length per second in the pitch black trying to keep the correct angle, surrounded by hundreds of bees that are crowding them,” Nieh says. Beekeepers and biologists know that some kinds of bees can learn from others of their kind — some bumblebees even tried soccer (SN: 2/23/17). But when it comes to waggle dancing, “I think people have assumed it’s genetic,” Nieh says. That would make this fancy footwork more like the chatty but innate communications of cuttlefish color change, for instance. The lab bee-castaway experiments instead show a nonhuman example of “social learning for sophisticated communication,” Nieh says. © Society for Science & the Public 2000–2023.

Keyword: Animal Communication; Evolution
Link ID: 28695 - Posted: 03.11.2023