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

By Azeen Ghorayshi For decades, male mice have been the default in scientific experiments that test new drugs or examine the connections of the brain. The reason? Female mice, which experience a four- to five-day cycle of fluctuating ovarian hormones, were thought to be too complicated. Accounting for the hormonal changes was viewed as too cumbersome and too expensive. But the estrous cycle has little to do with how female mice behave, according to a new study that used machine-learning software to track the second-to-second behavior of animals exploring an open space. Male mice actually exhibited more erratic behavior than females did. The study, published in the journal Current Biology on Tuesday, challenges century-old stereotypes that kept female animals out of laboratory research — and, until the 1990s, barred women from clinical trials. The new research is “tipping all of these assumptions about sex differences and the influence of hormones on their head,” said Rebecca Shansky, a behavioral neuroscientist at Northeastern University and a co-author of the new study. The cost of excluding females — whether human or animal — from scientific research is high. Women are almost twice as likely as men to experience severe side effects from drugs, most of which have dosages based on the initial testing done in men. Women also may not derive the same benefits from the drugs. Women “capable of becoming pregnant,” as the federal government put it, were largely excluded from clinical trials of drugs until 1993, when a new law required researchers funded by the National Institutes of Health to include women and minority groups. In the decades since, women have made up close to half of clinical research participants, though they still lag behind in studies of certain drugs, like those used to treat cardiovascular disease and psychiatric disorders. But a large sex gap persisted in basic science research using lab animals, studies that pave the way to medical breakthroughs. In neuroscience, according to a review published in 2010, studies of male lab animals outnumbered female ones by a factor of five. © 2023 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 28694 - Posted: 03.08.2023

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

Keyword: Development of the Brain; Learning & Memory
Link ID: 28693 - Posted: 03.08.2023

By Dana Mackenzie On October 2, 2022, four days after Hurricane Ian hit Florida, a search-and-rescue Rottweiler named Ares was walking the ravaged streets of Fort Myers when the moment came that he had been training for. Ares picked up a scent within a smashed home and raced upstairs, with his handler trailing behind, picking his way gingerly through the debris. They found a man who had been trapped inside his bathroom for two days after the ceiling caved in. Some 152 people died in Ian, one of Florida’s worst hurricanes, but that lucky man survived thanks to Ares’ ability to follow a scent to its source. We often take for granted the ability of a dog to find a person buried under rubble, a moth to follow a scent plume to its mate or a mosquito to smell the carbon dioxide you exhale. Yet navigating by nose is more difficult than it might appear, and scientists are still working out how animals do it. “What makes it hard is that odors, unlike light and sound, don’t travel in a straight line,” says Gautam Reddy, a biological physicist at Harvard University who coauthored a survey of the way animals locate odor sources in the 2022 Annual Review of Condensed Matter Physics. You can see the problem by looking at a plume of cigarette smoke. At first it rises and travels in a more or less straight path, but very soon it starts to oscillate and finally it starts to tumble chaotically, in a process called turbulent flow. How could an animal follow such a convoluted route back to its origin? Over the last couple of decades, a suite of new high-tech tools, ranging from genetic modification to virtual reality to mathematical models, have made it possible to explore olfactory navigation in radically different ways. The strategies that animals use, as well as their success rates, turn out to depend on a variety of factors, including the animal’s body shape, its cognitive abilities and the amount of turbulence in the odor plume. One day, this growing understanding may help scientists develop robots that can accomplish tasks that we now depend on animals for: dogs to search for missing people, pigs to search for truffles and, sometimes, rats to search for land mines. © 2023 Annual Reviews

Keyword: Chemical Senses (Smell & Taste)
Link ID: 28692 - Posted: 03.08.2023

Martha Bebinger For two decades — as opioid overdose deaths rose steadily — the federal government limited access to buprenorphine, a medication that addiction experts consider the gold-standard for treating patients with an opioid use disorder. Study after study shows it helps people continue addiction treatment while reducing the risk of overdose, and death. Clinicians who wanted to prescribe the medicine had to complete an 8-hour training. They could only treat a limited number of patients and had to keep special records. They were given a Drug Enforcement Administration (DEA) registration number starting with X, a designation that many doctors say made them a target for drug enforcement audits. "Just the process associated with taking care of our patients with a substance use disorder made us feel like, 'boy, this is dangerous stuff,'" says Dr. Bobby Mukkamala, who chairs the American Medical Association's task force on substance use disorder. "The science doesn't support that but the rigamarole suggested that." That rigamarole is mostly gone. Congress eliminated what became known as the "X-waiver" in legislation President Biden signed late last year. Now begins what some addiction experts are calling a truth serum moment. Was the X-waiver and the burdens that came with it the real reason only about 7% of clinicians in the U.S. were cleared to prescribe buprenorphine? Or was it an excuse that masked hesitation about treating addiction, if not outright disdain for these patients? There's great optimism among some leaders that getting rid of the X-waiver will expand access to buprenorphine and reduce overdoses. One study from 2021 shows taking buprenorphine reduces the risk by 50%. The medication is an opioid that produces much weaker effects than heroin or fentanyl and reduces cravings for those deadlier drugs. © 2023 npr

Keyword: Drug Abuse
Link ID: 28691 - Posted: 03.08.2023

By Joshua C. Kendall Schizophrenia has long been understood to be among the most serious and intractable of all mental disorders. The condition typically begins in early adulthood and lasts a lifetime. Its hallmark features include hallucinations, withdrawal from social situations, and serious problems in cognition, such as a highly irrational belief system and a limited attention span. In “Malady of the Mind: Schizophrenia and the Path to Prevention,” a comprehensive history of this perplexing mental disorder from the Ancient World to the present, Jeffrey A. Lieberman argues that psychiatry has finally turned a corner in determining both what causes schizophrenia and how to treat it. “Due to the progress and success of science,” he concludes, schizophrenia is “a malady of the mind no more.” BOOK REVIEW — “Malady of the Mind: Schizophrenia and the Path to Prevention,” by Jeffrey A. Lieberman (Simon & Schuster, 528 pages). It’s a bold pronouncement to make, given that Lieberman himself admits that the history of psychiatry is filled with declarations of victory over a disorder that nonetheless continues to defy efforts to pin it down. Several once-heralded treatments — say, insulin coma therapy and ice-pick lobotomies, which were both popular in the 1940s — are now dismissed as barbaric. Likewise, while antipsychotic medications, which were introduced with great fanfare in the mid-1950s and remain today’s treatment of choice, can reduce the intensity of the most troubling symptoms for some patients, they are far from a cure. The chapters on past approaches are elegantly written and are helpful in giving context to current debates about how best to address this devastating illness.

Keyword: Schizophrenia
Link ID: 28690 - Posted: 03.08.2023

By Marta Zaraska The Neumayer III polar station sits near the edge of Antarctica’s unforgiving Ekström Ice Shelf. During the winter, when temperatures can plunge below minus 50 degrees Celsius and the winds can climb to more than 100 kilometers per hour, no one can come or go from the station. Its isolation is essential to the meteorological, atmospheric and geophysical science experiments conducted there by the mere handful of scientists who staff the station during the winter months and endure its frigid loneliness. But a few years ago, the station also became the site for a study of loneliness itself. A team of scientists in Germany wanted to see whether the social isolation and environmental monotony marked the brains of people making long Antarctic stays. Eight expeditioners working at the Neumayer III station for 14 months agreed to have their brains scanned before and after their mission and to have their brain chemistry and cognitive performance monitored during their stay. (A ninth crew member also participated but could not have their brain scanned for medical reasons.) As the researchers described in 2019, in comparison to a control group, the socially isolated team lost volume in their prefrontal cortex — the region at the front of the brain, just behind the forehead, that is chiefly responsible for decision-making and problem-solving. They also had lower levels of brain-derived neurotrophic factor, a protein that nurtures the development and survival of nerve cells in the brain. The reduction persisted for at least a month and a half after the team’s return from Antarctica. It’s uncertain how much of this was due purely to the social isolation of the experience. But the results are consistent with evidence from more recent studies that chronic loneliness significantly alters the brain in ways that only worsen the problem. Neuroscience suggests that loneliness doesn’t necessarily result from a lack of opportunity to meet others or a fear of social interactions. Instead, circuits in our brain and changes in our behavior can trap us in a catch-22 situation: While we desire connection with others, we view them as unreliable, judgmental and unfriendly. Consequently, we keep our distance, consciously or unconsciously spurning potential opportunities for connections. Simons Foundation All Rights Reserved © 2023

Keyword: Stress; Attention
Link ID: 28689 - Posted: 03.04.2023

By Eva Holland Kris Walterson doesn’t remember exactly how he got to the bathroom, very early on a Friday morning — only that once he got himself there, his feet would no longer obey him. He crouched down and tried to lift them up with his hands before sliding to the floor. He didn’t feel panicked about the problem, or even nervous really. But when he tried to get up, he kept falling down again: slamming his back against the bathtub, making a racket of cabinet doors. It didn’t make sense to him then, why his legs wouldn’t lock into place underneath him. He had a pair of fuzzy socks on, and he tried pulling them off, thinking that bare feet might get better traction on the bathroom floor. That didn’t work, either. When his mother came from her bedroom to investigate the noise, he tried to tell her that he couldn’t stand, that he needed her help. But he couldn’t seem to make her understand, and instead of hauling him up she called 911. After he was loaded into an ambulance at his home in Calgary, Alberta, a paramedic warned him that he would soon hear the sirens, and he did. The sound is one of the last things he remembers from that morning. Walterson, who was 60, was experiencing a severe ischemic stroke — the type of stroke caused by a blockage, usually a blood clot, in a blood vessel of the brain. The ischemic variety represents roughly 85 percent of all strokes. The other type, hemorrhagic stroke, is a yin to the ischemic yang: While a blockage prevents blood flow to portions of the brain, starving it of oxygen, a hemorrhage means blood is unleashed, flowing when and where it shouldn’t. In both cases, too much blood or too little, a result is the rapid death of the affected brain cells. When Walterson arrived at Foothills Medical Center, a large hospital in Calgary, he was rushed to the imaging department, where CT scans confirmed the existence and location of the clot. It was an M1 occlusion, meaning a blockage in the first and largest branch of his middle cerebral artery. © 2023 The New York Times Company

Keyword: Stroke
Link ID: 28688 - Posted: 03.04.2023

Sara Reardon Emotions such as fear and anxiety can make the heart beat faster. Now a study in mice has found that the reverse is also true — artificially increasing the heart rate can raise anxiety levels1. Links between emotions and physical sensations are familiar to everyone: hairs rising on the backs of your arms when you hear an eerie sound, or the sinking feeling in your gut when you receive bad news. But the question of whether emotions drive bodily functions or vice versa has long vexed researchers, because it is hard to control either factor independently. “It was a chicken-and-egg question that has been the subject of debate for a century,” says Karl Deisseroth, a neuroscientist at Stanford University in California. He learned about this conundrum — first proposed by the psychologist William James in the 1880s — while at medical school and says the question has haunted him ever since. To test the phenomenon directly, Deisseroth and his colleagues turned to optogenetics, a method that involves using light to control cell activity. The team bioengineered mice to make muscle cells in the rodents’ hearts sensitive to light. The authors also designed tiny vests for the animals that emitted red light, which could pass through the rodents’ bodies all the way to their hearts. When a mouse’s vest emitted a pulse of light, the animal’s engineered heart muscles fired, causing the heart to beat. The team trained the animals to expect a shock if they pressed a lever for a water reward. Using the optogenetic system, the team raised the animals’ heart rates from their normal 660 beats per minute to 900. When their hearts started racing, mice became less willing to press the lever or to explore open areas, suggesting that they were more anxious. But for animals in other contexts, the externally increased heart rate had no effect, suggesting that the brain and the heart worked together to produce anxiety. © 2023 Springer Nature Limited

Keyword: Stress; Emotions
Link ID: 28687 - Posted: 03.04.2023

By Sam Jones Dolphins, pilot whales and sperm whales use echolocation clicks to hunt and subdue their prey. But the animals, known as toothed whales, also produce other sounds for social communication, like grunts and high-pitched whistles. For decades, scientists speculated that something in the nasal cavity was responsible for this range of sounds, but the mechanics were unclear. Now, researchers have uncovered how structures in the nose, called phonic lips, allow toothed whales to produce sounds at different registers, similar to the way the human voice functions, all while conserving air deep beneath the ocean’s surface. And the animals use the vocal fry register for echolocation. Yes, that vocal fryyyy. The work was published in the journal Science on Thursday. Bottlenose Sounds A sequence of vocal registers from a bottlenose dolphin: Echolocation clicks made with vocal fry; the bursts of standard vocalization; and whistles. Studying the structures responsible for whale sound production has been no small task. Over the last few decades, “there was a lot of circumstantial evidence — people filming things with X-rays or triangulating sound with different hydrophones,” said Coen P.H. Elemans, a biologist at the University of Southern Denmark. Taking a new approach, Dr. Elemans and colleagues inserted endoscopes into the nasal cavities of trained Atlantic bottlenose dolphins and harbor porpoises to get high-speed footage during sound production. They found that sound was indeed being produced in the nose. But to confirm that the phonic lips were involved — and to see if their movement was driven by muscles or by airflow — they created an experimental setup with deceased (beached or bycatch) harbor porpoises, filming the phonic lips as air was pushed through the nasal complex. They saw that the phonic lips would briefly separate and then collide back together, causing a tissue vibration that would release sound into the surrounding water. But relying on air-driven sound production would not seem to be the best idea if your food is in the murky deep. “One thousand meters down, you have 1 percent of the air you had at the surface,” said Peter Madsen, a zoophysiologist at Aarhus University in Denmark, who has been tagging toothed whales for decades and is a co-author of the study. “To me, it’s always been super provocative to see a sperm whale or beaked whale or pilot whale dive deep, clicking happily, while having the knowledge in the back of my head that they’re supposed to use air for this.” © 2023 The New York Times Company

Keyword: Animal Communication; Evolution
Link ID: 28686 - Posted: 03.04.2023

Rachel Treisman A man in southwest Florida died after becoming infected with a rare brain-eating amoeba, which state health officials say was "possibly as a result of sinus rinse practices utilizing tap water." The Florida Department of Health in Charlotte County confirmed Thursday that the unidentified man died of Naegleria fowleri. State and local health and environmental agencies "continue to coordinate on this ongoing investigation, implement protective measures, and take any necessary corrective actions," they added. The single-celled amoeba lives in warm fresh water and, once ingested through the nose, can cause a rare but almost-always fatal brain infection known as primary amebic meningoencephalitis (PAM). The Centers for Disease Control and Prevention has tallied 157 PAM infections in the U.S. between 1962 and 2022, with only four known survivors (a fifth, a Florida teenager, has been fighting for his life since last summer, according to an online fundraiser by his family). Agency data suggests this is the first such infection ever reported in February or March. Infections are most common in Southern states and during warmer months, when more people are swimming — and submerging their heads — in lakes and rivers. But they can also happen when people use contaminated tap water to rinse their sinuses, either as part of a religious ritual or an at-home cold remedy. The CDC says the disease progresses rapidly and usually causes death within about five days of symptom onset. © 2023 npr

Keyword: Neuroimmunology
Link ID: 28685 - Posted: 03.04.2023

By Tara C. Smith In The Last of Us, a video game series and recent television show, fungal pathogens are to blame for a zombie-like plague. Once infected, humans lose control over their bodies and become increasingly aggressive, seeking to infect others through violence. It’s a familiar trope: The same fungus, Ophiocordyceps, torments humanity in the movie The Girl With All the Gifts, while viruses do the work in the film 28 Days Later and the novel World War Z. But the concept of a pathogen that can manipulate its host’s behavior — against their will and often to their detriment — is not purely the work of fiction. In these zombie-like cases, the pathogen (whether it’s a virus, bacteria or fungus, or something else) acts specifically to change the behavior of its host. While we know a decent amount about these pathogens — including the very real Ophiocordyceps fungus, which does turn insects into unwitting agents of societal collapse — there’s still much to learn. So the Cordyceps fungus is real? “Cordyceps” has become a common catch-all name for a group of fungi that infect insects. This grouping includes the species Ophiocordyceps unilateralis, better known as the “zombie ant fungus.” It spreads by sprouting fungal structures that erupt through the ant’s head after its death. A regular column in which top researchers explore the process of discovery. This month’s columnist, Tara C. Smith, is a professor of epidemiology and infectious-disease researcher. The challenge for this reproductive strategy is that ants are social insects, and so they act to protect the colony from infections. As part of this behavior, ants typically remove dead ants from the nest. A lone dead ant outside the nest won’t spread the fungus. All Rights Reserved © 2023

Keyword: Neuroimmunology; Aggression
Link ID: 28684 - Posted: 02.25.2023

By Sujata Gupta Trish Tran narrates her life in staccato notes. “I remember carrying my little sister on my back because she’s too tired and walking through the huge sunflower fields … and me feeling so tired I didn’t think I could walk another step.” “I remember being in a taxi with my mother, coming back to the man who had been violently abusive to all of us…. Her words to me were, ‘Just trust me, Trish. Just trust me.’ ” “I’m waiting at a train station … to meet my mother who I haven’t seen in many years…. Hours pass and eventually I try to call her … and she says to me, ‘I’m sorry, Trish. My neighbor was upset, and I needed to stay back with them.’ And her voice was slurring quite a lot, so I knew she had been drinking.” Tran, who lives in Perth, Australia, is dispassionate as she describes a difficult childhood. Her account lacks what are generally considered classic signs of trauma: She makes no mention of flashbacks, appears to have a generally positive outlook and speaks with relative ease about distressing events. Yet she narrates her life growing up and living in the Australian Outback as a series of disconnected events; her life story lacks connective glue. That disjointed style is not how people, at least people in the West, tend to talk about themselves, says psychologist Christin Camia. Autobiographical accounts, like any good narrative, typically contain a curation of key past experiences, transitions linking those experiences and larger arcs about where life is headed. People use these stories to make sense of their lives, says Camia, of Zayed University’s Abu Dhabi campus in the United Arab Emirates. But a growing body of evidence from fields as wide-ranging as psychology, neuroscience, linguistics, philosophy and literary studies suggests that, as with Tran, trauma can shatter the narrative coherence of one’s life. People lose the plot. © Society for Science & the Public 2000–2023.

Keyword: Stress; Attention
Link ID: 28683 - Posted: 02.25.2023

Heidi Ledford Under the right circumstances, even moderately hungry mice prefer to socialize with the opposite sex than to eat, researchers have found1. In research published on 23 February in Cell Metabolism, scientists treated male mice with a technique that mimics the effects of leptin, a hormone that acts on the brain to suppress appetite. Treated mice were more likely to approach female mice than their food bowls — even if the test rodents had been deprived of food for almost an entire day. The findings reveal a surprising role for leptin in social behaviour. They are also a step towards understanding how animals prioritize different behavioural options in response to ongoing needs — an enduring question in neuroscience, says Gina Leinninger, who studies the neural regulation of feeding at Michigan State University in East Lansing. The paper “addresses a huge gap in the field”, she says. “When you no longer need to eat urgently, it should free you up to do other things.” The new work, Leinninger says, illuminates how the brain juggles these various demands. Food versus friends Neuroscientists Anne Petzold and Tatiana Korotkova at the University of Cologne in Germany, and their colleagues, sought to understand how such decision-making is affected by leptin, which activates a subset of cells in the brain and promotes a feeling of fullness. The researchers injected male mice with leptin and saw that it suppressed feeding, as expected — but also promoted interactions with female mice. The team examined neurons in the brain’s ‘hunger center’, the lateral hypothalamus, that are activated by leptin. The authors’ experiments showed that neurons that can sense leptin were activated when mice interacted with members of the opposite sex. Artificially activating those neurons using a technique called optogenetics raised the likelihood that a mouse would approach a member of the opposite sex. Both results suggest that leptin plays a part in promoting social behaviour. © 2023 Springer Nature Limited

Keyword: Obesity; Sexual Behavior
Link ID: 28682 - Posted: 02.25.2023

By Virat Markandeya It’s evening at the northern tip of the Red Sea, in the Gulf of Aqaba, and Tom Shlesinger readies to take a dive. During the day, the seafloor is full of life and color; at night it looks much more alien. Shlesinger is waiting for a phenomenon that occurs once a year for a plethora of coral species, often several nights after the full moon. Guided by a flashlight, he spots it: coral releasing a colorful bundle of eggs and sperm, tightly packed together. “You’re looking at it and it starts to flow to the surface,” Shlesinger says. “Then you raise your head, and you turn around, and you realize: All the colonies from the same species are doing it just now.” Some coral species release bundles of a pinkish- purplish color, others release ones that are yellow, green, white or various other hues. “It’s quite a nice, aesthetic sensation,” says Shlesinger, a marine ecologist at Tel Aviv University and the Interuniversity Institute for Marine Sciences in Eilat, Israel, who has witnessed the show during many years of diving. Corals usually spawn in the evening and night within a tight time window of 10 minutes to half an hour. “The timing is so precise, you can set your clock by the time it happens,” Shlesinger says. Moon-controlled rhythms in marine critters have been observed for centuries. There is calculated guesswork, for example, that in 1492 Christopher Columbus encountered a kind of glowing marine worm engaged in a lunar-timed mating dance, like the “flame of a small candle alternately raised and lowered.” Diverse animals such as sea mussels, corals, polychaete worms and certain fishes are thought to synchronize their reproductive behavior by the moon. The crucial reason is that such animals — for example, over a hundred coral species at the Great Barrier Reef — release their eggs before fertilization takes place, and synchronization maximizes the probability of an encounter between eggs and sperm. © 2023 Annual Reviews

Keyword: Biological Rhythms; Sexual Behavior
Link ID: 28681 - Posted: 02.25.2023

Diana Kwon Hundreds of scientists around the world are looking for ways to treat heart attacks. But few started where Hedva Haykin has: in the brain. Haykin, a doctoral student at the Technion — Israel Institute of Technology in Haifa, wants to know whether stimulating a region of the brain involved in positive emotion and motivation can influence how the heart heals. Late last year, in a small, windowless microscope room, she pulled out slides from a thin black box, one by one. On them were slices of hearts, no bigger than pumpkin seeds, from mice that had experienced heart attacks. Under a microscope, some of the samples were clearly marred by scars left in the aftermath of the infarction. Others showed mere speckles of damage visible among streaks of healthy, red-stained cells. The difference in the hearts’ appearance originated in the brain, Haykin explains. The healthier-looking samples came from mice that had received stimulation of a brain area involved in positive emotion and motivation. Those marked with scars were from unstimulated mice. “In the beginning we were sure that it was too good to be true,” Haykin says. It was only after repeating the experiment several times, she adds, that she was able to accept that the effect she was seeing was real. Haykin, alongside her supervisors at the Technion — Asya Rolls, a neuroimmunologist, and Lior Gepstein, a cardiologist — are trying to work out exactly how this happens. On the basis of their experiments so far, which have not yet been published, activation of this brain reward centre — called the ventral tegmental area (VTA) — seems to trigger immune changes that contribute to the reduction of scar tissue. This study has its roots in decades of research pointing to the contribution of a person’s psychological state to their heart health1. In a well-known condition known as ‘broken-heart syndrome’, an extremely stressful event can generate the symptoms of a heart attack — and can, in rare cases, be fatal. Conversely, studies have suggested that a positive mindset can lead to better outcomes in those with cardiovascular disease. But the mechanisms behind these links remain elusive.

Keyword: Neuroimmunology
Link ID: 28680 - Posted: 02.25.2023