Chapter 11. Emotions, Aggression, and Stress

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.

Links 21 - 40 of 3460

By Jude Coleman When it comes to tail wagging among dogs, some questions still hound researchers. We know that domesticated dogs (Canis familiaris) use their tails to communicate — with other dogs as well as humans — and even what various types of wags mean, researchers note in a new review of the scientific literature. But we don’t know why dogs seem to wag more than other canines or even how much of it is under their control, ethologist Silvia Leonetti and colleagues report January 17 in Biology Letters. “Among all possible animal behavior that humans experience in everyday life, domestic dog tail wagging is one of the most common,” says Leonetti, who is now at the University of Turin in Italy. “But a lot of dog behavior remains a scientific enigma.” So Leonetti and her colleagues pored through previous studies to figure out what elements of tail wagging are understood and which remain mysterious. They also hypothesized about the behavior’s origins: Perhaps tail wagging placates some human need for rhythm, the researchers suggest, or maybe the behavior is a genetic tagalong, a trait tied to others that humans bred into domesticated dogs. “People think wagging tail equals happy dog. But it’s actually a lot more complicated than that,” says Emily Bray, an expert in canine cognition at the University of Arizona in Tucson who was not involved with the work. Understanding why dogs wag their tails is important partly from an animal welfare perspective, she says, as it could help dog owners read their pups’ cues better. One main thing that researchers know about tail wagging is that it’s used predominantly for communication instead of locomotion, like a whale, or swatting away bugs, like a horse. Wagging also means different things depending on how the tail is wagged, such as its height or side-to-side movement. © Society for Science & the Public 2000–2024.

Keyword: Animal Communication; Emotions
Link ID: 29103 - Posted: 01.18.2024

By Elissa Welle Many of the physicians who worked on the current diagnostic and treatment guidelines for psychiatric conditions in the United States have financial ties to pharmaceutical companies, according to a study published today in The BMJ. Nearly 60 percent of the 92 U.S.-based physicians who shepherded the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, text revision (DSM-5-TR) accepted industry payments totaling $14.2 million during the three years prior to working on the manual, the study shows. The results raise questions about systemic “economies of influence” over a document used by public health officials, health insurance plans and drug regulators, says lead investigator Lisa Cosgrove, professor of counseling and school psychology and a faculty fellow at the Applied Ethics Center at the University of Massachusetts, Boston. “Financial conflicts of interest, industry ties don’t point to wrongdoing — we’re not saying that people did anything wrong consciously,” Cosgrove says. “It’s just implicit bias.” DSM-5-TR decision-makers were not allowed to receive more than $5,000 from industry, according to a statement to The Transmitter by a spokesperson for the American Psychiatric Association (APA), which published the DSM-5-TR in March 2022. And an independent committee reviewed financial and non-financial disclosures for all other contributors to the revision. The text revision centered on literature searches to incorporate new scientific findings since the publication of the DSM-5 in 2013, the spokesperson wrote. “Any rare, minor instances of content that connected a diagnosis to a therapy were omitted from DSM-5-TR,” the spokesperson wrote. “No content was found in the submitted text that related to a specific treatment for which industry funding may have been provided for related research.” © 2023 Simons Foundation.

Keyword: Depression; Schizophrenia
Link ID: 29096 - Posted: 01.13.2024

By Amber Dance 01.08.2024 We all want to be happy — and for decades, psychologists have tried to figure out how we might achieve that blissful state. The field’s many surveys and experiments have pointed to a variety of approaches, from giving stuff away to quitting Facebook to forcing one’s face into a toothy grin. But psychology has undergone serious upheaval over the last decade, as researchers realized that many studies were unreliable and unrepeatable. That has led to a closer scrutiny of psychological research methods, with the study of happiness no exception. So — what really makes us happy? Under today’s more careful microscope, some routes to happiness seem to hold up, while others appear not to, or have yet to re-prove themselves. Here’s what we know so far, and what remains to be reassessed, according to a new analysis in the Annual Review of Psychology. One long-standing hypothesis is that smiling makes you feel happier. In a classic 1988 study, researchers asked 92 Illinois undergraduates to hold a felt tip pen in their mouth either with their teeth, forcing an unnatural grin, or with their lips, making them pout. The students then looked at four examples of The Far Side comics. On average, those with the forced smiles found the one-panel comics slightly funnier than those with the forced pouts. But when 17 different research labs got together to retest the pen-clench smile’s effects on 1,894 new participants, the finding failed to hold up, the researchers reported in 2016. The repetition study was part of a broader effort to counter psychology’s reproducibility crisis, which in part has been attributed to the variety of ways in which researchers could examine and reanalyze their data until they arrived at publishable results. “It’s kind of like shooting a bunch of arrows at the wall and drawing the bullseye on after,” says Elizabeth Dunn, a social psychologist at the University of British Columbia in Vancouver and coauthor of the new Annual Review of Psychology paper.

Keyword: Emotions
Link ID: 29086 - Posted: 01.09.2024

By Max Kozlov Shredded iboga root, the main ingredient in the psychedelic drug ibogaine, is prepared for use in a traditional ceremony in Gabon.Credit: Rachel Nuwer Psychedelic drugs such as MDMA and psilocybin, the hallucinogenic compound found in magic mushrooms, have promised to revolutionize psychiatric treatments. Now, a small trial in military veterans suggests that a lesser-known, potent psychedelic drug called ibogaine could be used to treat traumatic brain injury (TBI). One month after ibogaine treatment, the veterans reported that TBI symptoms such as post-traumatic stress disorder (PTSD) and depression had decreased by more than 80%, on average1. “The drug seems to have a broad, dramatic and consistent effect,” says Nolan Williams, a neuroscientist at Stanford University in California and a co-author of the study. The results of the trial, which did not include a control group, are published today in Nature Medicine. These data support launching rigorous trials to test the drug, says Alan Davis, a clinical psychologist at the Ohio State University in Columbus. However, they note that MDMA and psilocybin, which are already in late-stage trials, will be “much better candidates for meeting the needs of this community”. Ibogaine will require years of study to determine its efficacy and safety, Davis says. Warfare’s lasting effects Ibogaine is made from the bark of a shrub (Tabernanthe iboga) native to Central Africa, where it is used for ceremonial purposes. Researchers have tended to shy away from exploring the use of ibogaine for the treatment of conditions other than opioid dependence and withdrawal2, because it is tightly regulated in many countries and can cause fatal heartbeat irregularities, says Maria Steenkamp, a clinical psychologist who studies PTSD in veterans at the NYU Grossman School of Medicine in New York City. But the available therapies for PTSD and other conditions don’t help everybody, Steenkamp says. “We are desperately in need of new interventions.” © 2024 Springer Nature Limited

Keyword: Stress; Drug Abuse
Link ID: 29082 - Posted: 01.06.2024

Saga Briggs Trauma is not merely a phenomenon of the mind but also a condition physically embedded in the body, often eluding our conscious awareness and affecting our overall health. That was the main argument in psychiatrist Bessel van der Kolk’s 2014 bestseller The Body Keeps the Score, which quickly became a modern classic among trauma researchers, clinicians, and survivors. The book shifted how many in the West view psychiatric illness, which was often viewed solely through a psychological or neurochemical lens, and it sparked new interest in more holistic treatments for trauma that had long been considered alternative: yoga, eye movement desensitization and reprocessing therapy (EMDR), the performing arts, and psychedelics, to name a few. But what does it really mean for the body to “keep the score”? Is it biologically possible for the viscera to actually store and release trauma? In his book, van der Kolk writes: “The body keeps the score. If the memory of trauma is encoded in the viscera, in heartbreaking and gut-wrenching emotions, in autoimmune disorders and skeletal/muscular problems, and if mind/brain/visceral communication is the royal road to emotion regulation, this demands a radical shift in our therapeutic assumptions.” Can the body “keep score”? Recently, neuroscientists have expressed skepticism over the notion that the body can “keep score” of anything. In a 2023 Big Think video, Lisa Feldman Barrett argued that everything, including trauma, is in our heads, and that “the brain keeps the score and the body is the scorecard.” In her view, everything we experience is constructed by the brain, which learns to predict how we will feel based on past experiences, issues, and sensations that seem to come from our body but actually come from our brain. “When you feel your heart beating, you are not feeling it in your chest, you are feeling it in your brain,” she said. “Your body is always sending sensory signals to the brain, of course, but emotions are made in the brain, not in the body. They are experienced in the brain, like everything else you experience, not in the body. If you experience a trauma, you experience it in your brain.”

Keyword: Emotions; Stress
Link ID: 29031 - Posted: 12.06.2023

By Ellen Barry At the root of post-traumatic stress disorder, or PTSD, is a memory that cannot be controlled. It may intrude on everyday activity, thrusting a person into the middle of a horrifying event, or surface as night terrors or flashbacks. Decades of treatment of military veterans and sexual assault survivors have left little doubt that traumatic memories function differently from other memories. A group of researchers at Yale University and the Icahn School of Medicine at Mount Sinai set out to find empirical evidence of those differences. The team conducted brain scans of 28 people with PTSD while they listened to recorded narrations of their own memories. Some of the recorded memories were neutral, some were simply “sad,” and some were traumatic. The brain scans found clear differences, the researchers reported in a paper published on Thursday in the journal Nature Neuroscience. The people listening to the sad memories, which often involved the death of a family member, showed consistently high engagement of the hippocampus, part of the brain that organizes and contextualizes memories. When the same people listened to their traumatic memories — of sexual assaults, fires, school shootings and terrorist attacks — the hippocampus was not involved. “What it tells us is that the brain is in a different state in the two memories,” said Daniela Schiller, a neuroscientist at the Icahn School of Medicine at Mount Sinai and one of the authors of the study. She noted that therapies for PTSD often sought to help people organize their memory so they can view it as distant from the present. “Now we find something that potentially can explain it in the brain,” she said. “The brain doesn’t look like it’s in a state of memory; it looks like it is a state of present experience.” Indeed, the authors conclude in the paper, “traumatic memories are not experienced as © 2023 The New York Times Company

Keyword: Learning & Memory; Stress
Link ID: 29030 - Posted: 12.02.2023

By Taylor Beck One sunny day this fall, I caught a glimpse of the new psychiatry. At a mental hospital near Yale University, a depressed patient was being injected with ketamine. For 40 minutes, the drug flowed into her arm, bound for cells in her brain. If it acts as expected, ketamine will become the first drug to quickly stop suicidal drive, with the potential to save many lives. Other studies of ketamine are evaluating its effect as a vaccination against depression and post-traumatic stress. Between them, the goal is nothing less than to redefine our understanding of mental illness itself. Depression is the most common mental illness in the United States, affecting 30 percent of Americans at some point in their lives. But despite half a century of research, ubiquitous advertising, and blockbuster sales, antidepressant drugs just don’t work very well. They treat depression as if it were caused by a chemical imbalance: Pump in more of one key ingredient, or sop up another, and you will have fixed the problem. But the correspondence between these chemicals (like serotonin) and depression is relatively weak. An emerging competitive theory, inspired in part by ketamine’s effectiveness, has it that psychiatric disease is less about chemical imbalance than structural changes in the brain—and that a main cause of these changes is psychological stress. “I really do think stress is to mental illness as cigarettes are to heart disease,” says Gerard Sanacora, the psychiatry professor running the ketamine trial at Yale. The theory describes stress grinding down individual neurons gradually, as storms do roof shingles. This, in turn, changes the nature of their connections to one another and the structure of the brain. Ketamine, along with some similar molecules, acts to strengthen the neuron against that damage, affecting not just the chemistry of the brain but also its structure. © 2023 NautilusNext Inc.,

Keyword: Depression; Stress
Link ID: 29027 - Posted: 12.02.2023

By Yasemin Saplakoglu From the moment you swallow a bite of food to the moment it exits your body, the gut is toiling to process this strange outside material. It has to break chunks down into small bits. It must distinguish healthy nutrients from toxins or pathogens and absorb only what is beneficial. And it does all this while moving the partially processed food one way through different factories of digestion — mouth, esophagus, stomach, through the intestines and out. “Digestion is required for survival,” said Marissa Scavuzzo, a postdoctoral researcher at Case Western Reserve University in Ohio. “We do it every day, but also, if you really think about it, it sounds very foreign and alien.” Breaking down food requires coordination across dozens of cell types and many tissues — from muscle cells and immune cells to blood and lymphatic vessels. Heading this effort is the gut’s very own network of nerve cells, known as the enteric nervous system, which weaves through the intestinal walls from the esophagus down to the rectum. This network can function nearly independently from the brain; indeed, its complexity has earned it the nickname “the second brain.” And just like the brain, it’s made up of two kinds of nervous system cells: neurons and glia. Glia, once thought to be mere glue that fills the space between neurons, were largely ignored in the brain for much of the 20th century. Clearly, neurons were the cells that made things happen: Through electrical and chemical signaling, they materialize our thoughts, feelings and actions. But in the last few decades, glia have shed their identity as passive servants. Neuroscientists have increasingly discovered that glia play physiological roles in the brain and nervous system that once seemed reserved for neurons. A similar glial reckoning is now happening in the gut. A number of studies have pointed to the varied active roles that enteric glia play in digestion, nutrient absorption, blood flow and immune responses. Others reveal the diversity of glial cells that exist in the gut, and how each type may fine-tune the system in previously unknown ways. One recent study, not yet peer-reviewed, has identified a new subset of glial cells that senses food as it moves through the digestive tract, signaling to the gut tissue to contract and move it along its way. All Rights Reserved © 2023

Keyword: Obesity; Glia
Link ID: 29018 - Posted: 11.22.2023

By Laura Sanders WASHINGTON — Brain scans could be used to predict how teenagers’ mental health will fare during a stressful time, an analysis that spanned the COVID-19 pandemic suggests. The findings, presented November 13 in a news briefing at the annual meeting of the Society for Neuroscience, may help explain why some people succumb to stress while others are more resilient. For a lot of research, “the study happens, and you report on the results, and that’s about it,” says Margot Wagner, a bioengineer at the University of California, San Diego who was not involved in the new work. But this research followed hundreds of teenagers over time, a study design that “means you can intervene and help way sooner than otherwise,” Wagner says. The pandemic was particularly tough for many teenagers, as isolation, worry and upheaval of daily routines affected them in ways that scientists are just now starting to see (SN: 1/3/23). A record number of young people are struggling with depression and anxiety, a mental health crisis that some scientists are calling “the second pandemic” (SN: 6/30/23). While many teenagers struggled during the pandemic, others did OK. Computational neuroscientist Caterina Stamoulis of Harvard Medical School and Boston Children’s Hospital investigated why responses differed using data collected as part of the Adolescent Brain Cognitive Development, or ABCD, study. That larger study — involving scientists at 21 research sites across the United States — aims to figure out how teenagers’ brains grow over the years. “This is the first time in history we’re looking at thousands of participants and getting these measures over time,” Wagner says. “It’s truly remarkable.” The ABCD study, begun in 2015, was well under way when COVID hit, so researchers possessed brain scans from before the pandemic. “Without the pandemic, we would not have been able to understand the impact of a long-lasting adverse event” that deeply affected the participants’ lives, changing their interactions with their family and friends, Stamoulis says. © Society for Science & the Public 2000–2023.

Keyword: Development of the Brain; Stress
Link ID: 29012 - Posted: 11.18.2023

By Veronique Greenwood When someone brushes a hand across your skin, it’s like a breeze blowing through a forest of countless small hairs. Nerves that surround your hair follicles detect that contact, and very far away in your brain, other cells fire. Some of the neurons responding to light contact might make you shiver and give you goose bumps. Some might tell you to move away. Or they might tell you to move closer. Scientists who study the sense of touch have explored which cells bear these messages, and they have made an intriguing discovery: Follicle cells triggered by hair movements release the neurotransmitters histamine and serotonin, chemical messengers linked to biological phenomena as varied as inflammation, muscle contraction and mood changes. The observation, reported in October in the journal Science Advances, lays the groundwork for tracing how gentle touch makes us feel the way it does. Studying hair follicles is challenging, because they begin to decay soon after being removed from the body, said Claire Higgins, a bioengineering professor at Imperial College London and an author of the study. So she and her colleagues went to a hair transplant clinic. There, they were able to look at freshly harvested follicles, which they gently prodded with a very small rod to simulate touch. The scientists knew from work done by other groups that the neurons in the skin surrounding hair follicles are capable of sensing movement. “When you brush your hair, you feel it because the sensory neurons are directly being stimulated,” Dr. Higgins said. But they were curious whether the cells of the follicle itself — the tube from which a hair sprouts — could be contributing to some of the feelings associated with more gentle touch. Not all of the follicle cells had movement sensors, but some did. The researchers identified these and watched them carefully as the rod touched them. “We found that when we stimulated our hair follicle cells, they actually released mood-regulating neurotransmitters serotonin and histamine,” Dr. Higgins said. © 2023 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 28999 - Posted: 11.11.2023

By Caren Chesler In 2019, Debra Halsch was diagnosed with smoldering multiple myeloma, a rare blood and bone marrow disorder that can develop into a type of blood cancer. Her doctors recommended chemotherapy, she said, but she feared the taxing side effects the drugs might wreak on her body. Instead, the life coach from Piermont, New York tried meditation. A friend had told Halsch, now 57, about Joe Dispenza, who holds week-long meditation retreats that regularly attract thousands of people and carry a $2,299 price tag. Halsch signed up for one in Cancun, Mexico and soon became a devotee. She now meditates for at least two hours a day and says her health has improved as a result. Goop, the health and lifestyle brand launched by actor and entrepreneur Gwyneth Paltrow in 2008, will have its own series on Netflix beginning January 24. Dispenza, a chiropractor who has written various self-help books, has said he believes the mind can heal the body. After all, he says he healed himself back in 1986, when a truck hit him while he was bicycling, breaking six vertebrae. Instead of surgery, Dispenza says he spent hours each day recreating his spine in his mind, visualizing it healthy and healed. After 11 weeks, the story goes, he was back on his feet. Halsch said she believes she can do the same for her illness. “If our thoughts and emotions can make our bodies sick, they can make us well, too,” she said. In an email to Undark, Rhadell Hovda, chief operating officer for Dispenza’s parent company, Encephalon, Inc., emphasized that Dispenza does not claim meditation can treat or cure cancer. However, he does “follow the evidence when it is presented,” and has encountered people at workshops and retreats “who claimed to have healed from many conditions.” For more than two decades, various studies have suggested that meditation and mindfulness — that is, being aware of the present moment — can help reduce and improve pain management, lending some credence to the notion that the brain can affect the body. Such results have helped the field grow into a multibillion-dollar industry, populated by meditation apps, guided workshops, and upscale retreats.

Keyword: Attention; Stress
Link ID: 28990 - Posted: 11.08.2023

Sara Reardon Psychedelic drugs have been undergoing a major makeover in psychiatry, earning mainstream acceptance that has eluded them for decades. In 2019, a variant of ketamine — an animal tranquillizer well known as a club drug — was approved by the US Food and Drug Administration (FDA) for treating post-traumatic stress disorder (PTSD). In May, Oregon opened its first treatment centre for administering psilocybin — the hallucinogenic compound found in magic mushrooms — following the state’s decision to legalize it (psilocybin remains illegal at the federal level). And, after decades of effort, the Multidisciplinary Association for Psychedelic Studies, a non-profit research organization in San Jose, California, formally asked the FDA for approval to market MDMA — also known as molly or ecstasy — as a treatment for PTSD. Most specialists expect the MDMA approval to go through on the weight of clinical evidence and popular support. Two large trials have shown that the drug can reduce the symptoms of PTSD when administered in controlled therapy sessions1,2. And it seems to do so more quickly than other treatments. But how MDMA and other psychedelics work is still largely a mystery, both because the drugs have long been illegal and because psychiatric conditions are difficult to study in animals. Psychedelic drug MDMA moves closer to US approval following success in PTSD trial With the regulatory landscape shifting, legal psychedelic research is becoming easier — and potentially more profitable. Neuroscientists, psychiatrists, pharmacologists, biochemists and others are entering the field, bringing fresh ideas about what the drugs do at a cellular and molecular level and trying to unravel how these mechanisms might help to relieve symptoms of psychiatric conditions. From a clinical perspective, understanding how the drugs work might not matter. “You don’t need to know the mechanism of the drug to have a very effective therapy,” says David Olson, a biochemist at the University of California, Davis. But, understanding more about psychedelics could lead to the development of proprietary drugs that are safer, less hallucinogenic and ultimately more effective. It could also affect the way psychedelics are administered in the clinic — helping providers to tailor treatments to each person. Several key questions are driving the basic research that progresses in the background as MDMA and others march towards the market. © 2023 Springer Nature Limited

Keyword: Depression; Stress
Link ID: 28986 - Posted: 11.04.2023

By Christa Lesté-Lasserre A gray cat stares quietly at a nearby orange tabby, squinting her eyes, flattening her ears, and licking her lips. The tabby glares back, wrinkles his nose, and pulls back his whiskers. Cat people know what’s about to go down: a fight. If looks and growls don’t resolve the budding tiff, claws will pop out and fur will fly. Those faces aren’t the only ones cats make at each other, of course—not by a long shot. In a study published this month in Behavioural Processes, researchers tallied 276 different feline facial expressions, used to communicate hostile and friendly intent and everything in between. What’s more, the team found, we humans might be to thank: Our feline friends may have evolved this range of sneers, smiles, and grimaces over the course of their 10,000-year history with us. “Many people still consider cats—erroneously—to be a largely nonsocial species,” says Daniel Mills, a veterinary behaviorist at the University of Lincoln who was not involved in the study. The facial expressions described in the new study suggest otherwise, he notes. “There is clearly a lot going on that we are not aware of.” Cats can be solitary creatures, but they often form friendships with fellow kitties in people’s homes or on the street; feral cats can live in colonies of thousands, sometimes taking over entire islands. Lauren Scott, a medical student and self-described cat person at the University of Kansas, long wondered how all these felines communicated with one another. There has to be love and diplomacy, not just fighting, yet most studies of feline expression have focused on aggression. Fortunately in 2021, Scott was studying at the University of California, Los Angeles (UCLA), just minutes from the CatCafé Lounge. There, human visitors can interact—and even do yoga—with dozens of group-housed, adoptable cats. From August to June, Scott video recorded 194 minutes of cats’ facial expressions, specifically those aimed at other cats, after the café had closed for the day. Then she and evolutionary psychologist Brittany Florkiewicz, also at UCLA at the time but now at Lyon College, coded all their facial muscle movements—excluding any related to breathing, chewing, yawning, and the like.

Keyword: Emotions; Evolution
Link ID: 28977 - Posted: 10.28.2023

By Charles Digges Is there any kind of fence that can make humans and elephants good neighbors? It’s a question Dominique Gonçalves has had to ponder as she leads the elephant ecology project at Mozambique’s Gorongosa National Park, which is not surrounded by a physical barrier. A number of pioneering studies throughout Sub-Saharan Africa over the past several years showed a solution that was simple and natural: bees. As it turns out, the tiny, ubiquitous honeybee has the power to terrify a mammal that’s 22 million times its size. In fact, even the sound of the insect’s buzz is enough to send a family of elephants into a panic, showed studies by Lucy King, an Oxford zoologist and preeminent researcher in human-elephant coexistence at the nonprofit Save the Elephants. Upon hearing the telltale hum, elephants will run, kick up dust, shake their heads as if trying to swat the bees out of the air, trumpeting distressed warnings to other elephants as they flee. Of course, a bee’s stinger can’t penetrate the thick hide of an elephant. But when bees swarm—and African bees swarm aggressively—hundreds of bees might sting an elephant in its most sensitive areas, like the trunk, the mouth, and eyes. And it works. Building on King’s insights, Paola Branco of the University of Idaho conducted a massive two-year-long experiment in Gorongosa that culminated in a 2019 paper she co-authored with King, Marc Stalmans, Gorongosa’s director of scientific services, Princeton zoologist Robert Pringle, and others.1 Their research aimed to settle tensions between human farmers and the park’s growing population of marauding pachyderms—with the help of bees. © 2023 NautilusNext Inc.,

Keyword: Emotions; Evolution
Link ID: 28976 - Posted: 10.28.2023

Christie Wilcox Adult horsehair worms look about how you’d expect given their name: They’re long, noodlelike creatures that resemble wiggling horse hairs. They live and reproduce in water, but their young only develop inside the bodies of other animals—usually terrestrial insects such as praying mantises. Once they’ve finished growing inside their unwitting vessel, the worms must convince their hosts to drown themselves to complete their life cycle. How these parasites manage to lethally manipulate their hosts has long puzzled scientists. Researchers behind a new study published today in Current Biology suggest horsehair worms possess hundreds of genes that allow them to hijack a mantis’ movement—and they may have acquired these genes directly from their ill-fated hosts. “The results are amazing,” says Clément Gilbert, an evolutionary biologist at the University of Paris-Saclay who wasn’t involved in the work. If it turns out to be true that so many of the mantises’ genes jumped over to the parasitic worms—a process known as horizontal gene transfer—then “this is by far the highest number of horizontally transferred genes that have been reported between two species of animals,” he adds. The phenomenon of parasites mind-controlling their hosts to an early grave has always intrigued Tappei Mishina, an evolutionary biologist at Kyushu University and the RIKEN Center for Biosystems Dynamics Research. “For more than 100 years, there have been horrifying observations of terrestrial insects jumping into water right before our eyes all over the world,” he says. He teamed up with ecologist Takuya Sato of the Center for Ecological Research at Kyoto University to investigate the genetic basis of their parasitism. They focused on horsehair or gordian worms, a group of parasitic animals related to nematodes. Many have complex life cycles involving multiple hosts, and the ones that live in freshwater must generally find their way into an insect to finish developing into adults. The genus Mishina, Sato, and their colleagues specialize in, known as Chordodes, infect mantises and can grow to nearly 1 meter long inside the palm-size insects’ abdomens.

Keyword: Genes & Behavior; Evolution
Link ID: 28971 - Posted: 10.25.2023

Marlys Fassett Itching can be uncomfortable, but it’s a normal part of your skin’s immune response to external threats. When you’re itching from an encounter with poison ivy or mosquitoes, consider that your urge to scratch may have evolved to get you to swat away disease-carrying pests. However, for many people who suffer from chronic skin diseases like eczema, the sensation of itch can fuel a vicious cycle of scratching that interrupts sleep, reduces productivity and prevents them from enjoying daily life. This cycle is caused by sensory neurons and skin immune cells working together to promote itching and skin inflammation. But, paradoxically, some of the mechanisms behind this feedback loop also stop inflammation from getting worse. In our newly published research, my team of immunologists and neuroscientists and I discovered that a specific type of itch-sensing neuron can push back on the itch-scratch-inflammation cycle in the presence of a small protein. This protein, called interleukin-31, or IL-31, is typically involved in triggering itching. This negative feedback loop – like the vicious cycle – is only possible because the itch-sensing nerve endings in your skin are closely intertwined with the millions of cells that make up your skin’s immune system. The protein IL-31 is key to the connection between the nervous and immune systems. This molecule is produced by some immune cells, and like other members of this molecule family, it specializes in helping immune cells communicate with each other. © 2010–2023, The Conversation US, Inc.

Keyword: Pain & Touch; Neuroimmunology
Link ID: 28961 - Posted: 10.14.2023

Perspective by Dan O'Brien I was 12 years old when I developed obsessive-compulsive disorder. My older brother had recently tried to kill himself by jumping from our attic window. I was the one who saw him first, as he limped around the side of the house, his back and hair matted with snow. Inside I found his suicide note and showed it to our mother. She collapsed in my arms, crying, and whispered, “This is a secret we must take to our graves.” Live well every day with tips and guidance on food, fitness and mental health, delivered to your inbox every Thursday. Before long, I found myself obsessing about any number of vague yet existential threats, and compulsively taking defensive action against them. I cycled through most of the classic OCD manifestations: avoiding cracks in the sidewalk, flipping light switches three, six, nine times (depending on my mood), checking and rechecking — and rechecking again — that our front and back doors were indeed locked. I had no idea what was happening to me. I simply knew with certainty that if I did not execute these actions correctly, my loved ones and I would suffer. And hypochondria, too: A book titled “Symptoms” lived in the tall bookcase behind the potted plant in the living room; one searched for one’s symptoms in an index up front, then proceeded to the indicated page where one would be provided with the most dire diagnosis imaginable. “Symptoms,” with its heft, its red-linen hardcover and tissue-thin paper, became my Bible. I touched things and people with trepidation and regret. I probed my body for swollen glands. My frequent handwashing desiccated my skin like a riverbed in drought, blood breaking through the cracks. I was forever certain that I was coming down with something catastrophic, like tuberculosis, AIDS, cancer. I was morally scrupulous, in the clinical sense, and prayed three times a day. (I wasn’t particularly religious; I was trying to cover all my bases.) Morning and evening prayer was easy, at home, but lunchtime at school could be tricky; I’d have to abscond to the boy’s room, or a shadowy, chain-link corner of the playground. I grew adept at praying without moving my lips in rote run-on sentences in which I begged God’s forgiveness for everything and anything I had done wrong in the past and would do wrong in the future.

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 28926 - Posted: 09.27.2023

Sara Reardon The psychedelic drug MDMA, also known as ecstasy or molly, has passed another key hurdle on its way to regulatory approval as a treatment for mental illness. A second large clinical trial has found that the drug — in combination with psychotherapy — is effective at treating post-traumatic stress disorder (PTSD). The results allow the trial’s sponsor to now seek approval from the US Food and Drug Administration (FDA) for MDMA’s use as a PTSD treatment for the general public, which might come as soon as next year. “It’s an important study,” says Matthias Liechti, a psychopharmacologist who studies MDMA at the University of Basel in Switzerland, but who was not involved with the trial or its sponsor. “It confirms MDMA works.” In June, Australia became the first country to allow physicians to prescribe MDMA for treating psychiatric conditions. MDMA is illegal in the United States and other countries because of the potential for its misuse. But the Multidisciplinary Association for Psychedelic Studies (MAPS), a non-profit organization in San Jose, California, has long been developing a proprietary protocol for using MDMA as a treatment for PTSD and other disorders. MAPS has been campaigning for its legalization — a move that could encourage other countries to follow suit. In 2021, researchers sponsored by MAPS reported the results of a study1 in which 90 people received a form of psychotherapy developed by the organization alongside either MDMA or a placebo. After three treatment sessions, 67% of those who received MDMA with therapy no longer qualified for a PTSD diagnosis, compared with 32% of those who received therapy and a placebo. The results were widely hailed as promising, but the FDA typically requires two placebo-controlled trials before a drug can be approved. The results of a second trial, involving 104 further individuals with PTSD and published on 14 September in Nature Medicine2, were similar to those of the original: 71% of people who received MDMA alongside therapy lost their PTSD diagnosis, compared with 48% of those who received a placebo and therapy. © 2023 Springer Nature Limited

Keyword: Drug Abuse; Stress
Link ID: 28911 - Posted: 09.16.2023

By Jonathan Moens When the war in Ukraine broke out, many countries and agencies around the world lent their support in the form of financial aid, weapons, and food. But Olga Chernoloz, a Ukrainian neuroscientist based in Canada, wanted to provide a different kind of assistance: a combination of therapy and the psychedelic drug MDMA. Such therapy, she said, could help countless people on the ground who are suffering from psychological trauma. “I thought that the most efficacious way I could be of help,” she told Undark, “would be to bring psychedelic-assisted therapy to Ukraine.” Chernoloz’s confidence stems in part from the results of clinical trials on MDMA to treat post-traumatic stress disorder in vulnerable populations, which suggest that such treatments may improve symptoms, or do away with them altogether. But the approach is experimental and has not yet cleared major regulatory hurdles in Canada, Europe, or the United States. Still, Chernoloz, who is a professor at the University of Ottawa, plans on carrying out clinical trials with Ukrainian refugees in a psychedelic center in the Netherlands in early 2024. This month, Chernoloz and her colleagues organized an education session for 20 Ukrainian therapists to learn about MDMA-assisted therapy for PTSD from the Multidisciplinary Association for Psychedelic Studies, or MAPS, one of the most influential organizations dedicated to education and promotion of psychedelic drugs.

Keyword: Stress
Link ID: 28878 - Posted: 08.24.2023

Nicola Davis Science correspondent Researchers have discovered a genetic variant that appears to influence the speed at which multiple sclerosis (MS) progresses, potentially paving the way for new treatments. According to the MS International Federation, about 2.9 million people worldwide have MS, a condition in which the insulating coating of the nerves in the brain and spinal cord is damaged by the immune system. The nerve fibres themselves can also become damaged. While some people have a relapsing remitting form of the disease, others experience gradual progression that in some can cause severe disability. Researchers say they have identified a genetic variant that appears to increase the severity of the disease. They found that people who inherit the variant from both parents need a walking aid almost four years sooner than those without. “This is a very substantial effect for a single genetic variant,” said Sergio Baranzini, a professor of neurology at the University of California, San Francisco and co-senior author of the study. “Furthermore, this variant affects genes that are active in the central nervous system, a clear contrast to variants that confer risk [of MS], which overwhelmingly affect the immune system.” The study, published in the journal Nature, was an international endeavour, involving 70 institutions around the world. To make their discovery, the team analysed genetic data from more than 12,000 people with MS, screening more than 7m genetic variants for associations with the speed of disease progression. The team found that one variant, nestled between two genes called DYSF and ZNF638, was associated with a more rapid increase in disability. © 2023 Guardian News & Media Limited

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 28840 - Posted: 07.01.2023