Chapter 15. Emotions, Aggression, and Stress

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By Angie Voyles Askham Keeping track of social hierarchies is crucial for any animal. Primates in particular must adapt their behaviors based on the status of those around them, or risk losing their own rank. “True, smart social behavior in humans and in monkeys is dependent on a full adjustment to the context,” says Katalin Gothard, professor of physiology and neuroscience at the University of Arizona. Multiple brain areas keep track of social information. Among them, the amygdala—known for processing emotions—responds to faces, facial expressions and social status, and activates as people learn social hierarchies. But the brain adapts this information for different social settings, a new study reveals: Neurons in the macaque amygdala encode knowledge about social status in a context-specific way, Gothard and her colleagues discovered. Just like people, macaques can infer social standing from videos, and the activity of amygdala cells captures information about both the identity of the individual they are watching and how that animal relates to others in the scene. These findings help explain how primates process information about social position, says Ralph Adolphs, professor of psychology and neuroscience at California Institute of Technology, who was not involved in the work. And because the monkeys could successfully learn this information from videos, the results open up a new avenue for studying how the primate brain encodes these relationships in a complex and dynamic way, he adds. “That’s a big step forward.” Like people, macaques have no physical traits that directly convey dominance, Gothard says. “The status of these individuals is inferred.” So she and her colleagues tested two macaques’ ability to understand a hierarchy that the team invented among four unfamiliar monkeys in a series of videos. Each clip simulated status-appropriate interactions between two of the four monkeys on a split screen to convey those two animals’ relative positions: a scene of a higher-ranked animal acting aggressive juxtaposed with one of a lower-ranked monkey smacking its lips in appeasement, for example. © 2024 Simons Foundation

Keyword: Emotions; Attention
Link ID: 29544 - Posted: 11.06.2024

By Claire Murashima What do you think of when you hear the term “OCD”? In pop culture, people with obsessive-compulsive disorder are often portrayed as meticulous to an extreme degree. They’re highly organized, perfectionistic, or germophobic — like Jack Nicholson’s character in the film As Good As It Gets, who tosses out bars of soap after using them once. Depictions like that aren’t inaccurate, but they’re not the whole story. Research shows that 1 in 40 American adults have OCD or will develop it at some point in their lives, according to the International OCD Foundation. Although the term “OCD” is often used casually, the disorder must be diagnosed by a medical professional. We wanted to take a closer look at how people with OCD cope with it every day as OCD Awareness Month wraps up. I live with OCD, and it impacts just about every aspect of my life. Growing up, I had to say a prayer before I ate anything, because I thought I’d vomit if I didn’t. Later in life, I struggled with flying, because I feared that I might vomit on the plane, or that someone might vomit near me. The fear of vomiting is called emetophobia, and it’s a common symptom of OCD — though it’s not talked about as often. People with OCD can experience very specific intrusive thoughts known as obsessions, and then engage in compulsions, which are ritualized behaviors to address them, according to the International OCD Foundation. Anxiety can be the underlying emotion of OCD — but unlike generalized anxiety disorder, the underlying emotion could also be a sense of disgust, wrongness or incompleteness, according to Dr. Christopher Pittenger, the director of the Yale School of Medicine OCD Research Clinic. © 2024 npr

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 29536 - Posted: 11.02.2024

By Claudia López Lloreda Success tends to breed success. For instance, when a mouse dominates its opponents over and over, it becomes increasingly aggressive—helping to ensure victory in future fights. This “winner effect” takes hold thanks to multiple changes in synaptic plasticity, according to new findings published today in Cell. The results begin to reveal the mechanisms behind various forms of aggression seen in animals, says Jacob Nordman, assistant professor of molecular and integrative physiology at Southern Illinois University, who was not involved in the work. “There’s some aggression that is defensive; there’s some aggression that is pathological; there’s some aggression that’s territorial,” he says. “There might be a set of behaviors and, in turn, a set of circuits and possibly plasticity within those circuits, that speak to that.” Innate aggression is controlled by the ventromedial hypothalamus (VMH)—also known as the “attack” center—which shapes an animal’s social behaviors and fear response. But aggression can be learned, too. When paired with a mouse that is naturally docile, a more dominant mouse will eventually attack the other—and if it prevails, it tends to pick even longer fights with rivals over the coming days, thanks to synapse strengthening and increased activity in the VMH, a 2020 study reported. Full-blown and more generalized aggression emerges after even longer winning streaks, and it involves additional mechanisms, the new study suggests: Changes to neuronal excitability and dendritic spine morphology help cement the animal’s hawkishness. “Aggression is malleable—you can shape it,” says Scott Russo, professor of neuroscience at the Icahn School of Medicine at Mount Sinai, who was not involved with the study. “It’s not something that’s defined only by genetics, but that actually these circuits that support aggressive social behavior can change as a consequence of experience.” © 2024 Simons Foundation

Keyword: Aggression; Hormones & Behavior
Link ID: 29524 - Posted: 10.19.2024

By Max Kozlov Forget the gauze and bandages: electrical stimulation near the ear might help to reduce bleeding. Researchers hope the technique could one day be used before surgery, childbirth and other events that pose a risk of dangerously uncontrolled bleeding. The treatment, called a ‘neural tourniquet’ by its creators, helps to turbocharge the activity of platelets, which are cell fragments that form blood clots, according to preliminary results presented at the 2024 Society for Neuroscience conference. “Anybody who’s worked in the emergency or operating room knows how gruesome it can be to lose somebody to bleeding,” Jared Huston, a trauma surgeon at the Feinstein Institutes for Medical Research in Manhasset, New York, who co-developed the treatment, tells Nature. “Bleeding can kill you much faster than sepsis.” Bleeding’s heavy toll Haemorrhage, or uncontrolled bleeding, accounts for about 60,000 deaths in the United States each year1. To try to reduce that number, Huston and his colleagues are developing a treatment that targets the vagus nerves, which are large networks of nerve fibres that link the body with the brain. Despite its name, the treatment does not work like a typical tourniquet that blocks blood flow to injured appendages. Instead, the electrical pulses help to stimulate the spleen, which stores about one-third of the body’s platelets. The stimulation prods the spleen to ready platelets to form a clot. To test the treatment, the researchers made small cuts in the ears of healthy pigs2. Compared with animals that didn’t receive the treatment, treated swine lost 50% less blood, and the duration of their bleeding was 40% shorter. © 2024 Springer Nature Limited

Keyword: Stress
Link ID: 29517 - Posted: 10.16.2024

By Jennifer Couzin-Frankel Even a mild concussion can cause disconcerting and sometimes lasting symptoms, such as trouble concentrating and dizziness. But can it make someone more likely to commit a crime? After all, a disproportionate number of people in the criminal justice system previously suffered a traumatic brain injury (TBI). But according to new research into the medical and juvenile justice records of Danish teenagers who suffered a blow to head as children, such injuries don’t cause criminal behavior. Although TBI and criminality often travel together, the researchers found in this Danish population it’s a case of correlation, not causation. “I think this study very clearly indicates that you can’t just [say], ‘Hey, my kid has a mild TBI, he or she is screwed,” says Joseph Schwartz, a criminologist at Florida State University who has studied the issue in juveniles and adults. At the same time, he cautions that there are important variables this study wasn’t designed to capture, such as the treatment received, the effect of repeat TBIs, and the circumstances surrounding the injury. All of these, he says, could influence criminal behavior in some people. Beyond showing high rates of past TBI among those charged with or convicted of crimes, research into this topic has been limited. Studies have found that mild TBI is associated with later behavioral problems, including impulsivity and inattentiveness, which are also linked with criminal behavior. At the same time, it’s well known that “the risk factors in the child and the family for TBIs are the same as the risk factors for delinquency,” including poverty and parental substance abuse, says Sheilagh Hodgins, a clinical psychologist at the University of Montreal. She notes, too, that impulsivity and attention and conduct disorders heighten the risk of sustaining a mild TBI in the first place. © 2024 American Association for the Advancement of Science.

Keyword: Brain Injury/Concussion; Aggression
Link ID: 29503 - Posted: 10.02.2024

Ian Sample Science editor Where does our personal politics come from? Does it trace back to our childhood, the views that surround us, the circumstances we are raised in? Is it all about nurture – or does nature have a say through the subtle levers of DNA? And where, in all of this, is the brain? Scientists have delved seriously into the roots of political belief for the past 50 years, prompted by the rise of sociobiology, the study of the biological basis of behaviour, and enabled by modern tools such as brain scanners and genome sequencers. The field is making headway, but teasing out the biology of behaviour is never straightforward. Take a study published last week. Researchers in Greece and the Netherlands examined MRI scans from nearly 1,000 Dutch people who had answered questionnaires on their personal politics. The work was a replication study, designed to see whether the results from a small 2011 study, bizarrely commissioned by the actor Colin Firth, stood up. Firth’s study, conducted at UCL, reported structural differences between conservative and liberal brains. Conservatives, on average, had a larger amygdala, a region linked to threat perception. Liberals, on average, had a larger anterior cingulate cortex, a region involved in decision-making. In the latest study of Dutch people, the researchers found no sign of a larger anterior cingulate cortex in liberals. They did, however, find evidence for a very slightly larger amygdala in conservatives. The MailOnline declared evidence that conservatives were more “compassionate”, but later changed their headline noting that the study said nothing about compassion. © 2024 Guardian News & Media Limited

Keyword: Emotions; Attention
Link ID: 29493 - Posted: 09.25.2024

By Gina Kolata and Stephanie Nolen The Lasker Awards, a prestigious set of prizes given for advances in medicine and public health research, were given on Thursday to scientists whose research helped lead to the discovery of a new class of obesity drugs, infectious disease specialists who worked on the drivers of H.I.V. infection and how to stop it, and a scientist who discovered a way the body protects itself from infectious diseases and cancer. The Laskers are highly regarded in the fields of biomedicine and are sometimes seen as foretelling recipients of the Nobel Prizes in the sciences. This year’s Lasker-DeBakey Clinical Medical Research Award went to three scientists for their work on GLP-1, the hormone that led to drugs like Wegovy (the same compound is the basis for Ozempic), which have transformed the treatment of obesity. They are Dr. Joel Habener, Svetlana Mojsov and Lotte Bjerre Knudsen. Each of the three honorees played a role at a key moment: finding the new hormone; finding the biologically active shorter form of GLP-1; and, finally, showing that the shorter form elicits weight loss. Of course, as almost always happens in science, many others also played key roles, and the Lasker Foundation mentioned some as part of its citation. And one of the honorees, Dr. Mojsov, is receiving what many deem a long overdue recognition. The story of GLP-1 begins with Dr. Habener, an endocrinologist who arrived in the mid-1970s at Massachusetts General Hospital, where he decided to work on diabetes. Most of the focus had been on insulin, which lowers blood sugar levels. But there is another hormone, glucagon, that raises it. Dr. Habener decided to try to find the gene for glucagon, hoping it would lead to a way to squelch the hormone and so lower blood sugar. Working with anglerfish, he discovered a gene for another mysterious protein that resembles glucagon. © 2024 The New York Times Company

Keyword: Obesity; Neuroimmunology
Link ID: 29488 - Posted: 09.21.2024

Does a whiff of pollen trigger a sneeze or a cough? Scientists have discovered nerve cells that cause one response versus another: ‘sneeze neurons’ in the nasal passages relay sneeze signals to the brain, and separate neurons send cough messages, according to a study1 performed in mice. The findings could lead to new and improved treatments for conditions such as allergies and chronic coughs. That’s welcome news because these conditions can be “incredibly frustrating” and the side effects of current treatments can be “incredibly problematic”, says pulmonologist Matthew Drake at Oregon Health & Science University in Portland, who was not involved in the work. The study was published today in Cell. Previous work2 categorized neurons in the mouse airway on the basis of the proteins complexes, called ion channels, that are carried on the cell surfaces. To work out which nose neurons cause sneezing, researchers exposed mice to various compounds, each known to activate specific types of ion channel. They struck gold when a substance called BAM 8-22 left the mice sneezing. The compound is known to activate an ion channel called MrgprC11, leading the researchers to suspect that neurons carrying MrgprC11 cause sneezing. Indeed, when the researchers deleted MrgprC11 from the suspected sneeze neurons and then gave mice the flu, they found themselves with sick, but sneezeless, mice. Even with the sneeze neurons out of the picture, the sick mice continued to have cough-like reactions to influenza infection. Using methods similar to those that homed in on the sneeze neurons, the researchers tracked the cough response to a set of neurons in the trachea that express a signalling chemical called somatostatin. Viruses “evolve very quickly”, says neuroscientist and study co-author Qin Liu at Washington University in St. Louis, Missouri. That could explain why there are two separate systems capable of detecting and clearing them from the airways. © 2024 Springer Nature Limited

Keyword: Neuroimmunology
Link ID: 29466 - Posted: 09.07.2024

By Julian Nowogrodzki A newly devised ‘brain clock’ can determine whether a person’s brain is ageing faster than their chronological age would suggest1. Brains age faster in women, countries with more inequality and Latin American countries, the clock indicates. “The way your brain ages, it’s not just about years. It’s about where you live, what you do, your socio-economic level, the level of pollution you have in your environment,” says Agustín Ibáñez, the study’s lead author and a neuroscientist at Adolfo Ibáñez University in Santiago. “Any country that wants to invest in the brain health of the people, they need to address structural inequalities.” The work is “truly impressive”, says neuroscientist Vladimir Hachinski at Western University in London, Canada, who was not involved in the study. It was published on 26 August in Nature Medicine. Only connect The researchers looked at brain ageing by assessing a complex form of functional connectivity, a measure of the extent to which brain regions are interacting with one another. Functional connectivity generally declines with age. The authors drew on data from 15 countries: 7 (Mexico, Cuba, Colombia, Peru, Brazil, Chile and Argentina) that are in Latin America or the Caribbean and 8 (China, Japan, the United States, Italy, Greece, Turkey, the United Kingdom and Ireland) that are not. Of the 5,306 participants, some were healthy, some had Alzheimer’s disease or another form of dementia and some had mild cognitive impairment, a precursor to dementia. The researchers measured participants’ resting brain activity — that when they were doing nothing in particular — using either functional magnetic resonance imaging (fMRI) or electroencephalography (EEG). The first technique measures blood flow in the brain, and the second measures brain-wave activity. © 2024 Springer Nature Limited

Keyword: Development of the Brain; Stress
Link ID: 29458 - Posted: 08.31.2024

By R. Douglas Fields It is late at night. You are alone and wandering empty streets in search of your parked car when you hear footsteps creeping up from behind. Your heart pounds, your blood pressure skyrockets. Goose bumps appear on your arms, sweat on your palms. Your stomach knots and your muscles coil, ready to sprint or fight. Now imagine the same scene, but without any of the body’s innate responses to an external threat. Would you still feel afraid? Experiences like this reveal the tight integration between brain and body in the creation of mind — the collage of thoughts, perceptions, feelings and personality unique to each of us. The capabilities of the brain alone are astonishing. The supreme organ gives most people a vivid sensory perception of the world. It can preserve memories, enable us to learn and speak, generate emotions and consciousness. But those who might attempt to preserve their mind by uploading its data into a computer miss a critical point: The body is essential to the mind. How is this crucial brain-body connection orchestrated? The answer involves the very unusual vagus nerve. The longest nerve in the body, it wends its way from the brain throughout the head and trunk, issuing commands to our organs and receiving sensations from them. Much of the bewildering range of functions it regulates, such as mood, learning, sexual arousal and fear, are automatic and operate without conscious control. These complex responses engage a constellation of cerebral circuits that link brain and body. The vagus nerve is, in one way of thinking, the conduit of the mind. Nerves are typically named for the specific functions they perform. Optic nerves carry signals from the eyes to the brain for vision. Auditory nerves conduct acoustic information for hearing. The best that early anatomists could do with this nerve, however, was to call it the “vagus,” from the Latin for “wandering.” The wandering nerve was apparent to the first anatomists, notably Galen, the Greek polymath who lived until around the year 216. But centuries of study were required to grasp its complex anatomy and function. This effort is ongoing: Research on the vagus nerve is at the forefront of neuroscience today. © 2024.Simons Foundation

Keyword: Emotions; Obesity
Link ID: 29454 - Posted: 08.28.2024

By Elyse Weingarten In 2016, Canada enacted the Medical Assistance in Dying, or MAID, law, allowing individuals with a terminal illness to receive help from a medical professional to end their life. Following a superior court ruling, the legislation was expanded in 2021 to include nearly anyone with a “grievous and irremediable medical condition” causing “enduring physical or psychological suffering that is intolerable to them.” Whether mental illnesses such as depression, schizophrenia, and addiction should be considered “grievous and irremediable” quickly emerged as the subject of intense debate. Initially slated to go into effect in March 2023, a new mental health provision of the law was postponed a year due to public outcry both in Canada and abroad. Then, in February, Health Minister Mark Holland announced it had been delayed again — this time until 2027 — to allow more time for the country’s health care system to prepare. I was horrified by the news of the law’s latest expansion — a reaction that surprised me. Having grown up with a seriously mentally ill family member, I know first-hand how destructive mental illness can be, and I have no illusion that it is always treatable. Additionally, I support assisted suicide in cases of grave and terminal physical illness, so why do I find it so unacceptable to offer it to people who are intractably mentally ill? For nearly half a century, the Western understanding of mental illness has been shaped to adhere to the larger biomedical concepts of disease and wellness. Biological psychiatry, or the biomedical model, views mental illnesses as organically based disorders of the brain, physiologically indistinguishable from other diseases. The Canadian MAID law’s inclusion of mental illness is the culmination of this framework. Yet the widespread condemnation that the amendment received (that the bill’s previous iterations did not) demonstrates that mental and physical illness — though worthy of the same respect — are in no way equivalent, and that we can recognize this intuitively.

Keyword: Depression; Schizophrenia
Link ID: 29449 - Posted: 08.22.2024

By Sara Reardon Stress can make people feel sick, and bacteria in the gut might be to blame, according to a study1 in mice. The research suggests that a stressed brain directly shuts down specific glands in the gut, affecting gut bacteria and the body’s broader immune system. The study “is a technical tour de force”, says neuroscientist John Cryan at University College Cork in Ireland, who reviewed the study. Most work on the gut–brain connection has focused on how bacteria affect the brain, so Cryan welcomes research into how psychological states can exert ‘top-down’ control of bacteria. “It’s a really cool part of the puzzle”, he says. The research was published on 8 August in Cell. Researchers have long known that the gut and brain ‘talk’ to each other. Under stress, the brain spurs the release of hormones that can trigger gut conditions such as inflammatory bowel disease. And certain bacteria in the gut can release chemical signals that affect the brain and behaviour. Your brain could be controlling how sick you get — and how you recover But the neural communication pathways are less well understood. To find out more, neuroscientist Ivan de Araujo at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, and his colleagues focused on small organs called Brunner’s glands that are found in the walls of the small intestine. Little is known about these glands, other than that they produce mucus and contain numerous neurons. De Araujo’s team found that removing the Brunner’s glands of mice made the animals more susceptible to infection. It also raised markers of inflammation, a flood of immune chemicals and cells that can damage tissues. The team saw a similar effect in humans: people who’d had tumours removed from the part of the gut containing Brunner’s glands had higher levels of white blood cells — a marker of inflammation — than people who’d had tumours removed from other areas. © 2024 Springer Nature Limited

Keyword: Stress; Neuroimmunology
Link ID: 29432 - Posted: 08.13.2024

Joe Hernandez If a human or another animal close to them dies, does a cat grieve the loss? That was the question a team of researchers from Oakland University in Michigan set out to answer when they surveyed hundreds of cat owners about their cat’s behavior after another cat or dog in the household passed away. The data showed that cats exhibited behaviors associated with grief — such as eating and playing less — more often after the death of a fellow pet, suggesting they may in fact have been in mourning. “It made me a little more optimistic that they are forming attachments with each other,” said Jennifer Vonk, a professor of psychology at Oakland University, who co-authored the study, published in the journal Applied Animal Behaviour Science. “It’s not that I want the cats to be sad,” Vonk went on, “[but] there is a part of us, I think, as humans that wants to think that if something happens to us our pets would miss us.” Though animals from elephants to horses to dogs have been shown to express signs of grief, less is known about the emotional life of the domesticated house cat. Vonk said she knew of only one other study on grief in domestic cats. For their research, Vonk and her coauthor, Brittany Greene, surveyed 412 cat caregivers about how their feline companion acted after another pet in the house died. They found that, after the death of a fellow pet, cats on average sought more attention from their owners, spent more time alone, appeared to look for the deceased animal, ate less and slept more. © 2024 npr

Keyword: Emotions; Evolution
Link ID: 29426 - Posted: 08.11.2024

By Michael S. Rosenwald Dr. J. Robin Warren, an Australian pathologist who shared a Nobel Prize for discovering that most stomach ulcers were caused by the bacterium Helicobacter pylori — and not, as had been widely believed, stress, alcohol or spicy foods — died on July 23 in Inglewood, Australia. He was 87. His death, at a care home, was announced by the University of Western Australia in Perth, where he was an emeritus professor for many years. His daughter-in-law Gigi Warren said the cause was complications after a recent fall. In 1984, Dr. Warren and his collaborator, the gastroenterologist Barry Marshall, published a paper in the British medical journal The Lancet describing their finding that the spiral-shaped bacterium now commonly called H. pylori festered in the stomachs of patients with ulcers and gastritis. Dr. Warren had first noticed the bacterium on a gastric biopsy sample in 1979. The paper’s conclusion upended centuries of conventional wisdom about the cause of ulcers. (Psychoanalysts had even written of the “peptic ulcer personality.”) Doctors typically prescribed stress reduction, a bland diet and, starting in 1977, drugs like Tagamet and Zantac to tame the burning acids. Severe cases were sometimes treated with surgery. When the study was published, gastroenterologists were skeptical. They expressed concern about whether to trust potentially paradigm-shifting findings made by two unknown researchers in Australia. And the idea that bacteria could even grow in the stomach was considered blasphemy. “For about 100 years, or 1,000 years, the standard teaching in medicine was that the stomach was sterile and nothing grew there because of corrosive gastric juices,” Dr. Warren told The New York Times in 2005 after he and Dr. Marshall won the Nobel Prize in Physiology or Medicine. “So everybody believed there were no bacteria in the stomach. When I said they were there, no one believed it.” © 2024 The New York Times Company

Keyword: Stress
Link ID: 29425 - Posted: 08.11.2024

By Ellen Barry In recent decades, mental health providers began screening for “adverse childhood experiences” — generally defined as abuse, neglect, violence, family dissolution and poverty — as risk factors for later disorders. But what if other things are just as damaging? Researchers who conducted a large study of adults in Denmark, published on Wednesday in the journal JAMA Psychiatry, found something they had not expected: Adults who moved frequently in childhood have significantly more risk of suffering from depression than their counterparts who stayed put in a community. In fact, the risk of moving frequently in childhood was significantly greater than the risk of living in a poor neighborhood, said Clive Sabel, a professor at the University of Plymouth and the paper’s lead author. “Even if you came from the most income-deprived communities, not moving — being a ‘stayer’ — was protective for your health,” said Dr. Sabel, a geographer who studies the effect of environment on disease. “I’ll flip it around by saying, even if you come from a rich neighborhood, but you moved more than once, that your chances of depression were higher than if you hadn’t moved and come from the poorest quantile neighborhoods,” he added. The study, a collaboration by Aarhus University, the University of Manchester and the University of Plymouth, included all Danes born between 1982 and 2003, more than a million people. Of those, 35,098, or around 2.3 percent, received diagnoses of depression from a psychiatric hospital. Are you concerned for your teen? If you worry that your teen might be experiencing depression or suicidal thoughts, there are a few things you can do to help. Dr. Christine Moutier, the chief medical officer of the American Foundation for Suicide © 2024 The New York Times Company

Keyword: Depression; Stress
Link ID: 29395 - Posted: 07.18.2024

By Freda Kreier Dogs’ ability to feel your pain could be innate. It is the result of centuries of co-evolution with humans, suggests a community-science study that compared the responses of dogs and pet pigs to the sound of humans crying and humming. The results were published on 2 July in Animal Behaviour1. Humans pay attention to how the animals in their lives are feeling, and it seems that this attentiveness is reciprocal. Researchers have found that horses will stop and listen longer to human growls than to laughter2. Pigs respond more strongly to sounds made by people than wild boars do3. But studies testing whether the animals are just reacting to weird human sounds, or are capable of true emotional contagion — the ability to interpret and reflect people’s emotional states — are thin on the ground. Most animals can accurately echo the feelings of only other members of their species. But studies have shown that dogs (Canis familiaris) can mirror the emotions of the people around them4,5. One question is whether this emotional contagion is rooted in ‘universal vocal signals of emotion ’ that can be understood by all domesticated animals, or is specific to companion animals such as dogs. To test this, researchers compared the stress response of dogs and pet pigs (Sus scrofa domesticus) to human sounds. Pet sounds Like dogs, pet pigs are social animals that are from a young age raised around people. But unlike dogs, pigs have been kept as livestock for most of their history with humans. So, if emotional contagion can be learnt through just proximity to people, pet pigs should respond in similar ways to dogs. The team recruited dog or pig owners around the world to film themselves in a room with their pets while playing recorded sounds of crying or humming. Researchers then tallied the number of stress behaviours — such as whining and yawning for dogs, and rapid ear flicks for pigs — exhibited during the experiment. © 2024 Springer Nature Limited

Keyword: Emotions; Evolution
Link ID: 29394 - Posted: 07.18.2024

By Erin Garcia de Jesús In spring 2022, a handful of red foxes in Wisconsin were behaving oddly. Veterinary pathologist Betsy Elsmo learned that a local wildlife rehabilitation center was caring for foxes with neurological symptoms like seizures, tremors, uncoordinated movements and lethargy. But tests for common pathogens like canine distemper virus and rabies that typically cause the symptoms came back negative. Then a red fox kit tested positive for influenza A. This group of viruses includes seasonal flus that cause respiratory disease in people and many other strains that commonly circulate among animals such as waterfowl and other birds. “I was surprised,” says Elsmo, of the University of Wisconsin–Madison. “And to be honest, at first I kind of wrote it off.” That is, until a veterinary technician at the rehab center sent Elsmo a study describing cases of avian influenza in red foxes in the Netherlands. Examinations of the Wisconsin kit’s tissues under the microscope revealed lesions in the brain, lung and heart that matched what had been seen in the Netherlands animals. “And I thought, I think it is [bird flu],” she recalls. Additional testing confirmed the diagnosis in the kit and the other foxes, Elsmo and colleagues reported in the December 2023 Emerging Infectious Diseases. The animals had contracted a lethal strain of H5N1 avian influenza that emerged in late 2020 in Europe and has since spread around the world. At the time infections were discovered in the Wisconsin red foxes, bird flu was expanding its incursion into North America. Since H5N1 arrived on North American shores in December 2021, it has infected animals as wide-ranging as polar bears, skunks, sea lions, bottlenosed dolphins and cows (SN: 7/8/24). And one unwelcome revelation of the ongoing outbreak is the virus’s propensity to invade the brains of myriad mammals. © Society for Science & the Public 2000–2024.

Keyword: Stress
Link ID: 29392 - Posted: 07.13.2024

By Dana G. Smith In July 2016, a heat wave hit Boston, with daytime temperatures averaging 92 degrees for five days in a row. Some local university students who were staying in town for the summer got lucky and were living in dorms with central air-conditioning. Other students, not so much — they were stuck in older dorms without A.C. Jose Guillermo Cedeño Laurent, a Harvard researcher at the time, decided to take advantage of this natural experiment to see how heat, and especially heat at night, affected the young adults’ cognitive performance. He had 44 students perform math and self-control tests five days before the temperature rose, every day during the heat wave, and two days after. “Many of us think that we are immune to heat,” said Dr. Cedeño, now an assistant professor of environmental and occupational health and justice at Rutgers University. “So something that I wanted to test was whether that was really true.” It turns out even young, healthy college students are affected by high temperatures. During the hottest days, the students in the un-air-conditioned dorms, where nighttime temperatures averaged 79 degrees, performed significantly worse on the tests they took every morning than the students with A.C., whose rooms stayed a pleasant 71 degrees. A heat wave is once again blanketing the Northeast, South and Midwest. High temperatures can have an alarming effect on our bodies, raising the risk for heart attacks, heatstroke and death, particularly among older adults and people with chronic diseases. But heat also takes a toll on our brains, impairing cognition and making us irritable, impulsive and aggressive. Numerous studies in lab settings have produced similar results to Dr. Cedeño’s research, with scores on cognitive tests falling as scientists raised the temperature in the room. One investigation found that just a four-degree increase — which participants described as still feeling comfortable — led to a 10 percent average drop in performance across tests of memory, reaction time and executive functioning. © 2024 The New York Times Company

Keyword: Aggression
Link ID: 29370 - Posted: 06.26.2024

By Esther Landhuis Last month, researchers discovered cells in the brainstem that regulate inflammation throughout the body. In response to an injury, these nerve cells not only sense inflammatory molecules, but also dial their circulating levels up and down to keep infections from harming healthy tissues. The discovery adds control of the immune system to the brainstem’s core functions — a list that also includes monitoring heart rate, breathing and aspects of taste — and suggests new potential targets for treating inflammatory disorders like arthritis and inflammatory bowel disease. During an intense workout or high-stakes exam, your brain can sense the spike in your heart rate and help restore a normal rhythm. Likewise, the brain can help stabilize your blood pressure by triggering chemical signals that widen or constrict blood vessels. Such feats often go unnoticed, but they illustrate a fundamental concept of physiology known as homeostasis — the capacity of organisms to keep their internal systems working smoothly and stably amid shifting circumstances. Now, in a paper published on May 1 in Nature, researchers describe how homeostatic control extends even to the sprawl of cells and tissues that comprise our immune system. The team applied a clever genetic approach in mice to identify cells in the brainstem that adjust immune reactions to pathogens and other outside triggers. These neurons operate like a “volume controller” that keeps the animals’ inflammatory responses within a physiological range, said paper author Hao Jin, a neuroimmunologist at the National Institute of Allergy and Infectious Diseases. © 2024 Simons Foundation.

Keyword: Miscellaneous
Link ID: 29361 - Posted: 06.15.2024

By Ellen Barry Post-traumatic stress disorder diagnoses among college students more than doubled between 2017 and 2022, climbing most sharply as the coronavirus pandemic shut down campuses and upended young adults’ lives, according to new research published on Thursday. The prevalence of PTSD rose to 7.5 percent from 3.4 percent during that period, according to the findings. Researchers analyzed responses from more than 390,000 participants in the Healthy Minds Study, an annual web-based survey. “The magnitude of this rise is indeed shocking,” said Yusen Zhai, the paper’s lead author, who heads the community counseling clinic at the University of Alabama at Birmingham. His clinic had seen more young people struggling in the aftermath of traumatic events. So he expected an increase, but not such a large one. Dr. Zhai, an assistant professor in the Department of Human Studies, attributed the rise to “broader societal stressors” on college students, such as campus shootings, social unrest and the sudden loss of loved ones from the coronavirus. PTSD is a mental health disorder characterized by intrusive thoughts, flashbacks and heightened sensitivity to reminders of an event, continuing more than a month after it occurs. It is a relatively common disorder, with an estimated 5 percent of adults in the United States experiencing it in any given year, according to the most recent epidemiological survey conducted by the Department of Health and Human Services. Lifetime prevalence is 8 percent in women and 4 percent in men, the survey found. The new research also found a sharp rise in the prevalence of a similar condition, acute stress disorder, which is diagnosed less than a month after a trauma. Diagnoses rose to 0.7 percent among college students in 2022, up from 0.2 percent five years earlier. Use of mental health care increased nationally during the pandemic, as teletherapy made it far easier to see clinicians. Treatment for anxiety disorders increased most steeply, followed by PTSD, bipolar disorder and depression, according to economists who analyzed more than 1.5 million insurance claims for clinician visits between 2020 and 2022. © 2024 The New York Times Company

Keyword: Stress
Link ID: 29350 - Posted: 06.08.2024