Chapter 11. Emotions, Aggression, and Stress
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By Michael Balter Humans are generally highly cooperative and often impressively altruistic, quicker than any other animal species to help out strangers in need. A new study suggests that our lineage got that way by adopting so-called cooperative breeding: the caring for infants not just by the mother, but also by other members of the family and sometimes even unrelated adults. In addition to helping us get along with others, the advance led to the development of language and complex civilizations, the authors say. Cooperative breeding is not unique to humans. Up to 10% of birds are cooperative breeders, as are meerkats and New World monkeys such as tamarins and marmosets. But our closest primate relatives, great apes such as chimpanzees, are not cooperative breeders. Because the human and chimpanzee lineages split between 5 million and 7 million years ago, and humans are the only apes that engage in cooperative breeding, researchers have puzzled over how this helping behavior might have evolved all over again on the human line. In the late 1990s, Sarah Blaffer Hrdy, now an anthropologist emeritus at the University of California, Davis, proposed the cooperative breeding hypothesis. According to her model, early in their evolution humans added cooperative breeding behaviors to their already existing advanced ape cognition, leading to a powerful combination of smarts and sociality that fueled even bigger brains, the evolution of language, and unprecedented levels of cooperation. Soon after Hrdy’s proposal, anthropologists Carel van Schaik and Judith Burkart of the University of Zurich in Switzerland began to test some of these ideas, demonstrating that cooperatively breeding primates like marmosets engaged in seemingly altruistic behavior by helping other marmosets get food with no immediate reward to themselves. © 2014 American Association for the Advancement of Science.
by Bethany Brookshire When a laboratory mouse and a house mouse come nose to nose for the first time, each one is encountering something it has never seen before. They are both Mus musculus. But the wild mouse is facing a larger, fatter, calmer and less aggressive version of itself that’s the result of brother-to-sister inbreeding for generations, resulting in mice that are almost completely genetically identical. Laboratory mice are incredibly valuable tools for research into diseases from Alzheimer’s to Zellweger syndrome. Scientists have a deep understanding of lab mouse DNA, and can use that knowledge to study how specific genes may control certain behaviors and underlie disease. But with all the inbreeding comes some traits that, while desirable in a lab mouse, may not reflect the behavior of an animal in the wild. So for some questions, and some behaviors, scientists might need something a bit wilder. A new study takes lab mice back to their roots and along the way uncovers a new gene function. Lea Chalfin and colleagues at the Weizmann Institute of Science in Rohovot, Israel, bred laboratory mice with wild mice for 10 generations. The result was a mouse with wild mouse genes and wild mouse behavior — with a few important lab mouse genes mixed in. The technique allows scientists to place specific mutations in a wild mouse. The results have interesting implications for studying the mouse species, and might provide some new ways to study human disease as well. Chalfin and her colleagues were especially interested in behaviors linked to female aggression. © Society for Science & the Public 2000 - 2013
|By Christie Nicholson Children who experience neglect, abuse and poverty have a tougher time as adults than do well-cared-for kids. Now there’s evidence that such stress can actually change the size of brain structures responsible for learning, memory and processing emotion. The finding is in the journal Biological Psychiatry. [Jamie L. Hanson et al, Behavioral Problems After Early Life Stress: Contributions of the Hippocampus and Amygdala] Researchers took images of the brains of 12-year-olds who had suffered either physical abuse or neglect or had grown up poor. From the images the scientists were able to measure the size of the amygdala and hippocampus—two structures involved in emotional processing and memory. And they compared the sizes of these structures with those of 12-year-old children who were raised in middle-class families and had not been abused. And they found that the stressed children had significantly smaller amygdalas and hippocampuses than did the kids from the more nurturing environments. Early stress has been associated with depression, anxiety, cancer and lack of career success later on in adulthood. This study on the sizes of brain regions may offer physiological clues to why what happens to toddlers can have such a profound impact decades later. © 2014 Scientific American
Greta Kaul It was a rainy day, and earthworms wriggled out of the ground and began to arrange themselves on the pavement as Julian Plumadore walked to his community college zoology class in 1991. They spelled out messages only he could read. "I was very frightened to be a custodian of that kind of cosmic information and be able to do absolutely nothing about it," Plumadore said. Other times, there were voices - demons screaming - telling him he was going to hell. Plumadore was eventually diagnosed as having schizoaffective disorder, a psychosis that combines the hallucinations of schizophrenia with a mood disorder like depression. People with psychotic disorders, of which schizophrenia is the most severe, have hallucinations, like the voices Plumadore was hearing, that are divorced from reality. Now, a Stanford researcher suggests that the voices he experienced might have been different if he had grown up somewhere other than the U.S. If he were from India, he might have heard family members telling him to do household chores. If he were from Ghana, he might have heard the voice of God guiding him. For a study published in June, Tanya Luhrmann, a Stanford anthropologist, and other researchers interviewed 60 people who met the criteria for schizophrenia: 20 from in and around San Mateo, 20 from India and 20 from Ghana. Though the patients heard both positive and negative voices no matter where they were from, those in India and in Ghana tended to have less negative experiences than Americans: They could more often identify who was talking to them and had less violent hallucinations. Though the study isn't conclusive, Luhrmann believes the differences in voice-hearing between cultures may be a clue into how social expectations and environment shape the way people hear those imaginary voices. © 2014 Hearst Communications, Inc.
By NATALIE ANGIER SOUTH LUANGWA NATIONAL PARK, ZAMBIA — We saw the impala first, a young buck with a proud set of ridged and twisted horns, like helical rebar, bounding across the open plain at full, desperate gallop. But why? A moment later somebody in our vehicle gasped, and the answer became clear. Rising up behind the antelope, as though conjured on movie cue from the aubergine glow of the late afternoon, were six African wild dogs, running in single file. They moved with military grace and precision, their steps synchronized, their radio-dish ears cocked forward, their long, puppet-stick legs barely skimming the ground. Still, the impala had such a jump on them that the dogs couldn’t possibly catch up — could they? We gunned the engine and followed. The pace quickened. The dogs’ discipline held steady. They were closing the gap and oh, no, did I really want to watch the kill? To my embarrassed relief, the violence was taken off-screen, when prey and predators suddenly dashed up a hill and into obscuring bushes. By the time we reached the site, the dogs were well into their communal feast, their dark muzzles glazed with bright red blood, their white-tipped tails wagging in furious joy. “They are the most enthusiastic animals,” said Rosie Woodroffe of the Institute of Zoology in London, who has studied wild dogs for the last 20 years. “Other predators may be bigger and fiercer, but I would argue that there is nothing so enthusiastic as a wild dog,” she said. “They live the life domestic dogs wish they could live.” In 1997, while devising an action plan to help save the wild dog species, Lycaon pictus, Dr. Woodroffe felt anything but exuberant. Wild dogs were considered among the most endangered of Africa’s mammals; Dr. Woodroffe had yet to see one in the wild, and she feared she never would. © 2014 The New York Times Company
Helen Shen Most people gradually recover from trauma, but a small fraction of individuals develop post-traumatic stress disorder (PTSD) — prompting scientists to look for the biological underpinnings of this extreme response to traumatic situations such as warfare, car accidents and natural disasters. Research published on 11 August in Proceedings of the National Academy of Sciences identifies up to 334 genes that may be involved in vulnerability to post-traumatic stress in rats1. Most animal studies of stress use intense stimuli such as electric shocks, designed to produce large, group differences between exposed and unexposed animals. But Nikolaos Daskalakis and his colleagues tried a subtler approach to elicit a wide range of individual responses in rats that had all experienced the same trauma — more closely mimicking the variability of human responses to disturbing events. "We wanted to capture the differences between a susceptible individual and one that is not susceptible to the same experience," says Daskalakis, a neuroendocrinologist at the Icahn School of Medicine at Mount Sinai in New York. The researchers exposed around 100 rats to soiled cat litter — which evokes a feared predator — and tested the animals one week later for lingering effects of the trauma. About one-quarter of the exposed animals were classified as 'extreme' responders, showing high levels of anxiety and startling easily on hearing loud noises. Another quarter of the animals were 'minimal' responders, and exhibited anxiety levels similar to those of non-exposed rats. © 2014 Nature Publishing Group
By DANIEL J. LEVITIN THIS month, many Americans will take time off from work to go on vacation, catch up on household projects and simply be with family and friends. And many of us will feel guilty for doing so. We will worry about all of the emails piling up at work, and in many cases continue to compulsively check email during our precious time off. But beware the false break. Make sure you have a real one. The summer vacation is more than a quaint tradition. Along with family time, mealtime and weekends, it is an important way that we can make the most of our beautiful brains. Every day we’re assaulted with facts, pseudofacts, news feeds and jibber-jabber, coming from all directions. According to a 2011 study, on a typical day, we take in the equivalent of about 174 newspapers’ worth of information, five times as much as we did in 1986. As the world’s 21,274 television stations produce some 85,000 hours of original programming every day (by 2003 figures), we watch an average of five hours of television per day. For every hour of YouTube video you watch, there are 5,999 hours of new video just posted! If you’re feeling overwhelmed, there’s a reason: The processing capacity of the conscious mind is limited. This is a result of how the brain’s attentional system evolved. Our brains have two dominant modes of attention: the task-positive network and the task-negative network (they’re called networks because they comprise distributed networks of neurons, like electrical circuits within the brain). The task-positive network is active when you’re actively engaged in a task, focused on it, and undistracted; neuroscientists have taken to calling it the central executive. The task-negative network is active when your mind is wandering; this is the daydreaming mode. These two attentional networks operate like a seesaw in the brain: when one is active the other is not. © 2014 The New York Times Company
Simon Makin Fish that have been exposed to a common anti-anxiety drug are more active and have better chances of survival than unexposed fish, researchers report in Environmental Research Letters1. The results suggest that standard methods for assessing the environmental impact of pharmaceuticals in waterways might miss some of the drugs' effects because they focus exclusively on harms, according to the authors. In the study, researchers led by Jonatan Klaminder at Umeå University in Sweden exposed Eurasian perch (Perca fluviatilis) to oxazepam, one of a widely used class of anti-anxiety drugs called benzodiazepines. Standard ecotoxicology experiments use unstressed, healthy fish that have been bred in labs. Control groups are designed to have 100% survival rates so that decreases in survival in the test group are easy to detect by comparison. But it is difficult to detect any increase in survival rates when the control group already has nearly complete survival. So Klaminder and his colleagues used the opposite approach. They exposed fish to the drug at two sensitive life stages: two-year-old wild fish taken from a Swedish lake that had only recently thawed after winter, and strings of roes — fish eggs that contain embryos undergoing development. These are more realistic conditions, the researchers say, as animals in the wild often experience high mortality. The researchers used oxazepam at a high concentration of 1,000 micrograms per litre and at a low concentration of 1 μg l−1. The low dose is relevant to aquatic environments in urban areas, because oxazepam concentrations of 1.9 μg l−1 have been measured in effluents from wastewater treatment plants. © 2014 Nature Publishing Group,
Link ID: 19928 - Posted: 08.09.2014
By DOUGLAS QUENQUA A tiny part of the brain keeps track of painful experiences and helps determine how we will react to them in the future, scientists say. The findings could be a boon to depression treatments. The habenula (pronounced ha-BEN-you-la), a part of the brain less than half the size of a pea, has been shown in animal studies to activate during painful or unpleasant episodes. Using M.R.I.s to produce powerful brain scans, researchers at University College London tracked the habenulas in subjects who were hooked up to electric shock machines. The subjects were presented with a series of photographs, some of which were followed by increasingly strong shocks. Soon, when the subjects were shown pictures associated with shocks, their habenulas would light up. “The habenula seems to track the associations with electric shocks becoming stronger and stronger,” said Jonathan Roiser, a neuroscientist at the college and an author of the study, published in The Proceedings of the National Academy of Sciences. The habenula appeared to have an effect on motivation, too. The subjects had been asked to occasionally press a button, just to show they were awake. They were much slower to do so when their habenula was active. In fact, the more slowly they responded, the more reliably their habenulas tracked associations with shocks. In animals, the habenula has been shown to suppress production of dopamine, a chemical that drives motivation. Perhaps, the researchers say, an overactive habenula can cause the feelings of impending doom and low motivation common in people with depression. © 2014 The New York Times Company
Emily Underwood Since swine flu swept the globe in 2009, scientists have scrambled to determine why a small percentage of children in Europe who received the flu vaccine Pandemrix developed narcolepsy, an incurable brain disorder that causes irresistible sleepiness. This week, a promising explanation was dealt a setback when prominent sleep scientist Emmanuel Mignot of Stanford University in Palo Alto, California, and colleagues retracted their influential study reporting a potential link between the H1N1 virus used to make the vaccine and narcolepsy. Some researchers were taken aback. “This was one of the most important pieces of work on narcolepsy that has come out,” says neuroimmunologist Lawrence Steinman, a close friend and colleague of Mignot’s, who is also at Stanford. The retraction, announced in Science Translational Medicine (STM), “really caught me by surprise,” he says. Others say that journal editors should have detected problems with the study’s methodology. The work provided the first substantiation of an autoimmune mechanism for narcolepsy, which could explain the Pandemrix side effect, researchers say. The vaccine, used only in Europe, seems to have triggered the disease in roughly one out of 15,000 children who received it. The affected children carried a gene variant for a particular human leukocyte antigen (HLA) type—a molecule that presents foreign proteins to immune cells—considered necessary for developing narcolepsy. In the 18 December 2013 issue of STM, Mignot and colleagues reported that T cells from people with narcolepsy, but not from healthy controls, are primed to attack by hypocretin, a hormone that regulates wakefulness. They also showed molecular similarities between fragments of the H1N1 virus and the hypocretin molecule and suggested that these fragments might fool the immune system into attacking hypocretin-producing cells. © 2014 American Association for the Advancement of Science
By Caelainn Hogan A simple blood test could determine a person’s risk of suicide and provide a future tool of prevention to stem suicide rates. In a study published online Wednesday in the American Journal of Psychiatry, researchers say they have discovered a genetic indicator of a person’s vulnerability to the effects of stress and anxiety and, therefore, the risk of suicidal thoughts or attempts. The Johns Hopkins researchers looked at how a group of chemicals known as methyls affect the gene SKA2, which modifies how the brain reacts to stress hormones. If the gene’s function is impaired by a chemical change, someone who is stressed won’t be able to shut down the effect of the stress hormone, which would be like having a faulty brake pad in a car for the fear center of the brain, worsening the impact of even everyday stresses. Researchers studied about 150 postmortem brain samples of healthy people and those with mental illness, including some who had committed suicide. They found that those who died by suicide had significantly higher levels of the chemical that altered the SKA2 gene. As a result of the gene’s modification, it was not able to “switch off” the effect of the stress hormone. The researchers then tested sets of blood samples from more than 325 participants in the Johns Hopkins Center for Prevention Research study to see whether they could determine those who were at greater risk of suicide by the same biomarker. They were able to guess with 80 to 90 percent accuracy whether a person had thoughts of suicide or made an attempt by looking at the single gene, while accounting for age, gender and levels of stress or anxiety.
By ANNA NORTH What does it mean to be lonely? It’s tempting to equate the feeling with a dearth of social interaction, but some people are now saying that it’s more complicated than that — and that true loneliness might be dangerous. In a story at Medium, Robin Marantz Henig busts some common loneliness myths. Lonely people aren’t necessarily weird or uncool: Ms. Henig cites a study of Ohio State undergrads showing that “those who called themselves lonely had just as much ‘social capital’ — defined by physical attractiveness, height, weight, socioeconomic status, and academic achievement — as their non-lonely peers.” And they may not be actually alone: “The students at Ohio State who were lonely belonged to as many clubs and had as many roommates as those who were ‘socially embedded.’ And while some studies indicate that living alone puts people at greater risk for loneliness, living with a spouse is not necessarily any protection.” Rather, loneliness may be psychological. The lonely, writes Ms. Henig, are more likely than others “to feel put upon and misunderstood” in social situations, to see “social danger even where none might exist.” She writes: “People grow lonely because of the gloomy stories they tell themselves. And, in a cruel twist, the loneliness itself can further distort their thinking, making them misread other people’s good intentions, which in turn causes them to withdraw to protect themselves from further rejection — and causes other people to keep them at arm’s length.” This distancing can have a physical impact; Ms. Henig argues that loneliness deserves further study, in part because it may increase the risk of high blood pressure, sleep problems and Alzheimer’s disease. © 2014 The New York Times Company
|By Fikri Birey What’s the difference between you and a rat? The list is unsurprisingly long but now, we can cross a universal human experience — feelings of regret — off of it. A new study shows for the first time that rats regret bad decisions and learn from them. In addition to existentialist suggestions of a rat’s regret — and what that takes away from, or adds to, being “human” — the study is highly relevant to basic brain research. Researchers demonstrated that we can tap into complex internal states of rodents if we hone in on the right behavior and the right neurons. There is a significant literature on what brain regions are representative of certain states, like reward predictions and value calculations, but the study, powered by a novel behavioral test, is able to put together such discrete behavioral correlates into a “rat” definition of regret. Finding better animal models of human behavior constitute a long-standing challenge in neuroscience: It has been difficult to authentically recapitulate mental states in animal models of neuropsychiatric disorders: For example, an attempt to model depression in rodents can often go no further than relatively coarse approximations of the core symptoms like guilt or sadness, which often translates to behaviors like social avoidance or anhedonia in rodents. The inability to efficiently approach the questions of mental abnormalities is a major problem. Depression is currently ranked as the leading cause of disability globally, and it’s estimated that by 2020, depression will lead 1.5 million people to end their lives by suicide. Now, thanks to a simple yet well-conceived series of experiments by Steiner and Redish, a compound behavior like regret is fully open to investigation. The investigators use a spatial decision-making set-up called “Restaurant Row”: an arena with four zones where four different flavors of food (banana, cherry, chocolate or unflavored) are introduced in sequence. © 2014 Scientific American
By STEPHANIE FAIRYINGTON A few months ago, I was on a Manhattan-bound D train heading to work when a man with a chunky, noisy newspaper got on and sat next to me. As I watched him softly turn the pages of his paper, a chill spread like carbonated bubbles through the back of my head, instantly relaxing me and bringing me to the verge of sweet slumber. It wasn’t the first time I’d felt this sensation at the sound of rustling paper — I’ve experienced it as far back as I can remember. But it suddenly occurred to me that, as a lifelong insomniac, I might be able to put it to use by reproducing the experience digitally whenever sleep refused to come. Under the sheets of my bed that night, I plugged in some earphones, opened the YouTube app on my phone and searched for “Sound of pages.” What I discovered stunned me. There were nearly 2.6 million videos depicting a phenomenon called autonomous sensory meridian response, or A.S.M.R., designed to evoke a tingling sensation that travels over the scalp or other parts of the body in response to auditory, olfactory or visual forms of stimulation. The sound of rustling pages, it turns out, is just one of many A.S.M.R. triggers. The most popular stimuli include whispering; tapping or scratching; performing repetitive, mundane tasks like folding towels or sorting baseball cards; and role-playing, where the videographer, usually a breathy woman, softly talks into the camera and pretends to give a haircut, for example, or an eye examination. The videos span 30 minutes on average, but some last more than an hour. For those not wired for A.S.M.R. — and even for those who, like me, apparently are — the videos and the cast of characters who produce them — sometimes called “ASMRtists” or “tingle-smiths” — can seem weird, creepy or just plain boring. (Try pitching the pleasures of watching a nerdy German guy slowly and silently assemble a computer for 30 minutes.) © 2014 The New York Times Company
By CATHERINE SAINT LOUIS “This has happened before,” she tells herself. “It’s nowhere near as bad as before, and it will pass.” Robbie Pinter’s 21-year-old son, Nicholas, is upset again. He yells. He obsesses about something that can’t be changed. Even good news may throw him off. So Dr. Pinter breathes deeply, as she was taught, focusing on each intake and release. She talks herself through the crisis, reminding herself that this is how Nicholas copes with his autism and bipolar disorder. With these simple techniques, Dr. Pinter, who teaches English at Belmont University in Nashville, blunts the stress of parenting a child with severe developmental disabilities. Dr. Pinter, who said she descends from “a long line of the most nervous women,” credits her mindfulness practice with giving her the tools to cope with whatever might come her way. “It is very powerful,” she said. All parents endure stress, but studies show that parents of children with developmental disabilities, like autism, experience depression and anxiety far more often. Struggling to obtain crucial support services, the financial strain of paying for various therapies, the relentless worry over everything from wandering to the future — all of it can be overwhelming. “The toll stress-wise is just enormous, and we know that we don’t do a really great job of helping parents cope with it,” said Dr. Fred R. Volkmar, the director of Child Study Center at Yale University School of Medicine. “Having a child that has a disability, it’s all-encompassing,” he added. “You could see how people would lose themselves.” But a study published last week in the journal Pediatrics offers hope. It found that just six weeks of training in simple techniques led to significant reductions in stress, depression and anxiety among these parents. © 2014 The New York Times Company
By KATE MURPHY ONE of the biggest complaints in modern society is being overscheduled, overcommitted and overextended. Ask people at a social gathering how they are and the stock answer is “super busy,” “crazy busy” or “insanely busy.” Nobody is just “fine” anymore. When people aren’t super busy at work, they are crazy busy exercising, entertaining or taking their kids to Chinese lessons. Or maybe they are insanely busy playing fantasy football, tracing their genealogy or churning their own butter. And if there is ever a still moment for reflective thought — say, while waiting in line at the grocery store or sitting in traffic — out comes the mobile device. So it’s worth noting a study published last month in the journal Science, which shows how far people will go to avoid introspection. “We had noted how wedded to our devices we all seem to be and that people seem to find any excuse they can to keep busy,” said Timothy Wilson, a psychology professor at the University of Virginia and lead author of the study. “No one had done a simple study letting people go off on their own and think.” The results surprised him and have created a stir in the psychology and neuroscience communities. In 11 experiments involving more than 700 people, the majority of participants reported that they found it unpleasant to be alone in a room with their thoughts for just 6 to 15 minutes. Moreover, in one experiment, 64 percent of men and 15 percent of women began self-administering electric shocks when left alone to think. These same people, by the way, had previously said they would pay money to avoid receiving the painful jolt. It didn’t matter if the subjects engaged in the contemplative exercise at home or in the laboratory, or if they were given suggestions of what to think about, like a coming vacation; they just didn’t like being in their own heads. © 2014 The New York Times Company
By MICHAEL INZLICHT and SUKHVINDER OBHI I FEEL your pain. These words are famously associated with Bill Clinton, who as a politician seemed to ooze empathy. A skeptic might wonder, though, whether he truly was personally distressed by the suffering of average Americans. Can people in high positions of power — presidents, bosses, celebrities, even dominant spouses — easily empathize with those beneath them? Psychological research suggests the answer is no. Studies have repeatedly shown that participants who are in high positions of power (or who are temporarily induced to feel powerful) are less able to adopt the visual, cognitive or emotional perspective of other people, compared to participants who are powerless (or are made to feel so). For example, Michael Kraus, a psychologist now at the University of Illinois at Urbana-Champaign, and two colleagues found that among full-time employees of a public university, those who were higher in social class (as determined by level of education) were less able to accurately identify emotions in photographs of human faces than were co-workers who were lower in social class. (While social class and social power are admittedly not the same, they are strongly related.) Why does power leave people seemingly coldhearted? Some, like the Princeton psychologist Susan Fiske, have suggested that powerful people don’t attend well to others around them because they don’t need them in order to access important resources; as powerful people, they already have plentiful access to those. We suggest a different, albeit complementary, reason from cognitive neuroscience. On the basis of a study we recently published with the researcher Jeremy Hogeveen, in the Journal of Experimental Psychology: General, we contend that when people experience power, their brains fundamentally change how sensitive they are to the actions of others. © 2014 The New York Times Company
By JAMES GORMAN Any dog owner would testify that dogs are just as prone to jealousy as humans. But can one really compare Othello’s agony to Roscoe’s pique? The answer, according to Christine Harris, a psychologist at the University of California, San Diego, is that if you are petting another dog, Roscoe is going to show something that Dr. Harris thinks is a form of jealousy, even if not as complex and twisted as the adult human form. Other scientists agree there is something going on, but not all are convinced it is jealousy. And Roscoe and the rest of his tribe were, without exception, unavailable for comment. Dr. Harris had been studying human jealousy for years when she took this question on, inspired partly by the antics of her parents’ Border collies. When she petted them, “one would take his head and knock the other’s head away,” she said. It certainly looked like jealousy. But having studied humans, she was aware of different schools of thought about jealousy. Some scientists argue that jealousy requires complex thinking about self and others, which seems beyond dogs’ abilities. Others think that although our descriptions of jealousy are complex, the emotion itself may not be that complex. Dog emotions, as owners perceive them, have been studied before. In one case, Alexandra Horowitz, a cognitive scientist who is an adjunct associate professor at Barnard College and the author of “Inside of a Dog,” found that the so-called guilty look that dogs exhibit seemed to be more related to fear of punishment. Dr. Harris ventured into the tricky turf of dog emotion by devising a test based on work done with infants. © 2014 The New York Times Company
by Bethany Brookshire Even when we love our jobs, we all look forward to some time away. During the week, as stress builds up and deadlines accumulate, Friday looks better and better. Then, with a sigh of relief, the weekend arrives. But come Monday, it seems like the whole weight of responsibility just comes crashing down again. It’s not just you. Rats feel it, too. Rats given a two-day break from a stressful procedure show more signs of strain on “Monday” than rats who never got the weekend, researchers report July 11 in PLOS ONE. The results show that in some cases, an unpredictable getaway can cause more stress than just working through the pressure. Wei Zang, J. Amiel Rosenkranz and colleagues at the Rosalind Franklin University of School of Medicine and Science in Chicago wanted to understand how changes to a stressful situation alter an animal’s response to stress. Normally, when rats are exposed over and over to a stress such as a restraint (in which a rat is placed in a small tube where it can’t turn around or get out), they begin to get used to the stress. Over a few days, rats stop avoiding the tube and stay calmly in the restraint without struggling, until they are set free. Hormones like corticosterone — which spikes in response to stress — go down. This phenomenon is called habituation. Zhang and colleagues wanted to see what happens when this pattern of stress is interrupted. They restrained rats for 20 minutes each for five days. By day five, the animals were hanging out comfortably in the tubes. Then, the scientists introduced an interruption: They gave half of the rats two days off, a science-induced weekend. The scientists continued to restrain the other group of rats daily. © Society for Science & the Public 2000 - 2013
Link ID: 19872 - Posted: 07.23.2014
Sarah C. P. Williams The wheezing, coughing, and gasping for breath that come with a sudden asthma attack aren’t just the fault of an overactive immune system. A particularly sensitive bundle of neurons stretching from the brain to the lungs might be to blame as well, researchers have found. Drugs that alter these neurons could provide a new way to treat some types of asthma. “This is an exciting confirmation of an idea that’s been around for decades,” says Allison Fryer, a pulmonary pharmacology researcher at Oregon Health & Science University in Portland, who was not involved in the new study. An asthma attack can be brought on by a variety of triggers, including exercise, cold temperatures, pollen, and dust. During an attack, a person’s airways become inflamed, mucus clogs their lungs, and the muscles surrounding their airways tighten. Asthma is often considered a disease of the immune system because immune cells go into overdrive when they sense a trigger and cause inflammation. But a bundle of nerves that snakes through the neck and chest, the vagus nerve, has long been suspected to play a role; the cells it contains, after all, control the airway muscles. Studying which cell types and molecular pathways within the thick nerve bundle are involved, though, has been tough—the vagus contains a multitude of different cells that are physically intertwined. Working together at the Howard Hughes Medical Institute’s Janelia Farm Research Campus in Ashburn, Virginia, neurobiologists Dimitri Tränkner, now at the University of Utah in Salt Lake City, and Charles Zuker of Columbia University turned to genetics to work out the players. They selectively shut off different sets of the neurons in mice based on which genes each neuron expressed, rather than their physical location. Then, through a series of injections, they gave the animals an egg white allergy that causes asthmalike symptoms. © 2014 American Association for the Advancement of Science
Link ID: 19866 - Posted: 07.22.2014