Chapter 15. Emotions, Aggression, and Stress

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By Michael Price Good luck finding a legislative issue more controversial than gun violence—at least in the United States. Compounding the controversy is a dearth of reliable data, thanks largely to a de facto ban on federally funded firearms research enacted in 1996. Yet a new study funded by Harvard Business School suggests that one policy—a mandatory waiting period between the sale of a gun and its delivery—could save hundreds of U.S. lives each year if implemented nationally. “Absolutely, this study demonstrates a robust association between waiting periods and gun deaths,” says Margaret Formica, a public health researcher at the State University of New York Upstate Medical University in Syracuse who studies firearms deaths but wasn’t involved in the new work. “It’s an innovative way of looking at this issue.” More than 33,000 Americans die each year in gun-related incidents, including accidents, homicides, and suicides, about as many as in vehicle accidents. But regulations that place limits on the sale and ownership of firearms vary widely from state to state, and it’s unclear which measures might actually prevent gun violence. Some research from other countries has suggested that a “cooling off” period between the sale and delivery of a gun can tamp down suicidal impulses and anger-driven violence. So when Harvard University researchers were motivated to contribute to policy-relevant gun research in the wake of the 2012 Sandy Hook Elementary School shooting, such “waiting periods” were an easy jumping-off point. Not only was there past research, but data on waiting-period laws are relatively easy to track down. “Instead of saying, ‘Isn’t it a tragedy, children are dying, oh well, on to the next meeting,’ we decided we wanted to do something,” says Deepak Malhotra, a negotiation and conflict resolution researcher who co-authored the new study with economist Michael Luca. © 2017 American Association for the Advancement of Science

Keyword: Aggression
Link ID: 24205 - Posted: 10.17.2017

Carl Safina Last week footage of five young elephants being captured in Zimbabwe to sell to zoos travelled round the world. Parks officials used helicopters to find the elephant families, shot sedatives into the young ones, then hazed away family members who came to the aid of the drugged young ones as they fell. The film, shared exclusively with the Guardian, showed the young captives being trussed up and dragged on to trucks. In the final moments of footage, two men repeatedly kick a small dazed elephant in the head. Removing young elephants from their parents and sending them into captivity is largely justified on the basis that they do not feel and suffer as we do. For decades we have been admonished against anthropomorphism – imbuing animals with human-type emotions such as sadness or love. But, actually, humans have these emotions because other animals do as well. Brain science, evolutionary biology, and behavioural science now show that elephants, humans, and many other animals share a near-identical nervous system and likely experience near-identical basic emotions. Human and elephant brains are bathed in the same chemicals that create mood and motivation in us. We are all mammals, and under the skin we are kin. Scientists have watched rats’ brains as they dream, and dogs’ brains showing love. In fact, sperm whales’ family structure is nearly identical to that of elephants. Animals living in stable social groups – apes and monkeys, wolves and wild dogs, hyenas and cats, various birds, some dolphins and others, know who they are and whom they are with. © 2017 Guardian News and Media Limited

Keyword: Emotions; Evolution
Link ID: 24197 - Posted: 10.16.2017

By Jessica Hamzelou A rare sighting of a chimpanzee giving birth in the wild came to a grisly conclusion. Within seconds of the birth, the baby was snatched away and eaten by a male of the same group. The observation explains why female chimpanzees tend to go into hiding for weeks or months when they have their babies. Little is known about how chimpanzees give birth in the wild because only five births have ever been observed, says Hitonaru Nishie of Kyoto University in Japan. Nishie and his colleagues have been studying chimpanzees in Tanzania’s Mahale mountains for the last few years. One of the reasons so few have been witnessed is that the soon-to-be mothers often leave the group when the baby is due, and don’t return until the infant is weeks or months old. This absence has been described as a chimpanzee’s “maternity leave”. So Nishie and his colleague Michio Nakamura were surprised when, at around 11 am one December day, a female member of the chimpanzee group they were observing began to give birth in front of the 20 other members. As soon as the baby was out – and before the mother had even had a chance to touch it – the baby was snatched away by a male member of the group, who then disappeared into the bush. The researchers found him around 1½ hours later, sitting up a tree and eating the infant from the lower half of its body. He ate the entire body within an hour. © Copyright New Scientist Ltd.

Keyword: Aggression
Link ID: 24193 - Posted: 10.14.2017

Jo Marchant Male scientists are more likely to share their published work than are women — but only with other men, a study of hundreds of researchers has found. Humans are generally considered to be a highly cooperative species, says Jorg Massen, a cognitive biologist at the University of Vienna. But most of the evidence for that assumption comes from artificial situations such as computerized cooperation tasks. “I wanted to test human prosociality in an everyday situation,” he says. So he chose one of the most competitive situations he could think of: his own field of research psychology. To investigate cooperation among psychologists, Massen turned his fellow researchers into guinea pigs. He and his colleagues e-mailed nearly 300 researchers and asked them to share either a PDF of one of their latest papers, or some raw data (pretending that they wanted to include it in a meta-analysis). The results were published in Scientific Reports on 10 October1. In general, the scientists contacted were highly cooperative, with almost 80% willing to share a PDF and almost 60% willing to send raw data. “I was surprised,” says Massen. “Humans are prosocial even in this competitive field.” Even more unexpected, however, was a strong gender difference in how the scientists responded to the request for help. Massen and his colleagues had wondered whether men might respond more favourably to women, or vice versa. In fact, men were more likely to share, but only with other men. A male–male request was 15% more likely to be granted than any other gender combination. © 2017 Macmillan Publishers Limited,

Keyword: Sexual Behavior; Aggression
Link ID: 24188 - Posted: 10.13.2017

By Bret Stetka The concept of mindfulness involves focusing on your present situation and state of mind. This can mean awareness of your surroundings, emotions and breathing—or, more simply, enjoying each bite of a really good sandwich. Research in recent decades has linked mindfulness practices to a staggering collection of possible health benefits. Tuning into the world around you may provide a sense of well-being, an array of studies claim. Multiple reports link mindfulness with improved cognitive functioning. One study even suggests it may preserve the tips of our chromosomes, which whither away as we age. Yet many psychologists, neuroscientists and meditation experts are afraid that hype is outpacing the science. In an article released this week in Perspectives on Psychological Science, 15 prominent psychologists and cognitive scientists caution that despite its popularity and supposed benefits, scientific data on mindfulness is woefully lacking. Many of the studies on mindfulness and meditation, the authors wrote, are poorly designed—compromised by inconsistent definitions of what mindfulness actually is, and often void of a control group to rule out the placebo effect. The new paper cites a 2015 review published in American Psychologist reporting that only around 9 percent of research into mindfulness-based interventions has been tested in clinical trials that included a control group. © 2017 Scientific American

Keyword: Stress; Attention
Link ID: 24182 - Posted: 10.12.2017

By BENOIT DENIZET-LEWIS The disintegration of Jake’s life took him by surprise. It happened early in his junior year of high school, while he was taking three Advanced Placement classes, running on his school’s cross-country team and traveling to Model United Nations conferences. It was a lot to handle, but Jake — the likable, hard-working oldest sibling in a suburban North Carolina family — was the kind of teenager who handled things. Though he was not prone to boastfulness, the fact was he had never really failed at anything. Not coincidentally, failure was one of Jake’s biggest fears. He worried about it privately; maybe he couldn’t keep up with his peers, maybe he wouldn’t succeed in life. The relentless drive to avoid such a fate seemed to come from deep inside him. He considered it a strength. Jake’s parents knew he could be high-strung; in middle school, they sent him to a therapist when he was too scared to sleep in his own room. But nothing prepared them for the day two years ago when Jake, then 17, seemingly “ran 150 miles per hour into a brick wall,” his mother said. He refused to go to school and curled up in the fetal position on the floor. “I just can’t take it!” he screamed. “You just don’t understand!” Jake was right — his parents didn’t understand. Jake didn’t really understand, either. But he also wasn’t good at verbalizing what he thought he knew: that going to school suddenly felt impossible, that people were undoubtedly judging him, that nothing he did felt good enough. “All of a sudden I couldn’t do anything,” he said. “I was so afraid.” His tall, lanky frame succumbed, too. His stomach hurt. He had migraines. “You know how a normal person might have their stomach lurch if they walk into a classroom and there’s a pop quiz?” he told me. “Well, I basically started having that feeling all the time.” © 2017 The New York Times Company

Keyword: Development of the Brain; Stress
Link ID: 24174 - Posted: 10.11.2017

By Jessica Wright No one except Gregory Kapothanasis knows exactly what upset him today. On this hot day in July, he went to his day program for adults with developmental disabilities, as he has done without incident five days a week for the past four years. But then things unraveled. According to the program’s report, he grabbed a staff member’s arm hard enough to bruise it. Then, on the bus during the daily outing, he started screaming and hitting his seat. Now, several hours later, he is finally home, but there is a stranger in his living room. Bouncing from one couch to another, clutching a faded beige blanket stolen from his aunt’s dog, Kapothanasis still seems out of sorts. His mother, Irene — who has cared for him, with the help of home aides, for all of his 24 years — is playing over the day’s events, trying to figure out what triggered him. His outburst is disturbingly reminiscent of a difficult period that peaked six years ago but is uncharacteristic of the young man today. Kapothanasis loves interacting with other people, going to the beach and dining at DiMillo’s, a floating restaurant in a decommissioned car ferry in Portland, Maine. Kapothanasis has autism and speaks only a few words: He can’t explain what happened this morning. Did he have constipation and discomfort, as his doctor suggested? Did he get bored of the day’s program, causing him to act out? Had something occurred on the bus previously that made him fear that part of his day? All his mother can do is wonder — and try to make his evening better. © 2017 Scientific American,

Keyword: Autism; Stress
Link ID: 24168 - Posted: 10.10.2017

By Emma Yasinski Scientists and physicians have tried countless methods to treat the nightmares, anxiety, and flashbacks of posttraumatic stress disorder (PTSD) in soldiers, from talk therapy to drugs designed to press the “delete” button on specific memories. Now, one group of researchers proposes another solution: Prevent the condition in the first place by predicting who is most likely to get it. In a new study, they say a 105-question survey already given to all U.S. soldiers may be able to do just that. “It’s a very important study,” says Sharon Dekel, who studies PTSD at Harvard Medical School in Boston, but was not involved in the new work. Only a minority of people exposed to trauma develop the disorder, and the new work may lead to better screening methods for this “vulnerable population,” she adds. U.S. Army soldiers have taken the Global Assessment Tool (GAT), a survey about their mental health, every 2 years since 2009. The confidential questionnaire asks soldiers to rate their agreement with statements like “My leaders respect and value me,” and “I believe there is a purpose to my life.” It’s meant to help soldiers understand their own strengths and weaknesses. But Yu-Chu Shen, a health economics researcher at the Naval Postgraduate School in Monterey, California, wondered whether the survey could also predict the likelihood of someone developing PTSD or depression. So she and colleagues designed a study to see how soldiers’ GAT scores aligned with later illnesses. They looked at 63,186 recruits who enlisted in the Army between 2009 and 2012 and had not yet been exposed to combat. The team then compared the scores with how the same soldiers fared on a postduty comprehensive health assessment that also looked for signs of PTSD and depression. © 2017 American Association for the Advancement of Science

Keyword: Stress
Link ID: 24152 - Posted: 10.05.2017

By Simon Makin About 10 years ago David Adam scratched his finger on a barbed wire fence. The cut was shallow, but drew blood. As a science journalist and author of The Man Who Couldn't Stop: OCD and the True Story of a Life Lost in Thought, a book about his own struggles with obsessive-compulsive disorder, Adam had a good idea of what was in store. His OCD involved an obsessive fear of contracting HIV and produced a set of compulsive behaviors revolving around blood. In this instance he hurried home to get some tissue and returned to check there was not already any blood on the barbed-wire. “I looked and saw there was no blood on the tissue, looked underneath the fence, saw there was no blood, turned to walk away, and had to do it all again, and again and again,” he says. “You get stuck in this horrific cycle, where all the evidence you use to form judgments in everyday life tells you there’s no blood. And if anyone asked, you’d say ‘no.’ Yet, when you ask yourself, you say ‘maybe.’” Such compulsive behaviors, and the obsessions to which they are typically linked are what define OCD. Far from merely excessive tidiness, the mental disorder can have a devastating impact on a person’s life. Adam's story illustrates a curious feature of the condition. Sufferers are usually well aware their behavior is irrational but cannot stop themselves from doing whatever it is they feel compelled to do. Advertisement A new study published September 28 in Neuron uses mathematical modeling of decision-making during a simple game to provide insight into what might be going on. The game looked at a critical aspect of the way we perceive the world. Normally, a person's confidence about their knowledge of the surrounding environment guides their actions. “If I think it’s going to rain, I'm going to take an umbrella,” says lead author Matilde Vaghi. The study shows this link between belief and action is broken to some extent in people with OCD. As a consequence, what they do conflicts with what they know. This insight suggests compulsive behaviors are a core feature rather than merely a consequence of obsessions or a result of inaccurate beliefs. © 2017 Scientific America

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 24150 - Posted: 10.05.2017

By Caroline Williams We are used to hearing that meditation is good for the brain, but now it seems that not just any kind of meditation will do. Just like physical exercise, the kind of improvements you get depends on exactly how you train – and most of us are doing it all wrong. That the brain changes physically when we learn a new skill, like juggling or playing a musical instrument, has been known for over a decade. Previous studies had suggested that meditation does something similar for parts of the brain involved in focused attention. Two new studies published in Science Advances suggest that certain kinds of meditation can change social and emotional circuitry, too. The research comes out of the ReSource Project at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and looked at the effects of three different meditation techniques on the brains and bodies of more than 300 volunteers over 9 months. One technique was based on mindfulness meditation, and taught people to direct attention to the breath or body. A second type concentrated on compassion and emotional connection via loving kindness meditations and non-judgmental problem-sharing sessions with a partner. A final method encouraged people to think about issues from different points of view, also via a mix of partnered sessions and solo meditation. In one study, MRI scans taken after each three-month course showed that parts of the cortex involved in the specific skill that was trained grew thicker in comparison with scans from a control group. © Copyright New Scientist Ltd.

Keyword: Stress
Link ID: 24149 - Posted: 10.05.2017

Jon Hamilton Fresh evidence that the body's immune system interacts directly with the brain could lead to a new understanding of diseases from multiple sclerosis to Alzheimer's. A study of human and monkey brains found lymphatic vessels — a key part of the body's immune system — in a membrane that surrounds the brain and nervous system, a team reported Tuesday in the online journal eLife. Lymphatic vessels are a part of the lymphatic system, which extends throughout the body much like our network of veins and arteries. Instead of carrying blood, though, these vessels carry a clear fluid called lymph, which contains both immune cells and waste products. The new finding bolsters recent evidence in rodents that the brain interacts with the body's lymphatic system to help fend off diseases and remove waste. Until a few years ago, scientists believed that the brain's immune and waste removal systems operated independently. The discovery of lymphatic vessels near the surface of the brain could lead to a better understanding of multiple sclerosis, which seems to be triggered by a glitch in the immune system, says Dr. Daniel Reich, an author of the study and a senior investigator at the National Institute of Neurological Disorders and Stroke. © 2017 npr

Keyword: Alzheimers; Neuroimmunology
Link ID: 24146 - Posted: 10.04.2017

/ By Shayla Love Just after lunchtime, on a blistering summer day in Washington D.C., cultural psychologist Yulia Chentsova-Dutton is showing me the stars. They’re on her computer screen at Georgetown University, and labelled disturbingly: insomnia, anhedonia, headache, social withdrawal, chronic pain, and more. Each star represents a somatic or emotional sensation linked to depression. “There’s the way people express depression … and then there’s what Chinese people do.” Chentsova-Dutton’s father was an astronomer. She’s found a way to use what he studied, the night sky, to understand her own research: how culture can influence the way we feel and express emotion. If you look up, there are thousands of stars, she says. You can’t possibly take them all in. So, each culture has invented schemas to remember them by, constellations. She pushes a button, and several of the depression stars are connected by a thin yellow line. “This is depression according the DSM,” she says, referring to the Diagnostic and Statistical Manual of Mental Disorders. “This,” she says, pushing another button, “is a Chinese model of depression.” The constellation changes, morphing into a different shape. New stars pop up, most having to do with the body: dizziness, fatigue, loss of energy. Chentsova-Dutton and her colleagues have been comparing these two constellations — of Chinese and Western emotion — for years, trying to explain a long-standing assumption about Chinese culture. Since the 1980s, cultural psychologists had been finding that, in a variety of empirically demonstrable ways, Chinese people tend to express their feelings, particularly psychological distress, through their bodies — a process known as somatization. Copyright 2017 Undark

Keyword: Emotions; Depression
Link ID: 24140 - Posted: 10.03.2017

By John Horgan “The Forgotten Era of Brain Chips,” published in Scientific American in October 2005, has provoked as much interest as anything I’ve ever written. It focuses on Jose Manuel Rodriguez Delgado, a pioneer in brain-stimulation research. I keep hearing from journalists and others wanting more information on Delgado, whom I interviewed in 2005 and who died in 2011. Delgado fascinates conspiracy theorists, too. An article on Infowars.com describes him as a “madman” who believed that “no human being has an inherent right to his own personality.” Given widespread interest in and misinformation about Delgado, whose work prefigures current research on brain implants (see “Further Reading”), I’m posting an edited version of my 2005 article. --John Horgan Once among the world’s most acclaimed scientists, Jose Manuel Rodriguez Delgado has become an urban legend, whose career is shrouded in misinformation. Delgado pioneered that most unnerving of technologies, the brain chip, which manipulates the mind by electrically stimulating neural tissue with implanted electrodes. Long a McGuffin of science fictions, from The Terminal Man to The Matrix, brain chips are now being tested as treatments for epilepsy, Parkinson’s disease, paralysis, depression, and other disorders. In part because it was relatively unencumbered by ethical regulations, Delgado’s research rivaled and even surpassed much of what is being done today. In 1965, The New York Times reported on its front page that he had stopped a charging bull in its tracks by sending a radio signal to a device implanted in its brain. He also implanted radio-equipped electrode arrays, which he called “stimoceivers,” in dogs, cats, monkeys, chimpanzees, gibbons, and humans. With the push of a button, he could evoke smiles, snarls, bliss, terror, hunger, garrulousness, lust, and other responses. © 2017 Scientific American,

Keyword: Aggression
Link ID: 24131 - Posted: 10.02.2017

By Christina Leuker, Wouter van den Bos, Jon M. Jachimowicz It is often easier to access someone else’s heart than their mind. We can nearly effortlessly pick up on our partner’s mood or sense that a friend dismisses our plans, without them even speaking a word. But how do we know what is going on in their heads? How do we get this special access to the most private of domains—the human mind? A growing body of research reveals that looking at their eyes may be a neglected and powerful way to do so. The phrases “the eyes are the window to the soul” and “I can see it in your eyes” certainly sound poetic. Many singers, songwriters and writers have capitalized on it. But it turns out that the eyes really might be the windows to the soul. And here’s the great thing about eyes: even if people don’t want you to know how they feel, they can’t change how their eyes behave. So how does this work? The first thing to look for is changes in pupil size. A famous study published in 1960 suggests that how wide or narrow pupils are reflects how information is processed, and how relevant it is. In their experiment, the two experimental psychologists Hess and Polt of the University of Chicago asked male and female participants to look at semi-nude pictures of both sexes. Female participants’ pupil sizes increased in response to viewing men, and male participants’ pupils increased in response to viewing women. In subsequent studies, Hess and Polt find that homosexual participants looking at semi-nude pictures of men (but not women) also had larger pupils. This should come to no surprise: after all, pupils can also reflect how aroused we are. But women’s pupils also responded to pictures of mothers holding babies. Hence, changes in pupil size don’t only reflect how aroused we are, but also how relevant and interesting what we see is. © 2017 Scientific American,

Keyword: Emotions
Link ID: 24129 - Posted: 09.30.2017

Christie Wilcox Many tadpoles ward off predators with potent poisons — but those toxins also seem to help win battles with their own kind, a new study finds. Tadpoles of common toads (Bufo bufo) are more poisonous when raised in crowded conditions, which may give them a competitive edge, according to the work published on 23 September in Functional Ecology1. Many noxious plant species are known to modulate their defences to fend off different threats2, but it is less clear whether animals possess similar toxin-tuning abilities. Although predation pressure is known to induce tadpole chemical defences3, the new findings are the first unequivocal evidence of toxin synthesis spurred by competition in vertebrate animals. Being poisonous can make a species essentially inedible to predators, but making potent toxins comes at a metabolic cost — so it’s best to make that investment count. “It would be very profitable for such animals to kill two birds with one stone by using their anti-predatory toxins as chemical weapons against their competitors, too,” says the study’s lead author, Veronika Bókony, an ecologist with the Hungarian Academy of Sciences in Budapest. Common toads are equipped with bufadienolides, potent toxins that cause harm by accelerating and disrupting the heart’s rhythms4. Field studies have found that common toad toxicity varies geographically, with the intensity of competition being the most reliable predictor5. But it has been unclear whether such patterns occur because populations are genetically isolated from one another in different ponds, or whether they reflect defences induced by environmental factors. © 2017 Macmillan Publishers Limited,

Keyword: Neurotoxins; Evolution
Link ID: 24124 - Posted: 09.30.2017

By Avi Selk Five minutes in the life of a guppy in the terrible spring of 2015: You’re swimming around with your friends in a tank. You’ve been here for days. Food falls from the sky. Everything is fine. Then suddenly, you’re netted up and dropped into an alien world, all alone, just you and the glass. You panic at first, but in time your courage returns and you investigate. Glass wall; glass wall; glass wall; glass wall. A scrap of plastic on the aquarium floor provides the only scant shelter. Hmm … Splash! A huge beak crashes into the water. If you knew what the University of Exeter is, you might wonder how a heron even got inside. Instead, you just cower under the plastic and wait for death. But the beak does not return, and you peek out after a minute or so, and soon the net delivers you back to familiar surroundings. Food and friends again. The terrible memory fades, and life returns to normal. For three days. Then the net again, and the same strange tank of terror. Again and again and again — for you are a guppy in Tom Houslay’s lab, and he wants to understand the very core of your being. The fish could have been any one of the 105 Trinidadian guppies that Houslay’s team at Exeter’s Penryn campus subjected to regular doses of fear two years ago, in an effort to determine whether they have personalities. It turns out they do, of a sort. According to the team’s study, published Monday in the journal Functional Ecology, each fish demonstrated a unique response to stress — which they endured every three days in the form of a pulley-rigged lawn-ornament heron named “Grim,” or a predatory cichlid suddenly revealed on the other side of the glass. “Some of them go straight to the shelter,” said Houslay, an evolutionary biologist and the study’s lead author. “Some just stop moving, maybe hoping they won’t be seen. Some rush to the side and just swim up and down trying to escape.” © 1996-2017 The Washington Post

Keyword: Aggression; Emotions
Link ID: 24118 - Posted: 09.28.2017

By BENEDICT CAREY The brain damage was so severe that scientists all but gasped. Aaron Hernandez, the former New England Patriots tight end, was convicted of murder and killed himself in prison last April at age 27. An autopsy revealed that he had brain injuries akin to that seen in afflicted former players in their 60s, researchers announced on Thursday. The sheer extent of the damage turns on its head the usual question about violence and so-called chronic traumatic encephalopathy. If accumulated head trauma can cause such damage, might the injuries in turn lead to murder and suicide? It’s a natural presumption to make, given the tragic suicides of Junior Seau, Dave Duerson and other former football players diagnosed post-mortem with C.T.E. And it’s a question that the courts will have to wrestle with. On Friday, the National Football League vowed to defend itself against a lawsuit filed on behalf of Mr. Hernandez’s daughter and fiancée, who claims that his injuries and death were a direct result of his participation in football. The science itself — like most attempts to link brain biology to behavior — is murkier. In recent decades, researchers have made extraordinary strides in understanding the workings of brain cells, neural circuits and anatomy. Yet drawing a direct line from those basic findings to what people do out in the world is dicey, given the ineffable interplay between circumstance, relationships and personality. What scientists — from such diverse fields as psychiatry, neurology and substance use — can say is that the arrows seem to be pointing in the same direction. A number of brain states raise the risk of acting out violently, and the evidence so far, while incomplete, suggests that C.T.E. may be one of them. Dr. Samuel Gandy, director of the N.F.L. neurology program at Mount Sinai Medical Center, said that rage and irritability “are far and away the most prominent symptoms” among former players with likely C.T.E., in his research. His group has identified 10 of 24 former players who probably have C.T.E. © 2017 The New York Times Company

Keyword: Brain Injury/Concussion; Aggression
Link ID: 24104 - Posted: 09.23.2017

By NATALIE ANGIER Tom Vaughan, a photographer then living in Colorado’s Mancos Valley, kept a hummingbird feeder outside his house. One morning, he stepped through the portico door and noticed a black-chinned hummingbird dangling from the side of the red plastic feeder like a stray Christmas ornament. At first, Mr. Vaughan thought he knew what was going on. “I’d previously seen a hummingbird in a state of torpor,” he said, “when it was hanging straight down by its feet, regenerating its batteries, before dropping down and flying off.” On closer inspection, Mr. Vaughan saw that the hummingbird was hanging not by its feet but by its head. And forget about jumping its batteries: the bird was in the grip of a three-inch-long green praying mantis. The mantis was clinging with its back legs to the rim of the feeder, holding its feathered catch in its powerful, seemingly reverent front legs, and methodically chewing through the hummingbird’s skull to get at the nutritious brain tissue within. “It was staring at me as it fed,” Mr. Vaughan said. “Of course, I took a picture of it.” Startled by the clicking shutter, the mantis dropped its partially decapitated meal, crawled under the feeder — and began menacing two hummingbirds on the other side. “Talk about cognitive dissonance,” Mr. Vaughan said. “I always thought of mantises as wonderful things to have in your garden to get rid of bugs, but it turns out they sometimes go for larger prey, too.” “It gave me new respect for mantises,” he added. © 2017 The New York Times Company

Keyword: Aggression
Link ID: 24101 - Posted: 09.23.2017

While immune cells called neutrophils are known to act as infantry in the body’s war on germs, a National Institutes of Health-funded study suggests they can act as medics as well. By studying rodents, researchers showed that instead of attacking germs, some neutrophils may help heal the brain after an intracerebral hemorrhage, a form of stroke caused by ruptured blood vessels. The study suggests that two neutrophil-related proteins may play critical roles in protecting the brain from stroke-induced damage and could be used as treatments for intracerebral hemorrhage. “Intracerebral hemorrhage is a damaging and often fatal form of stroke for which there are no effective medicines,” said Jaroslaw Aronowski, M.D., Ph.D., professor, department of neurology, at the University of Texas Health Science Center at Houston, and senior author of the study published in Nature Communications. “Our results are a hopeful first step towards developing a treatment for this devastating form of stroke.” Accounting for 10 to 15 percent of all strokes, intracerebral hemorrhages happen when blood vessels rupture and leak blood into the brain, often leading to death or long-term disability. Chronic high blood pressure is the leading risk factor for these types of strokes. The initial phase of damage appears to be caused by the pressure of blood leaking into the brain. Over time, further damage may be caused by the accumulation of toxic levels of blood products, infiltrating immune cells, and swelling. Decades of research suggest that neutrophils are some of the earliest immune cells to respond to a hemorrhage, and that they may both harm and heal the brain.

Keyword: Stroke; Neuroimmunology
Link ID: 24090 - Posted: 09.21.2017

By Jessica Hamzelou Aggression and sexual behaviour are controlled by the same brain cells in male mice – but not in females. The finding suggests that males are more likely to become aggressive when they see a potential mate than females. The brain regions that contain these cells look similar in mice and humans, say the researchers behind the study, but they don’t yet know if their finding has relevance to human behaviour. Similar to humans, male mice are, on the whole, more aggressive than females. Because of this, most research into aggression has overlooked females, says Dayu Lin at New York University. “I would say 90 per cent of aggression studies have been done in males,” she says. “We know very little about aggression in females.” But females can be aggressive too. For instance, female mice can be aggressive when protecting their newborn pups. In 2011, Lin and her colleagues studied a region of the brain called the hypothalamus, responsible for regulating many different behaviours. They discovered a set of cells within this region in male mice that controlled both aggressive and sexual behaviours. When the cells were shut off, the mice didn’t mate or show aggression, but both behaviours could be triggered when the cells were stimulated. © Copyright New Scientist Ltd.

Keyword: Aggression; Sexual Behavior
Link ID: 24076 - Posted: 09.19.2017