By Amanda Onion Belly fat can be deadly, and is linked to a host of chronic diseases, including heart disease and type 2 diabetes. But as many of us probably know, it can be hard to lose weight in this area. Now it seems that inflammation of immune cells may be to blame, and we may be able to use drugs to help us burn off our belly flab. Christina Cammel, of the Yale School of Medicine, and her colleagues have been investigating macrophages – immune cells that normally track down and gobble up pathogens in the body. But as we age, there’s evidence that the macrophages in belly fat become inflamed. To see what effect this might have, Cammel’s team isolated macrophages from the fat tissue of young and old mice, and sequenced the DNA from these cells. They found that the genomes of the aged macrophages expressed more genes that hinder a group of molecules that spread signals between nerve cells, called catecholamines. The genes do this by activating an enzyme that suppresses these neurotransmitters. The boosted activity of this enzyme in aged immune cells in the belly fat of older mice effectively block signals telling the body that there is fat there that is available to burn for energy. “We found [that] macrophages in belly fat interfere with signals in a way that’s new to us,” says Cammel. © Copyright New Scientist Ltd.

Keyword: Obesity; Depression
Link ID: 24120 - Posted: 09.28.2017

By GRETCHEN REYNOLDS For most of us, temptations are everywhere, from the dessert buffet to the online shoe boutique. But a new study suggests that exercise might be a simple if unexpected way to increase our willpower and perhaps help us to avoid making impulsive choices that we will later regret. Self-control is one of those concepts that we all recognize and applaud but do not necessarily practice. It requires forgoing things that entice us, which, let’s face it, is not fun. On the other hand, lack of self-control can be consequential for health and well-being, often contributing to problems like weight gain, depression or money woes. Given these impacts, scientists and therapists have been interested in finding ways to increase people’s self-restraint. Various types of behavioral therapies and counseling have shown promise. But such techniques typically require professional assistance and have for the most part been used to treat people with abnormally high levels of impulsiveness. There have been few scientifically validated options available to help those of us who might want to be just a little better at resisting our more devilish urges. So for the new study, which was published recently in Behavior Modification, a group of researchers at the University of Kansas in Lawrence began wondering about exercise. Exercise is known to have considerable psychological effects. It can raise moods, for example, and expand people’s sense of what they are capable of doing. So perhaps, the researchers speculated, exercise might alter how well people can control their impulses. To find out, the scientists decided first to mount a tiny pilot study, involving only four men and women. © 2017 The New York Times Company

Keyword: Obesity; Attention
Link ID: 24119 - Posted: 09.28.2017

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

Greta Jochem Concussions have gotten a lot of attention in recent years, especially as professional football players' brains have shown signs of degenerative brain disease linked with repeated blows to the head. Now, a new analysis confirms what many doctors fear — that concussions start showing up at a high rate in teens who are active in contact sports. About 20 percent of teens said they have been diagnosed with at least one concussion. And nearly 6 percent said they've been diagnosed with more than one, according to a research letter published Tuesday in the Journal of the American Medical Association. The Centers for Disease Control and Prevention says concussions can result in headaches, nausea and irritability. While most people do not suffer from long-term impacts from a concussion, between 10 percent and 20 percent may experience symptoms like depression, headaches or difficulty concentrating. Some people experience sleep problems, and multiple concussions are one way to cause chronic traumatic encephalopathy, a degenerative brain disease notably found in some NFL players. The letter's authors looked at 13,000 questionnaire responses from the 2016 version of Monitoring the Future. Each year since 1975, the study, run by the University of Michigan Survey Research Center, has surveyed high school students all over the country about their behaviors and attitudes. According to Philip Veliz, an author of the JAMA letter and an assistant research professor at the University of Michigan's Institute for Research on Women & Gender, in 2016, the survey added a question asking whether students had ever had a concussion. © 2017 npr

Keyword: Brain Injury/Concussion; Development of the Brain
Link ID: 24117 - Posted: 09.28.2017

Hannah Devlin A 35-year-old man who had been in a persistant vegetative state (PVS) for 15 years has shown signs of consciousness after receiving a pioneering therapy involving nerve stimulation. The treatment challenges a widely-accepted view that there is no prospect of a patient recovering consciousness if they have been in PVS for longer than 12 months. Since sustaining severe brain injuries in a car accident, the man had been completely unaware of the world around him. But when fitted with an implant to stimulate the vagus nerve, which travels into the brain stem, the man appeared to flicker back into a state of consciousness. He started to track objects with his eyes, began to stay awake while being read a story and his eyes opened wide in surprise when the examiner suddenly moved her face close to the patient’s. He could even respond to some simple requests, such as turning his head when asked – although this took about a minute. Angela Sirigu, who led the work at the Institut des Sciences Cognitives Marc Jeannerod in Lyon, France, said: “He is still paralysed, he cannot talk, but he can respond. Now he is more aware.” Niels Birbaumer, of the University of Tübingen and a pioneer of brain-computer interfaces to help patients with neurological disorders communicate, said the findings, published in the journal Current Biology, raised pressing ethical issues. “Many of these patients may and will have been neglected, and passive euthanasia may happen often in a vegetative state,” he said. “This paper is a warning to all those believing that this state is hopeless after a year.” © 2017 Guardian News and Media Limited

Keyword: Consciousness
Link ID: 24116 - Posted: 09.26.2017

By Anil Ananthaswamy “We were very happy when we saw him reacting,” says Angela Sirigu of the French National Centre for Scientific Research in Bron, leader of the team that has “woken” a man from a vegetative state. “This patient is like our baby. We are very attached to him. He’ll always remain in our hearts, because he’s our first patient.” Sirigu and her colleagues chose the 35-year-old man to be the first to trial vagus nerve stimulation because his condition had not improved for 15 years. They reasoned that any improvements in his behaviour would be down to the stimulation and not simply chance fluctuations. Before the stimulation started, the man was unresponsive, and his eyes were shut for most of the day. If open, they would stare into empty space, says Sirigu. “You had the feeling he was not looking at you.” That changed once her team began stimulating his vagus nerve. Almost immediately, he began opening his eyes more often. About a month after stimulation began, his behavioural improvements started stabilising. “His eyes were moving around as if he wanted to follow me,” says Sirigu. He then began to respond to instructions to turn his gaze from one side of the bed to another. When a clinician asked him to smile, he’d react by raising his left cheek. When the team played some of his favourite music by French singer Jean-Jacques Goldman, the man had tears in his eyes. Sirigu says vagus nerve stimulation activates the neuroendocrinal system, which can explain the tears. But it happened at the same time as he listened to his preferred music, says Sirigu. “What can we say? We can conclude that there was an emotional reaction.” © Copyright New Scientist Ltd.

Keyword: Consciousness
Link ID: 24115 - Posted: 09.26.2017

By JANE E. BRODY Now and then I hear someone (myself included) proclaim “my brain is on overload.” This is not surprising given the myriad complex tasks the brain performs, among them enabling you to learn, plan, remember, communicate, see, hear and smell. Perhaps also not surprising, a growing number of studies have linked compromised sensory functions like poor vision and hearing to a decline in cognitive abilities. The brain, it seems, can do only so much, and when it must struggle to make sense of the world – from reading the words on a page to understanding the spoken word – it may be less able to perform other important tasks. While a cause-and-effect relationship has yet to be established, evidence is gradually increasing to suggest that uncorrected deficits in vision and hearing can accelerate cognitive decline. National statistics demonstrate the importance of this relationship. The number of Americans with poor vision, often undetected among older adults, is expected to double by 2050; hearing loss – mostly untreated or undertreated – afflicts nearly two-thirds of adults over 70; both vision and hearing impairment occur in one person in nine age 80 and older (fewer than one in five have neither), and the prevalence of dementia is now doubling every 20 years. The latest study, published in August in JAMA Ophthalmology, found that among a representative sample of nearly 3,000 older Americans and a second sample of 30,000 Medicare beneficiaries, poor vision was associated with poor cognition. The two data sets used different measurements of cognitive abilities like memory, orientation and planning, and the consistency of their findings suggests that the association between vision impairment and compromised brain function is real, the researchers concluded. © 2017 The New York Times Company

Keyword: Vision; Hearing
Link ID: 24114 - Posted: 09.26.2017

By ERICA CROMPTON I’ve been fired more times than I care to admit. I have even more resignation letters to my name. Work and paranoid schizophrenia aren’t exactly a recipe for success. At one job I had, on the ground floor of a city office, there were bars on the windows. The bars were no doubt put in for security reasons, like all the other shops and offices on the street. But I grew increasingly convinced that they were placed there just for me as part of a grand conspiracy. I have always felt that people are setting me up for heinous crimes or that I’ve committed one that I can’t remember and that the police are spying on me to gather evidence. With the windows I felt they’d been fitted by a stranger who knew of me, sometime before I started work, to send me the message that I would soon “be behind bars.” Seeing a policeman on the street outside the office or hearing a helicopter fly by would set my heart racing. I was convinced they’d finally come for me. I didn’t last long in that office. The sedative effects of my medications also mean I often oversleep and get into the office late. Really late. Sometimes 90 minutes late. The head of my department at another job I had didn’t seem to mind, as I always made the time up in the evening. But colleagues did mind, others in the office told me, including the girl who sat next to me. Back then, I wasn’t open about having schizophrenia. I didn’t want to stigmatize myself by giving reasons for my tardiness. So I assume people just thought I was lazy. Far too often, I would regard an off-the-cuff remark by a work colleague, a roll of the eyes when I offered an idea at a meeting, or a sigh when I arrived late, as aggressive and threatening, an insult directed toward me. © 2017 The New York Times Company

Keyword: Schizophrenia
Link ID: 24113 - Posted: 09.26.2017

By Mary Bates North American walnut sphinx moth caterpillars (Amorpha juglandis) look like easy meals for birds, but they have a trick up their sleeves—they produce whistles that sound like bird alarm calls, scaring potential predators away. At first, scientists suspected birds were simply startled by the loud noise. But a new study presented at the International Symposium on Acoustic Communication by Animals in Omaha in July suggests a more sophisticated mechanism: the caterpillar’s whistle appears to mimic a bird alarm call, sending avian predators scrambling for cover. “This is the first instance of deceptive alarm calling between an insect and a bird, and it’s a novel defense form for an insect,” says Jessica Lindsay, the study’s first author and a graduate student in the lab of Kristin Laidre at the University of Washington. “I think that’s pretty wild.” When pecked by a bird, the caterpillars whistle by compressing their bodies like an accordion and forcing air out through specialized holes in their sides. The whistles are impressively loud, considering they are made by a two-inch long insect. They have been measured at over 80 dB from 5 cm away from the caterpillar, similar to the loudness of a garbage disposal. In a laboratory experiment a few years ago, birds responded to caterpillar whistles by jumping away and abandoning their predation attempts. The authors of that study had attributed their behavior to a general startle response. © 1986-2017 The Scientist

Keyword: Evolution
Link ID: 24112 - Posted: 09.26.2017

By LISA SANDERS, M.D. “Mom?” the middle-aged man asked. He recognized the voice, but the words were muffled and strange. I’ll be right over, he said into the phone. The 15-minute drive from his small Connecticut town to his mother’s seemed to last forever. Had she had a stroke? She was 94, and though she’d always been healthy, at her age, anything could happen. He burst into her tidy brick home to find her sitting in the living room, waiting. Her eyes were bright but scared, and her voice was just a whisper. He helped her to his car, then raced to the community hospital a couple of towns over. The doctors in the emergency room were also worried about a stroke. Her left eyelid hung lower across her eye than her right. She was seeing double, she told them. And the left side of her mouth and tongue felt strangely heavy, making it hard to speak. Initial blood tests came back normal; so did the CT scan of her brain. It wasn’t clear what was wrong with the patient, so she was transferred to nearby Yale New Haven Hospital. Dr. Paul Sanmartin, a resident in the second year of his neurology training, met the patient early the next morning. He’d already heard about her from the overnight resident: a 94-year-old woman with the sudden onset of a droopy eyelid, double vision and difficulty speaking, probably due to a stroke. As he entered the room, he realized he wasn’t sure what 94 was supposed to look like, but this woman looked much younger. She did have a droopy left lid, but her eyes moved in what looked to him to be perfect alignment, and her speech, though quiet, was clear. The patient’s story was also different from what he expected. She had macular degeneration and had been getting shots in her left eye for more than a decade. Her last injection was nearly two weeks earlier, and she’d had double vision and the droopy eyelid on and off ever since. © 2017 The New York Times Company

Keyword: Movement Disorders
Link ID: 24111 - Posted: 09.26.2017

By Laurie McGinley The Food and Drug Administration has suspended experiments on the effects of nicotine in squirrel monkeys, research aimed at better understanding one of the most pernicious of addictions. Two weeks ago, British primatologist Jane Goodall wrote to FDA Commissioner Scott Gottlieb, urging an end to what she called “cruel and unnecessary” and “shameful” research. On Monday, he responded, saying that he had put a hold on the study this month “after learning of concerns related to the study you referenced.” He also said he has sent a medical team of primate experts to the FDA facility — the National Center for Toxicological Research in Arkansas — “to evaluate the safety and well-being of the monkeys and to understand whether there are additional precautions needed.” The research involved training adolescent and adult squirrel monkeys to press a lever to give themselves infusions of nicotine. Four monkeys in the studies, which began in 2014, have died, according to people close to the situation. The deaths are still being investigated, but nicotine overdose isn't seen as the likely cause. Gottlieb also told Goodall that he has appointed an FDA team, including senior career officials and guided by primate veterinarians, to assess the “science and integrity” of the animal research process for the study and whether the research should be resumed. If the study is terminated, he said, the monkeys will be sent to an alternative location that can provide appropriate long-term care. © 1996-2017 The Washington Post

Keyword: Animal Rights
Link ID: 24110 - Posted: 09.26.2017

Laura Sanders Frog brains get busy long before they’re fully formed. Just a day after fertilization, embryonic brains begin sending signals to far-off places in the body, helping oversee the layout of complex patterns of muscles and nerve fibers. And when the brain is missing, bodily chaos ensues, researchers report online September 25 in Nature Communications. The results, from brainless embryos and tadpoles, broaden scientists’ understanding of the types of signals involved in making sure bodies develop correctly, says developmental biologist Catherine McCusker of the University of Massachusetts Boston. Scientists are familiar with short-range signals among nearby cells that help pattern bodies. But because these newly described missives travel all the way from the brain to the far reaches of the body, they are “the first example of really long-range signals,” she says. Celia Herrera-Rincon of Tufts University in Medford, Mass., and colleagues came up with a simple approach to tease out the brain’s influence on the growing body. Just one day after fertilization, the scientists lopped off the still-forming brains of African clawed frog embryos. These embryos survive to become tadpoles even without brains, a quirk of biology that allowed the researchers to see whether the brain is required for the body’s development. The answer was a definite — and surprising — yes, Herrera-Rincon says. Long before the brain is mature, it’s already organizing and guiding organ behavior, she says. Brainless tadpoles had bungled patterns of muscles. Normally, muscle fibers form a stacked chevron pattern. But in tadpoles lacking a brain, this pattern didn’t form correctly. “The borders between segments are all wonky,” says study coauthor Michael Levin, also of Tufts University. “They can’t keep a straight line.” |© Society for Science & the Public 2000 - 2017.

Keyword: Development of the Brain
Link ID: 24109 - Posted: 09.25.2017

By Amy Lewis Stress, anxiety, and depression are emotions we all feel at some point in our lives, some people to a greater degree than others. Part of the human experience, right? “It may seem odd that my research focuses on the gut if I’m interested in the brain,” says John Cryan, a researcher at the APC Microbiome Institute at University College Cork in Ireland. “But when we think of how we express emotion in language, through sayings like ‘butterflies in your tummy’ and ‘gut feeling,’ it isn’t surprising that they’re connected.” In a recent study, Cryan and his colleagues reported a link between the microbiome and fear. By examining mice with and without gut bacteria, they discovered that the germ-free mice had blunted fear responses (Mol Psychiatr, doi:10.1038/mp.2017.100, 2017). Their findings may pave the way for the development of novel treatments for anxiety-related illnesses, including posttraumatic stress disorder. Researchers at Kyushu University in Japan were the first to show, in 2004, that bacteria in the gut can influence stress responses, prompting many subsequent investigations. Yet despite mounting research, scientists remain uncertain about exactly how the gut microbiome affects the brain. While some bacteria influence the brain through the vagus nerve, other strains seem to use different pathways. It is known, however, that the population of the gut microbiome begins in early life, and recent research suggests that disruptions to its normal development may influence future physical and mental health (Nat Commun, 6:7735, 2015). Researchers are finding that this gut-brain connection could have clinical implications, as influencing the gut microbiome through diet may serve to ameliorate some psychiatric disorders. Together with University College Cork colleague Ted Dinan, Cryan coined the term “psychobiotics” in 2013 to describe live organisms that, when ingested, produce health benefits in patients with psychiatric illness. These include foods containing probiotics, live strains of gut-friendly bacteria. © 1986-2017 The Scientist

Keyword: Obesity
Link ID: 24108 - Posted: 09.25.2017

Robin Dunbar, Angela Saini, Ben Garrod, Adam Rutherford We were all gearing up for the summer of love when, in 1967, Desmond Morris’s The Naked Ape took us by storm. Its pitch was that humans really were just apes, and much of our behaviour could be understood in terms of animal behaviour and its evolution. Yes, we were naked and bipedal, but beneath the veneer of culture lurked an ancestral avatar. With his zoologist’s training (he had had a distinguished career studying the behaviour of fishes and birds at Oxford University as part of the leading international group in this field), he gave us a picture of who we really are. In the laid-back, blue-smoke atmosphere of the hippy era, the book struck a chord with the wider public – if for no other reason than that, in the decade of free love, it asserted that humans had the largest penis for body size of all the primates. The early 1960s had seen the first field studies of monkeys and apes, and a corresponding interest in human evolution and the biology of contemporary hunter-gatherers. Morris latched on to the fact that the sexual division of labour (the men away hunting, the women at home gathering) necessitated some mechanism to ensure the sexual loyalty of one’s mate – this was the era of free love, after all. He suggested that becoming naked and developing new erogenous zones (notably, ear lobes and breasts), not to mention face-to-face copulation (all but unknown among animals), helped to maintain the couple’s loyalty to each other. Morris’s central claim, that much of our behaviour can be understood in the context of animal behaviour, has surely stood the test of time, even if some of the details haven’t. Our hairlessness (at around 2m years ago) long predates the rise of pair bonds (a mere 200,000 years ago). It owes its origins to the capacity to sweat copiously (another uniquely human trait) in order to allow us to travel longer distances across sunny savannahs. But he is probably still right that those bits of human behaviour that enhance sexual experience function to promote pair bonds – even if pair bonds are not lifelong in the way that many then assumed. © 2017 Guardian News and Media Limited

Keyword: Sexual Behavior; Evolution
Link ID: 24107 - Posted: 09.25.2017

Bruce Y. Lee , Contributor Sorry SpongeBob Square Pants. You too Yoda. Some people are on to your wandering eyes. According to a new study published in the journal Archives of Sexual Behavior, men with a high facial width-to-height ratio (FWHR) may have higher sex drives and be more likely to cheat. So if you believe this study, watch out for those partners with wide, microwave oven-shaped faces...right? Before you start bringing a tape measure to your dates or blaming your partner for having such a wide face, let's take a closer look at the study, which was actually a combination of two studies. Researchers from Nipissing University (Steven Arnocky, Justin M. Carré, Triana Ortiz, and Nicole Marley), Simon Fraser University (Brian M. Bird), Northern Ontario School of Medicine (Benjamin J. P. Moreau), and the University of Ottawa (Tracy Vaillancourt) conducted the studies. The first study recruited 145 heterosexual students, 69 men and 76 females, who were currently in romantic relationships, from a mid-sized Canadian university, measured the dimensions of their faces from facial photographs, and had them complete sexual drive questionnaires. The researchers calculated the FWHR by dividing the bi-zygomatic width of the face by the height of the upper face (i.e., the distance between the upper lip and brow) and found that both men and women who had higher FWHR's were more likely to report higher sex drives. The second study recruited 314 students (43% men) from a different small Canadian university, which was about 350 km away from the university where the first study was conducted. In addition to measuring the participant's FWHRs on facial photographs and sex drive via questionnaires, the researchers also had the participants complete questionnaires designed to measure attitudes towards and likelihood of infidelity or cheating.

Keyword: Sexual Behavior
Link ID: 24106 - Posted: 09.25.2017

Rachel Cooke Matthew Walker has learned to dread the question “What do you do?” At parties, it signals the end of his evening; thereafter, his new acquaintance will inevitably cling to him like ivy. On an aeroplane, it usually means that while everyone else watches movies or reads a thriller, he will find himself running an hours-long salon for the benefit of passengers and crew alike. “I’ve begun to lie,” he says. “Seriously. I just tell people I’m a dolphin trainer. It’s better for everyone.” Walker is a sleep scientist. To be specific, he is the director of the Center for Human Sleep Science at the University of California, Berkeley, a research institute whose goal – possibly unachievable – is to understand everything about sleep’s impact on us, from birth to death, in sickness and health. No wonder, then, that people long for his counsel. As the line between work and leisure grows ever more blurred, rare is the person who doesn’t worry about their sleep. But even as we contemplate the shadows beneath our eyes, most of us don’t know the half of it – and perhaps this is the real reason he has stopped telling strangers how he makes his living. When Walker talks about sleep he can’t, in all conscience, limit himself to whispering comforting nothings about camomile tea and warm baths. It’s his conviction that we are in the midst of a “catastrophic sleep-loss epidemic”, the consequences of which are far graver than any of us could imagine. This situation, he believes, is only likely to change if government gets involved. Walker has spent the last four and a half years writing Why We Sleep, a complex but urgent book that examines the effects of this epidemic close up, the idea being that once people know of the powerful links between sleep loss and, among other things, Alzheimer’s disease, cancer, diabetes, obesity and poor mental health, they will try harder to get the recommended eight hours a night (sleep deprivation, amazing as this may sound to Donald Trump types, constitutes anything less than seven hours). © 2017 Guardian News and Media Limited

Keyword: Sleep
Link ID: 24105 - Posted: 09.25.2017

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

Tina Hesman Saey A genetic risk factor for Alzheimer’s disease is a double, make that triple, whammy. In addition to speeding up the development of brain plaques associated with Alzheimer’s, a gene variant known as APOE4 also makes tau tangles — another signature of the disease — worse, researchers report online September 20 in Nature. APOE4 protein also ramps up brain inflammation that kills brain cells, neuroscientist David Holtzman of Washington University School of Medicine in St. Louis and colleagues have discovered. “This paper is a tour de force,” says Robert Vassar, a neuroscientist at Northwestern University Feinberg School of Medicine in Chicago. “It’s a seminal study that’s going to be a landmark in the field” of Alzheimer’s research, Vassar predicts. For more than 20 years, researchers have known that people who carry the E4 version of the APOE gene are at increased risk of developing Alzheimer’s. A version of the gene called APOE3 has no effect on Alzheimer’s risk, whereas the APOE2 version protects against the disease. Molecular details for how APOE protein, which helps clear cholesterol from the body, affects brain cells are not understood. But Holtzman and other researchers previously demonstrated that plaques of amyloid-beta protein build up faster in the brains of APOE4 carriers (SN: 7/30/11, p. 9). Having A-beta plaques isn’t enough to cause the disease, Holtzman says. Tangles of another protein called tau are also required. Once tau tangles accumulate, brain cells begin to die and people develop dementia. In a series of new experiments, Holtzman and colleagues now show, for the first time, that there’s also a link between APOE4 and tau tangles. |© Society for Science & the Public 2000 - 2017.

Keyword: Alzheimers
Link ID: 24103 - Posted: 09.23.2017

By Ruth Williams Contrary to the longstanding belief that puberty is largely controlled by hormones, new evidence shows that sexual touch is a powerful puberty promoter. Touching prepubescent female rats’ genitals can cause the brain region that responds to such tactile stimuli to double in size and their bodies to show signs of puberty up to three weeks earlier than non-stimulated females, according to a report in PLOS Biology today (September 21). The study reveals the hitherto unappreciated influence of physical sexual experience on the young brain and body. “The dominant idea has been that puberty is controlled in the brain and in behavior by the release of hormones . . . but there has been a smattering of findings over the years that additional environmental influences effect puberty and the onset of sexual behavior,” says Dan Feldman of the University of California, Berkeley, who was not involved in the study. This new work “suggests that maybe this is true and that actual tactile stimulation can be something that accelerates the onset of puberty,” he adds. Puberty in mammals is a period of dramatic changes not just to the body, but to behavior and brain function. Indeed, one of the most pronounced changes, recently observed in both male and female rats, is the doubling in size of the genital cortex, which is a part of the larger somatosensory cortex—the brain area associated with physical sensation. © 1986-2017 The Scientist

Keyword: Sexual Behavior; Development of the Brain
Link ID: 24102 - 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