By: Arthur Robin Williams, M.D., and Frances R. Levin, M.D. There's no shortage of statistics about the depth of America's opioid epidemic: 72,000 overdose deaths just last year, more than 2 million with problems, and so on. But numbers only begin to tell the whole story. Beth Macy, who has spent three decades reporting on central Appalachia—which she claims is the birthplace of the modern opioid epidemic—focuses her book on social and economic trends and how they affect ordinary people. Our reviewers, colleagues at the Columbia University Division on Substance Use Disorders, are well qualified to comment. A new volume can be added to the panoply of books detailing the tragedies of the 21st century opioid epidemic. Beth Macy’s Dopesick (Little Brown & Co., 2018) is anchored in a handful of increasingly vocal and public Appalachia families afflicted by the expansion of opioid dealing into small towns and suburbs formerly thought immune to inner-city plagues of addiction. Dopesick largely reads as a human interest story, a series of intertwined portrayals of grief and terror as young family members descend into OxyContin (one quarter of the local high school students had reported trying the drug within two years of its 1996 market launch), then heroin, then synthetic opioids, reflecting the epidemic’ s tragic course. These painful and personal stories form the heart of Macy’s book and make it perhaps the most empathic of the volumes regarding the epidemic. That she can represent a major drug dealer with as much compassion as the grieving families of teenagers and young adults who died because of his trade speaks to her Southern warmth. Her shrewd tirelessness as a journalist enables her to discern the fault lines of the stories that matter most. © 2018 The Dana Foundation

Keyword: Drug Abuse
Link ID: 25816 - Posted: 12.23.2018

By Kimon de Greef CAPE TOWN — A musician from South Africa had a tumor in his brain, so doctors opened a hole in his skull to remove it. But they had a crucial request: He must play his acoustic guitar during the surgery. The musician, Musa Manzini, a jazz bassist, was awake when the doctors performed the surgery last week, and video footage from the local media site News24 shows him strumming an acoustic guitar slowly as they operated. The technique, known as “awake craniotomy,” allows doctors to operate on delicate areas of the brain — like the right frontal lobe, the site of Mr. Manzini’s tumor — without causing damage. Presumably, had he hit a wrong note, it would have been an immediate signal for the surgeons to probe elsewhere. “It can be very difficult to tell the difference between the tumor and normal brain tissue,” said Dr. Basil Enicker, a specialist neurosurgeon who led the operation at Inkosi Albert Luthuli Central Hospital, in the coastal city of Durban. “Once you’re near a critical area, you can pick it up early, because he will tell you.” The surgery is not unusual. The first craniotomies date to prehistoric times, with fossil records showing that patients had holes drilled in their skulls — and survived — as early as 8,000 years ago. In the 1930s, the Canadian-American neurosurgeon Wilder Penfield pioneered modern craniotomies, which he used to treat epilepsy. The procedure has become fairly common globally since then, posing no greater technical challenge than regular brain surgery, Dr. Enicker said. But choosing patients is very important: People who cough, for example, or who cannot lie still for extended periods, are far more dangerous to operate on. © 2018 The New York Times Company

Keyword: Brain imaging; Epilepsy
Link ID: 25815 - Posted: 12.22.2018

Patricia Janak Drugs of abuse have complex pharmacological effects that trigger many changes in brain function. One of these effects, the direct or indirect activation of neurons that release the neurotransmitter dopamine, is common to all drugs of abuse and has long been assumed to contribute to the development of addiction. Writing in Nature, Pascoli et al.1 report on the neurobiological mechanisms induced by the repeated activation of dopamine neurons that might explain why some drug users seek reward despite facing negative consequences — a type of compulsive behaviour that is a defining feature of human addiction2. The authors took an optogenetics approach to mimic the activation of the brain’s dopamine systems by drugs of abuse: they used laser light delivered through an optical fibre to activate dopamine neurons in the ventral tegmental area (VTA) of the brains of genetically engineered mice. The mice could directly stimulate these neurons themselves by pressing a lever, and performed this action avidly during a test period of 40 minutes a day for almost 2 weeks. On subsequent days, the mice received a brief electric shock to their feet on one-third of the lever-pressing occasions, at random. Their behaviour under this condition revealed an intriguing variability: 40% of the mice (termed renouncers) greatly reduced the frequency of lever-pressing when given foot shocks (Fig. 1a), whereas the remaining 60% (perseverers) were willing to receive painful punishment for the opportunity to self-stimulate their dopamine neurons (Fig. 1b). As some of these authors have previously shown3, the persevering mice provide a model for persistent drug use despite negative consequences, and parallel the subset of human drug users whose drug use becomes compulsive. © 2018 Springer Nature Publishing AG

Keyword: Drug Abuse
Link ID: 25814 - Posted: 12.22.2018

Micaela Martinez, Kevin M. Bakker Does it ever seem like you’re invited to an awful lot of summer birthday gatherings? For good reason. In the United States, most births occur between June and early November. Count back nine months, and you’ll see that places most conceptions in the fall and winter. What’s going on? Is the crisp autumn air, or the joy (or anxiety) of the holiday season, triggering more unprotected sexual intercourse? Or is it something else entirely? It turns out reproduction is seasonal across all living organisms, from plants, to insects, to reptiles, to birds and mammals – including human beings. The ultimate explanation for this phenomenon is an evolutionary one. Earth’s environment is seasonal. Above or below the equator, the year is structured by the winter, spring, summer and fall. In equatorial regions, the wet and dry seasons punctuate the year. Organisms have evolved strategies to reproduce at the time of year that will maximize their lifetime reproductive success. Humans are no exception and maintain this evolutionary outcome: birth seasonality. Researchers, including us, have recently been working to understand more about why births are seasonal because these patterns can have a big impact on childhood disease outbreaks. The first studies demonstrating human birth seasonality date back to the early 1800s. © 2010–2018, The Conversation US, Inc.

Keyword: Biological Rhythms; Sexual Behavior
Link ID: 25813 - Posted: 12.22.2018

Rodrigo Pérez Ortega Nearly one-third of American adults sleep less than six hours each night, a broad new survey shows. Among nearly 400,000 respondents to the annual National Health Interview Survey, 32.9 percent reported this short sleep in 2017 — up from 28.6 percent in 2004 when researchers began noticing a slight drop in sleep time. That’s a 15 percent increase representing “more than 9 million people, which is about the population of New York City,” says coauthor Connor Sheehan, a sociologist at Arizona State University in Tempe. Analysis of the annual survey results — accounting for the U.S. population’s age distribution as well as respondents' marital status, income, employment and lifestyle — suggests people have been sleeping significantly less from 2013 onward, especially black adults, the researchers report online November 17 in Sleep. In 2017, 40.9 percent of black Americans were likely to report short sleep, as were 30.9 percent of whites and 32.9 percent of Hispanics, the researchers calculate. Zzz force Americans were more likely in 2017 to report sleeping less than six hours a night than in 2004, but the trend increased most among black and Hispanic people than among white respondents. This is the first study showing self-reported sleep declining among minorities over time, says Mercedes Carnethon, an epidemiologist at Northwestern University Feinberg School of Medicine in Chicago who was not involved in the study. |© Society for Science & the Public 2000 - 2018

Keyword: Sleep
Link ID: 25812 - Posted: 12.22.2018

Researchers at Howard Hughes Medical Institute (HHMI) have mapped the neuroanatomical regions of the brain of a female mosquito (Aedes aegypti). The researchers constructed the map of groups of neurons by immunostaining the mosquito’s brain for Brp, a synaptic protein, and imaged the brain with confocal microscopy. The atlas was made freely available online on January 31st. “We are trying to build the field of mosquito neurobiology,” says HHMI neurobiologist Leslie Vosshall, who led the work, in a press release. She says she hopes that the new atlas will let mosquito researchers from around the world share data and better understand which parts of the mosquito brain direct different behaviors. “Somewhere in that female brain is the drive to sense humans, fly toward humans, land on humans, and bite and drink the blood of humans,” she says. “Somewhere in that brain is where decision making, motivation, and hunger reside.” © 1986 - 2018 The Scientist

Keyword: Brain imaging
Link ID: 25811 - Posted: 12.22.2018

By Emily Willingham For centuries, some indigenous groups in South America have relied on a brew made from the parts of a local vine and a shrub. The effects of this drink, called ayahuasca, would begin with severe vomiting and diarrhea, but the real reason for drinking the tea was the hallucinating that followed. These visions were thought to uncover the secrets of the drinker’s poor health and point the way to a cure. Modern techniques have revealed that one of the compounds underlying these mystic experiences is the psychoactive drug harmine. What these first users of ayahuasca couldn’t have known was that, one day, this ingredient in their enlightening brew would be positioned as a key to treating diabetes. Such a cure is a long way off, but researchers took another step toward it when they combined naturally occurring harmine with a compound synthesized from scratch in a lab. Together, the pair can coax the insulin-producing pancreatic cells, called beta cells, into replicating at the fastest rates ever reported, according to findings published December 20 in Molecular Cell. Type 1 diabetes arises when the body turns on these cells and destroys them. Type 2 diabetes develops when these same cells wear out and can no longer make insulin. Either effect is a point of no return because the beta cells we make in early life are the only ones we’ll ever have. © 2018 Scientific American

Keyword: Drug Abuse; Obesity
Link ID: 25810 - Posted: 12.21.2018

Jon Hamilton Just in time for the winter solstice, scientists may have figured out how short days can lead to dark moods. Two recent studies suggest the culprit is a brain circuit that connects special light-sensing cells in the retina with brain areas that affect whether you are happy or sad. When these cells detect shorter days, they appear to use this pathway to send signals to the brain that can make a person feel glum or even depressed. "It's very likely that things like seasonal affective disorder involve this pathway," says Jerome Sanes, a professor of neuroscience at Brown University. Sanes was part of a team that found evidence of the brain circuit in people. The scientists presented their research in November at the Society for Neuroscience meeting. The work hasn't been published in a peer-reviewed journal yet, but the researchers plan to submit it. A few weeks earlier, a different team published a study suggesting a very similar circuit in mice. Together, the studies offer a strong argument that seasonal mood changes, which affect about 1 in 5 people, have a biological cause. The research also adds to the evidence that support light therapy as an appropriate treatment.. © 2018 npr

Keyword: Depression; Biological Rhythms
Link ID: 25809 - Posted: 12.21.2018

Laura Sanders Just a generation ago, common wisdom held that once a person reaches adulthood, the brain stops producing new nerve cells. Scientists countered that depressing prospect 20 years ago with signs that a grown-up brain can in fact replenish itself. The implications were huge: Maybe that process would offer a way to fight disorders such as depression and Alzheimer’s disease. This year, though, several pieces of contradictory evidence surfaced and a heated debate once again flared up. Today, we still don’t know whether the fully grown brain churns out new nerve cells. This year’s opening shot came March 7 in a controversial report in Nature. Contradicting several landmark findings that had convinced the scientific community that adults can make new nerve cells, researchers described an utter lack of dividing nerve cells, or neurons, in adult postmortem brain tissue (SN Online: 3/8/18). A return volley came a month later, when a different research group described loads of newborn neurons in postmortem brains, in an April 5 paper in Cell Stem Cell (SN: 5/12/18, p. 10). Scientific whiplash ensued when a third group found no new neurons in postmortem brains, describing the results in the July Cerebral Cortex. Still more neuroscientists jumped into the fray with commentaries and perspective articles. This ping-ponging over the rejuvenating powers of the brain is the most recent iteration of a question that still hasn’t been answered. The first encouraging news about brain cells came in 1998 when scientists looked at the brains of people who had been treated with a compound that marks DNA in newly born neurons. The compound turned up in cells in the adult hippocampus, a brain structure important for learning and memory. Those results, along with a 2013 study that used a different tagging method, suggested that the brain can pump out neurons throughout life. |© Society for Science & the Public 2000 - 2018

Keyword: Neurogenesis
Link ID: 25808 - Posted: 12.21.2018

By Steve Ayan Peter Carruthers, Distinguished University Professor of Philosophy at the University of Maryland, College Park, is an expert on the philosophy of mind who draws heavily on empirical psychology and cognitive neuroscience. He outlined many of his ideas on conscious thinking in his 2015 book The Centered Mind: What the Science of Working Memory Shows Us about the Nature of Human Thought. More recently, in 2017, he published a paper with the astonishing title of “The Illusion of Conscious Thought.” In the following excerpted conversation, Carruthers explains to editor Steve Ayan the reasons for his provocative proposal. What makes you think conscious thought is an illusion? I believe that the whole idea of conscious thought is an error. I came to this conclusion by following out the implications of the two of the main theories of consciousness. The first is what is called the Global Workspace Theory, which is associated with neuroscientists Stanislas Dehaene and Bernard Baars. Their theory states that to be considered conscious a mental state must be among the contents of working memory (the “user interface” of our minds) and thereby be available to other mental functions, such as decision-making and verbalization. Accordingly, conscious states are those that are “globally broadcast,” so to speak. The alternative view, proposed by Michael Graziano, David Rosenthal and others, holds that conscious mental states are simply those that you know of, that you are directly aware of in a way that doesn’t require you to interpret yourself. You do not have to read you own mind to know of them. Now, whichever view you adopt, it turns out that thoughts such as decisions and judgments should not be considered to be conscious. They are not accessible in working memory, nor are we directly aware of them. We merely have what I call “the illusion of immediacy”—the false impression that we know our thoughts directly. © 2018 Scientific American

Keyword: Consciousness
Link ID: 25807 - Posted: 12.21.2018

By Nicole Wetsman If a sign tells you To follow the purple skull to your destination, the answer seems simple: Veer left. But isolate the stripes that make up the skulls, and you’ll find neither skull has purple bones; in fact, all the bones are the same color. Slot them back into the banded setting, and they shift to purple and orange. The pigments morph because of the ­Munker-​White illusion, which shifts the perception of two identical color tones when they’re placed against different surrounding hues. No one knows for sure, but the illusion probably results from what David Novick, a computer scientist at the University of Texas at El Paso, calls the color-completion effect. The phenomenon causes an image to skew toward the color of the objects that surround it. In a black-and-white image, a gray element would appear lighter when it’s striped with white, and darker when banded with black. Many neuroscientists think that neural ­signals in charge of relaying information about the pigments in our visual field get averaged—creating a color somewhere in the middle. Here, one skull is covered by blue stripes in the foreground and the other with yellow ones. When the original skulls take on the characteristics of the separate surroundings, they look like different colors entirely. Don’t be fooled: Follow both skulls by going straight. Copyright © 2018 Popular Science

Keyword: Vision
Link ID: 25806 - Posted: 12.21.2018

By Laura Spinney A disease mystery with no shortage of leads now has an intriguing new one. Since the 1960s, thousands of children in poor, war-torn regions of East Africa have developed epilepsy-like seizures in which their heads bob to their chest; over time, the seizures worsen, cognitive problems develop, and the victims ultimately die. Researchers have proposed causes for nodding syndrome that include malnutrition, parasites, and viruses, but have not proved a clear link to any of them. Now, the first published examination of the brains of children who died after developing the condition suggests it has a key similarity to certain brain diseases of old age, such as Alzheimer's and Parkinson's: It leaves victims' brains riddled with fibrous tangles containing a protein called tau. "Nodding syndrome is a tauopathy," concludes Michael Pollanen, a pathologist at the University of Toronto in Canada who is lead author of a report published last month in Acta Neuropathologica. Pollanen believes the finding "suggests a totally new line of investigation" into the syndrome. As significant as the discovery of the tangles may be what his group of Canadian and Ugandan researchers didn't find: any sign of the brain inflammation that might be triggered by a parasite or virus. "Our hypothesis is that nodding syndrome is a neurodegenerative disease, like Alzheimer's," Pollanen says. Some who study the condition are skeptical, but the possibility excites researchers working on other tauopathies including Alzheimer's. Childhood forms of those diseases are exceedingly rare, but the nodding syndrome finding "means [tau deposition] is not an age-dependent problem," says John Hardy, of the UK Dementia Research Institute at University College London. Something else must have triggered the tauopathy in these children. And because nodding syndrome struck a small region of East Africa, over a specific time period—in Uganda, the condition appears to be vanishing—its trigger might be relatively easy to identify, and could shed light on the causes of diseases like Alzheimer's, Hardy and others say. © 2018 American Association for the Advancement of Science.

Keyword: Alzheimers; Parkinsons
Link ID: 25805 - Posted: 12.20.2018

Written by SHREEYA SINHA illustrations by ZACH LIEBERMAN and LESLYE DAVIS The opioid epidemic is devastating America. Overdoses have passed car crashes and gun violence to become the leading cause of death for Americans under 55. The epidemic has killed more people than H.I.V. at the peak of that disease, and its death toll exceeds those of the wars in Vietnam and Iraq combined. Funerals for young people have become common. Every 11 minutes, another life is lost. So why do so many people start using these drugs? Why don’t they stop? Some people are more susceptible to addiction than others. But nobody is immune. For many, opioids like heroin entice by bestowing an immediate sense of tranquility, only to trap the user in a vicious cycle that essentially rewires the brain. Getting hooked is nobody’s plan. Some turn to heroin because prescription painkillers are tough to get. Fentanyl, which is 50 times more potent than heroin, has snaked its way into other drugs like cocaine, Xanax and MDMA, widening the epidemic. To understand what goes through the minds and bodies of opioid users, The New York Times spent months interviewing users, family members and addiction experts. Using their insights, we created a visual representation of how the strong lure of these powerful drugs can hijack the brain. Dr. Pedro Mateu-Gelabert, one of the nation’s top opioid researchers, said this work brings “an emotional understanding” to the epidemic but “without glamorizing or oversimplifying.” You naturally produce endorphins, the body’s own version of opioids, which act in the reward circuits of the brain to make you feel good after you work out, hug a friend or eat your favorite foods. A drug like heroin creates a tidal wave in the reward circuits of the brain. To an outsider, it looks as though you have passed out. But on the inside you feel like a master of the universe, like you’re being “hugged by Jesus,” as one user said; there’s peace in your skin and not a single feeling of pain. You may remember this exact moment for years to come: where you were, what you wore, what you saw and what you heard. You may chase this feeling for years. As the high wears off, the brain regains its balance – but not for everyone. That’s the opioid trap for many people: In the beginning, no serious ill effects are apparent. But the brain rewires little by little with each use.

Keyword: Drug Abuse
Link ID: 25804 - Posted: 12.20.2018

By Jan Hoffman A Harvard addiction medicine specialist is getting calls from distraught parents around the country. A Stanford psychologist is getting calls from rattled school officials around the world. A federal agency has ordered a public hearing on the issue. Alarmed by the addictive nature of nicotine in e-cigarettes and its impact on the developing brain, public health experts are struggling to address a surging new problem: how to help teenagers quit vaping. Until now, the storm over e-cigarettes has largely focused on how to keep the products away from minors. But the pervasiveness of nicotine addiction among teenagers who already use the devices is now sinking in — and there is no clear science or treatment to help them stop. “Nobody is quite sure what to do with those wanting to quit, as this is all so new,” said Ira Sachnoff, president of Peer Resource Training and Consulting in San Francisco, which trains students to educate peers about smoking and vaping. “We are all searching for quit ideas and services for this new nicotine delivery method. It is desperately needed.” A harsh irony underlies the search for solutions: Devices that manufacturers designed to help adults quit smoking have become devices that teenagers who never smoked are themselves fighting to quit. The Food and Drug Administration and the attorney general of Massachusetts are investigating Juul Labs, the maker of the most popular e-cigarettes, to determine whether it deliberately lured teenagers with its sleek packaging and flavors. © 2018 The New York Times Company

Keyword: Drug Abuse
Link ID: 25803 - Posted: 12.20.2018

Cheryl Platzman Weinstock Sometimes a psychiatric crisis can be triggered by something small. For Alexia Phillips, 21, it was a heated argument with a close family member in February 2017. She remembers the fight blew up before she left the house to go to classes at Queens College in Flushing, New York. By midday, Phillips, then a sophomore, says she began to cry loudly and uncontrollably. "It really triggered me. I just got really angry really fast...I was crying so much I couldn't breathe and couldn't talk. I didn't know how to handle it," she says. As she would come to understand later, Phillips was experiencing symptoms of her underlying borderline personality disorder, anxiety and depression. But at the time, all she knew was she felt too overwhelmed to go home, or to go to class. She also didn't want anyone to see her like that. Finally, she went to her college counseling center for the first time and asked for help. Minutes later, Phillips' counselor, a college public safety officer and a paramedic trained to deal with psychiatric crises, calmly and unobtrusively escorted her to the back of the college through a quiet hallway door that led out to a parked ambulance sent from Zucker Hillside Hospital. She was ferried — without the lights or sirens — to be assessed at the hospital's special program for college students. This kind of response to a student crisis is unusual. In a lot of colleges, if staff think the student who's having a crisis may be unsafe, they have little choice but to call 911. Many schools lack resources to address serious crises and students are left to navigate the health care system on their own. © 2018 npr

Keyword: Schizophrenia; Depression
Link ID: 25802 - Posted: 12.20.2018

By Steve Ayan Research on the unconscious mind has shown that the brain makes judgments and decisions quickly and automatically. It continuously makes predictions about future events. According to the theory of the “predictive mind,” consciousness arises only when the brain’s implicit expectations fail to materialize. Higher cognitive processing in the cerebral cortex can occur without consciousness. The regions of the brain responsible for the emotions and motives, not the cortex, direct our conscious attention. In 1909 five men converged on Clark University in Massachusetts to conquer the New World with an idea. At the head of this little troupe was psychoanalyst Sigmund Freud. Ten years earlier Freud had introduced a new treatment for what was called “hysteria” in his book The Interpretation of Dreams. This work also introduced a scandalous view of the human psyche: underneath the surface of consciousness roils a largely inaccessible cauldron of deeply rooted drives, especially of sexual energy (the libido). These drives, held in check by socially inculcated morality, vent themselves in slips of the tongue, dreams and neuroses. The slips in turn provide evidence of the unconscious mind. At the invitation of psychologist G. Stanley Hall, Freud delivered five lectures at Clark. In the audience was philosopher William James, who had traveled from Harvard University to meet Freud. It is said that, as James departed, he told Freud, “The future of psychology belongs to your work.” And he was right. © 2018 Scientific American

Keyword: Consciousness; Attention
Link ID: 25801 - Posted: 12.20.2018

Phil Jaekl Driving a car is a complex task for a brain to coordinate. A driver may drink a cup of coffee and have a conversation with a passenger, all while safely piloting a vehicle through traffic. But all of this activity requires attention—that is, concentrating on the tasks and sources of information that matter and blocking out those that don’t. How the brain manages that orchestration is a long-standing scientific mystery. One prominent view, based on findings from human behavioral studies, is that the brain guides us through a world chock-full of sensory inputs by focusing a metaphorical spotlight on what it deems important, while filtering out relatively trivial details. Unlike some other, functionally well-defined aspects of cognition, this attentional spotlight has eluded scientific understanding. Its neural substrates have been particularly difficult to pin down to specific activities and locations in the brain—although several studies have implicated the frontoparietal network, which spans the frontal and parietal lobes of the brain. Meanwhile, attention studies involving visual tasks that require continuous focus—detecting a small object flashing on a cluttered computer screen, for example—have shown that task performance varies over short time intervals, with episodes of peak performance and of poor performance alternating on millisecond timescales. Such research suggests that the attentional spotlight might not be as constant as once thought. Yet, until now, researchers have not been able to directly connect these changes in performance to fluctuations in brain activity. © 1986 - 2018 The Scientist

Keyword: Attention
Link ID: 25800 - Posted: 12.20.2018

By Kuheli Dutt When neuroscientist Ben Barres delivered his first seminar, an audience member praised him, commenting that Ben’s work was much better than that of his sister, Barbara Barres. The irony? Ben Barres (now deceased), a transgender scientist was Barbara Barres before he transitioned to male. When New York Times columnist Brent Staples was a graduate student in Chicago’s Hyde Park, he found that white people on the street perceived him, an African American, as a threat to their safety. They were visibly tense around him, clutched their purses and sometimes even crossed the street to avoid him. But when he started whistling tunes from classical music, people suddenly weren’t afraid of him anymore—they relaxed and some even smiled at him. Implicit bias runs far deeper than we realize. A riddle used at implicit bias trainings goes like this: A father and his son are in a terrible car crash. The father dies at the scene. His son, in critical condition, is rushed to the hospital; he’s in the operating room, about to go under the knife. The surgeon says, “I can’t operate on this boy—he’s my son!” The audience is then asked how that’s possible. Responses include several scenarios: two gay fathers; one biological and one adopted father; one father and one priest (religious father); all of which are possible. However, an obvious answer that most people miss: the surgeon is the boy’s mother. Whether we like it or not, we are conditioned to associating surgeons with being male. © 2018 Scientific American,

Keyword: Attention
Link ID: 25799 - Posted: 12.20.2018

By Elizabeth Pennisi A 9-year study has uncovered some unusual behavior by common bottlenose dolphins (Tursiops truncatus) living off the coast of Slovenia. Within one population of this species, the animals have divided into two groups that avoid contact by hunting at different times of day—a social strategy not known in marine mammals. Researchers used photographs of the dolphins’ dorsal fins to individually identify them. They made many observations of 38 of the animals, carefully recording the time, date, and location of each sighting. The marine mammals divided into two major groups of 19 and 13 animals each, with six animals loosely making up a third group, the team reports today in Marine Biology. The 19 members of the larger group tended to hang out—and likely hunt—while following fishing trawlers in the Bay of Trieste, which is located at the eastern top of Italy’s “boot.” The second group’s cadre of 13 never associated with boats when in the Bay of Trieste. Although the dolphins hunted in the same area, they rarely saw each other, the researchers discovered, because the larger group was in that area only between 7 a.m. and 1 p.m. local time, whereas the smaller group showed up between 6 p.m. and 9 p.m. Other studies have documented groups of dolphins that divide up the waters where they hunt, but this is the first time these marine mammals have been shown to timeshare the sea, the researchers note. Although they don’t know why—or how—the dolphins set these schedules, the fact that the animals are never in the same place likely diminishes unfriendly encounters and reduces direct competition for food. © 2018 American Association for the Advancement of Science

Keyword: Aggression
Link ID: 25798 - Posted: 12.20.2018

Nicola Davis Having even one night without sleep leads people to view junk food more favourably, research suggests. Scientists attribute the effect to the way food rewards are processed by the brain. Previous studies have found that a lack of shuteye is linked to expanding waistlines, with some suggesting disrupted sleep might affect hormone levels, resulting in changes in how hungry or full people feel. But the latest study suggests that with hormones may have little to do with the phenomenon, and that the cause could be changes in the activity within and between regions of the brain involved in reward and regulation. . “Our data brings us a little closer to understanding the mechanism behind how sleep deprivation changes food valuation,” said Prof Jan Peters, a co-author of the research from the University of Cologne. Writing in the Journal of Neuroscience, Peters and colleagues describe how they recruited 32 healthy men aged between 19 and 33 and gave all of them the same dinner of pasta and veal, an apple and a strawberry yoghurt. Participants were then either sent home to bed wearing a sleep-tracking device, or kept awake in the laboratory all night with activities including parlour games. All returned the next morning to have their hunger and appetite rated, while 29 of the men had their levels of blood sugar measured, as well as levels of certain hormones linked to stress and appetite. Participants also took part in a game in which they were presented with pictures of 24 snack food items, such as chocolate bars, and 24 inedible items, including hats or mugs, and were first asked to rate how much they would be willing to pay for them on a scale of €0-€3. © 2018 Guardian News and Media Limited

Keyword: Sleep; Obesity
Link ID: 25797 - Posted: 12.18.2018