by Ariana Eunjung Cha) Sally Clark lost both her infant sons shortly after their births. In 1996, 11-week-old Christopher fell unconscious after being put to bed and never woke up. Two years later, 8-week-old Harry was found dead slumped forward in his bouncy chair. Doctors initially concluded the first boy had died of sudden infant death syndrome (SIDS) — in which a seemingly healthy baby dies without warning and without an obvious cause. But after Clark's second child died, prosecutors in the United Kingdom charged her with murder and put her on trial. According to scholars analyzing the widely publicized case, Clark was wrongly convicted based on a statistic. An expert witness for the prosecution claimed the chance of two cases of SIDS, in an affluent family like hers, was astronomically high — 1 in 73 million. Her defenders said the numbers assumed that SIDS strikes at random, even though we had no idea back then whether that was true. An important study published Wednesday in the Lancet shows a link between SIDS and a rare genetic mutation that would make some families more vulnerable than others — providing a possible explanation for situations like Clark's. The research involved 278 infants who died of SIDS, also called “crib death” or “cot death,” and 729 healthy controls. Four of those who died of SIDS had a variant of a gene called SCN4A associated with an impairment of breathing muscles, while no babies in the control group had it. Authors Michael Hanna from the United Kingdom's Medical Research Council's Center for Neuromuscular Diseases and Michael Ackerman from the Mayo Clinic in the United States wrote that these mutations are typically found in fewer than 5 out of 100,000 people. © 1996-2018 The Washington Post

Keyword: Sleep; Genes & Behavior
Link ID: 24795 - Posted: 03.29.2018

By NICHOLAS BAKALAR Being physically fit in midlife may reduce a woman’s risk for dementia. In 1968, Swedish researchers evaluated the cardiovascular fitness of 191 women ages 38 to 60, testing their endurance with an ergometer cycling test. Then they examined them periodically through 2012. Over the years, 44 women developed dementia. They categorized the women into three fitness groups based on peak workload in their cycling tests: low, medium and high. The incidence of all-cause dementia was 32 percent in the low fitness group, 25 percent for the medium, and 5 percent among those with a high fitness level. The average age at dementia was 11 years older in the high-fitness group than in the medium fitness group. Compared with medium fitness, high fitness decreased the risk of dementia by 88 percent. The study, in Neurology, controlled for many variables, including smoking, drinking, blood pressure and cholesterol, and the follow-up was very long. But the sample was small and the study is observational, and the authors draw no conclusions about cause and effect. Still, the senior author, Dr. Ingmar Skoog, a professor of psychiatry at the University of Gothenburg, said that women should get moving for many reasons. “If you start exercising,” he said, “you reduce your risk for cardiovascular disease, cancer and dementia. And you get immediate gratification by feeling better.” © 2018 The New York Times Company

Keyword: Alzheimers
Link ID: 24794 - Posted: 03.29.2018

Sara Reardon Jhon Kennedy was building a house for his family when he realized that his 45-year-old father was beginning to struggle with daily life. His dad tried to help with the construction project but often forgot to complete simple tasks. And he kept getting lost on the way home from work. Jhon Kennedy wasn’t surprised: his four uncles had also started to lose their memories, one by one. But their doctors in Colombia's rural Antioquia region, which is known for its mountainous terrain and coffee plantations, had never heard of early-onset dementia. It wasn’t until a cousin learned about a study of Alzheimer’s disease at the University of Antioquia in Medellín that Jhon Kennedy’s relatives understood the illness they faced. For more than three decades, researchers there have been tracking a genetic mutation — common in the region — that causes Alzheimer’s to strike people in their 40s and 50s. Later this year, a team at the university will begin scanning the brains of some Alzheimer’s-study participants with a technique that is available only in a few major medical centres worldwide. It will allow the researchers to track a protein called tau, which accumulates rapidly in the brains of people with the disease as symptoms begin to emerge. Watching tau form in real time could reveal the role it plays in Alzheimer’s, says Francisco Lopera, the neurologist who is leading the research. Many scientists have long believed that the disease is triggered by another protein, amyloid, that builds up in the brains of people with Alzheimer’s. But several drugs that reduce amyloid levels have failed to relieve the symptoms of the disease in clinical trials, increasing researchers’ interest in the role of tau. © 2018 Macmillan Publishers Limited,

Keyword: Alzheimers; Learning & Memory
Link ID: 24793 - Posted: 03.28.2018

By RANDI HUTTER EPSTEIN Getting a high testosterone reading offers bragging rights for some men of a certain age — and may explain in part the lure of testosterone supplements. But once you are within a normal range, does your level of testosterone, the male hormone touted to build energy, libido and confidence, really tell you that much? Probably not, experts say. Normal testosterone levels in men range from about 300 to 1,000 nanograms per deciliter of blood. Going from one number within the normal zone to another one may not pack much of a punch. “You don’t see the big improvement once men are within the normal range,” said Dr. Shalender Bhasin, an endocrinologist and professor of medicine at Harvard Medical School. The largest differences in terms of energy and sex drive are when men go from below-normal to normal levels. A 2015 study in JAMA found that sex drive improved among men who went from about 230, considered low, to 500, around the middle of what’s considered normal. There was no difference among men who moved within the normal range from 300 to 500. Testosterone does influence muscle size. The more testosterone a man takes, the larger the muscle — regardless of starting level, one reason the hormone is popular with young bodybuilders. But testosterone supplements do not seem to help frail older men walk farther or get out of chairs more easily, goals that doctors typically look for in aiding older patients. Beginning at age 30, testosterone levels drop, on average, about 1 percent a year. About 5 percent of men between the ages of 50 and 59 have low levels of testosterone along with symptoms like loss of libido and sluggishness, according to a few small studies. © 2018 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 24792 - Posted: 03.28.2018

By JAN HOFFMAN Medicare officials thought they had finally figured out how to do their part to fix the troubling problem of opioids being overprescribed to the old and disabled: In 2016, a staggering one in three of 43.6 million beneficiaries of the federal health insurance program had been prescribed the painkillers. Medicare, they decided, would now refuse to pay for long-term, high-dose prescriptions; a rule to that effect is expected to be approved on April 2. Some medical experts have praised the regulation as a check on addiction. But the proposal has also drawn a broad and clamorous blowback from many people who would be directly affected by it, including patients with chronic pain, primary care doctors and experts in pain management and addiction medicine. Critics say the rule would inject the government into the doctor-patient relationship and could throw patients who lost access to the drugs into withdrawal or even provoke them to buy dangerous street drugs. Although the number of opioid prescriptions has been declining since 2011, they noted, the rate of overdoses attributed to the painkillers and, increasingly, illegal fentanyl and heroin, has escalated. “The decision to taper opioids should be based on whether the benefits for pain and function outweigh the harm for that patient,” said Dr. Joanna L. Starrels, an opioid researcher and associate professor at Albert Einstein College of Medicine. “That takes a lot of clinical judgment. It’s individualized and nuanced. We can’t codify it with an arbitrary threshold.” Underlying the debate is a fundamental dilemma: how to curb access to the addictive drugs while ensuring that patients who need them can continue treatment. © 2018 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 24791 - Posted: 03.28.2018

By Virginia Morell As every dog lover—and scientist—knows, man’s best friend is good at reading faces. Dogs can tell the difference between happy and not-so-happy expressions, such as anger and sadness. Like us, they watch the left sides of peoples’ faces—where emotional cues first appear. And they even seem to be able to interpret our emotions and modulate their behavior accordingly. But what are the neural mechanisms that control how dogs process human faces? To find out, scientists trained eight dogs—mostly border collies—to lie still in a functional magnetic resonance imaging scanner while viewing photos of strangers with either happy or neutral expressions. The faces matched the gender of the dogs’ chief caretakers, because dogs have been shown to score lower on tasks involving faces of the opposite sex. The results: A happy human face produces a distinctive signature in a dog’s temporal lobe and other neural regions, the scientists report online this week on the preprint server bioRxiv. In a follow-up experiment, the pooches’ brains were scanned as they looked at faces expressing happiness, anger, fear, or sadness. The happiness pattern was so distinctive that a machine learning program could pick it out from brain activity linked to all the other emotions. (A similar “happiness” signature is found in humans.) That means, the researchers say, that our human emotions are represented in our pooches’ brains—which suggests that our canine pals really do know what we’re feeling. © 2018 American Association for the Advancement of Science.

Keyword: Emotions; Animal Communication
Link ID: 24790 - Posted: 03.28.2018

By GINA KOLATA It was one of those findings that would change medicine, Dr. Christopher Lewandowski thought. For years, doctors had tried — and failed — to find a treatment that would preserve the brains of stroke patients. The task was beginning to seem hopeless: Once a clot blocked a blood vessel supplying the brain, its cells quickly began to die. Patients and their families could only pray that the damage would not be too extensive. But then a large federal clinical trial proved that a so-called clot-buster drug, tissue plasminogen activator (T.P.A.), could prevent brain injury after a stroke by opening up the blocked vessel. Dr. Lewandowski, an emergency medicine physician at Henry Ford Health System in Detroit and the trial’s principal investigator, was ecstatic. “We felt the data was so strong we didn’t have to explain it” in the published report, he said. He was wrong. That groundbreaking clinical trial concluded 22 years ago, yet Dr. Lewandowski and others are still trying to explain the data to a powerful contingent of doubters. The skeptics teach medical students that T.P.A.is dangerous, causing brain hemorrhages, and that the studies that found a benefit were deeply flawed. Better to just let a stroke run its course, they say. It’s a perspective with real-world consequences. Close to 700,000 patients have strokes caused by blood clots each year and could be helped by T.P.A. Yet up to 30 percent of stroke victims who arrive at hospitals on time and are perfect candidates for the clot-buster do not receive it. The result: paralysis and muscle weakness; impaired cognition, speech or vision; emotional and behavioral dysfunction; and many other permanent neurological injuries. © 2018 The New York Times Company

Keyword: Stroke
Link ID: 24789 - Posted: 03.27.2018

Rachel Ehrenberg BOSTON — Conflicting results on whether brain stimulation helps or hinders memory may be explained by the electrodes’ precise location: whether they’re tickling white matter or gray matter. New research on epilepsy patients suggests that stimulating a particular stretch of the brain’s white matter — tissue that transfers nerve signals around the brain — improves performance on memory tests. But stimulating the same region’s gray matter, which contains the brain’s nerve cells, seems to impair memory, Nanthia Suthana, a cognitive neuroscientist at UCLA, reported March 25 at a meeting of the Cognitive Neuroscience Society. A groundbreaking study by Suthana and colleagues, published in 2012 the New England Journal of Medicine, found that people performed better on a memory task if their entorhinal cortex — a brain hub for memory and navigation — was given a low jolt of electricity during the task. But subsequent studies stimulating that area have had conflicting results. Follow-up work by Suthana suggests that activating the entorhinal cortex isn’t enough: Targeting a particular path of nerve fibers matters. “It’s a critical few millimeters that can make all the difference,” said Suthana. The research underscores the complexity of investigations of and potential treatments for memory loss, said Youssef Ezzyat, a neuroscientist at the University of Pennsylvania. Many variables seem to matter. Recent work by Ezzyat and colleagues found that the kind of brain activity during stimulation is also important, as is the precise timing of the stimulation (SN: 3/31/2018, p.16). |© Society for Science & the Public 2000 - 201

Keyword: Learning & Memory
Link ID: 24788 - Posted: 03.27.2018

by Amy Ellis Nutt In the first comprehensive imaging study of attention-deficit/hyperactivity disorder in preschoolers, researchers have found evidence that structural changes in the brain are already recognizable at the age of 4. “One of our big questions was thinking about an early-onset disorder and linking it to early-onset brain anomalies,” said Lisa Jacobson, one of the researchers involved in the study, which appeared Monday in the Journal of the International Neuropsychological Society. The results “tell us that this is not just a behavioral disorder. It is a neurological disorder.” The study found widespread reductions in the volume of gray matter in the brains of children with ADHD. And the more severe their behavior, the more their brains differed from those of children who were not diagnosed with ADHD, according to Jacobson, a pediatric neuropsychologist at Johns Hopkins University and the Kennedy Krieger Institute, an affiliate of Johns Hopkins and the site of the research. The most significant differences in brain volume were seen in the temporal and prefrontal lobes, including areas associated with activity, attention and motor control. The results seen in the preschoolers mirror those of earlier research in school-age children and adolescents. “When they designed the study, even [lead author] Mark Mahone did not think he would find these differences,” said James Griffin of the National Institutes of Health, which funded the research. Griffin is the deputy chief of NIH’s Child Development and Behavior branch. “They were surprised at how early these differences were already evident in the brain.” © 1996-2018 The Washington Post

Keyword: ADHD; Development of the Brain
Link ID: 24787 - Posted: 03.27.2018

Bruce Bower Groove patterns on the surface of modern chimpanzee brains throw a monkey wrench into proposals that some ancient southern African hominids evolved humanlike brain characteristics, a new study suggests. MRIs of eight living chimps reveal substantial variability in the shape and location of certain features on the brain surface. Some of these brains showed surface creases similar to ones that were thought to have signaled a turn toward humanlike brain organization in ancient hominids hundreds of thousands, if not millions, of years ago. Paleoanthropologist Dean Falk of Florida State University in Tallahassee and colleagues report their findings online March 13 in Brain, Behavior and Evolution. The study casts doubt on a 2014 paper by Falk that was based on casts of the inside of fossil braincases, called endocasts, which preserve impressions of these surface features. At the time, Falk argued that four endocasts from southern African hominids — three Australopithecus africanus and one Australopithecus sediba — showed folding patterns that suggested that brain reorganization was underway as early as 3 million years ago in a frontal area involved in human speech production. But MRIs of three of the chimp brains reveal comparable creases, the researchers found. Two other chimps display other frontal tissue furrows that Falk had also previously described as distinctly humanlike. |© Society for Science & the Public 2000 - 2018

Keyword: Evolution
Link ID: 24786 - Posted: 03.27.2018

by David Kohn This is a story about the importance of good timing. Two-thirds of Americans are overweight or obese. This excess weight contributes to a variety of health problems. Despite enormous effort over decades, the problem has proved extremely difficult to solve. Biologist Satchin Panda thinks we’re missing a key variable: Instead of focusing so much on what we eat, he says, we should pay more attention to when we eat. A researcher at the Salk Institute in San Diego, Panda argues that eating within a certain time window each day can help people lose weight and may help prevent illnesses including diabetes, heart disease and cancer. In animal studies, he and others have shown that limiting food intake to a period of eight to 12 hours can boost cognitive and physical performance, and may even lengthen life span. Known as time-restricted feeding, or TRF, the approach is simple: Eat more or less what you want, but don’t consume anything before or after the allotted time. Panda argues that humans’ circadian rhythm is not designed for a world with 24-7 access to food. “If you’re eating all the time, it messes up that pattern,” he says. For many if not most Americans, that pattern is deeply out of whack, and many of us eat from early morning until late at night. © 1996-2018 The Washington Post

Keyword: Obesity
Link ID: 24785 - Posted: 03.27.2018

By Abby Olena Some mouse mothers groom, lick, and nurse their babies more than others. In a study published in Science today (March 23), researchers demonstrate that this natural variation in maternal behavior is linked to the structure of pups’ genomes, specifically, the activation of one of the most common jumping genes in the genome, LINE-1. “What’s fascinating about the paper is the connection between experience, epigenetics, and restructuring of the genome,” says Moshe Szyf, a geneticist at McGill University in Montreal who did not participate in the work. “We usually think about epigenetics changes that don’t change the sequence, but here there was a connection of the maternal care, the change in methylation . . . and then restructuring.” Coauthor Tracy Bedrosian, who did the work as a postdoc at the Salk Institute and is now a scientist at Ohio-based Neurotechnology Innovations Translator, and her colleagues did not set out to study maternal behavior. Instead, they wanted to explore the effects of maternal stress and environmental enrichment on the retrotransposon LINE-1 (L1), which can copy and paste itself into new locations in the genome, in pups. To manipulate stress levels, they isolated and confined pregnant mice to a small area for a couple hours each day, and for enrichment, mice lived in groups in a large enclosure with toys and running wheels. Bedrosian says that they saw wild variations in L1 copy number between different litters of mice that didn’t seem to relate to their experimental manipulations. Perhaps, they reasoned, maternal behavior was involved. © 1986-2018 The Scientist

Keyword: Epigenetics; Sexual Behavior
Link ID: 24784 - Posted: 03.26.2018

By Aaron E. Carroll The endless array of diets that claim to help you shed pounds tend to fall into two camps: low fat or low carbohydrate. Some companies even claim that genetics can tell us which diet is better for which people. A rigorous recent study sought to settle the debate, and it had results to disappoint both camps. On the hopeful side, as The New York Times noted, people managed to lose weight no matter which of the two diets they followed. The study is worth a closer look to see what it did and did not prove. Researchers at Stanford University took more than 600 people (which is huge for a nutrition study) aged 18 to 50 who had a body mass index of 28 to 40 (25-30 is overweight, and 30 and over is obese). The study subjects had to be otherwise healthy. They couldn’t even be on statins, or drugs for Type 2 diabetes or hypertension, which might affect weight or energy expenditure. They were all randomly assigned to a healthful low-fat or a healthful low-carbohydrate diet, and they were clearly not blinded to which group they were in. All participants attended 22 instructional sessions over one year in groups of about 17 people. The sessions were held weekly at first and were then spaced out so that they were monthly in the last six months. Everyone was encouraged to reduce intake of the avoided nutrient to 20 grams per day over the first eight weeks, then participants slowly added fats or carbohydrates back to their diets until they reached the lowest level of intake they believed could be sustained for the long haul. Everyone was followed for a year (which is an eternity for a nutrition study). Everyone was encouraged to maximize vegetable intake; to minimize added sugar, refined flour and trans fat intake; and to focus on whole foods that were minimally processed. The subjects were also encouraged to cook at home as much as possible. © 2018 The New York Times Company

Keyword: Obesity
Link ID: 24783 - Posted: 03.26.2018

By Amina Zafar, Susan Caluori says a stroke saved her life. The 60-year-old Montreal woman had just run a half marathon in December 2015 when her husband noticed the left side of her face was drooping. She wanted to keep watching TV, but he insisted they go to the hospital. The doctors there treated her for a stroke, the facial droop, and she was discharged a week later. A couple of weeks passed, and she returned to the emergency department after becoming confused and disoriented and experiencing speech difficulties. It was then that doctors performed a series of tests that led them to identify a blood clot in one of her heart valves. With the help of a biopsy, they found the cause of the clot was a dangerous form of ovarian cancer. "The empress of subterfuge," her doctors called the cancer masquerading as a stroke. It turns out that it was the malignancy in her Fallopian tubes that was the source behind her drooping face and the mixed-up words that her kids had been teasing her about for two months prior to her emergency room visit. "The stroke saved my life. Yes, I have repercussions because of the strokes, but you know what, I'm alive because of them. If not [for them], they would have never have found the cancer," Caluori said. Caluori's presentation was so rare that her medical team wrote up the case report in a medical journal last year. "What alerted us to her having ovarian cancer is nothing in her abdomen or pelvis," said Dr. Ziggy Zeng, a gynecological oncologist at the McGill University Health Centre. "The disease is so cunning it presented itself with a clot." The ovarian cancer caused Caluori's blood to produce a clot that triggered the strokes, Zeng said. ©2018 CBC/Radio-Canada.

Keyword: Stroke
Link ID: 24782 - Posted: 03.26.2018

By Nora D. Volkow As a young scientist in the 1980s, I used then-new imaging technologies to look at the brains of people with drug addictions and, for comparison, people without drug problems. As we began to track and document these unique pictures of the brain, my colleagues and I realized that these images provided the first evidence in humans that there were changes in the brains of addicted individuals that could explain the compulsive nature of their drug taking. The changes were so stark that in some cases it was even possible to identify which people suffered from addiction just from looking at their brain images. Alan Leshner, who was the Director of the National Institute on Drug Abuse at the time, immediately understood the implications of those findings, and it helped solidify the concept of addiction as a brain disease. Over the past three decades, a scientific consensus has emerged that addiction is a chronic but treatable medical condition involving changes to circuits involved in reward, stress, and self-control; this has helped researchers identify neurobiological abnormalities that can be targeted with therapeutic intervention. It is also leading to the creation of improved ways of delivering addiction treatments in the healthcare system, and it has reduced stigma. Informed Americans no longer view addiction as a moral failing, and more and more policymakers are recognizing that punishment is an ineffective and inappropriate tool for addressing a person’s drug problems. Treatment is what is needed. © 2018 Scientific American, a Division of Nature America, Inc.

Keyword: Drug Abuse
Link ID: 24781 - Posted: 03.26.2018

Juliette Jowit The world’s first brain scanner that can be worn as people move around has been invented, by a team who hope the contraption can help children with neurological and mental disorders and reveal how the brain handles social situations. The new scalp caps – made on 3D printers – fit closely to the head, so can record the electromagnetic field produced by electrical currents between brain cells in much finer detail than previously. This design means the scanner can work in ways never possible before: subjects can move about, for example, and even play games with the equipment on, while medics can use it on groups such as babies, children and those with illnesses which cause them to move involuntarily. “This has the potential to revolutionise the brain imaging field, and transform the scientific and clinical questions that can be addressed with human brain imaging,” said Prof Gareth Barnes at University College London, one of three partners in the project. The other two are the University of Nottingham and the Wellcome Trust. The brain imaging technique known as magnetoencephalography, or MEG, has been helping scientists for decades, but in many cases has involved using huge contraptions that look like vintage hair salon driers. The scanners operated further from the head than the new devices, reducing the detail they recorded, and users had to remain incredibly still. © 2018 Guardian News and Media Limited

Keyword: Brain imaging
Link ID: 24780 - Posted: 03.22.2018

/ By Charles Schmidt In August of 2013, Shecara Norris moved with her husband and five young children into a rented colonial house in East Columbus, Ohio. She was in her late 20s and pregnant with her sixth child. The house was in a crime-ridden area that Norris describes as the “heart of the hood,” but it also had a lot of appeal, with wood floors, a dining room with a fireplace, and plenty of room for her growing family. Her son Michael — who had been born earlier that year — was a healthy baby with a strong personality. Shecara Norris with her son Michael, whose blood lead levels were once six times higher than a standard federal benchmark. Lowering that benchmark further, critics say, will make it harder for children like Michael to get the resources they need. Current policy “trivializes the continuing problem of clinical childhood lead poisoning in the interiors of our major cities,” one epidemiologist argued. But around the time of his second birthday, doctors found lead in Michael’s blood. At 30 micrograms per deciliter (mcg/dL), his blood lead levels were six times over the amount that triggers case management recommendations by the federal Centers for Disease Control and Prevention. State and local public health officials were notified, and Norris and her husband were told it wasn’t safe for Michael to remain in the house, though the family didn’t have the money to leave. To Norris, the diagnosis initially came as a shock, though it seems less surprising in hindsight. The house dates back nearly a century, to a time when lead paint was used routinely. Inspectors would later find that nearly every room was contaminated with the toxic metal, as were the front porch and the yard where Michael and his brothers and sisters would play. Lead is much more dangerous to young children than adults, targeting developing nervous systems and progressively lowering intelligence with increasing doses. All the Norris children had lead in their blood, but Michael’s levels were by far the highest. Copyright 2018 Undark

Keyword: Development of the Brain; Neurotoxins
Link ID: 24779 - Posted: 03.22.2018

By David Grimm After years of experiments, a protracted battle to grant them legal “personhood,” and a life spent bouncing between two scientific facilities, two of the world’s most famous research chimpanzees have finally retired. Hercules and Leo arrived this morning at Project Chimps, a 95-hectare sanctuary in the wooded hills of Morgantown, Georgia. In many ways, the pair had also become the face of a tortuously slow effort to move hundreds of the United States’s remaining research chimpanzees to wildlife refuges. Their arrival at Project Chimps suggests plans to retire these animals—which can live up to 50 years in captivity—may be back on track. “For the first time, there are more chimpanzees in sanctuaries than there are in labs,” says Stephen Ross, director of the Lester E. Fisher Center for the Study and Conservation of Apes at the Lincoln Park Zoo in Chicago, Illinois, and board chair of Chimp Haven in Keithville, Louisiana, the only sanctuary authorized to take government-owned chimps. “Hercules and Leo are representative of a movement that’s finally bearing fruit.” Hercules and Leo were born in 2006 at the New Iberia Research Center in Louisiana, home to the world’s largest collection of privately owned lab chimps. In 2011, New Iberia loaned the duo out to the State University of New York in Stony Brook. There, they lived in a three-room enclosure and researchers inserted small electrodes into their muscles to study the evolution of bipedal walking. While there, the Nonhuman Rights Project—an animal rights group based in Coral Springs, Florida—filed a lawsuit to have Hercules and Leo declared legal persons and moved to a sanctuary in Florida. Despite multiple appeals over 2 years, the effort failed, and the chimps were shipped back to New Iberia in 2015. © 2018 American Association for the Advancement of Scienc

Keyword: Animal Rights
Link ID: 24778 - Posted: 03.22.2018

Aimee Cunningham As mice plumped up on a high-fat diet, some of their taste buds vanished. This disappearing act could explain why some people with obesity seem to have a weakened sense of taste, which may compel them to eat more. Compared with siblings that were fed normal mouse chow, mice given high-fat meals lost about 25 percent of their taste buds over eight weeks. Buds went missing because mature taste bud cells died off more quickly, and fewer new cells developed to take their place. Chronic, low-level inflammation associated with obesity appears to be behind the loss, researchers report March 20 in PLOS Biology. Taste buds, each a collection of 50 to 100 cells, sense whether a food is sweet, sour, bitter, salty or umami (savory). These cells help identify safe and nourishing food, and stimulate reward centers in the brain. The tongue’s taste bud population is renewed regularly; each bud lasts about 10 days. Special cells called progenitor cells give rise to new taste bud cells that replace old ones. Some studies have suggested that taste becomes duller in people with obesity, although why that is has remained unclear. But if taste becomes less intense, “then maybe you don’t get the positive feeling that you should,” which could give way to more overeating, says study coauthor Robin Dando, who studies the biology of taste at Cornell University. Nearly 40 percent of U.S. adults have obesity, determined by a person’s body mass index, a ratio of weight to height. The condition is linked to a number of health problems, including heart disease, diabetes and cancer. |© Society for Science & the Public 2000 - 2018

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 24777 - Posted: 03.21.2018

By Shawna Williams | Humans like to fancy ourselves advanced, but there’s at least one area where cockroaches, and even nematodes, seem to have us beat: magnetoreception, the ability to sense variations in magnetic fields. To add insult to injury, our best human minds haven’t yet been able to answer basic questions about how the sense—also shared by some amphibians, fish, birds, and mammals—works. Joining the list now are zebrafish and medaka, as researchers reported in Nature Communications last month (February 23). Unlike in some animals, magnetoreception in the fish doesn’t require light to work. The study is “a promising beginning,” writes Roswitha Wiltschko, a researcher at Goethe University Frankfurt who has studied magnetoreception in birds, in an email to The Scientist. “[T]o demonstrate [sensitivity to magnetic direction] in two species whose genetics are known is novel, and this might form a basis for future investigations.” Animals as diverse as lobsters and pigeons are thought to use variations in Earth’s magnetic fields to orient themselves. One idea for how the sense might work is that magnetic fields could affect light-sensitive chemical reactions, possibly in structures in the retina known as cryptochromes. Another is that some animal cells contain magnetic field–sensitive metals that interact with mechanosensitive structures to produce a signal. © 1986-2018 The Scientist

Keyword: Pain & Touch
Link ID: 24776 - Posted: 03.21.2018