Nicola Davis Researchers in the US say they have managed to keep the brains of decapitated pigs alive outside of the body for up to 36 hours by circulating an oxygen-rich fluid through the organs. While the scientists, led by Yale University neuroscientist Nenad Sestan, say the brains are not conscious, they add the feat might help researchers to probe how the brain works, and aid studies into experimental treatments for diseases ranging from cancer to dementia. The revelation, disclosed in the MIT Technology Review and based on comments Sestan made at a meeting at the US National Institutes of Health in March, has received a mixed reaction in the scientific community. A neuroscientist explains: the need for ‘empathetic citizens’ - podcast Anna Devor, a neuroscientist at the University of California, San Diego, told the MIT Technology Review the feat could help researchers probe the connections between brain cells, allowing them to build a “brain atlas”. However others were quick to stress that the development did not mean humans could expect to cheat death any time soon, noting that it is not possible to transplant a brain into a new body. “That animal brain is not aware of anything, I am very confident of that,” Sestan is reported to have told the NIH meeting. But he noted that ethical considerations abound: “Hypothetically, somebody takes this technology, makes it better, and restores someone’s [brain] activity. That is restoring a human being. If that person has memory, I would be freaking out completely.” © 2018 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 24919 - Posted: 04.28.2018

by Melissa Healy Sometimes forgotten in the spiraling crisis of opiate abuse is a clinical fact about narcotic pain medications: Addiction is basically an unwanted side effect of drugs that are highly effective at blunting pain. Addiction, of course, is a particularly dangerous and disruptive side effect, since it hijacks a patient’s brain and demands escalating doses of opioid drugs to hold withdrawal symptoms at bay. What if there were a drug that did the job opioids do best — relieve pain — without prompting many of their negative side effects, especially addiction? A researcher from the University of Michigan Medical School may have done just that. Tomas Joaquin Fernandez has described a process for designing opioid-like drugs that would act on pain receptors in the brain while blocking the receptors responsible for fostering dependence and building tolerance. Using pain-relieving peptides released by the brain as models, Fernandez and colleagues developed a library of “peptidomimetics.” These agents were small enough to get into the brain, and they worked on different opioid receptors in different ways. When they tested one such compound in mice, they found that it not only relieved pain, it also induced less buildup of tolerance and less physical dependence than morphine. In other words, it was less addictive. © 1996-2018 The Washington Post

Keyword: Pain & Touch; Drug Abuse
Link ID: 24918 - Posted: 04.28.2018

John Henning Schumann Drew was in his early 30s. His medical history included alcohol abuse, but he had been sober for several months when he became my patient. His previous doctor had given him a prescription for Ativan, or lorazepam, which is frequently used to allay tremors and seizures from alcohol withdrawal. My first inclination was to wean him off the medication by lowering the dose and telling him to take it less frequently. But inertia is strong in medical care, and Drew prevailed upon me to continue providing lorazepam at his regular dose for another month while he solidified his situation with a new job. The next time I heard about him was a couple of weeks later when a colleague read me Drew's obituary in the local paper. There was no cause of death listed. But I knew he could have run into serious trouble if he had mixed alcohol or other drugs with his lorazepam. Lorazepam is a benzodiazepine, a class of medicines known as sedative-hypnotics. They're used frequently in the U.S. to treat anxiety and insomnia. Other drugs in the same category include Valium and Xanax. The problem with benzos, as they're also known, is that they're highly addictive medications, both physically and psychologically. Abruptly stopping them can lead to withdrawal symptoms like the ones Drew hoped to avoid when he kicked alcohol. Moreover, with long-term use, our metabolism adjusts to benzos. We need higher doses to achieve the same effects. © 2018 npr

Keyword: Drug Abuse
Link ID: 24917 - Posted: 04.28.2018

By Diana Kwon Scientists have long attempted to understand where, and how, the brain stores memories. At the beginning of the 20th century, German scientist Richard Semon coined the term “engram” to describe the hypothetical physical representations of memories in the brain. Then, in the 1940s, Canadian psychologist Donald Hebb proposed that, when neurons encoded memories, connections, called synapses, between coactivated memory, or engram, cells were strengthened—a theory that was famously paraphrased as neurons that “fire together, wire together.” These two ideas have become the cornerstone of memory research—and in the decades since they first emerged, scientists have amassed evidence supporting them. “Donald Hebb suggested that it’s not engram cells that are the critical part of storing the memory, it’s the synapse between engram cells,” says Bong-Kiun Kaang, a neuroscientist at Seoul National University in South Korea. However, he adds, while there has been much indirect evidence that such a process underlies memory formation, such as studies showing long-term potentiation (the process through which two simultaneously activated neurons show enhanced connectivity), direct evidence has been lacking. One of the key issues has been the lack of tools to directly observe this process, Kaang says. To overcome this limitation, he and his colleagues injected a virus containing recombinant DNA—coding for different colors of fluorescent proteins for engram and non-engram cells—into the brains of mice. Using this technique, the team was able to pinpoint which type of cell had connected with a postsynaptic neuron. The endeavor wasn’t easy. Developing the method and getting it to work experimentally was a painstaking process that took almost a decade, Kaang tells The Scientist. So when his team finally managed to get promising results around two years ago, “we were very excited,” he says. © 1986-2018 The Scientist

Keyword: Learning & Memory
Link ID: 24916 - Posted: 04.28.2018

Aided by advanced stem cell technology and tissue chips, National Institutes of Health-funded researchers used stem cells originally derived from a person’s skin to recreate interactions between blood vessels and neurons that may occur early in the formation of the fetal human spinal cord. The results published in Stem Cell Reports suggest that the system can mimic critical parts of the human nervous system, raising the possibility that it may one day, be used to test personalized treatments of neurological disorders. Led by Samuel Sances, Ph.D., and Clive N. Svendsen, Ph.D., Cedars-Sinai Board of Governors Regenerative Medicine Institute, Los Angeles, CA, the researchers first converted the stem cells into newborn spinal cord neurons or epithelial cells that line walls of brain blood vessels. In most experiments, each cell type was then injected into one of two chambers embedded side-by-side in thumb-sized, plastic tissue chips and allowed to grow. Six days after injections, the researchers found that the growing neurons exclusively filled their chambers while the growing blood vessel cells not only lined their chamber in a cobblestone pattern reminiscent of vessels in the body, but also snuck through the perforations in the chamber walls and contacted the neurons. This appeared to enhance maturation of both cell types, causing the neurons to fire more often and both cell types to be marked by some gene activity found in fetal spinal cord cells. Tissue chips are relatively new tools for medical research and since 2012 the NIH has funded several tissue-chip projects. Unlike traditional petri dish systems, tissue chips help researchers grow cells in more life-like environments. Using microprocessor manufacturing techniques, the chambers can be built to recreate the three-dimensional shapes of critical organ parts and the tight spaces that mimic the way viscous, bodily fluids normally flow around the cells.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 24915 - Posted: 04.28.2018

By CEYLAN YEGINSU LONDON — The anti-vaccine movement has come for the pets. A spreading fear of pet vaccines’ side effects has prompted the British Veterinary Association to issue a startling statement this week: Dogs cannot develop autism. The implicit message was that dog owners should keep vaccinating their pets against diseases like distemper and canine hepatitis because any concerns that the animals would develop autism after the injections were unfounded. The warning has a long tail. It grew out of an anti-vaccine theory that rippled across the United States and Europe as networks known as “anti-vaxxers” claimed that childhood vaccinations could cause autism. The belief, promoted by some celebrities like the television personality Jenny McCarthy, who says her son has autism, spurred many parents to begin boycotting traditional vaccines. The theory gained prominence in 1998, after a study published in the medical journal The Lancet purported to show a link between autism and the measles-mumps-rubella vaccination. It caused a firestorm in health circles and among parents, resulting in a significant drop in vaccination rates for children in Britain. But the study has since been thoroughly discredited. It was formally retracted by the medical magazine and its lead author, Andrew Wakefield, who at the time was a doctor at the Royal Free Hospital in London, was subsequently struck off the British medical register over ethical lapses. The theory, however, has jumped species. It is increasingly being applied to pets in the United States and is gaining momentum in Britain — raising concerns that the already low vaccination rates in this country could fall further. © 2018 The New York Times Company

Keyword: Autism
Link ID: 24914 - Posted: 04.28.2018

Ian Sample Science editor Scientists have raised hopes for more effective treatments for depression, a condition that affects over 300 million people globally, after mapping out the genetic foundations of the mental disorder in unprecedented detail. In the world’s largest investigation into the impact of DNA on the mental disorder, more than 200 researchers identified 44 gene variants that raise the risk of depression. Of those, 30 have never been connected to the condition before. By tripling the number of gene regions linked to depression, scientists now hope to understand more about why the disorder strikes some but not others, even when they have similar life experiences. The work could also help in the search for drugs to treat the condition which affects as many as one in four people over a lifetime. Sign up for Lab Notes - the Guardian's weekly science update Read more “If you have a lower genetic burden of depression, perhaps you are more resistant to the stresses we all experience in life,” said Cathryn Lewis, professor of statistical genetics and a senior author on the study at King’s College London. Previous work with twins suggests that genetics explains about 40% of depression, with the rest being driven by other biological factors and life experiences. If people are ranked according to the number of genetic risk factors for depression they carry, those in the top 10% are two-and-a-half times more likely to experience depression than those in the bottom 10%, Lewis said. © 2018 Guardian News and Media Limited

Keyword: Depression; Genes & Behavior
Link ID: 24913 - Posted: 04.27.2018

By Elizabeth Pennisi One of biology's great mysteries is how a single fertilized egg gives rise to the multitude of cell types, tissues, and organs that fit together to make a body. Now, a combination of single-cell sequencing technologies and computational tools is providing the most detailed picture yet of this process. In three papers online in Science this week, researchers report taking multiple snapshots of gene activity in most of the cells in developing zebrafish or frog embryos. They then assembled those data, taken at intervals of just minutes to hours, into coherent, cell-by-cell histories of how those embryos take shape. "My first reaction was, ‘Wow!’" says developmental biologist Robert Zinzen of the Berlin Institute for Medical Systems Biology. Just last week, two other papers online in Science traced cell-by-cell gene activity in planaria, simple flatworms, as they regenerated after being cut into pieces. In vertebrates, "the complexity is much higher," Zinzen notes. Yet the researchers managed to track the emerging identities of thousands of cells and their progeny. "I think the future of development will be to routinely single-cell sequence embryos," says Detlev Arendt, an evolutionary developmental biologist at the European Molecular Biology Laboratory in Heidelberg, Germany. All these studies started by gently dissolving embryos of different stages in special solutions, then shaking or stirring them to free individual cells. For each cell, the researchers then determined the sequences of all the strands of messenger RNA (mRNA), which reflect the genes being transcribed. © 2018 American Association for the Advancement of Science.

Keyword: Development of the Brain
Link ID: 24912 - Posted: 04.27.2018

By Abby Olena Scientists have known for decades that many animals—including birds and sea turtles—use Earth’s magnetic field to navigate over long distances, but understanding how they do so remains a mystery. In 2015, a group from the University of Texas at Austin reported in eLife that a tiny nematode worm, Caenorhabditis elegans, orients to Earth’s magnetic field using a specific pair of neurons. The findings raised the possibility that C. elegans might be an appropriate model system to dig deeper into how animals sense magnetic fields. But earlier this month (April 13) in a comment published in eLife, researchers from the Research Institute of Molecular Pathology in Austria describe unsuccessful attempts to reproduce the results of the 2015 study. “Studying animal magnetoreception is really difficult,” says Miriam Goodman, a sensory biologist at Stanford University who is not affiliated with either group. “I think that we will remain in a situation where we have passionate disagreement until we’ve identified what cells or molecules function as receptors, and that still remains unknown,” she adds. The authors of the original study stand by their results, as they describe in a response also published in eLife. “We know a whole lot about how animals see the world and hear the world and touch it,” but magnetosensing is still something that nobody really knows much about, Andrés Vidal-Gadea, a behavioral neuroscientist at Illinois State University, tells The Scientist. As a postdoc in Jonathan Pierce’s lab at the University of Texas, Vidal-Gadea combined his interest in magnetic sensing, cultivated during a past summer as an undergraduate researcher, and his postdoctoral focus on C. elegans to investigate whether worms might detect magnetic fields. “I just thought that was really exciting, both because the behavior is fascinating and because there is so much work to be done,” he says. © 1986-2018 The Scientist

Keyword: Miscellaneous
Link ID: 24911 - Posted: 04.27.2018

/ By Cathleen O'Grady Growing up in Saudi Arabia, Aciel Eshky didn’t get the memo that science was for boys. When she was around 10 years old, her aunt started to teach her basic computer programming. From there, going on to a degree in computer science seemed like a natural fit. So when a classmate in her master’s program abroad told her that women were weaker than men at math, it came as a shock. “I was really annoyed,” Eshky says. “I felt like I was being bullied.” “If that means that you get fewer women in certain subjects, and more women in other subjects like psychology, it’s not necessarily a catastrophe.” Despite its dismal reputation for gender equality, Saudi Arabia has a surprising level of female graduates in the so-called STEM fields (science, technology, engineering, and mathematics). Ranked among the bottom 20 countries in the World Economic Forum’s Global Gender Gap Index in 2015, women nonetheless made up 39 percent of graduates in a cluster of “core” STEM subjects. This number is higher than Iceland’s 35 percent, even though the Nordic country ranks number one for gender equality. Norway, which has the second-highest level of gender equity, sees only 26 percent of women graduating with STEM degrees. Taken together with these numbers, Eshky’s experience is illustrative of the so-called “gender-equality paradox” reported in a recent headline-grabbing paper: Countries ranking higher on measures of gender equality, the study found, tend to have fewer women pursuing a STEM education than those further down the gender equality ranks. Copyright 2018 Undark

Keyword: Sexual Behavior
Link ID: 24910 - Posted: 04.27.2018

by Anne Ewbank By day, Janelle Letzen is a postdoctoral research fellow in clinical psychology at Johns Hopkins University. There, she researches the sobering subject of chronic pain. But in January of this year, Letzen decided to combine science with her hobby: sushi art. Using brightly colored tuna, avocado, and “krab” meat, her Instagram account the_sushi_scientist visually explains topics ranging from neuroscience to geology. The sections of the brain that control language, depicted in fish and rice. The sections of the brain that control language, depicted in fish and rice. Her sushi-making habit began in 2017 as a New Year’s resolution to learn a new skill. She settled on sushi, but as an edible medium for art. It wasn’t long before she fell in love with it. She recalls thinking that her two passions, science and sushi, could be combined. On Instagram, she began explaining neuroscience topics with fish and rice. Cucumber rolls stand in as synaptic terminals, and short videos of sushi rolls darting around a plate explain subjects such as how neurons chemically communicate. Her work is part of a larger movement, Letzen explains. Researchers and teachers are using what she calls “scienstagrams” to inform audiences visually. Letzen and other “science communicators” make science approachable and understandable. In this day and age, Letzen says, that’s especially important in a world of abundant information and misinformation. She believes that her followers are mostly medical professionals and students interested in biopsychology and neuroscience, her own fields of study. “But I’m also trying to target more informal learners as well, by making science more tangible,” she says. Professors have been using her work to explain concepts to their students, “which has been great.” © 2018 Atlas Obscura.

Keyword: Miscellaneous
Link ID: 24909 - Posted: 04.27.2018

By Abby Olena At both three and nine weeks after guinea pigs’ cochleae were treated with nanoparticles loaded with Hes1 siRNA, the authors observed what are likely immature hair cells. MODIFIED FROM X. DU ET AL., MOLECULAR THERAPY, 2018Loud sounds, infections, toxins, and aging can all cause hearing loss by damaging so-called hair cells in the cochlea of the inner ear. In a study published today (April 18) in Molecular Therapy, researchers stimulated hair cell renewal with small interfering RNAs (siRNAs) delivered via nanoparticles to the cochlea of adult guinea pigs, restoring some of the animals’ hearing. “There are millions of people suffering from deafness” caused by hair cell loss, says Zheng-Yi Chen, who studies hair cell regeneration at Harvard University and was not involved in the work. “If you can regenerate hair cells, then we really have potential to target treatment for those patients.” Some vertebrates—chickens and zebrafish, for instance—regenerate their hair cells after damage. Hair cells of mammals, on the other hand, don’t sprout anew after being damaged, explaining why injuries can cause life-long hearing impairments. Recent research suggests that there might be a workaround, by manipulating signaling pathways that can lead to hair cell differentiation. That’s where Richard Kopke comes in. © 1986-2018 The Scientist

Keyword: Hearing
Link ID: 24908 - Posted: 04.27.2018

Nita A. Farahany, Henry T. Greely and 15 colleagues. If researchers could create brain tissue in the laboratory that might appear to have conscious experiences or subjective phenomenal states, would that tissue deserve any of the protections routinely given to human or animal research subjects? This question might seem outlandish. Certainly, today’s experimental models are far from having such capabilities. But various models are now being developed to better understand the human brain, including miniaturized, simplified versions of brain tissue grown in a dish from stem cells — brain organoids1,2. And advances keep being made. These models could provide a much more accurate representation of normal and abnormal human brain function and development than animal models can (although animal models will remain useful for many goals). In fact, the promise of brain surrogates is such that abandoning them seems itself unethical, given the vast amount of human suffering caused by neurological and psychiatric disorders, and given that most therapies for these diseases developed in animal models fail to work in people. Yet the closer the proxy gets to a functioning human brain, the more ethically problematic it becomes. “We believe it would be unethical to stop the research at this point.” There is now a need for clear guidelines for research, albeit ones that can be adapted to new discoveries. This is the conclusion of many neuroscientists, stem-cell biologists, ethicists and philosophers — ourselves included — who gathered in the past year to explore the ethical dilemmas raised by brain organoids and related neuroscience tools. A workshop was held in May 2017 at the Duke Initiative for Science & Society at Duke University in Durham, North Carolina, with limited support from the US National Institutes of Health (NIH) BRAIN Initiative. A similar US meeting was held last month on related topics. Here we lay out some of the issues that we think researchers, funders, review boards and the public should discuss as a first step to guiding research on brain surrogates. © 2018 Macmillan Publishers Limited

Keyword: Development of the Brain
Link ID: 24907 - Posted: 04.26.2018

Ian Sample Science editor “I have never seen so many brains out of their heads before!” declares Dr Michael Hfuhruhurr, the world-renowned neurosurgeon played by Steve Martin who has a love affair with a brain in a jar in the 1983 movie, The Man with Two Brains. Thirty five years on, the prospect of falling for a disembodied brain is still looking slim, but researchers have made such progress in growing and maintaining human brain tissue in the lab that a group of scientists, lawyers, ethicists and philosophers have called for an ethical debate about the work. Writing in the journal Nature on Wednesday, 17 experts argue that it is time to consider what guidelines might be needed for dealing with lumps of human brain tissue, because the more complex they become the greater the chance that they gain consciousness, feel pleasure, pain and distress, and deserve rights of their own. “It’s not an imminent issue, but the closer these models come to being like human brains, the more we potentially edge towards the ethical problems of human experimentation,” said Prof Hank Greely, director of the Center for Law and the Biosciences at Stanford University in California. “Right now, I see no reason to be worried about consciousness in a six million neuron, half-a-centimetre-wide, hollow ball of cells, but we do need to be thinking about this,” he said. © 2018 Guardian News and Media Limited

Keyword: Development of the Brain
Link ID: 24906 - Posted: 04.26.2018

Sarah Boseley Health editor Some antidepressants and bladder medicines could be linked to dementia, according to a team of scientists who are calling for doctors to think about “de-prescribing” them where possible. Tricyclic antidepressants such as amitriptyline, which are also prescribed for pain and to help with sleeping, and one of the SSRI class, paroxetine (also known as Seroxat), are implicated by the largest ever study to look at this possible risk. Amitriptyline was in the news in February, named as the most effective of the antidepressants in a study. Some Parkinson’s drugs are also linked to a raised dementia risk. As a group, these are known as anticholinergic drugs. There are 1.5 to 2 million people in England alone on this type of drug. It is already known that they can cause short-term confusion and raise people’s risk of a fall. One in five people taking an antidepressant is on an anticholinergic drug, usually amitriptyline. The researchers warn that the increasing tendency for older people to be taking a cocktail of drugs for different conditions may be part of the problem. “In the last 20 years, the number of older individuals taking five or more medicines has quadrupled,” said Dr Ian Maidment, senior lecturer in clinical pharmacy at Aston University. “Many of these medicines will have some anticholinergic activity and, in the light of today’s findings, we have to consider whether the risks of dementia outweigh the benefits from taking a cocktail of prescribed drugs. © 2018 Guardian News and Media Limited

Keyword: Alzheimers; Depression
Link ID: 24905 - Posted: 04.26.2018

By KATE ZERNIKE Recognizing what it called “the troubling reality” that electronic cigarettes have become “wildly popular with kids,” the Food and Drug Administration on Tuesday announced a major crackdown on the vaping industry, particularly on the trendy Juul devices, aimed at curbing sales to young people. The agency said it had started an undercover sting operation this month targeting retailers of Juuls, including gas stations, convenience stores and online retailers like eBay. So far, the F.D.A. has issued warning letters to 40 that it says violated the law preventing sales of vaping devices to anyone under 21. The agency also demanded that Juul Labs turn over company documents about the marketing and research behind its products, including reports on focus groups and toxicology, to determine whether Juul is intentionally appealing to the youth market despite its statements to the contrary and despite knowing its addictive potential. It said it planned to issue similar letters to other manufacturers of popular vaping products as well. “We don’t yet fully understand why these products are so popular among youth,” the agency’s commissioner, Dr. Scott Gottlieb, said in a statement. “But it’s imperative that we figure it out, and fast. These documents may help us get there.” Schools across the country say they were blindsided by the number of students turning up with Juuls last fall. Nicknamed the iPhone of e-cigarettes, Juuls resemble thumb drives, produce little plume, and smell like fruit or other flavorings, making them so concealable that students can vape in class. Students who would never think to smoke a cigarette post videos of themselves doing tricks with vaping devices on social media. Schools, fearing students are becoming addicted to nicotine, are suspending students as young as middle school for vaping. © 2018 The New York Times Company

Keyword: Drug Abuse
Link ID: 24904 - Posted: 04.26.2018

by Lenny Bernstein White House physician Ronny L. Jackson allegedly provided travelers on White House trips with Ambien, a prescription sedative that is widely regarded as a safe drug that poses little risk of addiction. Nearly 30 million Americans take it for it insomnia — the vast majority of them in its generic form, zolpidem — for a single night or for longer periods of sleeplessness. But that doesn't mean a physician can hand out the drug “like candy,” as Sen. Jon Tester (D-Mont.) said Jackson did, without inquiring about other medications a patient might be taking, drug history or other medical issues, experts said. “Any physician prescribing a controlled substance should have a doctor-patient relationship, just because of knowing the other health problems and the other medications,” said Cathy Goldstein, an assistant professor of neurology at the University of Michigan School of Medicine and a physician at the Michigan Medicine Sleep Disorders Center. Taking Ambien, “you could get hurt. You could be disruptive, especially if you're using it with alcohol.” Ambien and the stimulant Provigil, which Tester said Jackson dispensed to help travelers awaken, are Schedule IV controlled substances in the government's five-category ranking of drugs' risk of abuse. But like any medication, they pose some risk, particularly in certain groups. © 1996-2018 The Washington Post

Keyword: Sleep
Link ID: 24903 - Posted: 04.26.2018

By NICHOLAS BAKALAR Over-the-counter pain pills are safer and more effective than prescription opioids for controlling the pain following dental procedures, a review of the evidence has found. Researchers analyzed five reviews of studies of medication and medication combinations for pain relief. They included only reviews of high or moderate methodological quality. The data included many randomized trials on the use of oral medication for the most severe kinds of postoperative dental pain — for example, the pain following the extraction of a molar. More than three dozen drugs and drug combinations were tested in various dosages. The study is in The Journal of the American Dental Association. The researchers conclude that the most effective pain relief with the fewest side effects comes from a combination of 400 milligrams of ibuprofen (Advil and other brands) with 1,000 milligrams of acetaminophen (Tylenol). No opioid or opioid-containing medicine or any other combination of drugs was more effective. A co-author, Anita Aminoshariae, an associate professor at Case Western University, said there may be some people who can get relief only with opioids. But for most patients, she said, opioids are not only less effective, they also have unpleasant side effects, including nausea, constipation and dizziness. They also carry a high risk of addiction. “You have to start with an NSAID,” she said, meaning a nonsteroidal anti-inflammatory drug. “If that doesn’t work, add Tylenol. No one should go home in pain, but opioids should not be the first choice.” © 2018 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 24902 - Posted: 04.26.2018

By Kerry Grens Thermometers in the mouse brain are responsible for a lack of appetite the animals feel after a vigorous workout. Simply firing up heat-sensing receptors on cells in the mouse hypothalamus can reproduce the same appetite-suppressing effects of exercise, researchers report today (April 24) in PLOS Biology. “Our study provides evidence that body temperature can act as a biological signal that regulates feeding behavior, just like hormones and nutrients do,” says coauthor Young-Hwan Jo, a neuroscientist at Albert Einstein College of Medicine, in a press release. It’s a fairly common observation among people that working out staves off hunger for a short while afterward. And it turns out the same is true in mice. Jo’s group had mice run a treadmill for 40 minutes, and observed that their brains were warmer and they ate less for the next hour. To see what might be responsible for this effect, Jo and his colleagues centered in on the hypothalamus, given its role in regulating eating. They found that in mice, neurons in the hypothalamus—specifically, in the arcuate nucleus (ARC) of the hypothalamus—produce heat-sensitive receptors called TRPV1. Through a variety of methods, including the application of capsaicin, a compound found in hot chili peppers, the investigators revealed that flipping on TRPV1 could tamp down mice’s appetites. On the flip side, disrupting the receptor wiped out the appetite-suppressing effects of exercise. © 1986-2018 The Scientist

Keyword: Obesity; Pain & Touch
Link ID: 24901 - Posted: 04.26.2018

By Catherine Matacic Four years after Frank Seifart started documenting endangered dialects in Colombia, the guerillas came. In 2004, soldiers from the Revolutionary Armed Forces of Colombia swept past the Amazonian village where he did most of his fieldwork. The linguist reluctantly left for another village, south of the Peruvian border. When he got there, the chief was away. In the central roundhouse, an old man beat out a rhythm on two enormous drums: “A stranger has arrived. Come home.” And the chief did. It was the first time Seifart, now at the University of Cologne and the French National Center for Scientific Research in Lyon, had heard the traditional drums not just making music, but sending a message. Now, he and his colleagues have published the first in-depth study of how the drummers do it: Tiny variations in the time between beats match how words in the spoken language are vocalized. The finding, reported today in the Royal Society Open Science, reveals how the group known as the Bora can create complex drummed messages. It may also help explain how the rest of us “get” what others are saying at loud cocktail parties, by detecting those tiny variations in time even when other sounds are drowned out. “It is quite innovative,” says descriptive linguist Katarzyna Wojtylak, a postdoctoral research fellow at James Cook University in Cairns, Australia, who has studied the language and drumming systems of the Witoto, a related group. “Nobody has ever done such an extensive and detailed analysis of rhythm in a drummed language.” © 2018 American Association for the Advancement of Science.

Keyword: Language
Link ID: 24900 - Posted: 04.25.2018