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Allison Whitten Every time a human or machine learns how to get better at a task, a trail of evidence is left behind. A sequence of physical changes — to cells in a brain or to numerical values in an algorithm — underlie the improved performance. But how the system figures out exactly what changes to make is no small feat. It’s called the credit assignment problem, in which a brain or artificial intelligence system must pinpoint which pieces in its pipeline are responsible for errors and then make the necessary changes. Put more simply: It’s a blame game to find who’s at fault. AI engineers solved the credit assignment problem for machines with a powerful algorithm called backpropagation, popularized in 1986 with the work of Geoffrey Hinton, David Rumelhart and Ronald Williams. It’s now the workhorse that powers learning in the most successful AI systems, known as deep neural networks, which have hidden layers of artificial “neurons” between their input and output layers. And now, in a paper published in Nature Neuroscience in May, scientists may finally have found an equivalent for living brains that could work in real time. A team of researchers led by Richard Naud of the University of Ottawa and Blake Richards of McGill University and the Mila AI Institute in Quebec revealed a new model of the brain’s learning algorithm that can mimic the backpropagation process. It appears so realistic that experimental neuroscientists have taken notice and are now interested in studying real neurons to find out whether the brain is actually doing it. Simons Foundation All Rights Reserved © 2021

Keyword: Learning & Memory
Link ID: 28044 - Posted: 10.20.2021

by Angie Voyles Askham The gut microbiome is having a moment. An explosion of research over the past decade has delved into a possible connection between the microbiome and brain conditions, including autism. Once-fringe microbial treatments for autism, such as fecal transplants and probiotic pills, are receiving serious scientific attention and funding. It’s still an open question, however, whether the microbiome has a direct effect on autism traits. The most promising data supporting this idea involve altering a mouse’s gut flora, but it is not clear exactly what the mechanism is or if this work translates to people. And the evidence from human studies linking microbes to autism is thin, if a 2021 review of the literature is any guide. Adding to the uncertainty, new unpublished data from one of the largest human studies yet suggests that the link between an atypical gut microbiome and autism is driven solely by a difference in diet. At least four small firms are spearheading early-stage trials of ‘bug as drug’ treatments for autism-associated traits. But until those trials play out, the role of the microbiome in autism is far from clear, says Gaspar Taroncher-Oldenburg, a consultant on microbiome research for the Simons Foundation, Spectrum’s parent organization. “There’s no denying that the microbiome is part of the [autism] conversation,” Taroncher-Oldenburg says. “But it’s a very complex conversation, and we’re only starting to scratch the surface.” A potential connection between the gut microbiome and autism first surfaced in the 1990s, after parents reported changes in their autistic children’s behavior when the children took antibiotics, which kill some gut bacteria. A 2000 study following up on this idea showed that 8 of 10 autistic children taking an antibiotic had temporary improvements in their speech and sociability. Later work associated an atypical gut microbiome with unusual social behaviors in mice. © 2021 Simons Foundation

Keyword: Autism
Link ID: 28043 - Posted: 10.20.2021

Bill Chappell People with mild or moderate hearing loss could soon be able to buy hearing aids without a medical exam or special fitting, under a new rule being proposed by the Food and Drug Administration. The agency says 37.5 million American adults have difficulty hearing. "Today's move by FDA takes us one step closer to the goal of making hearing aids more accessible and affordable for the tens of millions of people who experience mild to moderate hearing loss," Health and Human Services Secretary Xavier Becerra said as he announced the proposed rule on Tuesday. There is no timeline yet for when consumers might be able to buy an FDA-regulated over-the-counter (OTC) hearing aid. The proposed rule is now up for 90 days of public comment. The Hearing Loss Association of America, a consumer advocacy group, welcomed the proposal. "This is one step closer to seeing OTC hearing devices on the market," Barbara Kelley, the group's executive director, said in an email to NPR. "We hope adults will be encouraged to take that important first step toward good hearing health." Advocates and lawmakers have been calling for OTC hearing aids for years, including in a big push in 2017, when Sen. Elizabeth Warren, D-Mass., and co-sponsor Sen. Chuck Grassley, R-Iowa, introduced the bipartisan Over-the-Counter Hearing Aid Act. The legislators are now praising the FDA's move. © 2021 npr

Keyword: Hearing
Link ID: 28042 - Posted: 10.20.2021

Jordana Cepelewicz Leaping, scurrying, flying and swimming through their natural habitats, animals compile a mental map of the world around them — one that they use to navigate home, find food and locate other points of vital interest. Neuroscientists have chiseled away at the problem of how animals do this for decades. A crucial piece of the solution is an elegant neural code that researchers uncovered by monitoring the brains of rats in laboratory settings. That landmark discovery was awarded a Nobel Prize in 2014, and many scientists think the code could be a key component of how the brain handles other abstract forms of information. Yet lab animals in a box with a flat floor only need to navigate through two dimensions, and researchers are now finding that extending the lessons of that situation to the real world is full of challenges and pitfalls. In a pair of studies recently published in Nature and Nature Neuroscience, scientists working with bats and rats showed — to their surprise — that the brain encodes 3D spaces very differently from 2D ones, employing a mechanism that they are still struggling to describe and understand. “We expected something else entirely,” said Nachum Ulanovsky, a neurobiologist at the Weizmann Institute of Science in Israel who led the work in Nature and has studied neural representations of 3D spaces for more than 10 years. “We had to reboot our thinking.” The findings suggest that neuroscientists might need to reconsider what they thought they knew about how the brain encodes natural environments and how animals navigate those spaces. The work also hints at the possibility that other cognitive processes, including memory, might operate very differently than researchers have come to believe. Simons Foundation All Rights Reserved © 2021

Keyword: Learning & Memory
Link ID: 28041 - Posted: 10.16.2021

Brenda Patoine Science likes to package its successes in neat stories that show a clear progression from this to that. The “bench-to-bedside” story—when biological insights yield targeted treatments—is a long-time favorite. Reality, however, doesn’t always cooperate, and history is littered with basic-science discoveries that seemed important but failed to yield viable treatments. When they do succeed, it’s cause for celebration—and awards. Migraine research is an example. Although it is the second most disabling condition in the world, affecting one billion people, migraine had long been relegated to the backwaters of scientific research. Only recently has research bloomed—scientific papers sharply increased from the 1990s onward, with discoveries in basic science driving a new class of drugs that some in the field are calling game changers. This year, the recognition of four migraine researchers with a major neuroscience award has pushed the field into the limelight of science. The 2021 Brain Prize recognizes science that embodies the so-called bench-to-bedside research described above. That’s a jargony term scientists seem to love that denotes the rare and wonderful occurrence when laboratory research aimed at illuminating fundamental mechanisms (the “bench”) yields insights that lead to drugs that ultimately help millions of sick people (the “bedside”). In the case of migraine research, the leading character is a neuropeptide called calcitonin gene-related peptide (CGRP). © 2021 The Dana Foundation.

Keyword: Pain & Touch
Link ID: 28040 - Posted: 10.16.2021

ByRachel Fritts Across North America, hundreds of bird species waste time and energy raising chicks that aren’t their own. They’re the victims of a “brood parasite” called the cowbird, which adds its own egg to their clutch, tricking another species into raising its offspring. One target, the yellow warbler, has a special call to warn egg-warming females when cowbirds are casing the area. Now, researchers have found the females act on that warning 1 day later—suggesting their long-term memories might be much better than thought. “It’s a very sophisticated and subtle behavioral response,” says Erick Greene, a behavioral ecologist at the University of Montana, Missoula, who was not involved in the study. “Am I surprised? I guess I’m more in awe. It’s pretty dang cool.” Birds have been dazzling scientists with their intellects for decades. Western scrub jays, for instance, can remember where they’ve stored food for the winter—and can even keep track of when it will spoil. There’s evidence that other birds might have a similarly impressive ability to remember certain meaningful calls. “Animals are smart in the context in which they need to be smart,” says Mark Hauber, an animal behavior researcher at the University of Illinois, Urbana-Champaign (UIUC), and the Institute of Advanced Studies in Berlin, who co-authored the new study. He wanted to see whether yellow warblers had the capacity to remember their own important warning call known as a seet. Shelby Lawson The birds make the staccato sound of this call only when a cowbird is near. When yellow warbler females hear it, they go back to their nests and sit tight. (It could just as well be called a “seat” call.) But it’s been unclear whether they still remember the warning in the morning. © 2021 American Association for the Advancement of Science.

Keyword: Animal Communication; Learning & Memory
Link ID: 28039 - Posted: 10.16.2021

by Charles Q. Choi Chronic electrical stimulation of the fornix, a bundle of nerve fibers deep in the brain, rescues learning and memory deficits in mice with mutations of the autism-linked gene CDKL5, according to new research. The results support previous work in mice suggesting that electrical jolts to this fiber tract, which links brain regions involved in memory, could help address cognitive problems in multiple models of neurodevelopmental conditions. These animal studies all use deep brain stimulation (DBS), in which electrodes are placed chronically or, in some cases, permanently in specific neuroanatomical regions. In people, severe cognitive impairment, including memory and learning deficits, is a central feature of cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder, which results from mutations that impair production of the CDKL5 protein. Other characteristics include autism traits and epileptic seizures. “Our hope is to help CDKL5 deficiency patients with at least some aspects of their problems — for example, intellectual disability,” says lead investigator Jianrong Tang, associate professor of pediatrics at the Baylor College of Medicine in Houston, Texas. Little is known about how the loss of CDKL5 affects brain circuitry. In the new study, Tang and his colleagues analyzed the brain’s memory center, the hippocampus, in mice with CDKL5 mutations. The connections between neurons there were less flexible, they found, which likely contributed to the animals’ deficits in learning and memory. The mutations also strengthened inhibitory signals in the dentate gyrus, a part of the hippocampus that helps form new memories. © 2021 Simons Foundation

Keyword: Learning & Memory
Link ID: 28038 - Posted: 10.16.2021

Abby Olena Most people enjoy umami flavor, which is perceived when a taste receptor called T1R1/T1R3 senses the amino acid glutamate. In some other mammals, such as mice, however, this same receptor is much less sensitive to glutamate. In a new study published August 26 in Current Biology, researchers uncover the molecular basis for this difference. They show that the receptor evolved in humans and some other primates away from mostly binding free nucleotides, which are common in insects, to preferentially binding glutamate, which is abundant in leaves. The authors argue that the change facilitated a major evolutionary shift in these primates toward a plant-heavy diet. “The question always comes up about the evolution of umami taste: In humans, our receptor is narrowly tuned to glutamate, and we never had a good answer for why,” says Maude Baldwin, a sensory biologist at the Max Planck Institute for Ornithology in Germany. She was not involved in the new work, but coauthored a 2014 study with Yasuka Toda, who is also a coauthor on the new paper, showing that the T1R1/T1R3 receptor is responsible for sweet taste in hummingbirds. In the new study, the authors find “that this narrow tuning has evolved convergently multiple times [and] that it’s related to folivory,” she says, calling the paper “a hallmark, fantastic study, and one that will become a textbook example of how taste evolution can relate to diet and how to address these types of questions in a rigorous, comprehensive manner.” © 1986–2021 The Scientist.

Keyword: Chemical Senses (Smell & Taste); Evolution
Link ID: 28037 - Posted: 10.16.2021

by Angie Voyles Askham An intranasal form of the hormone oxytocin is no more effective than placebo at increasing social behaviors in autistic children, according to what may be the largest clinical trial of the treatment to date. The results were published today in The New England Journal of Medicine. Because of oxytocin’s role in strengthening social bonds, researchers have considered it as a candidate treatment for autism for more than a decade. Small trials hinted that the hormone could improve social skills in some autistic people, such as those with low blood levels of oxytocin or infants with Prader-Willi syndrome, an autism-related condition. But the new results, based on 250 autistic children, suggest that “oxytocin, at least in its current form, is probably not helpful for the majority of kids with autism,” says Evdokia Anagnostou, professor of pediatrics at University of Toronto in Canada, who was not involved in the new work. The null results “change things,” says lead researcher Linmarie Sikich, associate professor of psychiatry and behavioral sciences at the Duke Center for Autism and Brain Development in Durham, North Carolina. “Most people still felt like there was a good chance that this would be treatment for many people with autism.” This type of research is prone to publication bias, in which non-significant results are less likely to be published than significant ones, says Daniel Quintana, senior researcher in biological psychiatry at the University of Oslo in Norway, who was not involved in the study. For that reason, the new work is “an important contribution to the field,” he says, but “it does not alone put to rest the idea of using intranasal oxytocin as an autism treatment.” © 2021 Simons Foundation

Keyword: Autism; Hormones & Behavior
Link ID: 28036 - Posted: 10.16.2021

By Jane E. Brody It’s no surprise that when a person gets a diagnosis of heart disease, cancer or some other life-limiting or life-threatening physical ailment, they become anxious or depressed. But the reverse can also be true: Undue anxiety or depression can foster the development of a serious physical disease, and even impede the ability to withstand or recover from one. The potential consequences are particularly timely, as the ongoing stress and disruptions of the pandemic continue to take a toll on mental health. The human organism does not recognize the medical profession’s artificial separation of mental and physical ills. Rather, mind and body form a two-way street. What happens inside a person’s head can have damaging effects throughout the body, as well as the other way around. An untreated mental illness can significantly increase the risk of becoming physically ill, and physical disorders may result in behaviors that make mental conditions worse. In studies that tracked how patients with breast cancer fared, for example, Dr. David Spiegel and his colleagues at Stanford University School of Medicine showed decades ago that women whose depression was easing lived longer than those whose depression was getting worse. His research and other studies have clearly shown that “the brain is intimately connected to the body and the body to the brain,” Dr. Spiegel said in an interview. “The body tends to react to mental stress as if it was a physical stress.” Despite such evidence, he and other experts say, chronic emotional distress is too often overlooked by doctors. Commonly, a physician will prescribe a therapy for physical ailments like heart disease or diabetes, only to wonder why some patients get worse instead of better. © 2021 The New York Times Company

Keyword: Depression
Link ID: 28034 - Posted: 10.13.2021

By Jamie Friedlander Serrano My dad was planning a trip to Cannon Beach, a small coastal town in Oregon that I love. Yet when I sat down to email him some recommendations, I drew a blank. I couldn’t remember the name of the state park we visited or the breakfast spot we adored. Even the name of the hotel we stayed at eluded me. U.S. coronavirus cases tracker and map Since giving birth to my year-old daughter, I’ve had countless moments like this. I have trouble recalling words, forget to respond to text messages, and even missed an appointment. What I’m experiencing is often called “mommy brain”— the forgetful, foggy and scatterbrained feeling many pregnant women and new mothers experience. But is mommy brain real? Anecdotally, yes. Ask any new mom if she has felt the above, and she'll likely say she has — as many as 80 percent of new moms report feelings of mommy brain. Scientifically, it also appears the answer is yes: A growing body of research supports the argument that moms' brains change during pregnancy and after giving birth. A clear explanation for the phenomenon still remains somewhat elusive, however. There are countless variables that experts say contribute to mommy brain, such as fluctuating hormones postpartum, sleep deprivation in dealing with a new baby, anxiety over new parenthood, elevated stress levels, and a general of lives that having a baby forces. Put together, it’s only natural that changes in mental processing would occur, says Moriah Thomason, Barakett associate professor of child and adolescent psychiatry at New York University School of Medicine. When our brain needs to make space for a new priority — keeping a baby alive — remembering a grocery list takes a back seat. “Does it mean that you literally cannot do those things that you used to do as well? Probably not,” she says. “It’s just not the most important thing for you to be accessing.” © 1996-2021 The Washington Post

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 28033 - Posted: 10.13.2021

By Matt Richtel and Sheila Kaplan The Food and Drug Administration for the first time on Tuesday authorized an electronic cigarette to be sold in the United States, a significant turn in one of the most contentious public health debates in decades. In greenlighting a device and tobacco-flavored cartridges marketed by R.J. Reynolds under the brand name Vuse, the agency signaled that it believed that the help certain vaping devices offer smokers to quit traditional cigarettes is more significant than the risks of ensnaring a new generation. “The authorized products’ aerosols are significantly less toxic than combusted cigarettes based on available data,” the F.D.A. said in a statement announcing the decision. The statement concluded, “The F.D.A. determined that the potential benefit to smokers who switch completely or significantly reduce their cigarette use, would outweigh the risk to youth.” The watershed decision could pave the way for authorization of some other electronic cigarettes, including those of the once-dominant maker Juul, to stay on the market. For more than a year, the manufacturers of e-cigarettes have been in a holding pattern — most of their products on the market but awaiting official authorization — as the F.D.A. has investigated whether they were a benefit or a danger to public health. “The importance of the F.D.A. authorizing a vaping product as ‘appropriate for the protection of public health’ should not be understated,” said Gregory Conley, president of the American Vaping Association, an industry group. He added, “Now that the F.D.A. has acted, we are hopeful that adult consumers and health communicators will begin to understand the harm reduction benefits offered by these and other smoke-free products.” © 2021 The New York Times Company

Keyword: Drug Abuse
Link ID: 28032 - Posted: 10.13.2021

Barbara Jacquelyn Sahakian Christelle Langley Katrin Amunts While humans have walked on the Moon and sent probes all over the solar system, our understanding of our own brain is still severely lacking. We do not have complete knowledge of how brain structure, chemicals and connectivity interact to produce our thoughts and behaviours. But this isn’t from an absence of ambition. It is nearly eight years since the start of the Human Brain Project (HBP) in Europe, which aims to unravel the brain’s mysteries. After a difficult start, the project has made substantial discoveries and innovation, relevant for tackling clinical disorders, as well as technological advances – and it has two more years to go. It has also created EBRAINS, an open research infrastructure built on the scientific advances and tools developed by the project’s research teams, and making them available to the scientific community via a shared digital platform – a new achievement for collaborative research and instrumental in the achievements listed below. 1. Human brain atlas The project has created a unique multilevel human brain atlas based on several aspects of brain organisation, including its structure on the smallest of scales, its function and connectivity. This atlas provides a large number of tools to visualise data and work with them. Researchers can automatically extract data from the atlas using a special tool to run a simulation for modelling the brains of specific patients. This can help to inform clinicians of the optimal treatment option. © 2010–2021, The Conversation US, Inc.

Keyword: Brain imaging
Link ID: 28031 - Posted: 10.13.2021

By Dave Itzkoff Selma Blair could only talk for a half-hour in our first session. That was as long as she trusted her brain and her body to cooperate — any longer and she feared that her focus might start to wander or her speech might begin to trail. “We’re being responsible in knowing that smaller moments will be clearer moments,” she said. For Blair no day is free from the effects of multiple sclerosis, the autoimmune disease that she learned she had in 2018 but that she believes began attacking her central nervous system many years earlier. This particular Friday in September had started out especially tough: She said she woke up in her Los Angeles home feeling “just bad as all get out,” but she found that talking with people helped alleviate her discomfort. Blair said she had had good conversations earlier in the day and that she had been looking forward to ours. So, if she needed to take a break during this interview, she said with a delighted cackle, “it just means you’re boring me.” An unparalleled lack of inhibition has always defined Blair’s best-known work. She is 49 now, with a résumé that includes seminal works of teensploitation (“Cruel Intentions”), comedy (“Legally Blonde”) and comic-book adventure (“Hellboy”). ImageBlair in one of her signature roles, as a fellow law student opposite Reese Witherspoon in “Legally Blonde.” That same unbridled bluntness persists in all her interactions, whether scripted or spontaneous, with cameras on or off, even when she is sharing her account of the time she went on “The Tonight Show” wearing a strappy top she accidentally put on sideways. It is a story she told me proudly, within five minutes of our introduction on a video call, while her fingers made a maelstrom of her close-cropped, bleached-blond hair. (By way of explaining this style choice, she burst into a brassy, Ethel Merman-esque voice and sang, “I want to be a shiksa.”) But Blair’s candor has come to mean something more in the three years since she went public about her M.S. diagnosis. Now, whether she is posting personal diaries on social media or appearing on a red carpet, she understands she is a representative with an opportunity to educate a wider audience about what she and others with M.S. are experiencing. © 2021 The New York Times Company

Keyword: Multiple Sclerosis
Link ID: 28030 - Posted: 10.13.2021

Alison Abbott Imagine looking at Earth from space and being able to listen in on what individuals are saying to each other. That’s about how challenging it is to understand how the brain works. From the organ’s wrinkled surface, zoom in a million-fold and you’ll see a kaleidoscope of cells of different shapes and sizes, which branch off and reach out to each other. Zoom in a further 100,000 times and you’ll see the cells’ inner workings — the tiny structures in each one, the points of contact between them and the long-distance connections between brain areas. Scientists have made maps such as these for the worm1 and fly2 brains, and for tiny parts of the mouse3 and human4 brains. But those charts are just the start. To truly understand how the brain works, neuroscientists also need to know how each of the roughly 1,000 types of cell thought to exist in the brain speak to each other in their different electrical dialects. With that kind of complete, finely contoured map, they could really begin to explain the networks that drive how we think and behave. Such maps are emerging, including in a series of papers published this week that catalogue the cell types in the brain. Results are streaming in from government efforts to understand and stem the increasing burden of brain disorders in their ageing populations. These projects, launched over the past decade, aim to systematically chart the brain’s connections and catalogue its cell types and their physiological properties. It’s an onerous undertaking. “But knowing all the brain cell types, how they connect with each other and how they interact, will open up an entirely new set of therapies that we can’t even imagine today,” says Josh Gordon, director of the US National Institute of Mental Health (NIMH) in Bethesda, Maryland. © 2021 Springer Nature Limited

Keyword: Brain imaging; Development of the Brain
Link ID: 28029 - Posted: 10.09.2021

ByJocelyn Kaiser A common genetic variant called APOE4 raises a person’s risk of Alzheimer’s disease. It also poses a puzzle: If APOE4 is so bad for us, why hasn’t it been weeded out from the population? A new study finds that, surprisingly, the APOE4 variant has positive cognitive impacts: It may not only boost short-term memory, but also protect against subtle memory loss early in the course of Alzheimer’s disease. “There is something about the possession of an APOE4 allele which is providing some positive impacts on your cognitive function,” even in people whose brains are primed for Alzheimer’s, says neurologist Jonathan Schott of University College London (UCL), co-leader of the study. That could not only help explain why the variant persists, but also guide Alzheimer’s treatments, he says. The APOE gene codes for a protein called apolipoprotein E, which helps metabolize fats. About one in four people carry one copy of the version called APOE4 that roughly triples the risk for late-onset Alzheimer’s disease. (A few people have two copies of APOE4, which raises the risk 12-fold or more.) When a harmful gene remains in a population across hundreds of thousands of years, one possible explanation for its staying power is that one copy is beneficial. For example, people with one copy of the sickle cell gene are protected from malaria. Scientists have known for years that people with APOE4 are more likely to develop sticky amyloid protein plaques in their brains; many researchers think these may contribute to Alzheimer’s by triggering other changes that lead to neuronal death. Yet several small studies have hinted that APOE4 could have benefits, such as boosting fertility and cognition. Last year, a larger study found that APOE4 carriers across a range of ages perform slightly better than noncarriers on a test requiring them to quickly recall an object and its location. © 2021 American Association for the Advancement of Science.

Keyword: Alzheimers; Genes & Behavior
Link ID: 28028 - Posted: 10.09.2021

Allison Aubrey The "diet" in diet drinks may be a false promise for some soda lovers. True, they deliver the fizz and taste of a soda experience, without the calories. Yet, new research shows they also can leave people with increased food cravings. A study published recently in JAMA Network Open adds to the evidence that drinks made with sucralose may stimulate the appetite, at least among some people, and the study gives some clues as to why. "We found that females and people with obesity had greater brain reward activity" after consuming the artificial sweetener, says study author Katie Page, a physician specializing in obesity at the University of Southern California. Both groups also had a reduction in the hormone that inhibits appetite, and they ate more food after they consumed drinks with sucralose, compared with after regular sugar-sweetened drinks. In contrast, the study found males and people of healthy weight did not have an increase in either brain reward activity or hunger response, suggesting they're not affected in the same way. The study notes that most earlier research focused on males and people of normal weight. But this finding suggests that diet drinks sweetened with sucralose could be disadvantageous to the people who could benefit most from an effective diet strategy. © 2021 npr

Keyword: Obesity; Sexual Behavior
Link ID: 28027 - Posted: 10.09.2021

By Trishla Ostwal Juan Negro crouched in the shadows just outside a cave, wearing his headlamp. For a brief moment, he wasn’t an ornithologist at the Spanish National Research Council’s Doñana Biological Station in Seville. He was a Neandertal, intent on catching dinner. As he waited in the cold, dark hours of the night, crowlike birds called choughs entered the cave. The “Neandertal” then stealthily snuck in and began the hunt. This idea to role-play started with butchered bird bones. Piles of ancient tool- and tooth-nicked choughs bones have been found in the same caves that Neandertals frequented, evidence suggesting that the ancient hominids chowed down on the birds. But catching choughs is tricky. During the day, they fly far to feed on invertebrates, seeds and fruits. At night though, their behavior practically turns them into sitting ducks. The birds roost in groups and often return to the same spot, even if they’ve been disturbed or preyed on there before. So the question was, how might Neandertals have managed to catch these avian prey? To find out, Negro and his colleagues decided to act like, well, Neandertals. Wielding bare hands along with butterfly nets and lamps — proxy for nets (SN: 04/09/20) and fire (SN: 2/20/14) that Neandertals may have had at hand— teams of two to 10 researchers silently snuck into caves and other spots across Spain, where the birds roost to see how many choughs they could catch. a person inside a building attempting to catch a bird © Society for Science & the Public 2000–2021

Keyword: Evolution
Link ID: 28026 - Posted: 10.09.2021

Jordana Cepelewicz We often appreciate the world around us in terms of its glorious sights, stirring sounds and evocative smells, all of which mark important stimuli and changes in our environment. But senses that are no less crucial to our survival are often taken for granted, including our abilities to register heat, cold and touch, a form of perception called somatosensation. Because of them, we can feel the warmth of the sun or the gentle caress of a breeze against our skin, as well as the positions and movement of our own bodies. In fact, the somatosensory neurons that make all these sensations possible constitute the largest sensory system in mammals. Scientists knew that for somatosensation to occur, there must be molecular receptors on some cells that could detect temperature and touch, and could convert those stimuli into electrical and chemical signals for the nervous system to process. For the discovery of some of those receptors David Julius, a physiologist at the University of California, San Francisco, and Ardem Patapoutian, a molecular biologist and neuroscientist at Scripps Research in La Jolla, have now been awarded the 2021 Nobel Prize in Physiology or Medicine. Julius and his colleagues started with questions about receptors for heat and pain. To find answers, they turned to capsaicin, the compound that causes us to experience a burning and sometimes painful sensation when we eat chili peppers or other spicy food. Based on our physiological response to the chemical, which includes sweating, capsaicin seemed to be inducing the nervous system to register a change in body temperature. To figure out how, Julius and his team screened millions of DNA fragments for a gene that could induce a response to the compound in cells that typically don’t react to it at all. After an arduous search, and what the Nobel Prize committee called “a high-risk project,” the researchers identified a gene that allowed cells to sense capsaicin. It encoded a novel ion channel protein, later called TRPV1, that Julius and his team discovered could be activated by hot temperatures perceived as painful. All Rights Reserved © 2021

Keyword: Pain & Touch
Link ID: 28025 - Posted: 10.06.2021

By Gretchen Reynolds For better health and a longer life span, exercise is more important than weight loss, especially if you are overweight or obese, according to an interesting new review of the relationships between fitness, weight, heart health and longevity. The study, which analyzed the results of hundreds of previous studies of weight loss and workouts in men and women, found that obese people typically lower their risks of heart disease and premature death far more by gaining fitness than by dropping weight or dieting. The review adds to mounting evidence that most of us can be healthy at any weight, if we are also active enough. I have written frequently in this column about the science of exercise and weight loss, much of which is, frankly, dispiriting, if your goal is to be thinner. This past research overwhelmingly shows that people who start to exercise rarely lose much, if any, weight, unless they also cut back substantially on food intake. Exercise simply burns too few calories, in general, to aid in weight reduction. We also tend to compensate for some portion of the meager caloric outlay from exercise by eating more afterward or moving less or unconsciously dialing back on our bodies’ metabolic operations to reduce overall daily energy expenditure, as I wrote about in last week’s column. Glenn Gaesser, a professor of exercise physiology at Arizona State University in Phoenix, is well versed in the inadequacies of workouts for fat loss. For decades, he has been studying the effects of physical activity on people’s body compositions and metabolisms, as well as their endurance, with a particular focus on people who are obese. Much of his past research has underscored the futility of workouts for weight loss. In a 2015 experiment he oversaw, for instance, 81 sedentary, overweight women began a new routine of walking three times a week for 30 minutes. After 12 weeks, a few of them had shed some body fat, but 55 of them had gained weight. In other studies from Dr. Gaesser’s lab, though, overweight and obese people with significant health problems, including high blood pressure, poor cholesterol profiles or insulin resistance, a marker for Type 2 diabetes, showed considerable improvements in those conditions after they started exercising, whether they dropped any weight or not. Seeing these results, Dr. Gaesser began to wonder if fitness might enable overweight people to enjoy sound metabolic health, whatever their body mass numbers, and potentially live just as long as thinner people — or even longer, if the slender people happened to be out of shape. © 2021 The New York Times Company

Keyword: Obesity
Link ID: 28024 - Posted: 10.06.2021