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

Keyword: Evolution
Link ID: 24112 - Posted: 09.26.2017

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

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

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

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

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

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

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

Keyword: Obesity
Link ID: 24108 - Posted: 09.25.2017

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

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

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

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

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

Keyword: Sleep
Link ID: 24105 - Posted: 09.25.2017

By BENEDICT CAREY The brain damage was so severe that scientists all but gasped. Aaron Hernandez, the former New England Patriots tight end, was convicted of murder and killed himself in prison last April at age 27. An autopsy revealed that he had brain injuries akin to that seen in afflicted former players in their 60s, researchers announced on Thursday. The sheer extent of the damage turns on its head the usual question about violence and so-called chronic traumatic encephalopathy. If accumulated head trauma can cause such damage, might the injuries in turn lead to murder and suicide? It’s a natural presumption to make, given the tragic suicides of Junior Seau, Dave Duerson and other former football players diagnosed post-mortem with C.T.E. And it’s a question that the courts will have to wrestle with. On Friday, the National Football League vowed to defend itself against a lawsuit filed on behalf of Mr. Hernandez’s daughter and fiancée, who claims that his injuries and death were a direct result of his participation in football. The science itself — like most attempts to link brain biology to behavior — is murkier. In recent decades, researchers have made extraordinary strides in understanding the workings of brain cells, neural circuits and anatomy. Yet drawing a direct line from those basic findings to what people do out in the world is dicey, given the ineffable interplay between circumstance, relationships and personality. What scientists — from such diverse fields as psychiatry, neurology and substance use — can say is that the arrows seem to be pointing in the same direction. A number of brain states raise the risk of acting out violently, and the evidence so far, while incomplete, suggests that C.T.E. may be one of them. Dr. Samuel Gandy, director of the N.F.L. neurology program at Mount Sinai Medical Center, said that rage and irritability “are far and away the most prominent symptoms” among former players with likely C.T.E., in his research. His group has identified 10 of 24 former players who probably have C.T.E. © 2017 The New York Times Company

Keyword: Brain Injury/Concussion; Aggression
Link ID: 24104 - Posted: 09.23.2017

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

Keyword: Alzheimers
Link ID: 24103 - Posted: 09.23.2017

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

Keyword: Sexual Behavior; Development of the Brain
Link ID: 24102 - Posted: 09.23.2017

By NATALIE ANGIER Tom Vaughan, a photographer then living in Colorado’s Mancos Valley, kept a hummingbird feeder outside his house. One morning, he stepped through the portico door and noticed a black-chinned hummingbird dangling from the side of the red plastic feeder like a stray Christmas ornament. At first, Mr. Vaughan thought he knew what was going on. “I’d previously seen a hummingbird in a state of torpor,” he said, “when it was hanging straight down by its feet, regenerating its batteries, before dropping down and flying off.” On closer inspection, Mr. Vaughan saw that the hummingbird was hanging not by its feet but by its head. And forget about jumping its batteries: the bird was in the grip of a three-inch-long green praying mantis. The mantis was clinging with its back legs to the rim of the feeder, holding its feathered catch in its powerful, seemingly reverent front legs, and methodically chewing through the hummingbird’s skull to get at the nutritious brain tissue within. “It was staring at me as it fed,” Mr. Vaughan said. “Of course, I took a picture of it.” Startled by the clicking shutter, the mantis dropped its partially decapitated meal, crawled under the feeder — and began menacing two hummingbirds on the other side. “Talk about cognitive dissonance,” Mr. Vaughan said. “I always thought of mantises as wonderful things to have in your garden to get rid of bugs, but it turns out they sometimes go for larger prey, too.” “It gave me new respect for mantises,” he added. © 2017 The New York Times Company

Keyword: Aggression
Link ID: 24101 - Posted: 09.23.2017

By Anna Azvolinsky To define human consciousness at the neuronal level is among the most difficult of tasks for neuroscience. Still, researchers have made inroads, most recently by sinking electrodes deep with the brains of epilepsy patients and recording the activity of single neurons as the awake patients described whether they observed an image flashed before them. Previous work had found that the stronger the individual neuron activity, the more likely it is to be associated with conscious perception. In this latest study, published today (September 21) in Current Biology, researchers from the University of Bonn Medical Center in Germany find a second factor—timing—that appears important to the brain’s conscious awareness. Firing of single neurons within the medial temporal lobe (MTL), which is important for long-term memory, was weaker and delayed when human subjects were not aware of seeing an image compared to when they reported seeing one. “[The authors] contribute a major piece of the puzzle of human consciousness with a set of data that is very impressive,” says Rafael Malach, a neurobiologist who studies the human brain at the Weizmann Institute of Science in Israel and who was not involved in the work. “This is a well-designed study done in a medical setting that generated a unique dataset that is not easy to obtain,” says Itzhak Fried, a professor of neurosurgery at the Geffen School of Medicine at the University of California, Los Angeles, who was also not involved in the work but who has previously collaborated with one of the study’s authors, Florian Mormann. © 1986-2017 The Scientist

Keyword: Consciousness
Link ID: 24100 - Posted: 09.23.2017

By Neuroskeptic A new paper asks why neuroscience hasn’t had more “impact on our daily lives.” The article, Neuroscience and everyday life: facing the translation problem, comes from Dutch researchers Jolien C. Francken and Marc Slors. It’s a thought-provoking piece, but it left me feeling that the authors are expecting too much from neuroscience. I don’t think insights from neuroscience are likely to change our lives any time soon. Francken and Slors describe a disconnect between neuroscience research and everyday life, which they dub the ‘translation problem’. The root of the problem, they say, is that while neuroscience uses words drawn from everyday experience – ‘lying’, ‘love’, ‘memory’, and so on – neuroscientists rarely use these terms in the usual sense. Instead, neuroscientists will study particular aspects of the phenomena in question, using particular (often highly artificial) experimental tasks. As a result, say Francken and Slors, the neuroscience of (say) ‘love’ does not directly relate to ‘love’ as the average person would use the word: We should be cautious in interpreting the outcomes of neuroscience experiments simply as, say, results about ‘lying ’, ‘free will ’, ‘love’, or any other folk-psychological category. How then can neuroscientific findings be translated in terms that speak to our practical concerns in a nonmisleading, non-naive way? They go on to discuss the nature of the translation problem in much more detail, as well as potential solutions.

Keyword: Miscellaneous
Link ID: 24099 - Posted: 09.23.2017

By Ann Gibbons Neandertals have long been seen as the James Deans of human evolution—they grew up fast, died young, and became legends. But now, a rare skeleton of a Neandertal child suggests that our closest cousins didn’t all lead such fast lives—and that our own long childhoods aren’t unique. The find may reveal how Neandertals, like humans, had enough energy to grow bigger brains. “We like the paper because it puts the idea of ‘Neanderthal exceptionalism’ to rest,” wrote anthropologist Marcia Ponce de León and neurobiologist Christoph Zollikofer from the University of Zurich in Switzerland (who are not authors of the new study) in an email. “RIP.” Researchers have long known that modern humans take almost twice as long as chimpanzees to reach adulthood and have wondered when and why our ancestors evolved the ability to prolong childhood and delay reproduction. Our distant ancestors, such as the famous fossil Lucy and other australopithecines, matured quickly and died young like chimps. Even early members of our own genus Homo, such as the 1.6-million-year-old skeleton of an H. erectus boy, grew up faster than we do. By providing your email address, you agree to send your email address to the publication. Information provided here is subject to Science's Privacy Policy. But by the time the earliest known members of our species, H. sapiens, were alive 300,000 years ago at Jebel Irhoud in Morocco, they were taking longer to grow up. A leading theory is that big brains are so metabolically expensive that humans have to delay the age of reproduction—and, hence, have longer childhoods—so first-time mothers are older and, thus, bigger and strong enough to have the energy to feed babies with such big brains after birth when their brains are doubling in size. © 2017 American Association for the Advancement of Science

Keyword: Evolution; Development of the Brain
Link ID: 24098 - Posted: 09.22.2017

By STEPH YIN Worms and fish do it. Birds and bees do it. But do jellyfish fall asleep? It seems like a simple question, but answering it required a multistep investigation by a trio of Caltech graduate students. Their answer, published Thursday in Current Biology, is that at least one group of jellyfish called Cassiopea, or the upside-down jellyfish, does snooze. The finding is the first documented example of sleep in an animal with a diffuse nerve net, a system of neurons that are spread throughout an organism and not organized around a brain. It challenges the common notion that sleep requires a brain. It also suggests sleep could be an ancient behavior because the group that includes jellyfish branched off from the last common ancestor of most living animals early on in evolution. Working together was natural for Claire Bedbrook, Michael Abrams and Ravi Nath. The three leading co-authors of the paper are all Ph.D. candidates in biology at the California Institute of Technology and close friends. The project started with an observation by Mr. Abrams that some upside-down jellyfish in his lab would immediately slow their pulsing when the lights were turned off. Over coffee one evening, he discussed this phenomenon with Mr. Nath, who had been studying sleep in roundworms and pondering whether other “simple” animals slept. The two decided to visit Mr. Abrams’s lab in the middle of the night, to see how the jellyfish were behaving. The Cassiopea, or upside-down, jellyfish, demonstrated patterns of behavior consistent with sleep, according to an experiment conducted by Caltech graduate students. Credit Jan Easter Photography In the darkened lab, they observed a tankful of jellyfish pulsing infrequently and staying still for long periods of time — jellyfish that looked, in other words, like they were sleeping. Ms. Bedbrook started to believe they were onto something. © 2017 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 24097 - Posted: 09.22.2017

Carrie Arnold The purpose and evolutionary origins of sleep are among the biggest mysteries in neuroscience. Every complex animal, from the humblest fruit fly to the largest blue whale, sleeps — yet scientists can’t explain why any organism would leave itself vulnerable to predators, and unable to eat or mate, for a large portion of the day. Now, researchers have demonstrated for the first time that even an organism without a brain — a kind of jellyfish — shows sleep-like behaviour, suggesting that the origins of sleep are more primitive than thought. Researchers observed that the rate at which Cassiopea jellyfish pulsed their bell decreased by one-third at night, and the animals were much slower to respond to external stimuli such as food or movement during that time. When deprived of their night-time rest, the jellies were less active the next day. “Everyone we talk to has an opinion about whether or not jellyfish sleep. It really forces them to grapple with the question of what sleep is,” says Ravi Nath, the paper’s first author and a molecular geneticist at the California Institute of Technology (Caltech) in Pasadena. The study was published on 21 September in Current Biology1. “This work provides compelling evidence for how early in evolution a sleep-like state evolved,” says Dion Dickman, a neuroscientist at the University of Southern California in Los Angeles. Nath is studying sleep in the worm Caenorhabditis elegans, but whenever he presented his work at research conferences, other scientists scoffed at the idea that such a simple animal could sleep. The question got Nath thinking: how minimal can an animal’s nervous system get before the creature lacks the ability to sleep? Nath’s obsession soon infected his friends and fellow Caltech PhD students Michael Abrams and Claire Bedbrook. Abrams works on jellyfish, and he suggested that one of these creatures would be a suitable model organism, because jellies have neurons but no central nervous system. Instead, their neurons connect in a decentralized neural net. © 2017 Macmillan Publishers Limited

Keyword: Sleep; Evolution
Link ID: 24096 - Posted: 09.22.2017

James Gorman Imagine a species that lived in a world of smells and didn’t pay a lot of attention to what things look like. What would members of that species use for a mirror? Would they even want a mirror? Yes, of course, we are talking about dogs, who usually don’t seem to understand the mirrors humans use. Sometimes they ignore them. Often they bark as if the dog in the mirror were a stranger. Scientists use mirrors to find out if animals recognize themselves, to see if they have some sense of self. Chimpanzees do very well on what is called the mirror test. A chimp will notice a mark on his face and perhaps even use the mirror to aid in removing it. He might use the mirror to examine parts of his body he can’t normally see, like the inside of his mouth. Researchers have reported that dolphins, one elephant and a magpie have also passed this test. Dogs have not, and that has raised questions about whether dogs might recognize themselves if another sense were tested. Alexandra Horowitz, a psychologist at Barnard College who studies the behavior of dogs and has written several books about them, decided to give dogs a chance at showing self-recognition on their own, smelly terms. In a recent study, she concludes that they do recognize the smell of their own urine. While some researchers find the study intriguing, the scientist who first developed that mirror mark test doesn’t think the evidence supports her conclusion. Still, even the idea of a smell mirror is mind (nose?) boggling. “I had always flirted with the idea in my head that there should be an olfactory mirror,” Dr. Horowitz said, acknowledging that “it could be horrifying for humans.” © 2017 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Consciousness
Link ID: 24095 - Posted: 09.22.2017

Katherine Ellen Foley, Youyou Zhou, Christopher Groskopf One way to understand long-term trends in medical and health research is to analyze the language used in massive bodies of literature produced in the different fields. To better understand the shifting focus of sex research since the field was established, we downloaded (with permission) 4,545 articles published in the Journal of Sex Research and the Archives of Sexual Behavior from 1970 to 2017, and tracked just over 1,000 of the most-used words in these studies. You can use the tool below to explore all of these words, and see how their frequency in the literature has changed over time. Beneath it, we’ve pulled out some of the most interesting trends we noticed and investigated possible explanations for why they’ve occurred. Humans have been having sex since as long as we’ve been on the planet, but it wasn’t until recently that we really started studying it. Sexology became a serious field just after World War II, starting with the work of Alfred Kinsey, a biologist at Indiana University, and later founder of the school’s Kinsey Institute, which today studies love and sexuality. Kinsey published his first book, Sexual Behavior in the Human Male, in 1948, followed by Sexual Behavior in the Human Female in 1953. In the 1960s, the field was further advanced by the work of lab mates (and lovers) William Masters and Victoria Johnson, who published the seminal Human Sexual Response in 1966.

Keyword: Sexual Behavior
Link ID: 24094 - Posted: 09.22.2017

By Gary Stix Donald Hebb was a famed Canadian scientist who produced key findings that ranged across the field of psychology, providing insights into perception, intelligence and emotion. He is perhaps best known, though, for his theory of learning and memory, which appears as an entry in most basic texts on neuroscience. But now an alternative theory—along with accompanying experimental evidence—fundamentally challenges some central tenets of Hebb’s thinking. It provides a detailed account of how cells and the electrical and molecular signals that activate them are involved in forming memories of a series of related events. Put forward in 1949, Hebb’s theory holds that when electrical activity in one neuron—perhaps triggered by observing one’s surroundings—repeatedly induces a neighboring “target cell” to fire electrical impulses, a process of conditioning occurs and strengthens the connection between the two neurons. This is a bit like doing arm curls with a weight; after repeated lifts the arm muscle grows stronger and the barbell gets easier to hoist. At the cellular level, repeated stimulation of one neuron by another enables the target cell to respond more readily the next time it is activated. In basic textbooks, this boils down to a simple adage to describe the physiology of learning and memory: “Cells that fire together, wire together.” Every theory requires experimental evidence, and scientists have toiled for years to validate Hebb’s idea in the laboratory. Many research findings have showed that when a neuron repeatedly fires off an electrical impulse (called an “action potential”) at virtually the same time as an adjacent neuron, their connection does indeed grow more efficient. The target cell fires more easily, and the signal transmitted is stronger. This process—known as long-term potentiation (LTP)—apparently induces physiological change or “plasticity” in target cells. LTP is routinely cited as a possible explanation for how the brain learns and forms memories at the cellular level. © 2017 Scientific American,

Keyword: Learning & Memory
Link ID: 24093 - Posted: 09.21.2017