by Ben Guarino Each year between February and June, the fish gather to spawn in Mexico's Colorado River Delta. The fish, a type of croaker called the Gulf corvina, meet in water as cloudy as chocolate milk. It's a reunion for the entire species, all members of which reproduce within a dozen-mile stretch of the delta. When the time is right, a few days before the new or full moons, the male fish begin to sing. To humans, the sound is machine guns going off just below the waterline. To female fish, the rapid burr-burr-burr is a Bing Crosby croon. Make that Bing cranked up to 11. Marine biologists who recorded the sound describe the animals as the “loudest fish ever documented,” said Timothy J. Rowell, at the Scripps Institution of Oceanography in California. Rowell and Brad E. Erisman, a University of Texas at Austin fisheries scientist, spent four days in 2014 snooping on the fish with sonar and underwater microphones. The land surrounding the delta is desolate, Rowell said. Fresh water that once fed wild greenery has been diverted to faucets and hoses. But the delta is alive with the sound of fish. “When you arrive at the channels of the delta, you can hear it in the air even while the engine is running on the boat,” Rowell said. © 1996-2017 The Washington Post

Keyword: Hearing; Animal Communication
Link ID: 24443 - Posted: 12.20.2017

Scientists have found a new way to explain the hearing loss caused by cisplatin, a powerful drug used to treat many forms of cancer. Using a highly sensitive technique to measure and map cisplatin in mouse and human inner ear tissues, researchers found that forms of cisplatin build up in the inner ear. They also found a region in the inner ear that could be targeted for efforts to prevent hearing loss from cisplatin. The study is published in Nature Communications (link is external), and was supported by the National Institute on Deafness and other Communications Disorders (NIDCD), part of the National Institutes of Health. Cisplatin and similar platinum-based drugs are prescribed for an estimated 10 to 20 percent of all cancer patients. The NIH’s National Cancer Institute supported research that led to the 1965 discovery of cisplatin and continued development leading to its success as an essential weapon in the battle against cancer. The drugs cause permanent hearing loss in 40 to 80 percent of adult patients and at least half of children who receive the drug. The new findings help explain why cisplatin is so toxic to the inner ear, and why hearing loss gets worse after each treatment, can occur long after treatment, and is more severe in children than adults. “Hearing loss can have a major impact on a person’s life,” said James F. Battey, Jr., M.D., Ph.D., director of NIDCD. “Many adults with hearing loss struggle with social isolation and depression, among other conditions. Children who lose their hearing often have problems with social development and keeping up at school. Helping to preserve hearing in cancer patients who benefit from these drugs would be a major contribution to the quality of their lives.”

Keyword: Hearing
Link ID: 24442 - Posted: 12.20.2017

By Simon Makin The brain's reward system learns the actions that produce positive outcomes, such as obtaining food or sex. It then reinforces the desire to initiate those behaviors by inducing pleasure in anticipation of the relevant action. But in some circumstances this system can become oversensitized to pleasurable but harmful behaviors, producing pathological impulses like drug addiction, binge eating and compulsive gambling. But what if we could spot impulsive urges in the brain and intervene to prevent the act? This is the promise of a new study published December 18 in Proceedings of the National Academy of Sciences, led by neurosurgeon Casey Halpern, of Stanford University. His team identified a “signature” of impulsive urges in part of the brain's reward-learning circuitry, the nucleus accumbens. Delivering electrical pulses to this region on detecting this activity reduced binge-eating behavior in mice. They also observed the same signature in a human brain, suggesting the technique has potential for treating a range of conditions involving compulsive behaviors. “We've identified a brain biomarker of loss of control,” Halpern says. “If we can use that to prevent any of these potentially dangerous actions, we can help a lot of people.” Researchers used a variation on deep-brain stimulation (DBS) in their experiments, a well-established treatment to diminish the shaking present in Parkinson's disease that is also showing promise in other conditions including depression and obsessive-compulsive disorder. Exactly how DBS has beneficial effects is still being debated, but there can be side effects. When treating movement disorders, patients may experience tingling and muscle contraction, says neurosurgeon Tipu Aziz of the University of Oxford. The long-term consequences in other regions are unknown but could include seizures, or effects on cognition, he says. © 2017 Scientific American,

Keyword: Drug Abuse; Obesity
Link ID: 24441 - Posted: 12.20.2017

Esther Landhuis Picture this: While reaching for the cookie jar — or cigarette or bottle of booze or other temptation — a sudden slap denies your outstretched hand. When the urge returns, out comes another slap. Now imagine those "slaps" occurring inside the brain, protecting you in moments of weakness. In a report published Monday in the Proceedings of the National Academy of Sciences, Stanford neuroscientists say they've achieved this sort of mind-reading in binge-eating mice. They found a telltale pattern of brain activity that comes up seconds before the animals start to pig out — and delivering a quick zap to that part of the brain kept the mice from overindulging. Whether this strategy could block harmful impulses in people remains unclear. For now the path seems promising. The current study used a brain stimulation device already approved for hard-to-treat epilepsy. And based on the new findings, a clinical trial testing this off-the-shelf system for some forms of obesity could start as early as next summer, says Casey Halpern, the study's leader and an assistant professor of neurosurgery at Stanford. He thinks the approach could also work for eating disorders and a range of other addictive or potentially life-threatening urges. As a physician-researcher, Halpern specializes in deep brain stimulation (DBS), a surgical treatment in which battery-powered implants send electrical pulses to brain areas where signals go awry. © 2017 npr

Keyword: Obesity; Drug Abuse
Link ID: 24440 - Posted: 12.19.2017

/ By Carrie Arnold Jim and Ida Hall buried their daughter Jerra in a family plot at the bottom of a grassy rise. Several times a year, Jim Hall drives just over a mile from his home on North Main Street in the town of St. Louis, Michigan to Jerra’s headstone in the back corner of Oak Grove Cemetery in his 1997 Chevy pickup. In the 12 years since complications from a rare heart defect claimed the life of their brown-haired toddler, her family continues to cover her grave with stuffed animals (frogs were her favorite). Hall gently sweeps off the leaves and debris covering the childhood paraphernalia and wipes his callused hands on a pair of worn jeans, his tall frame stooped by grief. He stops and stares at the inscription: “Two years, two months, too little.” “We didn’t know what else to write,” he said. “When your daughter is born with a heart condition and doesn’t survive, you just wonder.” Jim Hall’s exposure to PBB as a child makes him valuable in the hunt for the answer to a burning scientific question: Can a father’s exposure to environmental toxins impact the health of his progeny? Jerra’s headstone sits where an umbrella of majestic oaks gives way to the dreadlocks of vines and grasses of a small wetland in the geographic center of Michigan’s Lower Peninsula, a little more than a mile from the chemical plant that once produced a toxic flame retardant called PBB, short for polybrominated biphenyl. Hall can’t help but think it may have killed his little girl. Copyright 2017 Undark

Keyword: Development of the Brain; Epigenetics
Link ID: 24439 - Posted: 12.19.2017

By Elizabeth Quigley BBC Scotland news Scientists are close to establishing what causes a smell associated with sufferers of Parkinson's disease. They hope it could lead to the first diagnostic test for the disease. The breakthrough came after Joy Milne astonished doctors with her ability to detect the disease through smell under scientific conditions. A team from Manchester has found distinctive molecules that seem to be concentrated on the skin of Parkinson's patients. One in 500 people in the UK has Parkinson's - that is 127,000 across Britain. Musky smell It can leave them struggling to walk, speak and sleep. Currently there is no definitive test for the disease, with clinicians diagnosing patients by observing symptoms. This is how the disease has been diagnosed since 1817, when James Parkinson first established it as a recognised medical condition. However, that could change because of Joy Milne from Perth, whose husband Les was told he had Parkinson's at the age of 45. About a decade before her consultant anaesthetist husband was diagnosed, Joy noticed she could detect an unusual musky smell. Joy said: "We had a very tumultuous period, when he was about 34 or 35, where I kept saying to him, 'you've not showered. You've not brushed your teeth properly'. "It was a new smell - I didn't know what it was. I kept on saying to him, and he became quite upset about it. So I just had to be quiet." The retired nurse only linked the odour to the disease after meeting people with the same distinctive smell at a Parkinson's UK support group. © 2017 BBC.

Keyword: Parkinsons; Chemical Senses (Smell & Taste)
Link ID: 24438 - Posted: 12.19.2017

By Mary Bates Whip spiders, also known as tailless whip scorpions, are actually neither spiders nor scorpions. These strange creatures belong to a separate arachnid order called Amblypygi, meaning “blunt rump,” a reference to their lack of tails. Little was known about whip spiders before the turn of this century, but a recent flurry of behavioral and neurophysiological studies has opened a window into their unique sensory world. Researchers have discovered that some of the more than 150 species engage in curious behaviors, including homing, territorial defense, cannibalism, and tender social interactions—all mediated by a pair of unusual sensory organs. Like all arachnids, whip spiders have eight legs. However, they walk on only six. The front two legs are elongated, antennae-like sensory structures called antenniform legs. These legs, three to four times longer than the walking legs, are covered with different types of sensory hairs. They constantly sweep the environment in a whiplike motion, earning whip spiders their common name. Whip spiders use their antenniform legs the way a blind person uses a cane—except that in addition to feeling their environment, whip spiders can smell, taste, and hear with their antenniform legs. All aspects of a whip spider’s life center on the use of these legs, including hunting—whip spiders are dangerous predators, if you’re a small invertebrate that shares the arachnids’ tropical and subtropical ecosystems. When Eileen Hebets, a biologist at the University of Nebraska–Lincoln, recorded the prey capture behavior of the whip spider Phrynus marginemaculatus, she observed a well-choreographed pattern. © 1986-2017 The Scientist

Keyword: Chemical Senses (Smell & Taste); Pain & Touch
Link ID: 24437 - Posted: 12.19.2017

By Sarah DeWeerdt Older men and women are more likely than young ones to have a child with autism, according to multiple studies published in the past decade. Especially regarding fathers, this effect is one of the most consistent findings in the epidemiology of autism. The link between a mother’s age and autism is more complex: Women seem to be at an increased risk both when they are much older and much younger than average, according to some studies. Nailing down why either parent’s age influences autism risk has proved difficult, however. How do we know that older men are at elevated risk of fathering a child with autism? Epidemiologists have gathered data on large numbers of families and calculated how often men of different ages have a child with autism. The first rigorous study of this type, published in 2006, drew on medical records of 132,000 Israeli adolescents. It showed that men in their 30s were 1.6 times as likely to have a child with autism as men younger than 30. Men in their 40s had a sixfold increase in risk. Since then, scientists have conducted similar analyses of data on children born in California, Denmark and Sweden, as well as of an international data set on 5.7 million children. Nearly all of this research has shown an increased prevalence of autism among the children of older fathers. At what age does the risk increase for men? No one knows. The age ranges and ages of the men differ across studies, making results hard to compare. Overall, the findings indicate that the risk increases steadily over time rather than suddenly rising after a certain age. © 1996-2017 The Washington Post

Keyword: Autism; Epigenetics
Link ID: 24436 - Posted: 12.18.2017

Angus Chen Psychedelic drugs are getting a makeover, with scientists exploring their potential in treating debilitating conditions like cluster headaches, addiction or anxiety, with promising results. That's despite the fact that very few researchers are legally allowed to study psychedelics, largely because of LSD's decades-old reputation as a counterculture drug that sparked bad trips. Back in the 1960s, LSD was touted as a tool to shed social conventions and fast-forward to enlightenment – or as LSD advocate Timothy Leary memorably said, "Turn on, tune in, drop out." He was hardly the first to feel the chemical's allure. Back in the 1930s, Swiss chemist Albert Hofmann had shelved LSD after first testing it as a treatment for heart disease. But he couldn't shake the feeling that there was something more to it. After accidentally ingesting a bit and having a mild psychedelic experience, Hofmann decided to go further. He eats 250 micrograms of LSD and, scientist that he is, starts journaling his experience. He only gets one entry down before he starts having really intense hallucinations. As he bikes home, he feels like time and space are standing still and objects around him are warping and wavering in weird shapes. In the 1930's, Albert Hofmann accidentally ingested LSD during an experiment, which led him to experience a psychedelic reaction. © 2017 npr

Keyword: Drug Abuse
Link ID: 24435 - Posted: 12.18.2017

Nicola Davis Sexual interactions between snow monkeys and sika deer could be a new behavioural tradition within a group of monkeys observed in Japan, researchers have suggested. While the first report of a male Japanese macaque, or snow monkey, and female sika deer taking to each other was revealed earlier this year, scientists say they are now confident the behaviour is sexual after scrutinising adolescent females suggestively interacting with stags at Minoo in Japan. “The monkey-deer sexual interactions reported in our paper may reflect the early stage development of a new behavioural tradition at Minoo,” said Dr Noëlle Gunst-Leca, co-author of the study from the University of Lethbridge in Canada. While sexual interactions between closely related species have been seen for all manner of animals, from various species of fish to species of baboon, such liaisons are rare, with the sexual assault of king penguins by Antarctic fur seals the only other known example between distant species. But earlier this year, a study revealed a male Japanese macaque had been filmed mounting a female Sika deer at Yakushima island in southern Japan. Gunst-Leca said it wasn’t clear quite what was going on. “They were dealing with a single anecdotal event between one individual monkey and one individual deer, and the description they provided was short, vague and out of context,” she said. “As a result, even the sexual nature of this interaction was not clearly demonstrated.” © 2017 Guardian News and Media Limited

Keyword: Sexual Behavior
Link ID: 24434 - Posted: 12.18.2017

Jon Hamilton Older brains may forget more because they lose their rhythm at night. During deep sleep, older people have less coordination between two brain waves that are important to saving new memories, a team reports in the journal Neuron. "It's like a drummer that's perhaps just one beat off the rhythm," says Matt Walker, one of the paper's authors and a professor of neuroscience and psychology at the University of California, Berkeley. "The aging brain just doesn't seem to be able to synchronize its brain waves effectively." The finding appears to answer a long-standing question about how aging can affect memory even in people who do not have Alzheimer's or some other brain disease. "This is the first paper that actually found a cellular mechanism that might be affected during aging and therefore be responsible for a lack of memory consolidation during sleep," says Julie Seibt, a lecturer in sleep and plasticity at the University of Surrey in the U.K. Seibt was not involved in the new study. To confirm the finding, though, researchers will have to show that it's possible to cause memory problems in a young brain by disrupting these rhythms, Seibt says. The study was the result of an effort to understand how the sleeping brain turns short-term memories into memories that can last a lifetime, says Walker, the author of the book Why We Sleep. "What is it about sleep that seems to perform this elegant trick of cementing new facts into the neural architecture of the brain?" To find out, Walker and a team of scientists had 20 young adults learn 120 pairs of words. "Then we put electrodes on their head and we had them sleep," he says. The electrodes let researchers monitor the electrical waves produced by the brain during deep sleep. They focused on the interaction between slow waves, which occur every second or so, and faster waves called sleep spindles, which occur more than 12 times a second. © 2017 npr

Keyword: Sleep; Learning & Memory
Link ID: 24433 - Posted: 12.18.2017

by Bethany Brookshire An astonishing number of things that scientists know about brains and behavior are based on small groups of highly educated, mostly white people between the ages of 18 and 21. In other words, those conclusions are based on college students. College students make a convenient study population when you’re a researcher at a university. It makes for a biased sample, but one that’s still useful for some types of studies. It would be easy to think that for studies of, say, how the typical brain develops, a brain is just a brain, no matter who’s skull its resting in. A biased sample shouldn’t really matter, right? Wrong. Studies heavy in rich, well-educated brains may provide a picture of brain development that’s inaccurate for the American population at large, a recent study found. The results provide a strong argument for scientists to pay more attention to who, exactly, they’re studying in their brain imaging experiments. It’s “a solid piece of evidence showing that those of us in neuroimaging need to do a better job thinking about our sample, where it’s coming from and who we can generalize our findings to,” says Christopher Monk, who studies psychology and neuroscience at the University of Michigan in Ann Arbor. The new study is an example of what happens when epidemiology experiments — studies of patterns in health and disease — crash into studies of brain imaging. “In epidemiology we think about sample composition a lot,” notes Kaja LeWinn, an epidemiologist at the University of California in San Francisco. Who is in the study, where they live and what they do is crucial to finding out how disease patterns spread and what contributes to good health. But in conversations with her colleagues in psychiatry about brain imaging, LeWinn realized they weren’t thinking very much about whose brains they were looking at. Particularly when studying healthy populations, she says, there was an idea that “a brain is a brain is a brain.” |© Society for Science & the Public 2000 - 2017. All rights reserved.

Keyword: Brain imaging; Development of the Brain
Link ID: 24432 - Posted: 12.16.2017

By Simon Makin Researchers have known for some time that female athletes experience higher rates of concussion than their male counterparts, and also often suffer harsher symptoms and take longer to recover. But why women seem more vulnerable to such injuries has long remained a puzzle. Concussion symptoms range from headache, dizziness and confusion to memory loss, noise or light sensitivity, and irritability. Most people recover quickly but some develop problems lasting a year or more. A 2010 study led by neurologist Jeffrey Bazarian of the University of Rochester found that women—especially those of child-bearing age—had worse symptoms measured three months after injury. Several explanations have been proposed including sex hormones, neck structure and cerebral blood flow, but no one really knows what is to blame. Now, however, a study led by Douglas Smith, director of the Center for Brain Injury and Repair at the University of Pennsylvania, adds a new candidate: differences in axons—the output “wires” of neurons. Smith and his colleagues discovered differences in the size and structure of male and female axons, and found the female structure was more susceptible to damage. “The findings are intriguing,” says neuropsychologist Donna Broshek of the University of Virginia, who was not involved in the study. “Many theories have been put forth, including that—because of differences in cultural socialization—women are more likely to endorse symptoms.” But the new results, published online last month, “suggest that women report more symptoms because they are...experiencing more symptoms,” Broshek says. © 2017 Scientific American,

Keyword: Sexual Behavior; Brain Injury/Concussion
Link ID: 24431 - Posted: 12.16.2017

Laura Sanders If more nerve cells mean more smarts, then dogs beat cats, paws down, a new study on carnivores shows. That harsh reality may shock some friends of felines, but scientists say the real surprises are inside the brains of less popular carnivores. Raccoon brains are packed with nerve cells, for instance, while brown bear brains are sorely lacking. By comparing the numbers of nerve cells, or neurons, among eight species of carnivores (ferret, banded mongoose, raccoon, cat, dog, hyena, lion and brown bear), researchers now have a better understanding of how different-sized brains are built. This neural accounting, described in an upcoming Frontiers in Neuroanatomy paper, may ultimately help reveal how brain features relate to intelligence. For now, the multispecies tally raises more questions than it answers, says zoologist Sarah Benson-Amram of the University of Wyoming in Laramie. “It shows us that there’s a lot more out there that we need to study to really be able to understand the evolution of brain size and how it relates to cognition,” she says. Neuroscientist Suzana Herculano-Houzel of Vanderbilt University in Nashville and colleagues gathered brains from the different species of carnivores. For each animal, the researchers whipped up batches of “brain soup,” tissue dissolved in a detergent. Using a molecule that attaches selectively to neurons in this slurry, researchers could count the number of neurons in each bit of brain real estate. |© Society for Science & the Public 2000 - 2017.

Keyword: Evolution
Link ID: 24430 - Posted: 12.16.2017

Hannah Devlin Science correspondent They are diseases that threaten more than physical health: memories, personality, and the ability to move and speak are incrementally stolen. And until this year neurodegenerative diseases, from Alzheimer’s to ALS, had been entirely unstoppable. However, a breakthrough in Huntington’s disease this week suggests this bleak picture could be about to change. The landmark trial was the first to show that the genetic defect that causes Huntington’s could be corrected, raising hopes that the drug will become the first to slow the progress of the disease – or even stop it. The Huntington’s results alone would have been remarkable enough, but they come just a month after the same experimental class of drugs were revealed to help patients with a different degenerative disease, called Spinal Muscular Atrophy (SMA). Babies with the most severe form of SMA normally never develop the strength to sit up or roll over, but after four years on the drug, some of these children are starting to stand and take their first steps with a walker. The two trials have triggered a wave of optimism that drugs built on similar principles could be used to target a wide range of deadly brain disorders, possibly even Alzheimer’s and Parkinson’s. “I don’t want to overstate this too much, but this could be a turning point,” said Prof John Hardy, a neuroscientist at University College London who was awarded the Breakthrough prize for his work on Alzheimer’s. © 2017 Guardian News and Media Limited

Keyword: Huntingtons; Movement Disorders
Link ID: 24429 - Posted: 12.16.2017

By Roni Dengler Our brains don’t rest when we sleep. Electrical waves ripple through our noggins as our neurons talk to each other. Now, researchers have shown that when these waves don’t interact properly, we can lose our long-term memory. The work may help explain why older adults are so forgetful, and it could lead to new therapies to treat memory loss. To find out how sleep contributes to memory loss in old age, Randolph Helfrich, a neuroscientist at the University of California (UC), Berkeley, and his team gave healthy 70- and 20-year-olds a memory test. Participants were trained to match 120 common, short words—for example, “bird”—with nonsense words made of combinations of random syllables, like “jubu.” Once they learned the word-nonsense word combos, the volunteers played a version of the game “memory.” They had to match the word pairs twice: once about 10 minutes after they’d mastered the task, and again a few hours after waking from a full night’s rest. While they slept, researchers recorded the electrical activity in their brains. As expected, the older adults’ ability to remember the word pairs in the morning was worse than their young counterparts’. The electrical recordings revealed one reason. Two kinds of brain waves—slow oscillations, large undulations that promote restorative sleep, and sleep spindles, transient bursts of short waves—are tell-tale marks of deep, typically dreamless, non–rapid eye movement sleep. But these waves are out of sync in older people, the researchers report today in Neuron. This out-of-step activity, they say, interrupts communication between the parts of our brains that store short- and long-term memories. In effect, Helfrich says, the prefrontal cortex where long-term memories are stored needs to tell the hippocampus—the part of the brain where all memories go first—that it’s ready to receive information; if brain waves aren’t in sync, this communication gets lost. So do the memories. © 2017 American Association for the Advancement of Science

Keyword: Learning & Memory; Alzheimers
Link ID: 24428 - Posted: 12.15.2017

By PAM BELLUCK As the first babies born with brain damage from the Zika epidemic become 2-year-olds, the most severely affected are falling further behind in their development and will require a lifetime of care, according to a study published Thursday by the Centers for Disease Control and Prevention. The study, the first to comprehensively assess some of the oldest Zika babies in Brazil, focused on 15 of the most disabled children born with abnormally small heads, a condition called microcephaly. At about 22 months old, these children had the cognitive and physical development of babies younger than 6 months. They could not sit up or chew, and they had virtually no language. “A child might be making those raspberry sounds, but they are not making even the sort of consonant sounds like ‘mama, baba, dada,’” said Dr. Georgina Peacock, an author of the study and the director of the division of human development and disability at the C.D.C.’s National Center on Birth Defects and Developmental Disabilities. It is unclear how many of the nearly 3,000 Brazilian Zika babies born with microcephaly will have outcomes as severe as the children in the study, but the experiences of doctors working in Brazil suggest it could be hundreds. “It’s heartbreaking,” the C.D.C. director, Dr. Brenda Fitzgerald, said in an interview. “We would expect that these children are going to require enormous amounts of work and require enormous amounts of care.” The new study, conducted with the Brazilian Ministry of Health and other organizations, evaluated children in Paraíba state, part of Brazil’s northeastern region, which became the epicenter of the Zika crisis. The researchers initially studied 278 babies born in Paraíba between October 2015 and the end of January 2016. Of those, 122 families agreed to participate in follow-up evaluations this year. The study released Thursday involves what were considered the most severe of those cases, Dr. Peacock said. © 2017 The New York Times Company

Keyword: Development of the Brain
Link ID: 24427 - Posted: 12.15.2017

Scientists have identified differences in a group of genes they say might help explain why some people need a lot more sleep — and others less — than most. The study, conducted using fruit fly populations bred to model natural variations in human sleep patterns, provides new clues to how genes for sleep duration are linked to a wide variety of biological processes. Researchers say a better understanding of these processes could lead to new ways to treat sleep disorders such as insomnia and narcolepsy. Led by scientists with the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, the study will be published on Dec. 14 in PLOS Genetics. “This study is an important step toward solving one of the biggest mysteries in biology: the need to sleep,” says study leader Susan Harbison, Ph.D., an investigator in the Laboratory of Systems Genetics at NHLBI. “The involvement of highly diverse biological processes in sleep duration may help explain why the purpose of sleep has been so elusive.” Scientists have known for some time that, in addition to our biological clocks, genes play a key role in sleep and that sleep patterns can vary widely. But the exact genes controlling the duration of sleep and the biological processes that are linked to these genes have remained unclear. To learn more, scientists artificially bred 13 generations of wild fruit flies to produce flies that were either long sleepers (sleeping 18 hours each day) or short sleepers (sleeping three hours each day). The scientists then compared genetic data between the long and short sleepers and identified 126 differences among 80 genes that appear to be associated with sleep duration. They found that these genetic differences were tied to several important developmental and cell signaling pathways. Some of the genes identified have known functions in brain development, as well as roles in learning and memory, the researchers said.

Keyword: Sleep; Genes & Behavior
Link ID: 24426 - Posted: 12.15.2017

By NICHOLAS BAKALAR A new study suggests that vigorous physical activity may increase the risk for vision loss, a finding that has surprised and puzzled researchers. Using questionnaires, Korean researchers evaluated physical activity among 211,960 men and women ages 45 to 79 in 2002 and 2003. Then they tracked diagnoses of age-related macular degeneration, from 2009 to 2013. Macular degeneration, the progressive deterioration of the central area of the retina, is the leading cause of vision loss in the elderly. They found that exercising vigorously five or more days a week was associated with a 54 percent increased risk of macular degeneration in men. They did not find the association in women. The study, in JAMA Ophthalmology, controlled for more than 40 variables, including age, medical history, body mass index, prescription drug use and others. The authors write that excessive exercise might affect the eye’s choroid, a sensitive vascular membrane that surrounds the retina, but “epidemiologic studies cannot provide any evidence for the mechanism or pathology.” The authors acknowledge that the study depends partly on self-reports, which are not always reliable, and that it is an observational study that does not prove cause and effect. © 2017 The New York Times Company

Keyword: Vision
Link ID: 24425 - Posted: 12.15.2017

Amy Maxmen A study of some of the world’s most obscure marine life suggests that the central nervous system evolved independently several times — not just once, as previously thought1. The invertebrates in question belong to families scattered throughout the animal evolutionary tree, and they display a diversity of central nerve cord architectures. The creatures also activate genes involved with nervous system development in other, well-studied animals — but they often do it in non-neural ways, report the authors of the paper, published on 13 December in Nature. “This puts a stake in the heart of the idea of an ancestor with a central nerve cord,” says Greg Wray, an evolutionary developmental biologist at Duke University in Durham, North Carolina. “That opens up a lot of questions we don’t have answers to — like, if central nerve cords evolved independently in different lineages, why do they have so many similarities?” In 1875, German zoologist Anton Dohrn noted anatomical similarities between the central nerve cord that runs length-wise through the bodies of annelids — a group of invertebrates that includes earthworms — and the nerve cord in the spine of vertebrates. He proposed that the groups’ ancient common ancestor had a nerve cord that ran along its belly-side, as seen in annelids. He also suggested that this cord flipped to the back of the body in a more recent animal that gave rise to all vertebrates. © 2017 Macmillan Publishers Limited,

Keyword: Evolution; Development of the Brain
Link ID: 24424 - Posted: 12.14.2017