By TAMAR LEWIN Nearly 40 years after the world was jolted by the birth of the first test-tube baby, a new revolution in reproductive technology is on the horizon — and it promises to be far more controversial than in vitro fertilization ever was. Within a decade or two, researchers say, scientists will likely be able to create a baby from human skin cells that have been coaxed to grow into eggs and sperm and used to create embryos to implant in a womb. The process, in vitro gametogenesis, or I.V.G., so far has been used only in mice. But stem cell biologists say it is only a matter of time before it could be used in human reproduction — opening up mind-boggling possibilities. With I.V.G., two men could have a baby that was biologically related to both of them, by using skin cells from one to make an egg that would be fertilized by sperm from the other. Women with fertility problems could have eggs made from their skin cells, rather than go through the lengthy and expensive process of stimulating their ovaries to retrieve their eggs. “It gives me an unsettled feeling because we don’t know what this could lead to,” said Paul Knoepfler, a stem cell researcher at the University of California, Davis. “You can imagine one man providing both the eggs and the sperm, almost like cloning himself. You can imagine that eggs becoming so easily available would lead to designer babies.” © 2017 The New York Times Company

Keyword: Stem Cells; Development of the Brain
Link ID: 23622 - Posted: 05.17.2017

Nicola Davis Humans can determine a dog’s mood by the sound of its growl, scientists have found, with women showing greater ability than men. While previous studies have found that humans can unpick the context of barks, the latest study investigated whether the same was true of canine grumbles, with some previous research suggesting humans struggle to differentiate between playful and aggressive vocalisations. “It is an important thing that humans are capable [of recognising] the emotional state of another species just based on the vocal characteristics,” said Tamás Faragó, first author of the study from Eötvös Loránd University in Hungary. To tackle the conundrum, Faragó and colleagues used previously captured recordings of 18 dogs growling in three contexts: guarding food from other dogs, playing tug-of-war with humans, and being threatened by the approach of a stranger. The researchers monitored several features, including the length of each growl and its frequency. Two sets of the recordings, which included two growls from each context, were played to 40 adults. Each participant was asked to record their impression of the first set of growls on a sliding scale, rating their perception of the dog for five emotions: fear, aggression, despair, happiness and playfulness. © 2017 Guardian News and Media Limited

Keyword: Animal Communication; Sexual Behavior
Link ID: 23621 - Posted: 05.17.2017

By Sandrine Ceurstemont Hear them roar. Lionfish have been recorded making sounds for the first time. Decoding these sounds could give us an insight into secret lives of this voracious invasive species – and help us keep tabs on its spread. Many fish produce sounds to communicate with each other as low-pitched noises travel far underwater. “It’s a dominant mode of communication,” says Alex Bogdanoff at North Carolina State University. Bogdanoff and his team decided to investigate the lionfish’s ability to produce sound after hearing reports from several divers that they make noises. This invasive species has been spreading through the Caribbean and east coast of the US. They often devour several organisms at a time, which is drastically reducing some native fish populations and altering ecosystems. The team recorded the underwater soundscape in an outdoor tank for five days, at first with a single lionfish and then with a group of five individuals. Occasionally, they stirred up the water with a net to see whether stress caused the fish to make different sounds. The team found that the fish often produced a rhythmic sound similar to a heartbeat and to calls made by other fish. But they also produced another noise made up of a much quicker series of beats (listen to the audio file, below). “It sounds like the rapid beating of a drum,” says Bogdanoff. Lionfish seemed to alter their calls when they were agitated, producing quicker and louder pulses. In follow-up experiments, the team found that they made sounds throughout the day, but were more vocal in the morning and evening. Sounds are likely to vary between individuals as well. Bogdanoff and his team are now working on identifying these differences. They already have evidence that body size affects the noises that lionfish make. Males and females are likely to make different calls, so that they can find one another and reproduce. © Copyright New Scientist Ltd.

Keyword: ADHD
Link ID: 23620 - Posted: 05.17.2017

By ROXANNE KHAMSI What lengths will a dog go to for a bite of sausage? Last November, scientists at the University of Cambridge in Britain persuaded several dozen pet owners to bring their Labrador retrievers to its veterinary school for a true test of will. Inside a mostly empty white room, a research associate let each dog sniff a hot dog before demonstratively placing it inside a small plastic hamster cage on the floor and sealing it shut with black duct tape. Some of the Labs showed only passing interest in the trapped sausage and spent more time exploring the rest of the room. But others stayed laser-focused on the treat. One in particular, a black Labrador named Ash, went into a tizzy, banging the cage around and not giving up until he pried the tape loose with his teeth and ate the hot dog. As it turns out, Ash has more than just determination and a precise tooth grip. He also has a gene mutation linked to obesity. Ash is not overweight, perhaps because his owner keeps him on a rigid diet. But Eleanor Raffan, the researcher who designed the study, suspects his underlying gene mutation and his food-induced frenzy in the experiment are linked. She hasn’t yet analyzed all the data from this latest study, but it has become a mission of hers to understand what makes some canines so voracious. Raffan’s curiosity about this traces back 15 years, to when she became a veterinary surgeon and saw firsthand that certain breeds are more likely than others to put on extra weight. Shortly afterward, when scientists published the first complete dog genome, Raffan decided she wanted to search for DNA mutations that might contribute to heaviness. She got a doctorate in genetics and in 2013 began the GOdogs Project — short for the genetics of obesity in dogs — at Cambridge. She notes that because of the way people have bred dogs, there’s a small gene pool within each breed, making the animals simpler to study: “The way the jiggery-pokery of genetics works means that it’s remarkably easy to get to map the sites where disease-​causing genes are in dogs,” Raffan says. © 2017 The New York Times Company

Keyword: Obesity; Genes & Behavior
Link ID: 23619 - Posted: 05.16.2017

A healthy teenager in the US state of South Carolina died from drinking several highly-caffeinated drinks too quickly, a coroner has ruled. Davis Allen Cripe collapsed at a high school in April after drinking a McDonalds latte, a large Mountain Dew soft drink and an energy drink in just under two hours, Gary Watts said. The 16-year-old died from a "caffeine-induced cardiac event causing a probable arrhythmia". He had no pre-existing heart condition. The teenager weighed 90kg (200 lbs) but would not have been considered morbidly obese, Mr Watts said. "This is not a caffeine overdose," Mr Watts told Reuters news agency. "We're not saying that it was the total amount of caffeine in the system, it was just the way that it was ingested over that short period of time, and the chugging of the energy drink at the end was what the issue was with the cardiac arrhythmia." Caffeine would probably not have been seen as a factor in the teenager's death if witnesses had not been able to tell officials what he had been drinking before his death, the Richland County coroner said. The main witness could not say which brand of energy drink Davis drank but said it was from a container the size of a large soft drink. "We're not trying to speak out totally against caffeine," Mr Watts said. "We believe people need to pay attention to their caffeine intake and how they do it, just as they do with alcohol or cigarettes." The American Academy of Paediatrics (AAP) has warned against children and teenagers consuming energy drinks, saying their ingredients have not been tested on children and "no-one can ensure they are safe". It says they have side-effects including irregular heartbeats and blood pressure changes. © 2017 BBC.

Keyword: Drug Abuse
Link ID: 23618 - Posted: 05.16.2017

Aimee Cunningham For black adults, moving out of a racially segregated neighborhood is linked to a drop in blood pressure, according to a new study. The finding adds to growing evidence of an association between a lack of resources in many predominately black neighborhoods and adverse health conditions among their residents, such as diabetes and obesity. Systolic blood pressure — the pressure in blood vessels when the heart beats — of black adults who left their highly segregated communities decreased just over 1 millimeter of mercury on average, researchers report online May 15 in JAMA Internal Medicine. This decline, though small, could reduce the overall incidence of heart failure and coronary heart disease. “It’s the social conditions, not the segregation itself, that’s driving the relationship between segregation and blood pressure,” says Thomas LaVeist, a medical sociologist at George Washington University in Washington, D.C., who was not involved with the study. “Maybe hypertension is not so much a matter of being genetically predisposed.” That’s important, LaVeist adds, because it means that racial health disparity “can be fixed. It’s not necessarily contained in our DNA; it’s contained in the social DNA.” Racial segregation can impact a neighborhood’s school quality, employment opportunities or even whether there is a full-service grocery store nearby. Social policies that improve residents’ access to education, employment and fresh foods can “have spillover effects in health,” says Kiarri Kershaw, an epidemiologist at Northwestern University Feinberg School of Medicine in Chicago. © Society for Science & the Public 2000 - 2017.

Keyword: Stress
Link ID: 23617 - Posted: 05.16.2017

Katherine Hobson American Indian and Alaska Native families are much more likely to have an infant die suddenly and unexpectedly, and that risk has remained higher than in other ethnic groups since public health efforts were launched to prevent sudden infant death syndrome in the 1990s. African-American babies also face a higher risk, a study finds. American Indians and Alaska Natives had a rate of 177.6 sudden unexplained infant deaths per 100,000 live births in 2013 (down from 237.5 per 100,000 in 1995) compared with 172.4 for non-Hispanic blacks (down from 203), 84.5 for non-Hispanic whites (down from 93), 49.3 for Hispanics (down from 62.7) and 28.3 for Asians and Pacific Islanders (down from 59.3). The declines were statistically significant only among non-Hispanic blacks, Hispanics and Asians/Pacific Islanders. "There are still significant gaps and disparities between races and ethnicities," says Lori Feldman-Winter, a professor of pediatrics at Cooper University Health Care in Camden, N.J., who wasn't involved with this study but was a co-author of the most recent sleep guidelines from the American Academy of Pediatrics, released in the fall. Overall rates of sudden unexpected infant death, which includes sudden infant death syndrome as well as accidental suffocation or strangulation in bed and other unexplained deaths, declined sharply in the five or so years after a national campaign was launched in 1994 to encourage caregivers to put babies to sleep on their backs. But the rates have not declined since 2000. Researchers at the Centers for Disease Control and Prevention wanted to know whether those changes were uniform across racial and ethnic groups. © 2017 npr

Keyword: Development of the Brain; Sleep
Link ID: 23616 - Posted: 05.16.2017

By BENEDICT CAREY MONTREAL — The driving instructor wiped his brow with a handkerchief, and not just because of the heat. His student — a grown woman, squinting over the dashboard — was ramming the curb in an effort to parallel park. “We reached an agreement, right then and there: He let me pass the test, and I promised never to drive,” Brenda Milner said, smiling to herself at the decades-old memory. “You see, my spatial skills aren’t so good. That’s primarily a right-brain function.” Dr. Milner, a professor of psychology in the department of neurology and neurosurgery at McGill University in Montreal, is best known for discovering the seat of memory in the brain, the foundational finding of cognitive neuroscience. But she also has a knack for picking up on subtle quirks of human behavior and linking them to brain function — in the same way she had her own, during the driving test. At 98, Dr. Milner is not letting up in a nearly 70-year career to clarify the function of many brain regions — frontal lobes, and temporal; vision centers and tactile; the left hemisphere and the right — usually by painstakingly testing people with brain lesions, often from surgery. Her prominence long ago transcended gender, and she is impatient with those who expect her to be a social activist. It’s science first with Dr. Milner, say close colleagues, in her lab and her life. Perched recently on a chair in her small office, resplendent in a black satin dress and gold floral pin and banked by moldering towers of old files, she volleyed questions rather than answering them. “People think because I’m 98 years old I must be emerita,” she said. “Well, not at all. I’m still nosy, you know, curious.” Dr. Milner continues working, because she sees no reason not to. Neither McGill nor the affiliated Montreal Neurological Institute and Hospital has asked her to step aside. She has funding: In 2014 she won three prominent achievement awards, which came with money for research. She has a project: a continuing study to investigate how the healthy brain’s intellectual left hemisphere coordinates with its more aesthetic right one in thinking and memory. © 2017 The New York Times Company

Keyword: Learning & Memory
Link ID: 23615 - Posted: 05.16.2017

By Hannah Furfaro, Children whose fathers are highly intelligent are at a 31 percent higher risk of autism than those whose fathers are of average intelligence, according to unpublished results presented today at the 2017 International Meeting for Autism Research in San Francisco, California. The work supports observations that date back to the 1940s, when Leo Kanner and Hans Asperger noted in separate reports that the fathers of children with autism tended to be highly intelligent and in several cases worked in technical fields. A 2012 study also showed that children from regions in the Netherlands where high-tech jobs are prevalent are more likely to have autism than those who live in other regions. In the new study, lead investigator Renee Gardner, assistant professor at Karolinska Institutet in Stockholm, set out to investigate whether the historical lore has validity. She and her colleagues matched medical records for 309,803 children whose fathers were conscripted into the Swedish military with their father’s scores on the technical portion of the Swedish intelligence quotient (IQ) test. They found a one-third higher risk of autism in children whose fathers’ IQ scores are 111 or higher than in those whose fathers’ scores cluster around 100. The researchers controlled for possible confounding factors such as families’ socioeconomic status and parental age, education level and history of inpatient psychiatric treatment. IQ indicators: They found the opposite relationship between a father’s IQ and his child’s chances of having intellectual disability or attention deficit hyperactivity disorder (ADHD). In particular, children of men with an IQ of 75 or below had a four-and-a-half times higher risk of intellectual disability. The chance of ADHD was 65 percent higher than average for children whose fathers had an IQ in that low range. © 2017 Scientific American

Keyword: Autism; Intelligence
Link ID: 23614 - Posted: 05.15.2017

Michelle Trudeau Bears do it; bats do it. So do guinea pigs, dogs and humans. They all yawn. It's a common animal behavior, but one that is something of a mystery. There's still no consensus on the purpose of a yawn, says Robert Provine, professor of psychology and neuroscience at the University of Maryland, Baltimore County. Provine has studied what he calls "yawn science" since the early 1980s, and he's published dozens of research articles on it. He says the simple yawn is not so simple. "Yawning may have the dubious distinction of being the least understood common human behavior," Provine says. There are many causes for yawning. Boredom, sleepiness, hunger, anxiety and stress — all cause changes in brain chemistry, which can trigger a spontaneous yawn. But it's not clear what the yawn accomplishes. One possibility is the yawn perks you up by increasing heart rate, blood pressure and respiratory function. "[Yawning] stirs up our physiology and it plays an important role in shifting from one state to another," Provine says. When violinists get ready to go on stage to play a concerto, they often yawn, says Provine. So do Olympians right before a competition, or paratroopers getting ready to do their first jump. One study found that yawning has a similar impact on the brain as a dose of caffeine. But not all yawn researchers agree with this theory. © 2017 npr

Keyword: Emotions
Link ID: 23613 - Posted: 05.15.2017

By Susana Martinez-Conde There is something deeply disconcerting about mirrors. The myriad reflecting surfaces that surround us in our everyday lives help us conduct many necessary tasks, such as applying makeup, shaving, or driving a car. But despite our constant use of mirrors, our nervous systems remain surprisingly ill-equipped to grasp the mechanics of refraction and reflection. Some magic tricks take advantage of such perceptual limitations, and are the origin of phrases such as “it’s all smoke and mirrors,” or “it’s all done with mirrors.” Kokichi Sugihara, a mathematical engineer at Meiji University in Japan, has exploited our poor understanding of mirrors to create new and spectacular varieties of perceptual magic. Our May/June Illusions column features mirror-based illusions by Sugihara and others. How can you use a mirror to vanish half an object? To make your own half-disappearing hexagon, follow the diagram above (you can print it from this template). Part A is the upper half of the object, which you will need to fold along the two edges, forming 120-degree angles. Part B, or the lower half of the object, is a flat structure and should not be folded. Glue both parts together matching the “a” and “b” letters. For the strongest effect, tilt the mirror slightly downward. © 2017 Scientific American

Keyword: Vision
Link ID: 23612 - Posted: 05.15.2017

By STEPH YIN In most mammals, us included, biological sex is determined by a lottery between two letters: X and Y, the sex chromosomes. Inherit one X each from mom and dad, and develop ovaries, a womb and a vagina. Inherit an X from mom and a Y from dad, and develop testes and a penis. But there are rare, mysterious exceptions. A small number of rodents have no Y chromosomes, yet are born as either females or males, not hermaphrodites. Now, scientists may be one step closer to figuring out how sex determination works in one of these rodents. In a study published in Science Advances on Friday, Japanese scientists suggested that cells of the endangered Amami spiny rat, from Japan, are sexually flexible and capable of adapting to either ovaries or testes. When the researchers injected stem cells derived from a female rat into male embryos of laboratory mice, the cells developed into and survived as sperm precursors in adult males. The result was surprising since scientists have never been able to generate mature sperm from female stem cells, largely because sperm production normally requires the Y chromosome. Found only in the subtropical forests of an island in Japan called Amami Oshima, Amami spiny rats are threatened by habitat destruction, competition with black rats not native to the island and predation by mongooses and feral cats and dogs. Their range has been reduced to less than 300 square miles, an area smaller than New York City. Both female and male Amami spiny rats have only one X chromosome, an arrangement only known to occur in a handful of rodents among mammals. Arata Honda, associate professor at the University of Miyazaki and the lead author of the paper, said in an email that he was partly motivated to study Amami spiny rats in the hope that learning about them might reduce their risk of extinction. © 2017 The New York Times Company

Keyword: Sexual Behavior
Link ID: 23611 - Posted: 05.13.2017

By Helen Thomson People in a minimally conscious state have been “woken” for a whole week after a brief period of brain stimulation. The breakthrough suggests we may be on the verge of creating a device that can be used at home to help people with disorders of consciousness communicate with friends and family. People with severe brain trauma can fall into a coma. If they begin to show signs of arousal but not awareness, they are said to be in a vegetative state. If they then show fluctuating signs of awareness but cannot communicate, they are described as being minimally consciousness. In 2014, Steven Laureys at the University of Liège in Belgium and his colleagues discovered that 13 people with minimal consciousness and two people in a vegetative state could temporarily show new signs of awareness when given mild electrical stimulation. The people in the trial received transcranial direct current stimulation (tDCS), which uses low-level electrical stimulation to make neurons more or less likely to fire. This was applied once over an area of the brain called the prefrontal cortex, which is involved in “higher” cognitive functions such as consciousness. Soon after, they showed signs of consciousness, including moving their hands or following instructions using their eyes. Two people were even able to answer questions for 2 hours by moving their body, before drifting back into their previous state. © Copyright New Scientist Ltd.

Keyword: Consciousness
Link ID: 23610 - Posted: 05.13.2017

By Reuters People with attention-deficit/hyperactivity disorder are at increased risk of motor-vehicle accidents, but it is significantly reduced when they are taking ADHD medication, a 10-year study finds. The researchers estimate that 1 in 5 of the accidents among more than 2 million people with ADHD during the study period could have been avoided if these individuals had been receiving medication the entire time. “The patients should be aware of the potential risk of [crashes], and seek specific treatment advice from their doctors if they experience difficulties in driving from their condition,” said lead author Zheng Chang, of the Karolinska Institute in Stockholm. Chang said that motor-vehicle crashes kill more than 1.25 million people around the world each year. ADHD is a common disorder with symptoms that include poor sustained attention, impaired impulse control and hyperactivity, he added. Past studies have found that people with ADHD are at an increased risk for crashes and that medication may reduce symptoms and ultimately improve driving skills. To examine the risk of crashes with ADHD and how it is influenced by medication, the researchers analyzed U.S. commercial health insurance claims between 2005 and 2014. They identified 2,319,450 adults with an ADHD diagnosis, half of whom were older than 33. About 1.9 million of them received at least one prescription to treat their ADHD during the study period. © 1996-2017 The Washington Post

Keyword: ADHD; Attention
Link ID: 23609 - Posted: 05.13.2017

by Laura Sanders One of the most pressing and perplexing questions parents have to answer is what to do about screen time for little ones. Even scientists and doctors are stumped. That’s because no one knows how digital media such as smartphones, iPads and other screens affect children. The American Academy of Pediatrics recently put out guidelines, but that advice was based on a frustratingly slim body of scientific evidence, as I’ve covered. Scientists are just scratching the surface of how screen time might influence growing bodies and minds. Two recent studies point out how hard these answers are to get. But the studies also hint that the answers might be important. In the first study, Julia Ma at the University of Toronto and colleagues found that, in children younger than 2, the more time spent with a handheld screen, such as a smartphone or tablet, the more likely the child was to show signs of a speech delay. Ma presented the work May 6 at the 2017 Pediatric Academic Societies Meeting in San Francisco. The team used information gleaned from nearly 900 children’s 18-month checkups. Parents answered a questionnaire about their child’s mobile media use and then filled out a checklist designed to identify heightened risk of speech problems. This checklist is a screening tool that picks up potential signs of trouble; it doesn’t offer a diagnosis of a language delay, points out study coauthor Catherine Birken, a pediatrician at The Hospital for Sick Children in Toronto. Going into the study, the researchers didn’t have expectations about how many of these toddlers were using handheld screens. “We had very little clues, because there is almost no literature on the topic,” Birken says. “There’s just really not a lot there.” |© Society for Science & the Public 2000 - 2017

Keyword: Development of the Brain; Sleep
Link ID: 23608 - Posted: 05.13.2017

By Andy Coghlan Combining multiple tests could help doctors distinguish between two leading causes of cognitive decline at an earlier stage. Being able to separate the earliest signs of Alzheimer’s from another degenerative brain condition called dementia with Lewy bodies (DLB) could be crucial to finding treatments for both kinds of dementia. When someone starts to exhibit mild cognitive impairments, it is often difficult to tell whether these might be the earliest signs of Alzheimer’s or DLB, or just normal age-related declines in cognition. Yet this distinction is vital: so far, despite billions of dollars spent on research, progress towards drugs that stabilise or cure dementia has stalled. Many blame the failure on treating people too late and argue that the same drugs might work better if given a decade or two before symptoms fully develop. Now, Dilman Sadiq at University College London and her colleagues have attempted to rectify this problem by analysing clinical histories, the results of cognitive tests and psychiatric interviews with 429 people originally diagnosed with mild cognitive impairment, who were monitored for up to 14 years. Each person was diagnosed at one UK hospital between 1994 and 2015. Of this group, 107 progressed to Alzheimer’s, 21 to DLB and 164 remained stable with mild cognitive impairment. The rest developed a mixture of other conditions. Sadiq’s team used their findings to identify a variety of tests and symptom profiles that appear to predict which condition a person might get at the earliest stage of the disease. © Copyright New Scientist Ltd.

Keyword: Alzheimers
Link ID: 23607 - Posted: 05.13.2017

By FERRIS JABR Con Slobodchikoff and I approached the mountain meadow slowly, obliquely, softening our footfalls and conversing in whispers. It didn’t make much difference. Once we were within 50 feet of the clearing’s edge, the alarm sounded: short, shrill notes in rapid sequence, like rounds of sonic bullets. We had just trespassed on a prairie-dog colony. A North American analogue to Africa’s meerkat, the prairie dog is trepidation incarnate. It lives in subterranean societies of neighboring burrows, surfacing to forage during the day and rarely venturing more than a few hundred feet from the center of town. The moment it detects a hawk, coyote, human or any other threat, it cries out to alert the cohort and takes appropriate evasive action. A prairie dog’s voice has about as much acoustic appeal as a chew toy. French explorers called the rodents petits chiens because they thought they sounded like incessantly yippy versions of their pets back home. On this searing summer morning, Slobodchikoff had taken us to a tract of well-trodden wilderness on the grounds of the Museum of Northern Arizona in Flagstaff. Distressed squeaks flew from the grass, but the vegetation itself remained still; most of the prairie dogs had retreated underground. We continued along a dirt path bisecting the meadow, startling a prairie dog that was peering out of a burrow to our immediate right. It chirped at us a few times, then stared silently. “Hello,” Slobodchikoff said, stooping a bit. A stout bald man with a scraggly white beard and wine-dark lips, Slobodchikoff speaks with a gentler and more lilting voice than you might expect. “Hi, guy. What do you think? Are we worth calling about? Hmm?” Slobodchikoff, an emeritus professor of biology at Northern Arizona University, has been analyzing the sounds of prairie dogs for more than 30 years. Not long after he started, he learned that prairie dogs had distinct alarm calls for different predators. Around the same time, separate researchers found that a few other species had similar vocabularies of danger. What Slobodchikoff claimed to discover in the following decades, however, was extraordinary: Beyond identifying the type of predator, prairie-dog calls also specified its size, shape, color and speed; the animals could even combine the structural elements of their calls in novel ways to describe something they had never seen before. No scientist had ever put forward such a thorough guide to the native tongue of a wild species or discovered one so intricate. Prairie-dog communication is so complex, Slobodchikoff says — so expressive and rich in information — that it constitutes nothing less than language.

Keyword: Language; Evolution
Link ID: 23606 - Posted: 05.12.2017

Amy Maxmen Cells that prune connections between neurons in babies’ brains as they grow are thought to have a role in autism spectrum disorder. Now, a study suggests that the number and behaviour of these cells — called microglia — vary in boys and girls, a finding that could help to explain why many more boys are diagnosed with autism and related disorders. Donna Werling, a neurogeneticist at the University of California, San Francisco, and her colleagues found that genes associated with microglia are more active in male brains than in female brains in the months before birth. “This suggests there is something fundamentally different about male and female brain development,” she says. The research, to be presented on 13 May at the International Meeting for Autism Research in San Francisco, California, is still preliminary. Very little is known about how microglial trimming behaviour affects brain development. But the study by Werling’s team “is the kind of work that makes you say ‘Wow, this is really interesting, and we should take it seriously’”, says Kevin Pelphrey, a neuroscientist at Yale School of Medicine in New Haven, Connecticut. There are two to five times many males with autism as females. Although the disorder — whose cause remains elusive — is widely acknowledged to be underdiagnosed in girls, psychiatrists agree that there is a significant disparity between the numbers of male and female cases. It suggests that biological differences between the sexes are involved. © 2017 Macmillan Publishers Limited,

Keyword: Autism; Glia
Link ID: 23605 - Posted: 05.12.2017

By Lindzi Wessel You’ve probably heard that your sense of smell isn’t that great. After all, compared with a dog or even a mouse, the human olfactory system doesn’t take up that much space. And when was the last time you went sniffing the ground alongside your canine companion? But now, in a new review published today in Science, neuroscientist John McGann of Rutgers University in New Brunswick, New Jersey, argues that the myth of the nonessential nose is a huge mistake—one that has led scientists to neglect research in a critical and mysterious part of our minds. Science checked in with McGann to learn more about why he thinks our noses know more than we realize. Q: Many of us assume our sense of smell is terrible, especially compared with other animals. Where did this idea come from? A: I traced part of this history back to 19th century [anatomist and] anthropologist Paul Broca, who was interested in comparing brains across lots of different animals. Compared to the olfactory bulbs [the first stop for smell signals in the brain], the rest of the human brain is very large. So if you look at whole brains, the bulbs look like these tiny afterthoughts; if you look at a mouse or a rat, the olfactory bulb seems quite big. You can almost forgive Broca for thinking that they didn't matter because they look so small comparatively. Broca believed that a key part of having free will was not being forced to do things by odors. And he thought of smell as this almost dirty, animalistic thing that compelled behaviors—it compelled animals to have sex with each other and things like that. So he put humans in the nonsmeller category—not because they couldn't smell, but because we had free will and could decide how to respond to smells. The idea also got picked up by Sigmund Freud, who then thought of smell as an animalistic thing that had to be left behind as a person grew into a rational adult. So you had in psychology, philosophy, and anthropology all these different pathways leading to presumption that humans didn't have a good sense of smell. © 2017 American Association for the Advancement of Scienc

Keyword: Chemical Senses (Smell & Taste)
Link ID: 23604 - Posted: 05.12.2017

By GINA KOLATA Researchers have traced the cause of a baffling brain disorder to a surprising source: a particular type of bacteria living in the gut. Scientists increasingly suspect that the body’s vast community of bacteria — the microbiome — may play a role in the development of a wide variety of diseases, from obesity to perhaps even autism. The new study, published on Wednesday in Nature, is among the first to suggest convincingly that these bacteria may initiate disease in seemingly unrelated organs, and in completely unexpected ways. Researchers “need to be thinking more broadly about the indirect role of the microbiome” in influencing even diseases that have no obvious link to the gut, said Dr. David Relman, professor of microbiology and immunology at Stanford. The researchers studied hereditary cerebral cavernous malformations — blood-filled bubbles that protrude from veins in the brain and can leak blood or burst at any time. The findings do not point to a cure, but they do suggest a way to prevent these brain defects in children who inherit a mutated gene that can cause them. Researchers warned, though, that it is too soon to say whether the potential treatment — antibiotics, followed by a fecal transplant — will work. “Caution, caution, caution,” urged Dr. Mark Ginsberg, a professor of medicine at the University of California, San Diego, who was not involved in the new study. Still, he added, “The findings are very convincing.” When Dr. Mark Kahn, professor of cardiovascular medicine at the University of Pennsylvania’s Perelman School of Medicine, began this work, the microbiome was the last thing on his mind. © 2017 The New York Times Company

Keyword: Stroke; Epilepsy
Link ID: 23603 - Posted: 05.11.2017