By Lise Eliot As efforts to improve diversity in science, technology, engineering and maths accelerate, so the voices of those who question those efforts seem to get louder. They say the STEM gender gap has its roots in innate biology, that men are inherently better at or more interested in these subjects. One of their favourite supporting arguments is that differences in male and female brains are clearly influenced by prenatal testosterone. Is there any truth in this claim? As a biologist, I appreciate that genes and hormones are important in brain and behavioural development. But my research over the past 20 years indicates that the differences between boys’ and girls’ brains are subtle, and that testosterone isn’t a key determinant of interest in or aptitude for STEM subjects. First, in spite of decades of MRI studies, there is little evidence that boys’ higher prenatal exposure to testosterone affects their brain structure or function. Most recently, the two largest studies of the brains of newborns found no difference between boys’ and girls’ functional brain networks and that prenatal testosterone exposure had a surprisingly weak effect on specific neural structures. Even the most clear-cut gender difference in infant behaviour – verbal ability, which develops more slowly in boys – hasn’t been linked to prenatal testosterone. Of course, male and female brains are different, but not in the way the diversity critics claim. At birth, boys’ brains are 6 per cent larger on average than those of girls, but boys’ birthweight is also typically about 7 per cent heavier. This difference in brain size has long been known to parallel sex differences in height and weight across the lifespan. Every other organ, such as the heart and kidneys, is also some 15 per cent larger in males. © Copyright New Scientist Ltd.

Keyword: Sexual Behavior
Link ID: 24172 - Posted: 10.11.2017

By Toni Clarke, (Reuters) - Spark Therapeutics Inc’s experimental gene therapy for a rare inherited form of blindness is effective, though it is unclear whether the benefit lasts over time, according to a preliminary review by the U.S. Food and Drug Administration. The therapy, Luxturna, or voretigene neparvovec, would be the first-ever gene therapy for any inherited disease to be approved in the United States. The FDA’s review, posted on Tuesday on the agency’s website, comes two days ahead of a meeting of outside advisers who will discuss the treatment and recommend whether it should be approved. Advertisement Michael Yee, an analyst at Jefferies, said the FDA documents “look fairly benign and as expected,” and said he expects the advisory panel is likely to vote in favor of approval. The FDA noted there is no available long-term data to show whether the effectiveness of the therapy is maintained after a year, so the clinical benefit beyond that “is unclear.” Inherited retinal diseases are a group of rare conditions caused by mutations in one or more than 220 different genes, including one known as RPE65, which tells cells how to produce a crucial enzyme needed for normal vision. Spark studied Luxturna in people with one of these conditions, Leber congenital aumaurosis, whose disease was mediated by defects in the RPE65 gene. Clinical trial results showed 93 percent of participants experienced some improvement in their functional vision as measured by their ability to navigate obstacles in poor light. © 2017 Scientific American,

Keyword: Vision
Link ID: 24171 - Posted: 10.11.2017

By Josh Gabbatiss Some female dolphins have evolved a secret weapon in their sexual arms race with males: vaginas that protect them from fertilisation by unwelcome partners. Penises come in a wide variety of shapes and sizes, especially in dolphins and other cetaceans. That seems to imply a similar diversity in vaginas, but Dara Orbach of Dalhousie University, Canada, says there is “a huge lag” in our understanding of female genitalia. That is partly because it is tricky to visualise vaginal structure. To overcome this problem, Orbach has created silicone moulds of cetaceans’ vaginas, revealing complex folds and spirals. “There’s this unparalleled level of vaginal diversity that we had no idea existed before,” Orbach says. Similarly complex vaginal structures are found in several species of duck. Orbach’s collaborator Patricia Brennan of Mount Holyoke College, Massachusetts, has previously found evidence that duck vaginas have evolved to make it harder for males to force copulation. So Orbach wondered if female cetaceans’ unusual vaginas had also evolved to keep out unwanted sperm. Orbach, Brennan and their colleagues obtained genitals from marine mammals that had died of natural causes: common and bottlenose dolphins, common porpoises and common seals. They inflated the males’ penises with saline to see how they looked when they were erect, and compared them with the vaginal moulds. They also took CT scans of penises inserted into the corresponding vaginas, to determine whether they fitted in easily and the best positions. © Copyright New Scientist Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 24170 - Posted: 10.11.2017

Nicola Davis “Woman seems to differ from man in mental disposition, chiefly in her greater tenderness and less selfishness,” wrote Charles Darwin in The Descent of Man. Now scientists claim that the stereotype is supported by evidence that the brain’s reward system may be geared towards more “prosocial” behaviour in women. “It was known that women and men behave differently, but it was not known why, or how this comes about in the brain,” said Philippe Tobler, associate professor of neuroeconomics and social neuroscience at the University of Zurich, and co-author of the research. The team note it is not clear whether the gender differences they see in the brain’s reward system are in any way “innate”, or whether they are the result of social pressures, but in short: women seem to get more of a chemical reward for being generous than men do. “It is known that girls receive different kinds of feedback than boys for being prosocial,” said Tobler. “It is perfectly conceivable that [the root of the differences here are] only cultural – we simply don’t know.” Writing in the journal Nature Human Behaviour, Tobler and colleagues from Germany, Switzerland and the Netherlands carried out two studies looking at whether dopamine, a neurotransmitter that plays a crucial role in the brain’s reward system, is linked to different social behaviours in men and women. In the first, a group of 56 men and women were randomly allocated to two groups, and either given a placebo or amisulpride – a drug that blocks the action of dopamine in the brain. Neither the scientists nor the participants knew which pill was taken. © 2017 Guardian News and Media Limited

Keyword: Sexual Behavior
Link ID: 24169 - Posted: 10.10.2017

By Jessica Wright No one except Gregory Kapothanasis knows exactly what upset him today. On this hot day in July, he went to his day program for adults with developmental disabilities, as he has done without incident five days a week for the past four years. But then things unraveled. According to the program’s report, he grabbed a staff member’s arm hard enough to bruise it. Then, on the bus during the daily outing, he started screaming and hitting his seat. Now, several hours later, he is finally home, but there is a stranger in his living room. Bouncing from one couch to another, clutching a faded beige blanket stolen from his aunt’s dog, Kapothanasis still seems out of sorts. His mother, Irene — who has cared for him, with the help of home aides, for all of his 24 years — is playing over the day’s events, trying to figure out what triggered him. His outburst is disturbingly reminiscent of a difficult period that peaked six years ago but is uncharacteristic of the young man today. Kapothanasis loves interacting with other people, going to the beach and dining at DiMillo’s, a floating restaurant in a decommissioned car ferry in Portland, Maine. Kapothanasis has autism and speaks only a few words: He can’t explain what happened this morning. Did he have constipation and discomfort, as his doctor suggested? Did he get bored of the day’s program, causing him to act out? Had something occurred on the bus previously that made him fear that part of his day? All his mother can do is wonder — and try to make his evening better. © 2017 Scientific American,

Keyword: Autism; Stress
Link ID: 24168 - Posted: 10.10.2017

By HEATHER MURPHY Michal Kosinski felt he had good reason to teach a machine to detect sexual orientation. An Israeli start-up had started hawking a service that predicted terrorist proclivities based on facial analysis. Chinese companies were developing facial recognition software not only to catch known criminals — but also to help the government predict who might break the law next. And all around Silicon Valley, where Dr. Kosinski works as a professor at Stanford Graduate School of Business, entrepreneurs were talking about faces as if they were gold waiting to be mined. Few seemed concerned. So to call attention to the privacy risks, he decided to show that it was possible to use facial recognition analysis to detect something intimate, something “people should have full rights to keep private.” After considering atheism, he settled on sexual orientation. Whether he has now created “A.I. gaydar,” and whether that’s even an ethical line of inquiry, has been hotly debated over the past several weeks, ever since a draft of his study was posted online. Presented with photos of gay men and straight men, a computer program was able to determine which of the two was gay with 81 percent accuracy, according to Dr. Kosinski and co-author Yilun Wang’s paper. The backlash has been fierce. “I imagined I’d raise the alarm,” Dr. Kosinski said in an interview. “Now I’m paying the price.” He’d just had a meeting with campus police “because of the number of death threats.” © 2017 The New York Times Company

Keyword: Sexual Behavior
Link ID: 24167 - Posted: 10.10.2017

By Frances Stead Sellers October 8 at 9:00 AM One late-summer day last year, my surroundings started playing tricks with me. The letters I typed on my computer screen looked fuzzy. Objects on my desk seemed to slip sideways, escaping their own outlines. My colleagues, viewed across the room, appeared to have shifted slightly so that now they stood or sat as ghostly silhouettes beside themselves. I put it down to fatigue or lack of food. The next morning, neither sleep nor sustenance had cured me. I squinted my way out of my apartment and reached for the handrail that runs alongside the front steps. As my left arm extended, my forearm divided somewhere between my elbow and my wrist, so that now I had two left hands and 10 fingers, groping for two railings that ran not parallel to one another but diverged into the distance. Below my four feet, the neat brick geometry of a Capitol Hill sidewalk had become a muddled mosaic. I looked up to see two identically dressed men, swinging their arms in unison as they marched, lockstep, toward me. I closed one eye and then the other. Both worked well. In fact, each restored reassuring order to the world: One man. One left hand. One railing. But when I tried to walk with only my right eye open, I keeled over to the side. I lost my balance — and a little confidence. “Not good,” the ophthalmologist murmured later that morning as he tracked the movement of my eyes from left to right and back again. Diplopia was his diagnosis. Greek for double vision. How did I feel? he asked. Had I had a virus? I needn’t go to the ER, he said, unless I developed a splitting headache or started vomiting. But I should see a neuro-ophthalmologist. Soon. © 1996-2017 The Washington Post

Keyword: Vision; Movement Disorders
Link ID: 24166 - Posted: 10.09.2017

By Leslie Kaufman It is 7 p.m. on a spring Friday, and the Highland Hospital emergency room in Oakland, one of the busiest trauma centers in northern California, is expecting. When the patient—a young bicyclist hit by a car—arrives, blood is streaming down his temples. From a warren of care rooms, a team of nearly a dozen doctors and nurses materializes and buzzes around the patient. Amelia Breyre, a first-year resident who looks not much older than a college sophomore, immediately takes charge. As soon as the team finishes immobilizing the victim, Breyre must begin making split-second decisions: X-ray? Intubate? Transfusion? She quickly determines there is no internal bleeding or need for surgery and orders up neck X-rays after bandaging the patient’s head. Breyre will make a half-dozen similar critical choices tonight. Highland, a teaching hospital, is perhaps the most selective emergency-medical residency in the nation. To be here, she must be outstanding. To succeed, though, she must stay sharp. That quality of focus—amid the chaos and battered ­humanity that comes through Highland’s doors—is itself in need of urgent care. Andrew Herring, an emergency-room doctor who supervises Breyre and 40 other residents, is worried about the team. ER doctors are shift workers, and their hours are spread over a dizzying, ever-changing schedule of mornings, afternoons, and nights that total 20 ­different shifts a month. That’s meant to equally distribute the burden of nocturnal work across an entire team of physicians. But despite those good intentions, Herring says, the result is that every single one of them is exhausted and sleep ­deprived. That’s dangerous for doctor and patient alike.

Keyword: Biological Rhythms
Link ID: 24165 - Posted: 10.09.2017

Children with attention deficit hyperactivity disorder may fidget, tap and swivel around in a chair much more than normally developing children because it helps them to learn complex material, psychologists have found. ADHD is often perceived as a behavioural problem because it can result in symptoms such as inattention, impulsivity, and hyperactivity that can affect social interaction and learning. Scientists increasingly recognize ADHD as a brain disorder that affects about five per cent of the school-age population. Now brain tests show children with ADHD tend to learn less when sitting still compared to when they're moving. It is not for lack of motivation, says Prof. Mark Rapport, a child psychopathology researcher who focuses on ADHD at the University of Central Florida in Orlando. Rapport and his colleagues set out to test an observation made by many parents — that children with ADHD can pay attention if they are doing an activity they enjoy. They put 32 boys aged eight to 12 with ADHD and 30 of their peers who are not affected by the disorder through a battery of memory and other tests. Participants watched two videos on separate days: an instructional math lesson without performing the calculations, and a scene from Star Wars Episode 1 — The Phantom Menace. During the Star Wars movie, the boys with ADHD did not squirm more than other children, but when asked to concentrate on the math lesson, there was a difference between the two groups. "All children and all people in general, moved more when they were engaged in a working memory task. Kids with ADHD move about twice as much under the same conditions," Rapport said. ©2017 CBC/Radio-Canada.

Keyword: ADHD; Learning & Memory
Link ID: 24164 - Posted: 10.09.2017

By Frank Swain Just what you need in the age of ubiquitous surveillance: the latest cochlear implants will allow users stream audio directly from their iPhone into their cochlear nerve. Apple and implant manufacturer Cochlear have made “Made for iPhone” connectivity available for any hearing implants that use the next-generation Nucleus 7 sound processor. The advance means that these implants can also stream music and Netflix shows. The technology was first unveiled in 2014 when it was added to hearing aids such as the Starkey Halo and ReSound LiNX. But this is the first time it’s been linked into the central nervous system. While some cochlear implants already offer Bluetooth connectivity, these often require users to wear extra dongles or other intermediary devices to pick up digital signals, and then rebroadcast them to the hearing aid as radio. This technology simply beams the signal right into the brain. It’s also a better way to use Bluetooth. Bluetooth headsets have been commonplace since the early 2000s, but the energy-sapping technology has meant they are typically clunky devices with poor battery life. In 2014, Apple technicians developed a way to stream audio over the low energy Bluetooth format used by wearables such as FitBits. Now, tiny devices like hearing aids – and Apple’s Airpods — can stream audio signals for up to a week on a battery the size of an aspirin. © Copyright New Scientist Ltd.

Keyword: Hearing
Link ID: 24163 - Posted: 10.09.2017

By Neuroskeptic A curious flurry of headlines in praise of beer appeared this week: Beer really DOES make you happier! Key molecule boosts brain’s reward centre Drinking Beer Makes You Really Happy, Confirms Awesome New Study Drinking beer can make you happy, researchers claim It was reported that scientists from Germany have discovered that a molecule in beer called hordenine activates dopamine receptors in the brain, and thus produces a positive mood. The research in question was published back in March of this year, so I’m not sure why it only made the headlines this week – maybe Oktoberfest had something to do with it. Either way, the study did indeed find that hordenine is a dopamine D2 receptor agonist, but it’s not clear this has any relevance to beer drinkers. The German researchers, Sommer et al., are chemists, not neuroscientists. They used computational simulations to model whether 13,000 known ‘food-derived’ molecules would bind to the D2 receptor. The hordenine molecule was predicted to fit the receptor, and follow-up experiments showed that it does indeed bind to it, suggesting possible psychoactive properties.

Keyword: Drug Abuse
Link ID: 24162 - Posted: 10.09.2017

By HEATHER MURPHY Well done -- you are an atypical person. Usually people notice the other, smaller toothbrush first. Most people will quickly spot the toothbrush on the front of the counter, but take longer — or even fail to find — the much bigger one behind it. The oversight has to do with scale. People have a tendency to miss objects when their size is inconsistent with their surroundings, according to a recent study in Current Biology. This is just the latest in a robust body of research that reveals how expectations dramatically affect our ability to notice what’s around us. Though the image above was provided by the authors of the study to illuminate their point, the study was set up slightly differently. The researchers were interested not only in what people saw — but also in how their performance compared with computers. Flesh-and-blood participants and a deep neural network, a computer system with advanced machine vision, were given one second to select an object in a computer-rendered scene, such as the one below. The object could be absent, presented at scale or featured at four times scale. Is there a parking meter in this image? Once you know what to expect, of course, it's easier. In the study, the object was either absent, presented at scale or featured at four times scale. Humans missed giant objects about 13 percent more than normal-sized objects, the researchers found. Scale had no impact on machine performance. “We were surprised about how compelling of an effect it is,” said Miguel Eckstein, a psychologist at the University of California, Santa Barbara’s Vision and Image Understanding Laboratory and one of the authors. In particular, the first time a person examined a photo with a giant object, the object often seemed to be invisible. But it’s not a deficiency, he said: “This is a useful trick the brain does to rapidly process scenes and find what we are looking for.” © 2017 The New York Times Company

Keyword: Attention
Link ID: 24161 - Posted: 10.07.2017

Victoria Lorrimar Michael Burdett The idea of dangerous, inhumane artificial intelligence taking over the world is familiar to many of us, thanks to cautionary tales such as the Matrix and Terminator franchises. But what about the more sympathetic portrayals of robots? The benevolence of Arnold Schwarzenegger’s Terminator character in the later movies of the franchise may have been the exception in older portrayals of AI, but human-like machines are often represented more positively in contemporary films. Think of Ex Machina, Chappie or A.I. Artificial Intelligence. This shift is very likely representative of a wider shift in how we think about these technologies in reality. Blade Runner 2049, long-anticipated sequel to the original 1982 Blade Runner film, is a part of this shift. The ability of science fiction to inspire technological innovation is well-known. A lot of science fiction writers are scientists and technologists (Arthur C Clarke and Geoffrey Landis are two examples), and ideas from science fiction have sparked more serious scientific research (touch screens and tablet computers are common examples). But science fiction serves other purposes too. It can be a tool for exploring the social and ethical implications of technologies being developed now – a fictional laboratory for testing possible futures. It can also prepare us to deal with certain technologies as they arise in the real world. © 2010–2017, The Conversation US, Inc.

Keyword: Consciousness; Robotics
Link ID: 24160 - Posted: 10.07.2017

By Shawna Williams THE PAPER P. Réu et al., “The lifespan and turnover of microglia in the human brain,” Cell Rep, 20:779-84, 2017. A RENEWABLE RESOURCE? Evidence has emerged that some of the brain’s cells can be renewed in adulthood, but it is difficult to study the turnover of cells in the human brain. When it comes to microglia, immune cells that ward off infection in the central nervous system, it’s been unclear how “the maintenance of their numbers is controlled and to what extent they are exchanged,” says stem cell researcher Jonas Frisén of the Karolinska Institute in Sweden. NUCLEAR SIGNATURE Frisén and colleagues used brain tissue from autopsies, together with the known changes in concentrations of carbon-14 in the atmosphere over time, to estimate how frequently microglia are renewed. They also analyzed microglia from the donated brains of two patients who had received a labeled nucleoside as part of a cancer treatment trial in the 1990s. SLOW CHURN Microglia, which populate the brain as blood cell progenitors during fetal development, were replaced at a median rate of 28 percent per year; on average, the cells were 4.2 years old. For Marie-Ève Tremblay, a neuroscientist at the Université Laval in Québec City who was not involved in the study, what stands out is the range of microglia ages found—from brand-new to more than 20 years old. “That’s quite striking!” she writes in an email to The Scientist. © 1986-2017 The Scientist

Keyword: Glia; Development of the Brain
Link ID: 24159 - Posted: 10.07.2017

By Giorgia Guglielmi This mantis shrimp (Gonodactylus smithii) might have a much more elaborate brain than previously thought. That’s the conclusion of the first study to peer into the head of more than 200 crustaceans, including crabs, shrimp, and lobsters. Researchers discovered that the brain of mantis shrimp contains memory and learning centers, called mushroom bodies, which so far have been seen only in insects. The team also found similar structures in close relatives of these sea creatures: cleaner shrimp, pistol shrimp, and hermit crabs. This may not be a coincidence, the researchers say, because mantis shrimp and their brethren are the only crustaceans that hunt over long distances and might have to remember where to get food. But the finding, reported in eLife, is likely to stir debate: Scientists agree that mushroom bodies evolved after the insect lineage split off from the crustacean lineage about 480 million years ago; finding these learning centers in mantis shrimp means that either mushroom bodies are much more ancient than scientists realized and were lost in all crustaceans but mantis shrimp, or that these structures are similar to their counterparts in insects but have evolved independently. © 2017 American Association for the Advancement of Science.

Keyword: Learning & Memory; Evolution
Link ID: 24158 - Posted: 10.07.2017

By GINA KOLATA For the first time, doctors have used gene therapy to stave off a fatal degenerative brain disease, an achievement that some experts had thought impossible. The key to making the therapy work? One of medicine’s greatest villains: HIV. The patients were children who had inherited a mutated gene causing a rare disorder, adrenoleukodystrophy, or ALD. Nerve cells in the brain die, and in a few short years, children lose the ability to walk or talk. They become unable to eat without a feeding tube, to see, hear or think. They usually die within five years of diagnosis. The disease strikes about one in 20,000 boys; symptoms first occur at an average age of 7. The only treatment is a bone-marrow transplant — if a compatible donor can be found — or a transplant with cord blood, if it was saved at birth. But such transplants are an onerous and dangerous therapy, with a mortality rate as high as 20 percent. Some who survive are left with lifelong disabilities. Now a new study, published online in the New England Journal of Medicine, indicates that gene therapy can hold off ALD without side effects, but only if it is begun when the only signs of deterioration are changes in brain scans. The study involved 17 boys (the disease strikes males almost exclusively), ages 4 to 13. All got gene therapy. Two years later, 15 were functioning normally without obvious symptoms. “To me, it seems to be working,” said Dr. Jim Wilson, director of the gene therapy program at the University of Pennsylvania’s Perelman School of Medicine, who was not involved in the new study. © 2017 The New York Times Company

Keyword: Genes & Behavior; Development of the Brain
Link ID: 24157 - Posted: 10.06.2017

By Ann Gibbons The insult "You're a Neandertal!" has taken on dramatic new meaning in the past few years, as researchers have begun to identify the genes many of us inherited from our long-extinct relatives. By sequencing a remarkably complete genome from a 50,000-year-old bone fragment of a female Neandertal found in Vindija Cave in Croatia, researchers report online today in Science a new trove of gene variants that living people outside of Africa obtained from Neandertals. Some of this DNA could influence cholesterol levels, the accumulation of belly fat, and the risk of schizophrenia and other diseases. The genome is only the second from a Neandertal sequenced to such high quality that it can reliably reveal when, where, and what DNA was passed from Neandertals to modern humans—and which diseases it may be causing or preventing today. "It's really exciting because it's more than two times better to have two Neandertal genomes," says evolutionary genomicist Tony Capra of Vanderbilt University in Nashville. The first Neandertal genome was a composite drawn from three individuals from Vindija Cave. Then, over the past few years, ancient DNA researchers sequenced two more Neandertal genomes, including another high-quality sequence from an individual that lived 122,000 years ago in the Altai Mountains of Siberia. Together, the genomes showed that living Europeans and Asians carry traces of DNA from Neandertals who mated with members of Homo sapiens soon after our species left Africa. (Most Africans lack Neandertal DNA as a result.) © 2017 American Association for the Advancement of Science.

Keyword: Obesity; Evolution
Link ID: 24156 - Posted: 10.06.2017

Hannah Devlin French scientists have been criticised for concealing the death of the patient at the centre of a breakthrough in which consciousness was restored to a man in a persistent vegetative state. The treatment was hailed as a major advance in the field and suggested that the outlook for these patients and their families might be less bleak than was previously thought. However, it has emerged that the scientists behind the research withheld the fact that the man, who remains anonymous, died a few months after receiving the therapy. The team justified the decision, citing the family’s wish to keep the death private and a concern that people might have wrongly linked the therapy, which involved nerve stimulation, to the 35-year-old’s death from a lung infection. However, others said the decision had created an over-optimistic narrative of a patient on an upward trajectory. Damian Cruse, a cognitive neuroscientist at the University of Birmingham, said: “I do worry that the media coverage of the study gave a more hopeful message to other families in this situation than the message that perhaps would have been delivered with all of the facts … If we protect patient anonymity, then there’s no reason not to be able to tell the full story.” When the paper came out last month, Angela Sirigu, who led the work at the Institut des Sciences Cognitives Marc Jeannerod in Lyon, France, told the Guardian: “He is still paralysed, he cannot talk, but he can respond. Now he is more aware.” © 2017 Guardian News and Media Limited

Keyword: Consciousness
Link ID: 24155 - Posted: 10.06.2017

By Michael Price Expensive medications tend to make us feel better, even when they’re no different than cheap generics. But they can also make us feel worse, according to a new study. Researchers have found that we’re more likely to experience negative side effects when we take a drug we think is pricier—a flip side of the placebo effect known as the “nocebo” effect. The work could help doctors decide whether to recommend brand-name or generic drugs depending on each patient’s expectations. In the study, researchers asked 49 people to test out a purported anti-itch cream that, in reality, contained no active ingredient. Some got “Solestan® Creme,” a fake brand name in a sleek blue box designed to look like other expensive brands on the market. Others received “Imotadil-LeniPharma Creme”—another fake, this time housed in a chintzier orange box resembling those typically used for generic drugs. “I put a lot of effort into making the designs convincing,” says study leader Alexandra Tinnermann, a neuroscientist at University Medical Center Hamburg-Eppendorf in Germany. The researchers rubbed one of the two creams on the volunteers’ forearms and waited a few minutes for it soak in. They told the participants that the cream could cause increased sensitivity to pain—a known side effect of real medications called hyperalgesia. Then the scientists affixed a small device to the volunteers’ arms that delivered a brief flash of heat up to about 45°C (or 113°F). © 2017 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 24154 - Posted: 10.06.2017

By Clare Wilson OUR braininess may have evolved thanks to gene changes that made our brain cells less sticky. The cortex is the thin, highly folded outer layer of our brains and it is home to some of our most sophisticated mental abilities, such as planning, language and complex thoughts. Around three millimetres thick, this layer is folded into an intricate pattern of ridges and valleys, which allows the cortex to be large, but still fit into a relatively small space. Many larger mammals, such as primates, dolphins and horses, have various patterns of folds in their cortex, but folds are rarer in smaller animals like mice. So far, we have only identified a few genetic mutations that contributed to the evolution of the human brain, including ones that boosted the number of cells in the cortex. One theory about how the cortex came to be folded is that it buckled as the layer of cells expanded. Daniel del Toro at the Max Planck Institute of Neurobiology in Munich, Germany, and colleagues wondered if some of the genetic changes in our brain’s evolution might have been about more than just an increasing number of cells. They investigated the genes for two molecules – FLRT1 and FLRT3 – which make developing brain cells stick to each other more. Human brain cells produce only a small amount of these compounds, while mice brain cells make lots. Del Toro’s team created mice embryos that lacked functioning FLRT1 and FLRT3 genes, which meant their cortex cells were only loosely attached to each other, like those of humans. © Copyright New Scientist Ltd.

Keyword: Development of the Brain; Learning & Memory
Link ID: 24153 - Posted: 10.05.2017