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Mo Costandi The human brain is immediately recognizable by its cortex (meaning bark in Latin), the prominent outer layer of tissue, with its characteristic pattern of ridges and furrows, which sits atop the deep structures. The cortex is just several millimetres thick, but has a surface area of about two-and-a-half square feet, and is therefore heavily convoluted so it can be packed into the skull. This fleshy landscape begins to form during the second trimester of pregnancy, and continues into the first year of life. It is often assumed to be the result of genetics, like most other aspects of brain development. Forty years ago, however, Harvard researchers put forward the controversial idea that the brain folds up because of physical forces, and a new study now provides the first evidence this. According to this old model, the brain’s folds form as a result of differential growth which causes the cortex to grow in size far more quickly than other brain structures, leading it to buckle and fold as its surface area increases, due to the constraints of the skull. To test this, Tuomos Tallinen of the University of Jyväskylä in Finland and his colleagues used magnetic resonance images to create a 3D-printed cast of an unfolded 22-week-old human brain. This was made with a technique called layer-by-layer drop casting, and consisted of a soft polymer core coated with a thin sheet of an absorbent elastomer gel representing the cortex. © 2016 Guardian News and Media Limited
Keyword: Development of the Brain
Link ID: 21857 - Posted: 02.04.2016
By Nicholas Bakalar Women with sleeping difficulties are at increased risk for Type 2 diabetes, researchers report. Scientists used data from 133,353 women who were generally healthy at the start of the study. During 10 years of follow-up, they found 6,407 cases of Type 2 diabetes. The researchers looked at four sleep problems: self-reported difficulty falling or staying asleep, frequent snoring, sleep duration of less than six hours, and either sleep apnea or rotating shift work. The study is in Diabetologia. Self-reported difficulty sleeping was associated with higher B.M.I., less physical activity, and more hypertension and depression. But even after adjusting for these and other health and behavioral characteristics, sleeping difficulty was still associated with a 22 percent increased risk for Type 2 diabetes. Compared to women with no sleep problems, those with two of the sleep conditions studied had double the risk, and those with all four had almost four times the risk of developing the illness. The senior author, Dr. Frank B. Hu, a professor of nutrition and epidemiology at Harvard, said that sleep problems are associated with excess secretion of two hormones: ghrelin, which increases appetite, and cortisol, which increases stress and insulin resistance. Both are linked to metabolic problems that increase the risk for diabetes. “And,” he added, “it’s not just quantity of sleep, but quality as well” that is associated with these health risks. © 2016 The New York Times Company
Heidi Ledford Difficulty with concentration, memory and other cognitive tasks is often associated with depression. In the past quarter of a century, a wave of drugs has transformed the treatment of depression. But the advances have struggled to come to grips with symptoms that often linger long after people start to feel better: cognitive problems such as memory loss and trouble concentrating. On 3 February, the US Food and Drug Administration (FDA) will convene a meeting of its scientific advisers to discuss whether such cognitive impairments are components of the disorder that drugs might be able to target — or just a result of depressed mood. The discussion will help the agency to decide whether two companies that sell the antidepressant vortioxetine should be allowed to label it as a treatment for the cognitive effects. A ‘yes’ could spur drug developers to invest in ways to test cognitive function during their antidepressant trials. Psychiatrists have long noted that some people with depression also struggle to concentrate and to make decisions. The question has been whether such difficulties are merely an offshoot of altered mood and would thus clear up without specific treatment, says Diego Pizzagalli, a neuroscientist at McLean Hospital, an affiliate of Harvard Medical School in Belmont, Massachusetts. But some patients who report improved mood after treatment still struggle with cognitive deficits — so psychiatrists sometimes prescribe concentration-enhancing drugs that are approved to treat attention deficit hyperactivity disorder to people with depression. © 2016 Nature Publishing Group
Fears over surveillance seem to figure large in the bird world, too. Ravens hide their food more quickly if they think they are being watched, even when no other bird is in sight. It’s the strongest evidence yet that ravens have a “theory of mind” – that they can attribute mental states such as knowledge to others. Many studies have shown that certain primates and birds behave differently in the presence of peers who might want to steal their food. While some researchers think this shows a theory of mind, others say they might just be reacting to visual cues, rather than having a mental representation of what others can see and know. Through the peephole Thomas Bugnyar and colleagues at the University of Vienna, Austria, devised an experiment to rule out the possibility that birds are responding to another’s cues. The setup involved two rooms separated by a wooden wall, with windows and peepholes that could be covered. First, a raven was given food with another raven in the next room, with the window open or covered, to see how quickly it caches its prize. With the window open, the birds hid their food more quickly and avoided going back to conceal it further. Then individual ravens were then trained to use the peephole to see where humans were putting food in the other room. The idea here was to allow the bird to realise it could be seen through the peephole. © Copyright Reed Business Information Ltd.
By Anna K. Bobak, Sarah Bate For years scientists have studied the biological basis of human speed, and reported that the fastest athletes are short and muscular in build. However, these conclusions were challenged in 2008 when a new athlete, substantially taller than previous world-record holders, was identified as the fastest man in history. Usain Bolt presented the purest expression of human speed on the planet – and raised the possibility that scientists may need to entirely change the way they think about human biometrics. In the same vein, one might ask whether examinations of the brain at its height of efficiency will present new insights into its workings. Although researchers have historically examined people with a very high IQ (i.e. those with more generalised skills), it has become more and more clear that some individuals only perform extraordinarily well on specific cognitive tasks. Among the most interesting of these is facial identity recognition. In fact, the extraordinary skills of these so-called “super-recognisers” do not seem to correlate with IQ or memory for objects, yet they claim to recognise faces which they have only briefly been seen before, or have undergone substantial changes in appearance. For instance, in a recent scientific report from our laboratory (unpublished), one super-recogniser described bumping into a girl from a children’s’ swimming class he coached as a teenager. He recognised her immediately, despite the fact that he’d not seen her for over ten years and she was now an adult. So how can these people change the way that scientists think about the human brain? For many years researchers have generally agreed that faces are “special.” © 2016 Scientific American
Link ID: 21853 - Posted: 02.03.2016
By JAN HOFFMAN One evening in the late fall, Lucien Majors, 84, sat at his kitchen table, his wife Jan by his side, as he described a recent dream. Mr. Majors had end-stage bladder cancer and was in renal failure. As he spoke with a doctor from Hospice Buffalo , he was alert but faltering. In the dream, he said, he was in his car with his great pal, Carmen. His three sons, teenagers, were in the back seat, joking around. “We’re driving down Clinton Street,” said Mr. Majors, his watery, pale blue eyes widening with delight at the thought of the road trip. “We were looking for the Grand Canyon.” And then they saw it. “We talked about how amazing, because there it was — all this time, the Grand Canyon was just at the end of Clinton Street!” Mr. Majors had not spoken with Carmen in more than 20 years. His sons are in their late 50s and early 60s. “Why do you think your boys were in the car?” asked Dr. Christopher W. Kerr, a Hospice Buffalo palliative care physician who researches the therapeutic role of patients’ end-of-life dreams and visions. “My sons are the greatest accomplishment of my life,” Mr. Majors said. He died three weeks later. For thousands of years, the dreams and visions of the dying have captivated cultures, which imbued them with sacred import. Anthropologists, theologians and sociologists have studied these so-called deathbed phenomena. They appear in medieval writings and Renaissance paintings, in Shakespearean works and set pieces from 19th-century American and British novels, particularly by Dickens. One of the most famous moments in film is the mysterious deathbed murmur in “Citizen Kane”: “Rosebud!” Even the law reveres a dying person’s final words, allowing them to be admitted as evidence in an unusual exception to hearsay rules. © 2016 The New York Times Company
Link ID: 21852 - Posted: 02.03.2016
By Sarah Knapton, Science Editor For women, shedding the pounds can feel like a unending struggle of dieting and exercise with little results. But a new study suggests that there could be a reason why females find it more difficult to lose weight than men. Researchers say hormones responsible for regulating appetite, physical activity and energy expenditure work differently in the sexes. "This could have broad implications for medications used to combat obesity, which at present largely ignore the sex of the individual." Professor Lora Heisler, University of Aberdeen The discovery could change the way obesity is tackled through targeted medication, experts at the University of Aberdeen believe. Working with teams from the University of Cambridge and the University of Michigan, they used a mouse model to study how weight gain differs in each sex depending on physical activity and energy expenditure. During the study, researchers were able to transform obese male into lean, healthy mice, but the same transformation did not occur in the female mice. Current obesity medications stimulate the production of POMC peptides in the brain which regulate appetite, increase energy expenditure through heat and encourage movement. But researchers found in female mice the hormones only regulated appetite - they did not have the extra benefits. © Copyright of Telegraph Media Group Limited 2016
By Laurel Hamers As one person at the dinner table leans back, stretches, and opens their mouth in a gaping yawn, others will soon follow suit. Catching a yawn is more likely to occur between relatives than strangers, and scientists believe it’s sign of empathy. Plus, other social primates like chimps and bonobos do it, too. A new study suggests that women (traditionally branded the more empathetic sex) might be more susceptible to copycat yawning than men. Researchers surreptitiously analyzed more than 4000 real-world yawns on planes and trains, in restaurants, and in offices. They noted when someone yawned, and then whether a nearby acquaintance or friend did the same within a 3-minute period. Men and women spontaneously yawned with about the same frequency. But when someone else yawned first, women were more likely than men to follow suit. Women picked up yawns about 55% of the time, whereas men only did so 40% of the time. Women tend to score higher than men on tests of empathy, and traditional female social roles (like child-rearing) place a higher emphasis on those traits. That might make women more attuned to others’ yawns, the researchers suggest. Gender roles aren’t as rigid in our modern society—but the yawning gap appears to linger. © 2016 American Association for the Advancement of Science
By SINDYA N. BHANOO Several studies suggest that men find women more attractive when they are in the ovulatory phase of their menstrual cycle. The thesis takes a strange turn in a new study in which women were questioned: Each subject was asked whether a woman in an image was likely to entice a man that she was dating. Although women do not find images of ovulatory women particularly attractive, scientists found, women with higher estrogen levels did perceive such images to be more threatening. Women with high estrogen, the researchers noted, have a high potential for fertility. “We’re still trying to pinpoint exactly what all is involved in this,” said Janek S. Lobmaier, a psychologist at the University of Bern. © 2016 The New York Times Company
By Jonathan Webb Science reporter, BBC News Scientists have reproduced the wrinkled shape of a human brain using a simple gel model with two layers. They made a solid replica of a foetal brain, still smooth and unfolded, and coated it with a second layer which expanded when dunked into a solvent. That expansion produced a network of furrows that was remarkably similar to the pattern seen in a real human brain. This suggests that brain folds are caused by physics: the outer part grows faster than the rest, and crumples. Such straightforward, mechanical buckling is one of several proposed explanations for the distinctive twists and turns of the brain's outermost blanket of cells, called the "cortex". Alternatively, researchers have suggested that biochemical signals might trigger expansion and contraction in particular parts of the sheet, or that the folds arise because of stronger connections between specific areas. "There have been several hypotheses, but the challenge has been that they are difficult to test experimentally," said Tuomas Tallinen, a soft matter physicist at the University of Jyväskylä in Finland and a co-author of the study, which appears in Nature Physics. "I think it's very significant... that we can actually recreate the folding process using this quite simple, physical model." Humans are one of just a few animals - among them whales, pigs and some other primates - that possess these iconic undulations. In other creatures, and early in development, the cortex is smooth. The replica in the study was based on an MRI brain scan from a 22-week-old foetus - the stage just before folds usually appear. © 2016 BBC.
Keyword: Development of the Brain
Link ID: 21848 - Posted: 02.02.2016
By Roni Caryn Rabin The first time she skipped an insulin dose, the 22-year-old said, it wasn’t planned. She was visiting her grandparents over a summer break from college and indulged in bags of potato chips and fistfuls of candy, but forgot to take the extra insulin that people with Type 1 diabetes, like her, require to keep their blood sugar levels in a normal range. She was already underweight after months of extreme dieting, but when she stepped on the scale the next day, she saw she had dropped several pounds overnight. “I put two and two together,” said the young woman, who lives in Boston and wished to remain anonymous. She soon developed a dangerous habit that she used to drive her weight down: She would binge, often consuming an entire pint of Ben & Jerry’s peanut butter cup ice cream, and then would deliberately skip the insulin supplements she needed. People with Type 1 diabetes, who don’t produce their own insulin, require continuous treatments with the hormone in order to get glucose from the bloodstream into the cells. When they skip or restrict their insulin, either by failing to take shots or manipulating an insulin pump, it causes sugars — and calories — to spill into the urine, causing rapid weight loss. But the consequences can be fatal. “I knew I was playing with fire, but I wasn’t thinking about my life, just my weight,” said the young woman, who was treated at The Renfrew Center of Boston, which specializes in treating eating disorders, and is in recovery. “I got used to my blood sugars running high all the time. I would get so nauseous I would throw up, which I knew was a serious sign that I should go to the hospital. It was very scary.” © 2016 The New York Times Company
Keyword: Anorexia & Bulimia
Link ID: 21847 - Posted: 02.02.2016
By Sara Solovitch It was November 2012 when Dennis Hartman, a Seattle business executive, managed to pull himself out of bed, force himself to shower for the first time in days and board a plane that would carry him across the country to a clinical trial at the National Institute of Mental Health (NIMH) in Bethesda. After a lifetime of profound depression, 25 years of therapy and cycling through 18 antidepressants and mood stabilizers, Hartman, then 46, had settled on a date and a plan to end it all. This clinical trial would be his last stab at salvation. For 40 minutes, he sat in a hospital room as an IV drip delivered ketamine through his system. Several more hours passed before it occurred to him that all his thoughts of suicide had evaporated. “My life will always be divided into the time before that first infusion and the time after,” Hartman says today. “That sense of suffering and pain draining away. I was bewildered by the absence of pain.” Ketamine, popularly known as the psychedelic club drug Special K, has been around since the early 1960s. It is a staple anesthetic in emergency rooms, regularly used for children when they come in with broken bones and dislocated shoulders. It’s an important tool in burn centers and veterinary medicine, as well as a notorious date-rape drug, known for its power to quickly numb and render someone immobile.
By Dwayne Godwin, Jorge Cham Drugs and other stimuli hijack dopamine signaling in the brain, causing changes that can lead to addiction © 2016 Scientific America
Keyword: Drug Abuse
Link ID: 21845 - Posted: 02.02.2016
By CATHERINE SAINT LOUIS The images pouring out of Brazil are haunting: struggling newborns with misshapen heads, cradled by mothers who desperately want to know whether their babies will ever walk or talk. There are thousands of these children in Brazil, and scientists fear thousands more might come as the Zika virus leaps across Latin America and the Caribbean. But the striking deformity at the center of the epidemic, microcephaly, is not new: It has pained families across the globe and mystified experts for decades. For parents, having a child with microcephaly can mean a life of uncertainty. The diagnosis usually comes halfway through pregnancy, if at all; the cause may never be determined — Zika virus is only suspected in the Brazilian cases, while many other factors are well documented. And no one can say what the future might hold for a particular child with microcephaly. For doctors, the diagnosis means an ailment with no treatment, no cure and no clear prognosis. If the condition surges, it will significantly burden a generation of new parents for decades. Dr. Hannah M. Tully, a neurologist at Seattle Children’s Hospital, sees the pain regularly, particularly among expectant parents who have just been told that an ultrasound showed their child to be microcephalic: “a terrible situation with which to be confronted in a pregnancy,” she said. An estimated 25,000 babies receive a microcephaly diagnosis each year in the United States. Microcephaly simply means that the baby’s head is abnormally small — sometimes just because the parents themselves have unusually small heads. “By itself, it doesn’t necessarily mean you have a neurological problem,” said Dr. Marc C. Patterson, a pediatric neurologist at the Mayo Clinic Children’s Center in Rochester, Minn. © 2016 The New York Times Company
Keyword: Development of the Brain
Link ID: 21844 - Posted: 02.01.2016
By Lisa Rapaport Mothers who are obese during pregnancy have almost twice the odds of having a child with autism as women who weigh less, a U.S. study suggests. When women are both obese and have diabetes, the autism risk for their child is at least quadrupled, researchers reported online January 29 in Pediatrics. "In terms of absolute risk, compared to common pediatric diseases such as obesity and asthma, the rate of autism spectrum disorder (ASD) in the U.S. population is relatively low, however, the personal, family and societal impact of ASD is enormous," said senior study author Dr. Xiaobin Wang, a public health and pediatrics researcher at Johns Hopkins University in Baltimore. About one in 68 children have ASD, according to the U.S. Centers for Disease Control and Prevention, or about 1.5 percent of U.S. children. The study findings suggest the risk rises closer to about 3 percent of babies born to women who are obese or have diabetes, and approaches 5 percent to 6 percent when mothers have the combination of obesity and diabetes. Wang and colleagues analyzed data on 2,734 mother-child pairs followed at Boston Medical Center between 1998 and 2014. Most of the children, 64 percent, weren't diagnosed with any other development disorders, but there were 102 kids who did receive an ASD diagnosis. © 2016 Scientific American
By BENEDICT CAREY A new approach to treating early schizophrenia, which includes family counseling, results in improvements in quality of life that make it worth the added expense, researchers reported on Monday. The study, published by the journal Schizophrenia Bulletin, is the first rigorous cost analysis of a federally backed treatment program that more than a dozen states have begun trying. In contrast to traditional outpatient care, which generally provides only services covered by insurance, like drugs and some psychotherapy, the new program offers other forms of support, such as help with jobs and school, as well as family counseling. The program also tries to include the patients — people struggling with a first psychotic “break” from reality, most of them in their late teens and 20s — as equals in decisions about care, including drug dosage. In a widely anticipated study last fall, called the Raise trial, researchers reported that after two years, people who got this more comprehensive care did better on a variety of measures than those who received the standard care. But the study found no evidence of related cost savings or differences in hospitalization rates, a prime driver of expense. As lawmakers in Washington are considering broad changes in mental health care, cost issues loom especially large. Outside experts said this analysis — which was based on the Raise trial data — was an important test of the new care program’s value. “This is the way cost analysis should be done,” Sherry Glied, a professor of public service and the dean of New York University’s graduate school of public service, said. “One way to think about it is to ask, if this program were a drug, would we pay for it? And the answer is yes.” © 2016 The New York Times Company
Link ID: 21842 - Posted: 02.01.2016
By Neuroskeptic We’ve learned this week that computers can play Go. But at least there’s one human activity they will never master: neuroscience. A computer will never be a neuroscientist. Except… hang on. A new paper just out in Neuroimage describes something called The Automatic Neuroscientist. Oh. So what is this new neuro-robot? According to its inventors, Romy Lorenz and colleagues of Imperial College London, it’s a framework for using “real-time fMRI in combination with modern machine-learning techniques to automatically design the optimal experiment to evoke a desired target brain state.” It works like this. You put someone in an MRI scanner and start an fMRI sequence to record their brain activity. The Automatic Neuroscientist (TAN) shows them a series of different stimuli (e.g. images or sounds) and measures the neural responses. It then learns which stimuli activate different parts of the brain, and works out the best stimuli in order to elicit a particular target pattern of brain activity (which is specified at the outset.) This is not an entirely new idea as Lorenz et al. acknowledge, but they say that theirs is the first general framework. Lorenz et al. conducted a proof-of-concept study in which they asked TAN to maximize the difference in brain activity between the lateral occipital cortex (LOC) and superior temporal cortex, by presenting visual and auditory stimuli of varying levels of complexity.
By Simon Makin Multi-color image of whole brain for brain imaging research. This image was created using a computer image processing program (called SUMA), which is used to make sense of data generated by functional Magnetic Resonance Imaging (fMRI). National Institute of Mental Health, National Institutes of Health Understanding how brains work is one of the greatest scientific challenges of our times, but despite the impression sometimes given in the popular press, researchers are still a long way from some basic levels of understanding. A project recently funded by the Obama administration's BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative is one of several approaches promising to deliver novel insights by developing new tools that involves a marriage of nanotechnology and optics. There are close to 100 billion neurons in the human brain. Researchers know a lot about how these individual cells behave, primarily through “electrophysiology,” which involves sticking fine electrodes into cells to record their electrical activity. We also know a fair amount about the gross organization of the brain into partially specialized anatomical regions, thanks to whole-brain imaging technologies like functional magnetic resonance imaging (fMRI), which measure how blood oxygen levels change as regions that work harder demand more oxygen to fuel metabolism. We know little, however, about how the brain is organized into distributed “circuits” that underlie faculties like, memory or perception. And we know even less about how, or even if, cells are arranged into “local processors” that might act as components in such networks. © 2016 Scientific American
Keyword: Brain imaging
Link ID: 21840 - Posted: 02.01.2016
By CHARLES SIEBERT Nearly 30 years ago, Lilly Love lost her way. She had just completed her five-year tour of duty as an Alaska-based Coast Guard helicopter rescue swimmer, one of an elite team of specialists who are lowered into rough, frigid seas to save foundering fishermen working in dangerous conditions. The day after she left active service, the helicopter she had flown in for the previous three years crashed in severe weather into the side of a mountain, killing six of her former crewmates. Devastated by the loss and overcome with guilt, Love chose as her penance to become one of the very fishermen she spent much of her time in the Coast Guard rescuing. In less than a year on the job, she nearly drowned twice after being dragged overboard in high seas by the hooks of heavy fishing lines. Love would not formally receive a diagnosis of severe post-traumatic stress disorder for another 15 years. In that time, she was married and divorced three times, came out as transgender and retreated periodically to Yelapa, Mexico, where she lived in an isolated cabin accessible only by water. She eventually ended up living on a boat in a Los Angeles marina, drinking heavily and taking an array of psychotropic drugs that doctors at the West Los Angeles Veterans Administration Medical Center began to prescribe with increasing frequency as Love proved resistant to traditional treatments like counseling and group therapy. One night, after her fifth stay in the center’s psych ward, she crashed her boat into a sea wall. Finally, in 2006, she was in the veterans’ garden and happened to catch sight of the parrots being housed in an unusual facility that opened a year earlier on the grounds of the center. ‘‘This place is why I’m still here,’’ Love, now 54, told me one day last summer as I watched her undergo one of her daily therapy sessions at the facility, known as Serenity Park, a name that would seem an utter anomaly to anyone who has ever been within 200 yards of the place. © 2016 The New York Times Company
Link ID: 21839 - Posted: 01.30.2016
By Mitch Leslie Identical twins may be alike in everything from their eye color to their favorite foods, but they can diverge in one important characteristic: their weight. A new study uncovers a molecular mechanism for obesity that might explain why one twin can be extremely overweight even while the other is thin. Heredity influences whether we become obese, but the genes researchers have linked to the condition don’t explain many of the differences in weight among people. Identical twins with nonidentical weights are a prime example. So what accounts for the variation? Changes in the intestinal microbiome—the collection of bacteria living in the gut—are one possibility. Another is epigenetic changes, or alterations in gene activity. These changes occur when molecules latch on to DNA or the proteins it wraps around, turning sets of genes “on” or “off.” Triggered by factors in the environment, epigenetic modifications can be passed down from one generation to the next. This type of transmission happened during the Hunger Winter, a famine that occurred when the Germans cut off food supplies to parts of the Netherlands in the final months of World War II. Mothers who were pregnant during the famine gave birth to children who were prone to obesity decades later, suggesting that the mothers’ diets had a lasting impact on their kids’ metabolism. However, which epigenetic changes in people promote obesity remains unclear. © 2016 American Association for the Advancement of Science