By CADE METZ SAN FRANCISCO — Machines are starting to learn tasks on their own. They are identifying faces, recognizing spoken words, reading medical scans and even carrying on their own conversations. All this is done through so-called neural networks, which are complex computer algorithms that learn tasks by analyzing vast amounts of data. But these neural networks create a problem that scientists are trying to solve: It is not always easy to tell how the machines arrive at their conclusions. On Tuesday, a team at Google took a small step toward addressing this issue with the unveiling of new research that offers the rough outlines of technology that shows how the machines are arriving at their decisions. “Even seeing part of how a decision was made can give you a lot of insight into the possible ways it can fail,” said Christopher Olah, a Google researcher. A growing number of A.I. researchers are now developing ways to better understand neural networks. Jeff Clune, a professor at University of Wyoming who now works in the A.I. lab at the ride-hailing company Uber, called this “artificial neuroscience.” Understanding how these systems work will become more important as they make decisions now made by humans, like who gets a job and how a self-driving car responds to emergencies. First proposed in the 1950s, neural networks are meant to mimic the web of neurons in the brain. But that is a rough analogy. These algorithms are really series of mathematical operations, and each operation represents a neuron. Google’s new research aims to show — in a highly visual way — how these mathematical operations perform discrete tasks, like recognizing objects in photos. © 2018 The New York Times Company

Keyword: Learning & Memory; Robotics
Link ID: 24729 - Posted: 03.07.2018

Bruce Bower People have evolved to sleep much less than chimps, baboons or any other primate studied so far. A large comparison of primate sleep patterns finds that most species get somewhere between nine and 15 hours of shut-eye daily, while humans average just seven. An analysis of several lifestyle and biological factors, however, predicts people should get 9.55 hours, researchers report online February 14 in the American Journal of Physical Anthropology. Most other primates in the study typically sleep as much as the scientists’ statistical models predict they should. Two long-standing features of human life have contributed to unusually short sleep times, argue evolutionary anthropologists Charles Nunn of Duke University and David Samson of the University of Toronto Mississauga. First, when humans’ ancestors descended from the trees to sleep on the ground, individuals probably had to spend more time awake to guard against predator attacks. Second, humans have faced intense pressure to learn and teach new skills and to make social connections at the expense of sleep. As sleep declined, rapid-eye movement, or REM — sleep linked to learning and memory (SN: 6/11/16, p. 15) — came to play an outsize role in human slumber, the researchers propose. Non-REM sleep accounts for an unexpectedly small share of human sleep, although it may also aid memory (SN: 7/12/14, p. 8), the scientists contend. “It’s pretty surprising that non-REM sleep time is so low in humans, but something had to give as we slept less,” Nunn says. |© Society for Science & the Public 2000 - 2018.

Keyword: Sleep; Evolution
Link ID: 24728 - Posted: 03.07.2018

By VERONIQUE GREENWOOD Ears are a peculiarly individual piece of anatomy. Those little fleshy seashells, whether they stick out or hang low, can be instantly recognizable in family portraits. And they aren’t just for show. Researchers have discovered that filling in an external part of the ear with a small piece of silicone drastically changes people’s ability to tell whether a sound came from above or below. But given time, the scientists show in a paper published Monday in the Journal of Neuroscience, the brain adjusts to the new shape, regaining the ability to pinpoint sounds with almost the same accuracy as before. Scientists already knew that our ability to tell where a sound is coming from arises in part from sound waves arriving at our ears at slightly different times. If a missing cellphone rings from the couch cushions to your right, the sound reaches your right ear first and your left ear slightly later. Then, your brain tells you where to look. But working out whether a sound is emanating from high up on a bookshelf or under the coffee table is not dependent on when the sound reaches your ears. Instead, said Régis Trapeau, a neuroscientist at the University of Montreal and author of the new paper, the determination involves the way the sound waves bounce off outer parts of your ear. Curious to see how the brain processed this information, the researchers set up a series of experiments using a dome of speakers, ear molds made of silicone and an fMRI machine to record brain activity. Before being fitted with the pieces of silicone, volunteers heard a number of sounds played around them and indicated where they thought the noises were coming from. In the next session, the same participants listened to the same sounds with the ear molds in. This time it was clear that something was very different. © 2018 The New York Times Company

Keyword: Hearing
Link ID: 24727 - Posted: 03.07.2018

By Michael Price When you hear a B-flat music note, do you see the color blue? Do the words in this sentence look red or green? If so, you may have synesthesia, a mysterious condition in which one sense consistently mingles with another. Now, for the first time, scientists have identified a handful of genes that might predispose people to synesthesia, offering a window to better understand disorders such as autism, which is also thought to involve abnormal brain connections. “It’s very exciting,” says Romke Rouw, a cognitive psychologist who studies synesthesia at the University of Amsterdam but who wasn’t involved in the study. “It provides a fascinating suggestion of a link between particular genetic variations and hyperconnectivity in the synesthetic brain.” For decades, many psychologists and neuroscientists were reluctant to research synesthesia. Some refused to acknowledge its existence, whereas others believed the phenomenon’s individual, subjective nature made it virtually impossible to study. But increasingly sophisticated survey methods have allowed scientists to confirm that some people—it’s unclear how many—do consistently and involuntarily experience this unusual condition. Synesthesia is thought to be at least somewhat heritable, as it frequently clusters within families. But genomic investigations so far have failed to turn up individual genes that might be responsible for it. © 2018 American Association for the Advancement of Science

Keyword: Development of the Brain
Link ID: 24726 - Posted: 03.06.2018

By DOUGLAS QUENQUA Claudio Mello was conducting research in Brazil’s Atlantic Forest about 20 years ago when he heard a curious sound. It was high-pitched and reedy, like a pin scratching metal. A cricket? A tree frog? No, a hummingbird. At least that’s what Dr. Mello, a behavioral neuroscientist at Oregon Health and Science University, concluded at the time. Despite extensive deforestation, the Atlantic Forest is one of Earth’s great cradles of biological diversity. It is home to about 2,200 species of animals, including about 40 species of hummingbirds. The variety of hummingbirds makes it difficult to isolate specific noises without sophisticated listening or recording devices. In 2015, Dr. Mello returned to the forest with microphones used to record high-frequency bat noises. The recordings he made confirmed that the calls were coming from black jacobin hummingbirds. The species is found in other parts of South America, too, and researchers are unsure whether the sound is emitted by males, females or both, although they have confirmed that juvenile black jacobins do not make them. When Dr. Mello and his team analyzed the noise — a triplet of syllables produced in rapid succession — they discovered it was well above the normal hearing range of birds. Peak hearing sensitivity for most birds is believed to rest between two to three kilohertz. (Humans are most sensitive to noises between one and four kilohertz.) “No one has ever described that a bird can hear even above 8, 9 kilohertz,” said Dr. Mello. But “the fundamental frequency of those calls was above 10 kilohertz,” he said. “That’s what was really amazing.” © 2018 The New York Times Company

Keyword: Hearing; Animal Communication
Link ID: 24725 - Posted: 03.06.2018

By Shawna Williams In recent years, US society has seen a sea change in the perception of transgender people, with celebrities such as Caitlyn Jenner and Laverne Cox becoming the recognizable faces of a marginalized population. Transgender rights have also become a mainstream political issue, and the idea that people should be referred to by the names and pronouns they find most fitting—whether or not these designations match those on their birth certificates, or align with the categories of male and female—is gaining acceptance. Yet a biological understanding of the contrast between the natal sex and the gender identity of transgender people remains elusive. In recent years, techniques such as functional magnetic resonance imaging (fMRI) have begun to yield clues to possible biological underpinnings of the condition known as gender dysphoria. In particular, researchers are identifying similarities and differences between aspects of the structure and function of the brains of trans- and cisgender individuals that could help explain the conviction that one’s gender and natal sex don’t match. The results may not have much effect on how gender dysphoria is diagnosed and treated, notes Baudewijntje Kreukels, who studies gender incongruence at VU University Medical Center in Amsterdam. “It’s really important that it will not be seen as, ‘When you see [gender dysphoria] in the brain, then it’s true.’” But the insights from such research could go a long way toward satisfying the desire of some transgender people to understand the roots of their condition, she adds. “In that way, it is good to find out if these differences between them and their sex assigned at birth are reflected by measures in the brain.” © 1986-2018 The Scientist

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 24724 - Posted: 03.06.2018

By JANE E. BRODY When The New York Times hired me to write about science and health 52 years ago, I was 40 pounds overweight. I’d spent the previous three years watching my weight rise as I hopped from one diet to the next in a futile attempt to shed the pounds most recently gained. No amount of exercise, and I did plenty of it, could compensate for how much I ate when I abandoned the latest weight loss scheme. I had become a living example of the adage: A diet is something one goes on to go off. Even daylong fasting failed me. When I finally ate supper, I couldn’t stop eating until I fell asleep, and sometimes awoke the next morning with partly chewed food in my mouth. I had dieted myself into a binge-eating disorder, and that really scared me. Clearly, something had to change. I finally regained control when I stopped dieting. I decided that if I was going to be fat, at least I could be healthy. I made a plan to eat three nutritious, satisfying meals every day with one small snack, which helped me overcome the temptation to binge in response to deprivation. Much to my surprise, a month later I had lost 10 pounds — eating! Eating good food, that is, and plenty of it. I continued the regimen without difficulty because it was not a diet. It was a way to live and a healthy one at that. And I continued to lose, about two pounds a month. Two years later, all the excess weight was gone. I never gained it back and never again went on a diet. (Even with a twin pregnancy, I gained only 36 pounds and lost them all when my sons were born at 6 pounds 13 ounces each.) The greatest challenge to lasting weight loss, especially for someone like me with a food addiction, is the fact that no one can give up eating. Rather, one has to learn a better — and permanent — way to handle food. © 2018 The New York Times Company

Keyword: Obesity
Link ID: 24723 - Posted: 03.06.2018

By Virginia Morell A dog searching for a lost child is typically given an item of clothing to smell. But what does that scent “look” like? To find out, scientists tested 48 dogs, half of which had special police or rescue training. In a laboratory room, the scientists slid each dog’s favorite toy across the floor to a hiding place, while the dog waited in another room. One researcher then brought the dog to the testing room and pointed at the starting point of the odor trail and told the dog, “Look for it! Bring it!” In one trial, the dog found either its favored toy or—surprise!—a different item. Many of the surprised dogs continued searching for the toy used to lay the scent trail—an indication that they had a mental representation of what they expected to find, the scientists report today in the Journal of Comparative Psychology. Both family dogs and working dogs scored about the same on the tests, confirming previous studies showing that education doesn’t necessarily improve a dog’s performance. Previous studies have shown that horses have mental images of their owners and other horses—based on the sounds of their voices and whinnies. But scientists know little about how smell and cognition are linked in animals that rely heavily on smell—such as dogs, elephants, and rats. Now, we have a better idea at least for our pooches: They picture what they’re searching for. © 2018 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 24722 - Posted: 03.06.2018

Simon Parkin In an unprecedented attack of candour, Sean Parker, the 38-year-old founding president of Facebook, recently admitted that the social network was founded not to unite us, but to distract us. “The thought process was: ‘How do we consume as much of your time and conscious attention as possible?’” he said at an event in Philadelphia in November. To achieve this goal, Facebook’s architects exploited a “vulnerability in human psychology”, explained Parker, who resigned from the company in 2005. Whenever someone likes or comments on a post or photograph, he said, “we… give you a little dopamine hit”. Facebook is an empire of empires, then, built upon a molecule. A neuroscientist explains: the need for ‘empathetic citizens’ - podcast Dopamine, discovered in 1957, is one of 20 or so major neurotransmitters, a fleet of chemicals that, like bicycle couriers weaving through traffic, carry urgent messages between neurons, nerves and other cells in the body. These neurotransmitters ensure our hearts keep beating, our lungs keep breathing and, in dopamine’s case, that we know to get a glass of water when we feel thirsty, or attempt to procreate so that our genes may survive our death. In the 1950s, dopamine was thought to be largely associated with physical movement after a study showed that Parkinsonism (a group of neurological disorders whose symptoms include tremors, slow movement and stiffness) was caused by dopamine deficiency. In the 1980s, that assumption changed following a series of experiments on rats by Wolfram Schultz, now a professor of neuroscience at Cambridge University, which showed that, inside the midbrain, dopamine relates to the reward we receive for an action. Dopamine, it seemed, was to do with desire, ambition, addiction and sex drive.

Keyword: Drug Abuse
Link ID: 24721 - Posted: 03.05.2018

By Dina Fine Maron After Richard Hodges pleaded guilty to cocaine possession and residential burglary, he appeared somewhat dazed and kept asking questions that had nothing to do with the plea process. That’s when the judge ordered that Hodges undergo a neuropsychological examination and magnetic resonance imaging (MRI) testing. Yet no irregularities turned up. Hodges, experts concluded, was faking it. His guilty plea would stand. But experts looking back at the 2007 case now say Hodges was part of a burgeoning trend: Criminal defense strategies are increasingly relying on neurological evidence—psychological evaluations, behavioral tests or brain scans—to potentially mitigate punishment. Defendants may cite earlier head traumas or brain disorders as underlying reasons for their behavior, hoping this will be factored into a court’s decisions. Such defenses have been employed for decades, mostly in death penalty cases. But as science has evolved in recent years, the practice has become more common in criminal cases ranging from drug offenses to robberies. Advertisement “The number of cases in which people try to introduce neurotechnological evidence in the trial or sentencing phase has gone up by leaps and bounds,” says Joshua Sanes, director of the Center for Brain Science at Harvard University. But such attempts may be outpacing the scientific evidence behind the technology, he adds. © 2018 Scientific American

Keyword: Consciousness
Link ID: 24720 - Posted: 03.05.2018

Clayton Dalton When patients arrive in the emergency room, nearly all but those with the most minor complaints get an IV. To draw blood, give medications, or administer fluids — the IV is the way doctors and nurses gain access to the body. Putting one in is quick and simple, and it's no more painful than a mild bee sting. Yet for some patients this routine procedure becomes excruciating. On my shifts as an emergency physician, I began to notice a strange pattern. These hypersensitive patients often had a history of using opioids. Shouldn't these patients be less susceptible to pain, instead of more so? As I looked into it, I found that I was far from the first to notice the paradox of heightened pain sensitivity with opioid use. An English physician in 1870 reported on morphine's tendency to "encourage the very pain it pretends to relieve." In 1880, a German doctor named Rossbach described a similar hypersensitivity to pain with opioid dependence. A century passed before the phenomenon received serious scientific attention. That's when American scientists showed that rats exhibited increased sensitivity to pain after exposure to morphine, a phenomenon that became known as opioid-induced hyperalgesia. By the 1990s the evidence for this unusual reaction in animals was strong, but whether it occurred in humans wasn't clear. © 2018 npr

Keyword: Pain & Touch; Drug Abuse
Link ID: 24719 - Posted: 03.05.2018

By Simon Makin Ketamine has been called the biggest thing to happen to psychiatry in 50 years, due to its uniquely rapid and sustained antidepressant effects. It improves symptoms in as little as 30 minutes, compared with weeks or even months for existing antidepressants, and is effective even for the roughly one third of patients with so-called treatment-resistant depression Although there are multiple theories, researchers do not quite know how ketamine combats depression. Now, new research has uncovered a mechanism that may, in part, explain ketamine's antidepressant properties. Two studies, recently published in Nature, describe a distinctive pattern of neural activity that may drive depression in a region called the lateral habenula (LHb); Ketamine, in turn, blocks this activity in depression-prone rats. Originally licensed as an anesthetic in 1970, ketamine has since gained fame as a party drug for causing out-of-body experiences, hallucinations and other psychosislike effects. Its antidepressant properties in humans were discovered almost 20 years ago. Ketamine does not directly influence the same chemical messengers as standard antidepressants such as serotonin but rather works via interaction with another chemical, glutamate—not usually associated with mood but rather with brain plasticity. One prominent idea about how it alleviates depression is by promoting the growth of new neural connections. “We provide a new angle for people to think about how this drug works,” says neuroscientist Hailan Hu of Zhejiang University in China, leader of the team that conducted both studies. If she is right, her group may have identified multiple new lines of attack for treating a condition the World Health Organization calls the leading cause of disability worldwide. © 2018 Scientific American

Keyword: Depression; Drug Abuse
Link ID: 24718 - Posted: 03.02.2018

By Katarina Zimmer Jermaine Jones’s first memory of being a “bit of a scientist” was discovering that toilet water is actually pretty clean. While conducting a science fair pro-ject during his junior year of high school in Virginia, he learned that “you get much more varied bacteria from the toilet seat as opposed to the water,” he explains. With encouragement from his aunt, who was a biologist, Jones chose to pursue a degree in science at the University of Virginia. Over the course of several undergraduate internships, he got a taste of different fields of research, from probing decision making in mice to examining the analgesic effects of rainforest plant extracts in Brazil. By the time Jones had earned his master’s degree from Old Dominion University, he was certain that investigating drug abuse would be a good fit for his two main interests, pharmacology and psychology. For his PhD, Jones moved to Washington, D.C., where he worked on elucidating the neurobiological mechanisms of cocaine’s aversive effects in rodent models with Anthony Riley, a behavioral pharmacologist at American University. At the same time, Jones examined the effects of knocking out genes encoding the neurotransmitter transporters that the drug acts upon in mice with neuroscientists George Uhl and Scott Hall at the National Institute on Drug Abuse. For his dissertation, “he was able to show, pretty unequivocally, the role of neuro-transmitter systems in the aversive effects of cocaine in these mice,” Riley recalls.1 © 1986-2018 The Scientist

Keyword: Drug Abuse; Genes & Behavior
Link ID: 24717 - Posted: 03.02.2018

Russell Bonduriansky Wouldn’t it be wonderful if we could bring back a deceased loved one? Such ideas used to be pure science fiction, but recent advances in biotechnology seem to have brought this possibility within reach (at least for the wealthy). When American singer-actress Barbra Streisand lost her beloved dog Sammie last year, she decided to have her cloned. She’s now raising Miss Scarlet and Miss Violet, both of whom are exact genetic replicas of Sammie. (You’ll be glad to know that any pet owner can do the same: for a mere US$100,000 or so, you too could have a genetic replica of your favourite cat or dog.) But Miss Scarlett and Miss Violet almost certainly won’t turn out to be identical, mini versions of Sammie. Research on cloning started in the 1960s, when British biologist John Gurdon showed that a frog egg’s nucleus (which contains the DNA) could be swapped for another nucleus extracted from an intestinal cell, and that such eggs could develop into tadpoles. This technique makes it possible to create individuals that share every single one of the thousands of genes in the original genome. By comparison, you share only about 50% of your genes with your mother. The same nucleus-swapping technique can be used with mammals. In 1996, Dolly the sheep became the first cloned mammal, and today the technology is available to clone a human being – if we wanted to. © 2010–2018, The Conversation US, Inc.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 24716 - Posted: 03.02.2018

By VERONIQUE GREENWOOD If you think about being thirsty at all, it seems like a fairly simple thought process: Find water. Drink it. Move on. But in fact there is something rather profound going on as you take that long, refreshing drink after a run or a hot day in the garden. As you become dehydrated, there is less water in your blood, and neurons in your brain send out the word that it’s time to look for water. Then, once you take a drink, you feel almost instantly satisfied. But if that is obvious, it is also mysterious. You aren’t pouring water directly into your bloodstream, after all. It will take at least 10 or 15 minutes, maybe longer, for the water in your stomach to make its way into the blood. And yet somehow, the brain knows. Sometimes that process isn’t as straightforward as it should be: People with a syndrome called polydipsia feel excessive thirst and drink enormous quantities of water. That can be dangerous, because if the blood is diluted too much, a person can die — a victim of water intoxication. As neuroscientists ponder how and why we thirst, a group of researchers at the California Institute of Technology has shed light on one small corner of the problem. Interested in how the brain keeps track of what the body is drinking, they have identified a set of neurons that receive messages as thirsty mice gulp down water. Passed around in the brain’s thirst centers, these messages seem to be behind the sensation of swift satisfaction that comes after a drink, and also suggest that it’s not just what is drunk, but how it is slurped down, that affects the brain. If the circuits work the same way in people, it may be key to understanding the neuroscience of what happens as we feel thirsty. In the last few years, biologists have been mapping the neurons within an area in the brain that regulates thirst, said Yuki Oka, a professor at Caltech and senior author of the new paper, which was published Wednesday in Nature. Cells in this region had been observed going quiet after an animal had water, but it was not clear exactly why. © 2018 The New York Times Company

Keyword: Miscellaneous
Link ID: 24715 - Posted: 03.01.2018

Terry Gross Antidepressants and medications for bipolar disorder can be life-changing and even lifesaving, but journalist Lauren Slater warns that the long-term side effects of these drugs are "cloaked in mystery." "As a nation, we're consuming them; we're gobbling them down," she says. "And we don't really know what we're taking into our bodies." Slater, who suffers from depression and bipolar disorder, has firsthand experience with psychotropic drugs; she has been taking medication for 35 years. Her new book, Blue Dreams, dedicates separate chapters to drugs such as Thorazine, lithium and psilocybin. Slater says she wanted to "unveil" the drugs by explaining their history, as well as how they work and the benefits and consequences for people who take them: "My goal was to almost try to make the drug into a character in and of itself. ... I wanted to bring these drugs alive." On how Thorazine changed the way mental illness was treated [Long] before Thorazine, people thought that mental illness was the result of what are called "humors" — blood, phlegm, bodily fluids that went out of whack. ... [Later, they] believed that it could be the result of hereditary genes gone wrong. But then Thorazine was invented, and that sort of was the kick-start to a whole bunch of other drugs being invented and to doctors and later the public at large thinking that mental illness was biochemical in nature. ... © 2018 npr

Keyword: Depression; Schizophrenia
Link ID: 24714 - Posted: 03.01.2018

Alice M. Gregory, Erin Leichman, Jodi Mindell Pairing the words “baby” and “sleep” can evoke strong emotions. Those who have had limited contact with little ones might interpret this word-combination as implying deep and prolonged slumber. For others, this union of words may elicit memories of prolonged periods of chaotic sleep (or what can feel like no sleep at all). Coping with the way babies sleep can be difficult. It’s not that babies don’t sleep. In fact, they sleep more than at any other stage of life. It’s more an issue of when they sleep. Newborns start by sleeping and waking around the clock. This is not always easy for parents. There is even research suggesting that in adults waking repeatedly at night can feel as bad as getting hardly any sleep in terms of attentional skills, fatigue levels and symptoms of depression. As to why infants wake at night, this is best explained by thinking about the two things that govern our sleep: the homeostatic and circadian processes. The crux of the homeostatic process is the straightforward idea that the longer we have been awake the greater our sleep drive (and the more sleepy we feel). It may take an adult an entire day to build up enough sleep drive to fall asleep at bedtime, but an infant may only need an hour or two of wakefulness before being able to drift off to sleep. The second process is circadian, which works like a clock. Adults typically feel more awake during the morning hours and sleepy at night, regardless of when we last slept. In very young babies this process is not yet developed. This means that sleep is more likely to occur at different points across the 24-hour day. © 2018 Guardian News and Media Limited

Keyword: Sleep; Development of the Brain
Link ID: 24713 - Posted: 03.01.2018

By NICHOLAS BAKALAR Some experts have suggested that there is an “obesity paradox,” the idea that obese people live longer than those of normal weight. But a new study found that obesity was associated with an increased risk for cardiovascular disease and a two- to three-year shorter life span. The study, in JAMA Cardiology, pooled data from 10 studies of 190,672 people followed from 1964 to 2015. Compared with those of normal weight, overweight men (body mass index of 25 to 29.9) had a 21 percent higher lifetime risk of cardiovascular disease and women a 32 percent higher risk. Among the obese (B.M.I. of 30 to 39.9), the risk was 67 percent higher for men and 85 percent higher for women, with even higher risk for those with a B.M.I. over 40. Longevity in men who were overweight but not obese was similar to that of men of normal weight. But they had an increased risk of cardiovascular disease at a younger age. “We were able to measure how much time is spent in healthy life years rather than just life span,” said the study’s senior author, Dr. Sadiya S. Khan, an assistant professor of medicine at Northwestern. “Maintaining a healthy B.M.I. is associated with a longer, healthier life, with less risk for cardiovascular disease.” © 2018 The New York Times Company

Keyword: Obesity
Link ID: 24712 - Posted: 03.01.2018

By NICHOLAS BAKALAR Overweight mothers are more likely to have overweight babies, and the gut bacteria the babies inherit may in part be to blame. Researchers report that overweight mothers are more likely to have a cesarean section, and that babies born by cesarean to those mothers have species of gut bacteria different from those in babies born to normal weight women. And that difference in the gut microbiome — specifically an abundance of bacteria of the family Lachnospiraceae in infants of overweight mothers — may contribute to an increased risk for obesity. The study included 935 mother-infant pairs. Compared to children born to normal weight mothers, those born vaginally to overweight women were more than three times as likely to be overweight by age 3. But C-section babies born to overweight mothers were more than five times as likely to be overweight. For normal weight mothers, vaginal or C-section delivery made no difference in the risk for overweight babies. The study, in JAMA Pediatrics, controlled for breast-feeding, antibiotic exposure and other factors. The senior author, Anita L. Kozyrskyj, a professor of pediatrics at the University of Alberta, said that there is no probiotic that would lead to a positive change in gut bacteria. “If a cesarean is unavoidable, there is no easy answer,” she added, “but breast-feeding is effective in helping to prevent infants from becoming overweight.” © 2018 The New York Times Company

Keyword: Obesity
Link ID: 24711 - Posted: 03.01.2018

Helen Thomson In March 2015, Li-Huei Tsai set up a tiny disco for some of the mice in her laboratory. For an hour each day, she placed them in a box lit only by a flickering strobe. The mice — which had been engineered to produce plaques of the peptide amyloid-β in the brain, a hallmark of Alzheimer’s disease — crawled about curiously. When Tsai later dissected them, those that had been to the mini dance parties had significantly lower levels of plaque than mice that had spent the same time in the dark1. Tsai, a neuroscientist at Massachusetts Institute of Technology (MIT) in Cambridge, says she checked the result; then checked it again. “For the longest time, I didn’t believe it,” she says. Her team had managed to clear amyloid from part of the brain with a flickering light. The strobe was tuned to 40 hertz and was designed to manipulate the rodents’ brainwaves, triggering a host of biological effects that eliminated the plaque-forming proteins. Although promising findings in mouse models of Alzheimer’s disease have been notoriously difficult to replicate in humans, the experiment offered some tantalizing possibilities. “The result was so mind-boggling and so robust, it took a while for the idea to sink in, but we knew we needed to work out a way of trying out the same thing in humans,” Tsai says. “There’s been an explosion in brain wave research…pick your area and different people are trying to apply extra cranial stimulation.” The neuroscience that’s making waves for a wide range of conditions. © 2018 Macmillan Publishers Limited,

Keyword: Alzheimers; Learning & Memory
Link ID: 24710 - Posted: 02.28.2018