By Alexandra Sacks, M.D. A new mother finally gets her fussy baby to sleep and steps into a relaxing hot shower — with her glasses on. At a family barbecue she can’t recall the name of a relative she rarely sees. It’s easy to laugh off such lapses as “mommy brain,” but there remains a cultural belief that pregnancy and child care impact a woman’s cognition and mental life, long after a baby is born. Women have often chalked up these changes to hormones, fatigue and the intoxicating love for a new baby. Hormones do affect cognition, and, as anyone who has ever done shift work or had jet lag knows, sleep deprivation saps our mental abilities. And the current evidence in scientific literature suggests that pregnancy changes the brain on a physical, cellular level in ways that we are only beginning to understand. However, there is no convincing scientific evidence that pregnancy causes an overall decline in cognitive performance or memory. Instead, most experts believe that pregnant women’s brain changes are an example of neuroplasticity, the process in which the brain changes throughout life by reorganizing connections in response to the stimulation of new experiences, and neurogenesis, the process of growth that allows for new learning. A 2016 study in Nature Neuroscience found that even two years after pregnancy, women had gray matter brain changes in regions involved in social cognition or the ability to empathically understand what is going on in the mind of another person, to put yourself in their shoes. It may be that some subtle aspects of memory are sacrificed to enhance other areas of cognition. A 2010 study in Psychoneuroendocrinology showed that pregnant women experienced some impairment in the ability to remember words, but did not show changes in other memory functions such as recognition or working memory. This means that these women might forget the name of a character in their favorite TV show, for example, but would have no trouble in the type of memory that involves learning, reasoning and comprehension. © 2018 The New York Times Company

Keyword: Sexual Behavior; Learning & Memory
Link ID: 24969 - Posted: 05.12.2018

By Neuroskeptic A new paper in ACS Chemical Neuroscience pulls no punches in claiming that most of what we know about the neuroscience of learning is wrong: Dendritic Learning as a Paradigm Shift in Brain Learning According to authors Shira Sardi and colleagues, the prevailing view which is that learning takes place in the synapses is mistaken. Instead, they say, ‘dendritic learning’ is how brain cells really store information. If a neuron is a tree, the dendrites are the branches, while the synapses are the leaves on the ends of those branches. Here’s how Sardi et al. explain their new theory: On the left we see the idea of synaptic learning, which proposes that each synapse can independently adjust its strength. On the right, we have dendritic learning, the idea that each neuron only has a small number of adjustable units, corresponding to the main dendritic branches. The evidence for dendritic learning, Sardi et al. say, comes from experiments using cultured neurons in which they found that a) some neurons are more likely to fire when stimulated in certain places, suggesting that dendrites can vary in their excitability and b) that these (presumed) dendritic excitability levels are plastic (they can ‘learn’.)

Keyword: Learning & Memory
Link ID: 24968 - Posted: 05.12.2018

Bruce Bower Language learning isn’t kid stuff anymore. In fact, it never was, a provocative new study concludes. A crucial period for learning the rules and structure of a language lasts up to around age 17 or 18, say psychologist Joshua Hartshorne of MIT and colleagues. Previous research had suggested that grammar-learning ability flourished in early childhood before hitting a dead end around age 5. If that were true, people who move to another country and try to learn a second language after the first few years of life should have a hard time achieving the fluency of native speakers. But that’s not so, Hartshorne’s team reports online May 2 in Cognition. In an online sample of unprecedented size, people who started learning English as a second language in an English-speaking country by age 10 to 12 ultimately mastered the new tongue as well as folks who had learned English and another language simultaneously from birth, the researchers say. Both groups, however, fell somewhat short of the grammatical fluency displayed by English-only speakers. After ages 10 to 12, new-to-English learners reached lower levels of fluency than those who started learning English at younger ages because time ran out when their grammar-absorbing ability plummeted starting around age 17. In another surprise, modest amounts of English learning among native and second-language speakers continued until around age 30, the investigators found, although most learning happened in the first 10 to 20 years of life. |© Society for Science & the Public 2000 - 2018

Keyword: Language; Development of the Brain
Link ID: 24967 - Posted: 05.12.2018

/ By David Dobbs If you think of beauty as something absolute — if you think Beyoncé or George Clooney is just beautiful, simple as that — Michael J. Ryan is here to tell you you’re wrong. Beauty, he asserts in this lovely and learned new book, exists only as a value-laden, capricious, and sometimes fleeting perception generated by the brain. Sexual selection is a counterintuitive theory that tries to explain bizarre forms and behavior. Even Darwin couldn’t quite wrap his mind around it. Beauty is literally in the eye of the beholder: It reveals itself only where and when the beholder thinks it does. In effect, then, to perceive beauty is to create it. And virtually all sexual species have evolved both the neural systems to perceive beauty and the traits that are or become so perceived. If you’re thinking this sounds circular and suspiciously chicken-and-egg, I’m here to tell you you’re right. Sexual selection is a complex, counterintuitive, three-pronged theory that seeks to explain both everyday sexual attraction and some of nature’s most bizarre forms, phenomena, and behavior. Even Darwin, who conceived the theory a century and a half ago, couldn’t quite wrap his mind around it, and the mature version that Ryan explores here is much and savagely disputed. The difficulty of explaining how sexual selection creates beauty is only Ryan’s first challenge. His second is that at least two notable books have already explained it memorably. The first, of course, was “The Descent of Man, and Selection in Relation to Sex” (Darwin’s “second most famous book,” notes Ryan), which explained it memorably but incompletely. Copyright 2018 Undark

Keyword: Emotions; Evolution
Link ID: 24966 - Posted: 05.12.2018

Michael Pollan first became interested in new research into psychedelic drugs in 2010, when a front-page story in the New York Times declared, “Hallucinogens Have Doctors Tuning in Again”. The story revealed how in a large-scale trial researchers had been giving terminally ill cancer patients large doses of psilocybin – the active ingredient in magic mushrooms – to help them deal with their “existential distress” as they approached death. The initial findings were markedly positive. Pollan, author of award-winning and bestselling books about botany, food politics and the way we eat, was born in 1955, a little too late for the Summer of Love. That New York Times story, however, was the beginning of an “adventure” that saw him not only explore the new research, but also detail the history of psychedelic drugs, the “moral panic” backlash against them and – partly through personal experiments with LSD, magic mushrooms and ayuhuasca, the “spiritual medicine” of Amazonian Indians – to examine whether they have a significant part to play in contemporary culture. The result of that inquiry is a compulsive book, How to Change Your Mind: Exploring the New Science of Psychedelics. This interview took place by phone last week. Pollan was speaking from his home in northern California. Do you see this book on psychedelics as a departure in your writing, or part of a continuum? Both, really. I have this abiding interest in how we interact with other plant and animal species and how they get ahead in nature by gratifying our desires. And one of those desires I have always been keenly interested in is the desire to change consciousness. You propose the idea at one point that neurochemistry is perhaps the language by which plants communicate with us. Isn’t it more that magic mushrooms have evolved a clever way of making themselves invaluable? They have. There is no intention involved, obviously. But evolution does not depend on intention. One strategy that these fungi seem to have hit on is manufacturing a chemical that can unlock these effects in the animal brain. Obviously some drug plants benefit us by relieving pain or boredom, but others do interesting things with consciousness.

Keyword: Drug Abuse; Depression
Link ID: 24965 - Posted: 05.12.2018

By Ashley Yeager At first glance, neurons and muscle cells are the stars of gross motor function. Muscle movement results from coordination between nerve and muscle cells: when an action potential arrives at the presynaptic neuron terminal, calcium ions flow, causing proteins to fuse with the cell membrane and release some of the neuron’s contents, including acetylcholine, into the cleft between the neuron and muscle cell. Acetylcholine binds to receptors on the muscle cell, sending calcium ions into it and causing it to contract. But there’s also a third kind of cell at neuromuscular junctions, a terminal/perisynaptic Schwann cell (TPSC). These cells are known to aid in synapse formation and in the repair of injured peripheral motor axons, but their possible role in synaptic communications has been largely ignored. Problems with synaptic communication can underlie muscle fatigue, notes neuroscientist Thomas Gould of the University of Nevada, Reno, in an email to The Scientist. “Because these cells are activated by synaptic activity, we wondered what the role of this activation was.” To investigate, he and his colleagues stimulated motor neurons from neonatal mouse diaphragm tissue producing a calcium indicator, and found that TPSCs released calcium ions from the endoplasmic reticulum into the cytosol and could take in potassium ions from the synaptic cleft between neurons and muscle cells. However, TPSCs lacking the protein purinergic 2Y1 receptor (P2Y1R) didn’t release calcium or appear to take in potassium ions. © 1986-2018 The Scientist

Keyword: Glia; Muscles
Link ID: 24964 - Posted: 05.12.2018

Laurel Hamers Toastier nest temperatures, rather than sex chromosomes, turn baby turtles female. Now, a genetic explanation for how temperature determines turtles’ sex is emerging: Scientists have identified a temperature-responsive gene that sets turtle embryos on a path to being either male or female. When researchers dialed down that gene early in development, turtle embryos incubating at the cooler climes that would normally yield males turned out female instead, researchers report in the May 11 Science. Scientists have struggled since the 1960s to explain how a temperature cue can flip the sex switch for turtles and other reptiles (SN Online: 1/8/18). That’s partly because gene-manipulating techniques that are well-established in mice don’t work in reptiles, says study coauthor Blanche Capel, a developmental biologist at Duke University School of Medicine. Previous studies showed certain genes, including one called Kdm6b, behaving differently in developing male and female turtles. But until recently, nobody had been able to tweak those genes to directly test which ones controlled sex. “This is the first venture down that path,” says Clare Holleley, an evolutionary geneticist at the Australian National Wildlife Collection in Canberra who wasn’t part of the study. “It's really quite a breakthrough.” In the new study, Capel’s lab collaborated with a group of Chinese researchers led by Chutian Ge of Zhejiang Wanli University in Ningbo. Ge’s team recently developed a way to lessen the activity of particular reptilian genes by injecting viruses bearing snippets of artificial RNA into developing eggs. |© Society for Science & the Public 2000 - 2018

Keyword: Sexual Behavior; Epigenetics
Link ID: 24963 - Posted: 05.11.2018

In a study of mice, National Institutes of Health-funded researchers describe a new circuit involved in fine-tuning the brain’s decision either to hide or confront threats. The study, published in Nature, was partially funded by the NIH’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. “Being able to manipulate specific circuits can uncover surprising relationships between brain areas and provide great insight into how the sensory, emotional, and behavioral centers work together to drive reactions,” said Jim Gnadt, Ph.D., program director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a team lead for the BRAIN Initiative. “The tools and technologies developed through the BRAIN Initiative have made studies such as this one possible.” A team of researchers led by Andrew Huberman, Ph.D., professor of neurobiology and of ophthalmology at Stanford University in California, investigated the role of the ventral midline thalamus (vMT) in determining how animals respond to visual threats. The thalamus is a brain region that acts as a relay station, taking in sensory information, such as what is seen and heard, and sorting out where in the brain to send that information. Dr. Huberman and his colleagues showed that the vMT was activated when mice were confronted with a threat, specifically a black circle that grew larger on top of their cage, mimicking the experience of something looming over them. When faced with the looming threat, the mice spent most of the time freezing or hiding and very little time rattling their tails, which is typically an aggressive response.

Keyword: Emotions; Aggression
Link ID: 24962 - Posted: 05.11.2018

Katie Nicholson, Joanne Levasseur Cannabidiol oil, or CBD, is generating a lot of buzz in the world of alternative medicine and many Canadians are buying in. The oil, which is extracted from marijuana plants, doesn't have the same mind-altering effects as smoking pot. People rub it on their achy joints or put it under their tongue to help them sleep. Some purveyors say it's completely legal in Canada and can be used for a long list of ailments, including epilepsy and multiple sclerosis. But federal authorities say CBD oil, which is widely available at head shops and online, is indeed illegal without a medical marijuana prescription. And its purported health benefits are also still in question. Cannabis products not yet legal Canadian affiliates of HempWorx, a multi-level marketing company based in Las Vegas, have been pushing CBD oil products through websites that say the product is allowed in Canada. They also list how much people should take for a long list of diseases. HempWorx did not respond to multiple interview requests. But in April, one of its Winnipeg-based affiliates told CBC News that its sale is "100 per cent legal." Under current Canadian law, the possession or sale of cannabidiol oil is illegal the same way other cannabis products are illegal. The same goes for importing or exporting the substance. The fact that it doesn't get you high doesn't matter. ©2018 CBC/Radio-Canada.

Keyword: Drug Abuse; Pain & Touch
Link ID: 24961 - Posted: 05.11.2018

A new discovery shows that opioids used to treat pain, such as morphine and oxycodone, produce their effects by binding to receptors inside neurons, contrary to conventional wisdom that they acted only on the same surface receptors as endogenous opioids, which are produced naturally in the brain. However, when researchers funded by the National Institute on Drug Abuse (NIDA) used a novel molecular probe to test that common assumption, they discovered that medically used opioids also bind to receptors that are not a target for the naturally occurring opioids. NIDA is part of the National Institutes of Health. This difference between how medically used and naturally made opioids interact with nerve cells may help guide the design of pain relievers that do not produce addiction or other adverse effects produced by morphine and other opioid medicines. “This ground-breaking study has uncovered important distinctions between the opioids that our brain makes naturally and therapeutic opioids that can be misused,” said NIDA Director Nora D. Volkow, M.D. “This information can be mined to better understand the potential adverse actions of medically prescribed opioids and how to manipulate the endogenous system to achieve optimal therapeutic results without the unhealthy side effects of tolerance, dependence, or addiction.” Naturally occurring opioids and medically used opioids alike bind to the mu-opioid receptor, a member of a widespread family of proteins known as G protein-coupled receptors (GPCRs). Recent advances in understanding the three-dimensional structure of GPCRs have enabled researchers to create a new type of antibody biosensor, called a nanobody, that generates a fluorescent signal when a GPCR is activated. This enables scientists to track chemicals as they move through cells and respond to stimuli.

Keyword: Pain & Touch; Drug Abuse
Link ID: 24960 - Posted: 05.11.2018

By Lina Zeldovich, You can draw a straight line from the initial descriptions of many conditions—claustrophobia, for example, or vertigo—to their diagnostic criteria. Not so with autism. Its history has taken a less direct path with several detours, according to Jeffrey Baker, professor of pediatrics and history at Duke University in Durham, North Carolina. Autism was originally described as a form of childhood schizophrenia and the result of cold parenting, then as a set of related developmental disorders, and finally as a spectrum condition with wide-ranging degrees of impairment. Along with these shifting views, its diagnostic criteria have changed as well. Here is how the Diagnostic and Statistical Manual of Mental Disorders (DSM), the diagnostic manual used in the United States, has reflected our evolving understanding of autism. Why was autism initially considered a psychiatric condition? When Leo Kanner, an Austrian-American psychiatrist and physician, first described autism in 1943, he wrote about children with “extreme autistic aloneness,” “delayed echolalia” and an “anxiously obsessive desire for the maintenance of sameness.” He also noted that the children were often intelligent and some had extraordinary memory. As a result, Kanner viewed autism as a profound emotional disturbance that does not affect cognition. In keeping with his perspective, the second edition of the DSM, the DSM-II, published in 1952, defined autism as a psychiatric condition—a form of childhood schizophrenia marked by a detachment from reality. During the 1950s and 1960s, autism was thought to be rooted in cold and unemotional mothers, whom Bruno Bettelheim dubbed “refrigerator mothers.” © 2018 American Association for the Advancement of Science.

Keyword: Autism
Link ID: 24959 - Posted: 05.10.2018

Maria Temming An artificial intelligence that navigates its environment much like mammals do could help solve a mystery about our own internal GPS. Equipped with virtual versions of specialized brain nerve cells called grid cells, the AI could easily solve and plan new routes through virtual mazes. That performance, described online May 9 in Nature, suggests the grid cells in animal brains play a critical role in path planning. “This is a big step forward” in understanding our own navigational neural circuitry, says Ingmar Kanitscheider, a computational neuroscientist at the University of Texas at Austin not involved in the work. The discovery that rats track their location with the help of grid cells, which project an imaginary hexagonal lattice onto an animal’s surroundings, earned a Norwegian research team the 2014 Nobel Prize in physiology or medicine (SN Online: 10/6/14). Neuroscientists suspected these cells, which have also been found in humans, might help not only give mammals an internal coordinate system, but also plan direct paths between points (SN Online: 8/5/13). To test that idea, neuroscientist Caswell Barry at University College London, along with colleagues at Google DeepMind, created an AI that contained virtual nerve cells, or neurons, whose activity resembled that of real grid cells. The researchers trained this AI to navigate virtual mazes by giving the system reward signals when it reached its destination. |© Society for Science & the Public 2000 - 2018

Keyword: Learning & Memory; Robotics
Link ID: 24958 - Posted: 05.10.2018

Alison Abbott Scientists have used artificial intelligence (AI) to recreate the complex neural codes that the brain uses to navigate through space. The feat demonstrates how powerful AI algorithms can assist conventional neuroscience research to test theories about the brain’s workings — but the approach is not going to put neuroscientists out of work just yet, say the researchers. “It really was a very striking and remarkable convergence of form and function.” The computer program, details of which were published in Nature on 9 May1, was developed by neuroscientists at University College London (UCL) and AI researchers at the London-based Google company DeepMind. It used a technique called deep learning — a type of AI inspired by the structures in the brain — to train a computer-simulated rat to track its position in a virtual environment. The program surprised the scientists by spontaneously generating hexagonal-shaped patterns of activity akin to those generated by navigational cells in the mammalian brain called grid cells. Grid cells have been shown in experiments with real rats to be fundamental to how an animal tracks its own position in space. What’s more, the simulated rat was able to use the grid-cell-like coding to navigate a virtual maze so well that it even learnt to take shortcuts. © 2018 Macmillan Publishers Limited,

Keyword: Learning & Memory; Robotics
Link ID: 24957 - Posted: 05.10.2018

by Karin Brulliard For several years, an animal rights organization has sought to convince New York courts that chimpanzees kept by private owners are “legal persons” with a right to be free. For several years, the courts have rejected that argument. New York’s highest court did the same on Tuesday, denying an appeal of a lower court’s refusal to grant writs of habeas corpus to two caged chimps named Tommy and Kiko. But in a striking concurring opinion that was cheered by the chimps’ advocates, one judge wrote that the legal question at the heart of the case — whether all animals are mere property or things — is far from settled. “Does an intelligent nonhuman animal who thinks and plans and appreciates life as human beings do have the right to the protection of the law against arbitrary cruelties and enforced detentions visited on him or her?” wrote Eugene Fahey, one of five Court of Appeals judges who ruled on the matter. “This is not merely a definitional question, but a deep dilemma of ethics and policy that demands our attention.” The 5-to-0 vote upheld a June decision by a lower appeals court that, like courts before it, ruled that chimpanzees could not be legal persons because they cannot take on legal duties. The Nonhuman Rights Project, which has asked courts to move Tommy and Kiko to a sanctuary, says the interpretation is flawed. The group’s director, Steven M. Wise, has noted in interviews that both infants or comatose people possess rights despite an inability to assume legal duties and that primate experts say chimps have rights and responsibilities within peer groups and in settings with humans. © 1996-2018 The Washington Post

Keyword: Animal Rights
Link ID: 24956 - Posted: 05.10.2018

By Nicholas Bakalar Some earlier observational studies have suggested that children who are exclusively breast-fed have higher I.Q.s through adolescence, and even higher incomes at age 30. But a randomized trial, a more rigorous type of study that better controls for socioeconomic and family variables, found that breast-feeding in infancy had no discernible effect on cognitive function by the time children reached age 16. Researchers studied 13,557 children in Belarus, assigning them as newborns either to a program that promoted exclusive and prolonged breast-feeding or to usual care. Mothers and children were followed with six pediatrician visits during the first year of life to assess breast-feeding habits. The study is in PLOS Medicine. At age 16, the children took tests measuring verbal and nonverbal memory, word recognition, executive function, visual-spatial orientation, information processing speed and fine motor skills. There was no difference in scores between the two groups, except that breast-feeders had slightly higher scores in verbal function. “If you want to breast-feed in hope of increasing cognitive functioning scores, you may find some benefits in the early years,” said the lead author, Seungmi Yang, an assistant professor of epidemiology at McGill University in Montreal. “But the effect is going to be reduced substantially at adolescence. Other factors, such as birth order and parental education, are more influential.” © 2018 The New York Times Company

Keyword: Development of the Brain; Intelligence
Link ID: 24955 - Posted: 05.10.2018

By Vanessa Zainzinger Two years ago, when the U.S. Congress approved a major rewrite of the nation’s chemical safety law, lawmakers ordered federal regulators to take steps to reduce the number of animals that companies use to test compounds for safety. But a recent analysis by two animal welfare groups found that the number of animal tests requested or required by the Environmental Protection Agency (EPA) jumped dramatically last year, from just a few dozen tests involving fewer than 7000 animals in 2016, to more than 300 tests involving some 75,000 rats, rabbits, and other vertebrates. The cause of the increase isn’t clear. But the new law imposes stricter requirements on a broader array of chemicals than its predecessor, including both new products and ones already on the market, and experts say EPA staff may be trying to comply by gathering more test data from companies. Both industry and animal welfare groups are alarmed by the trend, and are asking agency officials to clarify why they are requesting the tests—and how they plan to reduce the number in the future. In a 27 March letter to EPA officials, the two Washington, D.C.–based groups that produced the analysis—People for the Ethical Treatment of Animals (PETA) and the Physicians Committee for Responsible Medicine (PCRM)—wrote that the “appalling” number of animals being used in tests “indicates EPA is failing to balance” its responsibility to evaluate chemicals’ risks against its obligation to pursue alternatives to animal testing. © 2018 American Association for the Advancement of Science.

Keyword: Animal Rights
Link ID: 24954 - Posted: 05.09.2018

by Lindsey Bever For years, Kendra Jackson battled an incessantly runny nose — sniffling and sneezing, blowing and losing sleep each night. Jackson said she initially thought she was getting a cold, then, as her symptoms persisted, doctors suggested it was likely seasonal allergies, putting her among the more than 50 million Americans who struggle with them each year. But the symptoms never cleared up, and, as the years went by, Jackson started to worry that it might be something worse. She told ABC affiliate KETV this week her nose ran “like a waterfall, continuously, and then it would run to the back of my throat.” “Everywhere I went,” she added, “I always had a box of Puffs, always stuffed in my pocket.” She had frequent headaches. And she could rarely sleep. Doctors at Nebraska Medicine in Omaha recently diagnosed Jackson with a cerebrospinal fluid (CSF) leak, a condition in which the watery liquid surrounding the brain spills out through a hole or tear in the skull and then drains into the ears or the nose, according to Johns Hopkins Medicine. The doctors told Jackson that she was losing an estimated half-pint of the fluid per day through her nose, according to KETV. © 1996-2018 The Washington Post

Keyword: Pain & Touch; Brain Injury/Concussion
Link ID: 24953 - Posted: 05.09.2018

By Lloyd I. Sederer Psychoactive drugs chemically alter the brain and change the way we feel, think, perceive and understand our world. They are ubiquitous: alcohol, cannabis, opioids, tobacco, stimulants, sedatives and hallucinogens, to name a few. Some occur naturally—nature’s contribution to our bodies and psyches—and some are synthesized in labs to impact the same brain receptors as do those found in forests, deserts and open fields. We are in a psychoactive drug epidemic in our country, most notably the opioids, because of their tragic death toll. We need solutions to the epidemic to save lives, families and communities—and government treasuries. But if we focus only on the drug itself, whatever it may be, we will miss what really matters when it comes to how human beings respond to psychoactive agents. Here are nine things that matter when it comes to drugs: 1. Age. It’s one thing to start drinking or smoking dope when you are 21. It is very different when at 12 or 13 or 15, even 18. That’s because the human brain is still under construction until well into the 20s, later for males than females. It takes almost three decades for the brain to fully lay down the fatty substance, myelin, that surrounds the nerve connections and permits reflection and controls impulsive action, for the cortex to stand a chance against the drive centers deeper in the brain. Repetitive or high doses of psychoactive drugs like cannabis, alcohol and hallucinogens interfere with the normal development of the brain. Not a good thing, and cause for controls on the access youth can have to substances. © 2018 Scientific American

Keyword: Drug Abuse
Link ID: 24952 - Posted: 05.09.2018

By Gretchen Reynolds Exercise changes the brains and sperm of male animals in ways that later affect the brains and thinking skills of their offspring, according to a fascinating new study involving mice. The findings indicate that some of the brain benefits of physical activity may be passed along to children, even if a father does not begin to exercise until adulthood. We already have plenty of scientific evidence showing that exercise is good for our brains, whether we are mice or people. Among other effects, physical activity can strengthen the connections between neurons in the hippocampus, a crucial part of the brain involved in memory and learning. Stronger neuronal connections there generally mean sharper thinking. Studies also indicate that exercise, like other aspects of lifestyle, can alter how genes work — whether and when they get turned on or off, for instance — and those changes can get passed on to children. This process is known as epigenetics. But it had not been clear whether structural changes in the brain caused by exercise might also have epigenetic effects that would result in meaningful changes in the brains of the next generation. In other words, would exercise by a parent help to produce smarter babies? And, in particular, would this process occur in males, who contribute sperm but not a womb and its multitude of hormones, cells and tissues to their children? To find out, researchers at the German Center for Neurodegenerative Diseases in Göttingen, Germany, and other institutions gathered a large group of genetically identical male mice. Because the animals were genetically the same at the start, any differences in their bodies and behavior that cropped up later should be a result of lifestyle. © 2018 The New York Times Company

Keyword: Epigenetics; Learning & Memory
Link ID: 24951 - Posted: 05.09.2018

By Roni Dengler Just looking at a picture of a skinny model on the cover of Glamour or Elle makes many women feel bad about their own weight. Now, science is backing them up. The largest study of its kind finds images of thinner women make even healthy weight women less satisfied with their own bodies—but looking at heavier women makes them feel better. Researchers showed nearly 200 18- to 25-year-old female study participants with a “healthy” body mass index score between 19 and 25 images of normal-, underweight-, or overweight-looking women of the same age and ethnicity. All the images were originally of healthy weight women, but researchers altered some of the pictures to make the models appear larger or smaller by increasing or decreasing the width of the images by 150 pixels. Women who viewed images of the resulting healthy and “overweight” models reported feeling more satisfied with their own body size than women who viewed images of “underweight” models did. After looking at pictures of “underweight” models, women’s satisfaction with their own bodies hardly changed, whereas after seeing healthy weight models, women reported feeling nearly 9% more satisfied with their own body size, for example. Plus, women who viewed images of normal and overweight models perceived their own bodies as smaller, including women who came into the study already feeling highly dissatisfied with their bodies—similar to how eating disorder patients feel. Participants rated whether they thought they were too thin or too fat on a 0-to-10 scale when looking at themselves in a mirror. How they scored themselves dropped by almost 6% after looking at pictures of healthy and overweight models, researchers report today in Royal Society Open Science. In addition, these women felt better about themselves after seeing images of overweight women. And those differences in body satisfaction stuck around for 24 hours. © 2018 American Association for the Advancement of Science.

Keyword: Anorexia & Bulimia
Link ID: 24950 - Posted: 05.09.2018