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Laura Beil Neuroscientist Barbara Bendlin studies the brain as Alzheimer’s disease develops. When she goes home, she tries to leave her work in the lab. But one recent research project has crossed into her personal life: She now takes sleep much more seriously. Bendlin works at the University of Wisconsin–Madison, home to the Wisconsin Registry for Alzheimer’s Prevention, a study of more than 1,500 people who were ages 40 to 65 when they signed up. Members of the registry did not have symptoms of dementia when they volunteered, but more than 70 percent had a family history of Alzheimer’s disease. Since 2001, participants have been tested regularly for memory loss and other signs of the disease, such as the presence of amyloid-beta, a protein fragment that can clump into sticky plaques in the brain. Those plaques are a hallmark of Alzheimer’s, the most common form of dementia. Each person also fills out lengthy questionnaires about their lives in the hopes that one day the information will offer clues to the disease. Among the inquiries: How tired are you? Some answers to the sleep questions have been eye-opening. Bendlin and her colleagues identified 98 people from the registry who recorded their sleep quality and had brain scans. Those who slept badly — measured by such things as being tired during the day — tended to have more A-beta plaques visible on brain imaging, the researchers reported in 2015 in Neurobiology of Aging. |© Society for Science & the Public 2000 - 2018.

Keyword: Sleep; Alzheimers
Link ID: 25212 - Posted: 07.16.2018

Allison Aubrey Can't cool off this summer? Heat waves can slow us down in ways we may not realize. New research suggests heat stress can muddle our thinking, making simple math a little harder to do. "There's evidence that our brains are susceptible to temperature abnormalities," says Joe Allen, co-director of the Center for Climate, Health and the Global Environment at Harvard University. And as the climate changes, temperatures spike and heat waves are more frequent. To learn more about how the heat influences young, healthy adults, Allen and his colleagues studied college students living in dorms during a summer heat wave in Boston. Half of the students lived in buildings with central AC, where the indoor air temperature averaged 71 degrees. The other half lived in dorms with no AC, where air temperatures averaged almost 80 degrees. "In the morning, when they woke up, we pushed tests out to their cellphones," explains Allen. The students took two tests a day for 12 consecutive days. One test, which included basic addition and subtraction, measured cognitive speed and memory. A second test assessed attention and processing speed. "We found that the students who were in the non-air-conditioned buildings actually had slower reaction times: 13 percent lower performance on basic arithmetic tests, and nearly a 10 percent reduction in the number of correct responses per minute," Allen explains. The results, published in PLOS Medicine, may come as a surprise. "I think it's a little bit akin to the frog in the boiling water," Allen says. There's a "slow, steady — largely imperceptible — rise in temperature, and you don't realize it's having an impact on you." © 2018 npr

Keyword: Attention
Link ID: 25211 - Posted: 07.16.2018

by Melissa Healy An extra shot of testosterone, it seems, makes a man act like an animal. You know the type: one of those male birds that unfurls some of its most spectacular feathers when the ladies are around, or the buck who uses his crown of antlers to advertise his virility. In short, an animal prone to making showy displays of his power, beauty or wealth to win mates, gain allies and intimidate competitors. But for humans — American men, at least — new research suggests that this testosterone-driven display of prowess finds its expression in a preference for status goods. Whether it’s in his choice of top-shelf alcohol at the club, the watch on his wrist or the clothes he wears, a man under the influence of the male sex hormone is going to reach for the product that says to potential mates (and to competitors for those mates), “U can’t touch this.” This pursuit of status in the choice of manufactured goods is called “positional consumption.” It’s been a hot topic among evolutionary psychologists and now is finding its way into the study of marketing. Researchers from the Wharton School of the University of Pennsylvania gave a supply of gel to 243 men, ages 18 to 55, and asked them to rub it all over their upper body. Some of the gels contained testosterone, others a placebo. Then the researchers asked the subjects to look at pictures and descriptions of five pairs of items — including watches, jeans and jackets — and judge which ones they preferred. © 1996-2018 The Washington Post

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 25210 - Posted: 07.16.2018

By Vikram K. Jaswal and Nameera Akhtar One of the most widely held beliefs about autistic people — that they are not interested in other people — is almost certainly wrong. Our understanding of autism has changed quite a bit over the past century, but this particular belief has been remarkably persistent. Seventy-five years ago, the first published account of autism described its subjects as “happiest when left alone” and “impervious to people.” Even now, a National Institutes of Health fact sheet suggests that autistic people are “indifferent to social engagement,” and the Centers for Disease Control and Prevention claims that some “might not be interested in other people at all.” There is no question that autistic people can seem as though they are not interested in others. They may not make eye contact or they may repeat lines from movies that don’t seem relevant in the moment. They may flap their hands or rock their bodies in ways that other people find off-putting. But just because someone appears socially uninterested does not mean that he or she is. As we point out in a paper published last month in Behavioral and Brain Sciences, many autistic people say they are very interested in, and in some cases desperate for, social connection. They experience loneliness, say they want friends and even prefer two-player games to one-player games. As the autistic author Naoki Higashida writes, “I can’t believe that anyone born as a human being really wants to be left all on their own, not really,” adding, “The truth is, we’d love to be with other people.” So why do autistic people act in ways that make it appear they want to be left alone? Autism is a neurological condition that affects how people perceive, think and move. Autistic people say that some of their apparently unsociable behaviors result from these neurological characteristics. Paradoxically, they may behave in these ways when they are trying to engage with other people. © 2018 The New York Times Company

Keyword: Autism
Link ID: 25209 - Posted: 07.16.2018

By Kate Sheridan On Sunday, neuroscientist Brenda Milner turns 100, and she plans to celebrate in two ways: the World Cup finals, followed by a party. “I tipped France from the beginning of the tournament to win, but I must say that Croatia has really impressed me,” she told STAT recently. In her 100 years of life, our understanding of the nervous system has changed dramatically. For example, only a few decades before Milner was born, some scientists still believed the nervous system was an uninterrupted network throughout the body. Now we know it isn’t, and drugs are created specifically to manipulate the movement of chemicals across the gaps between neurons. Milner’s work in memory and language processing has contributed mightily to that shift in understanding, and her decades-long career has made her both witness and player to the growth of neuroscience as a field. Yet as she journeyed from Cambridge University to the British defense ministry during World War II to the Montreal Neurological Institute, perhaps no encounter has shaped her career — and the study of human cognition — as meeting a man in the late 1950’s known as Patient H.M. H.M. was a young man who had epilepsy — and until his death in 2008, very few people knew his real name. A few years before Milner met him, surgeons removed parts of his brain, including his hippocampus, where doctors then thought his seizures began. © 2018 STAT

Keyword: Learning & Memory
Link ID: 25208 - Posted: 07.16.2018

Laura Sanders Today’s young women are more likely to experience depression and anxiety during pregnancy than their mothers were, a generation-spanning survey finds. From 1990 to 1992, about 17 percent of young pregnant women in southwest England who participated in the study had signs of depressed mood. But the generation that followed, including these women’s daughters and sons’ partners, fared worse. Twenty-five percent of these young women, pregnant in 2012 to 2016, showed signs of depression, researchers report July 13 in JAMA Network Open. “We are talking about a lot of women,” says study coauthor Rebecca Pearson, a psychiatric epidemiologist at Bristol University in England. Earlier studies also had suggested that depression during and after pregnancy is relatively common (SN: 3/17/18, p. 16). But those studies are dated, Pearson says. “We know very little about the levels of depression and anxiety in new mums today,” she says. To measure symptoms of depression and anxiety, researchers used the Edinburgh Postnatal Depression Scale — 10 questions, each with a score of 0 to 3, written to reveal risk of depression during and after pregnancy. A combined score of 13 and above signals high levels of symptoms. From 1990 to 1992, 2,390 women between the ages of 19 and 24 took the survey while pregnant. Of these women, 408 — or 17 percent — scored 13 or higher, indicating worrisome levels of depression or anxiety. |© Society for Science & the Public 2000 - 2018.

Keyword: Depression; Hormones & Behavior
Link ID: 25207 - Posted: 07.14.2018

By Sarah Gibbens Can you remember how you felt the first time you rode a bike? What about your first kiss—or your first heartbreak? Memorable moments and the emotions they trigger can resonate in our minds for decades, accumulating and powerfully shaping who we are as individuals. But for those who experience severe trauma, such memories can be haunting, and brutally painful memories can leave people with life-altering mental conditions.  So, what if traumatic memories didn't have to cause so much pain? As our understanding of the human brain evolves, various groups of neuroscientists are inching closer to techniques that manipulate memory to treat conditions such as PTSD or Alzheimer’s.  For now, the work is mainly happening in other animals, such as mice. But as these initial trials show continued success, scientists are looking toward the potential for tests in people, while grappling with the ethical implications of what it means to change a fundamental piece of someone’s identity. Feasibly, we could alter human memory in the not too distant future—but does that mean we should? Neuroscientists usually define a singular memory as an engram—a physical change in brain tissue associated with a particular recollection. Recently, brain scans revealed that an engram isn't isolated to one region of the brain and instead manifests as a colorful splattering across the neural tissue.

Keyword: Learning & Memory
Link ID: 25206 - Posted: 07.14.2018

By Esther Landhuis From savoring a piece of cake to hugging a friend, many of life’s pleasures trigger a similar reaction in the brain—a surge of chemicals that tell the body “that was good, do it again.” Research published Friday in Nature Communications suggests this feel-good circuit may do much more. Using lab tools to activate that reward circuit in mice, scientists discovered that its chemical signals reach the immune system, empowering a subset of bone marrow cells to slow the growth of tumors. The findings have yet to be confirmed in humans. But given the reward system is linked with positive emotions, the research offers a physiological mechanism for how a person’s psychological state could help to stall cancer progression. Plenty of research measures the health impact of stress and negative feelings, says Erica Sloan, a biologist at Monash University in Melbourne, Australia. But the potential for immune activity to shift in response to positive influences through the brain’s reward center—“that’s what I think is really exciting,” says Sloan, who studies neural-immune activity in cancer but was not involved in the present study. The notion that the brain talks to the immune system isn’t new. One of the most compelling examples is the placebo effect—the centuries-old observation that sugar pills can work as well as evidence-based medicine in some people. For years scientists have tried to unravel the biology behind this mysterious phenomenon. © 2018 Scientific American

Keyword: Neuroimmunology; Learning & Memory
Link ID: 25205 - Posted: 07.14.2018

By Smitha Mundasad Global Health Correspondent, BBC News For many years, Dr Andrew Bastawrous could not see clearly enough to spot the leaves on trees or the stars in the sky. Teachers kept telling him he was lazy and he kept missing the football during games. Then, aged 12, his mother took him to have his eyes tested and that changed everything. Now he is a prize-winning eye doctor with a plan to use a smartphone app to bring better vision to millions of children around the world. Dr Bastawrous told the BBC: "I'll never forget that moment at the optometrist. I had trial lenses on and looked across the car park and saw the gravel on the road had so much detail I had had no idea about. "A couple of weeks later I got my first pair of glasses and that's when I saw stars for first time, started doing well at school and it completely transformed my life." Around the world 12 million children, like Dr Bastawrous, have sight problems that could be corrected by a pair of glasses. But in many areas, access to eye specialists is difficult - leaving children with visual impairments that can harm school work and, ultimately, their opportunities in later life. In rural Kenya, for example, there is one eye doctor for one million people. Meanwhile in the US, there is on average one ophthalmologist for every 15,800 people. In 2011 Dr Bastawrous - by now an eye doctor in England - decided to study the eye health of the population of Kitale, Kenya, as part of his PhD. He took about £100,000 of eye equipment in an attempt to set up 100 temporary eye clinics but found this didn't work, as reliable roads and electricity were scarce. It was realising that these same areas had great mobile phone coverage - with about 80% of the population owning a cell phone - that sparked the idea for Peek. © 2018 BBC.

Keyword: Vision
Link ID: 25204 - Posted: 07.14.2018

By Erica Goode Suppose that, seeking a fun evening out, you pay $175 for a ticket to a new Broadway musical. Seated in the balcony, you quickly realize that the acting is bad, the sets are ugly and no one, you suspect, will go home humming the melodies. Do you head out the door at the intermission, or stick it out for the duration? Studies of human decision-making suggest that most people will stay put, even though money spent in the past logically should have no bearing on the choice. This “sunk cost fallacy,” as economists call it, is one of many ways that humans allow emotions to affect their choices, sometimes to their own detriment. But the tendency to factor past investments into decision-making is apparently not limited to Homo sapiens. In a study published on Thursday in the journal Science, investigators at the University of Minnesota reported that mice and rats were just as likely as humans to be influenced by sunk costs. The more time they invested in waiting for a reward — in the case of the rodents, flavored pellets; in the case of the humans, entertaining videos — the less likely they were to quit the pursuit before the delay ended. “Whatever is going on in the humans is also going on in the nonhuman animals,” said A. David Redish, a professor of neuroscience at the University of Minnesota and an author of the study. This cross-species consistency, he and others said, suggested that in some decision-making situations, taking account of how much has already been invested might pay off. “Evolution by natural selection would not promote any behavior unless it had some — perhaps obscure — net overall benefit,” said Alex Kacelnik, a professor of behavioral ecology at Oxford, who praised the new study as “rigorous” in its methodology and “well designed.” © 2018 The New York Times Company

Keyword: Attention; Learning & Memory
Link ID: 25203 - Posted: 07.13.2018

Tina Hesman Saey MADISON, Wis. — Giving children with autism a healthier mix of gut bacteria as a way to improve behavioral symptoms continued to work even two years after treatment ended. The finding may solidify the connection between tummy troubles and autism, and provide more evidence that the gut microbiome — the collection of bacteria and other microbes that live in the intestines — can influence behavior. “It’s a long way from saying there’s a cure for autism,” says Michael Hylin, a neuroscientist at Southern Illinois University in Carbondale who was not involved in the work. “But I think it’s a promising approach. It’s one that’s worthwhile.” Children with autism spectrum disorders often have gastrointestinal problems. In previous studies, environmental engineer Rosa Krajmalnik-Brown of Arizona State University in Tempe and colleagues discovered that children with autism had fewer types of bacteria living in their guts than typically developing children did. And many of the kids were missing Prevotella bacteria, which may help regulate immune system actions. The researchers wondered whether altering the children’s cocktail of gut microbes to get a more diverse and healthier mix might help fix both the digestive issues and the behavioral symptoms associated with autism. In a small study of 18 children and teenagers with autism, the scientists gave kids fecal transplants from healthy donors over eight weeks. During and two months after the treatment, the kids had fewer gastrointestinal problems, including diarrhea, constipation, abdominal pain and indigestion than before the therapy. Autism symptoms, such as hyperactivity, repetitive actions and irritability, also improved and seemed to be getting even better at the end of the trial than immediately after treatment ended, the team reported last year in Microbiome. But no one knew whether the improvements would last. |© Society for Science & the Public 2000 - 2018.

Keyword: Autism; Hormones & Behavior
Link ID: 25202 - Posted: 07.13.2018

/ By Jeremy Samuel Faust Last year, the National Institute on Alcohol Abuse and Alcoholism, part of the federal National Institutes of Health, laid out plans for what is a rarity in the realm of public health: a high quality clinical trial. The “Moderate Alcohol and Cardiovascular Health Trial,” known as MACH15, was to be randomized so that some subjects would be selected to drink and some would not. It would follow participants “prospectively,” over time, not retrospectively. And in the end, the results were to be adjudicated by evaluators blinded to which subjects had been instructed to drink and which to abstain. The goal was an assessment of the effect of alcohol consumption on cardiovascular health. The methodologic problems of the MACH15 trial’s design are considerable. How the outcome measures ever passed muster defies logic. But last month, the National Institutes of Health took the unusual step of shutting down one of its own clinical trials — a $100 million dollar experiment gone wrong. The announcement followed an internal investigation, prompted by a dogged New York Times report, that uncovered inappropriate interactions between the alcohol industry (Anheuser-Busch InBev, Heineken, and others) and the NIAAA in the execution of MACH15. By law, federal health agencies can receive funding from for-profit industry. But direct courting of funding, coordination, and collaboration on research design, and excessive communications are not permitted, and according to The Times and the findings of the NIH’s subsequent internal investigation, these violations occurred early and often during the development of the MACH15 trial. The NIH report concluded that the actions uncovered “calls into question the impartiality of the process and thus casts doubt that the scientific knowledge gained from the study would be actionable or believable.” Copyright 2018 Undark

Keyword: Drug Abuse
Link ID: 25201 - Posted: 07.13.2018

By Jeré Longman Researchers have found flaws in some of the data that track and field officials used to formulate regulations for the complicated cases of Caster Semenya of South Africa, the two-time Olympic champion at 800 meters, and other female athletes with naturally elevated testosterone levels. Three independent researchers said they believed the mistakes called into question the validity of a 2017 study commissioned by track and field’s world governing body, the International Federation of Athletics Associations, or I.A.A.F., according to interviews and a paper written by the researchers and provided to The New York Times. The 2017 study was used to help devise regulations that could require some runners to undergo medical treatment to lower their hormone levels to remain eligible for the sport’s most prominent international competitions, like the Summer Games. The researchers have called for a retraction of the study, published last year in the British Journal of Sports Medicine. The study served as an underpinning for rules, scheduled to be enacted in November, which would establish permitted testosterone levels for athletes participating in women’s events from 400 meters to the mile. “They cannot use this study as an excuse or a reason for setting a testosterone level because the data they have presented is not solid,” one of the independent researchers, Erik Boye of Norway, said Thursday. The I.A.A.F. has updated its research, which was published last week, again in the British Journal of Sports Medicine. “The I.A.A.F. will not be seeking a retraction of the 2017 study,” the governing body said in a statement on Thursday. “The conclusions remain the same.” But the statement did little to dampen criticism by the independent researchers. The I.A.A.F. seems “bound to lose” an intended challenge by Semenya to the Court of Arbitration for Sport, a kind of Supreme Court for international athletics, said Boye, a cancer researcher and an antidoping expert. © 2018 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 25200 - Posted: 07.13.2018

By Nicholas Bakalar In a randomized clinical trial, researchers assigned 120 men and women with chronic back or neck pain to one of two treatments. The first group received the commonly recommended program of physical therapy and general exercises. The second received a program of “pain neuroscience education,” in which they learned about the function of neurons and synapses, the ways in which pain is transmitted along nerve fibers via the spinal cord to the brain, and how pain itself can modify central nervous system functions, producing pain with even the mildest stimulation. They also performed exercises, closely integrated with the education program, that gradually introduced increasingly difficult movements, concentrating on functionality rather than pain relief, and trying to continue exercising despite the pain. Treatment in both groups lasted three months, and researchers re-examined the participants at six and 12 months afterward. Compared to the controls, the neuroscience education group had higher pain thresholds, a significant reduction in disability, and improved self-reported physical and mental health. The study is in JAMA Neurology. “The main message is: Don’t be afraid of the pain,” said the lead author, Anneleen Malfliet, a doctoral candidate at the Free University of Brussels. “We know that worrying and giving attention to pain ultimately increases it. Staying active and moving is better than rest when it comes to chronic back and neck pain.” © 2018 The New York Times Company

Keyword: Pain & Touch
Link ID: 25199 - Posted: 07.13.2018

Alison Abbott On a sun-parched patch of land in Rehovot, Israel, two neuroscientists peer into the darkness of a 200-metre-long tunnel of their own design. The fabric panels of the snaking structure shimmer in the heat, while, inside, a study subject is navigating its dim length. Finally, out of the blackness bursts a bat, which executes a mid-air backflip to land upside down, hanging at the tunnel’s entrance. The vast majority of experiments probing navigation in the brain have been done in the confines of labs, using earthbound rats and mice. Ulanovsky broke with the convention. He constructed the flight tunnel on a disused plot on the grounds of the Weizmann Institute of Science — the first of several planned arenas — because he wanted to find out how a mammalian brain navigates a more natural environment. In particular, he wanted to know how brains deal with a third dimension. The tunnel, which Ulanovsky built in 2016, has already proved its scientific value. So have the bats. They have helped Ulanovsky to discover new aspects of the complex encoding of navigation — a fundamental brain function essential for survival. He has found a new cell type responsible for the bats’ 3D compass, and other cells that keep track of where other bats are in the environment. It is a hot area of study — navigation researchers won the 2014 Nobel Prize in Physiology or Medicine and the field is an increasingly prominent fixture at every big neuroscience conference. “Nachum’s boldness is impressive,” says Edvard Moser of the Kavli Institute for Systems Neuroscience in Trondheim, Norway, one of the 2014 Nobel laureates. “And it’s paid off — his approach is allowing important new questions to be addressed.” . © 2018 Springer Nature Limited.

Keyword: Hearing
Link ID: 25198 - Posted: 07.12.2018

by Bethany Brookshire An astonishing number of things that scientists know about brains and behavior are based on small groups of highly educated, mostly white people between the ages of 18 and 21. In other words, those conclusions are based on college students. College students make a convenient study population when you’re a researcher at a university. It makes for a biased sample, but one that’s still useful for some types of studies. It would be easy to think that for studies of, say, how the typical brain develops, a brain is just a brain, no matter who’s skull its resting in. A biased sample shouldn’t really matter, right? Wrong. Studies heavy in rich, well-educated brains may provide a picture of brain development that’s inaccurate for the American population at large, a recent study found. The results provide a strong argument for scientists to pay more attention to who, exactly, they’re studying in their brain imaging experiments. It’s “a solid piece of evidence showing that those of us in neuroimaging need to do a better job thinking about our sample, where it’s coming from and who we can generalize our findings to,” says Christopher Monk, who studies psychology and neuroscience at the University of Michigan in Ann Arbor. The new study is an example of what happens when epidemiology experiments — studies of patterns in health and disease — crash into studies of brain imaging. “In epidemiology we think about sample composition a lot,” notes Kaja LeWinn, an epidemiologist at the University of California in San Francisco. Who is in the study, where they live and what they do is crucial to finding out how disease patterns spread and what contributes to good health. But in conversations with her colleagues in psychiatry about brain imaging, LeWinn realized they weren’t thinking very much about whose brains they were looking at. Particularly when studying healthy populations, she says, there was an idea that “a brain is a brain is a brain.” |© Society for Science & the Public 2000 - 2018

Keyword: Development of the Brain
Link ID: 25197 - Posted: 07.12.2018

By Karen Weintraub No one can talk to a horse, of course. But a new study set out to find whether horses are trying to tell us something when they snort. In the study, published Wednesday in the journal PLOS ONE, researchers in France determined that the snorting exhale that horses often make may be a sign of a positive emotion. Mathilde Stomp, a doctoral student at the University of Rennes who led the research, said she set out to understand whether the snort could be used as an measure of the horse’s mood. She and her collaborators recorded 560 snorts among 48 privately owned and riding school horses. All the horses snorted — as little as once or as often as 13 times an hour. The horses mainly snorted during calm and relaxing activities, and those that spent more time out of doors snorted the most, the study found. When a horse was snorting, the researchers also recorded the animal’s ear position; forward-pointing ears are a known signal of a positive internal state, Ms. Stomp said. Researchers also developed a composite score of each animal’s stress level when snorting, with measurements including how much time a horse spent facing the wall in its stall, as well as its level of interaction with or aggressive behavior toward the researcher. Ms. Stomp said her work was motivated by the desire to help people better understand and meet the needs of their animals. “We think that with this acoustic indicator, maybe they will be able to test when their horses are in good conditions or not,” she said. Not all horses may be snorting in contentment, however, but rather in discomfort or simply acting on a physical need, akin to humans blowing their noses. Sue McDonnell, a specialist in equine physiology and behavior at the University of Pennsylvania School of Veterinary Medicine, said not enough is known to draw conclusions about a horse’s emotional state from its snorts. “I think it’s a huge overreach, an over-interpretation of their data,” she said. © 2018 The New York Times Company

Keyword: Emotions; Evolution
Link ID: 25196 - Posted: 07.12.2018

Yao-Hua Law It’s easy to tell a male from a female shark. Flip it over. If it has a pair of claspers — finger-like extensions jutting from the end of the pelvic fins — it is male; no claspers means female. Like a penis, claspers deliver sperm inside the female. That was marine biologist Alissa Barnes’ understanding until she dissected seven bigeye houndsharks (Iago omanesis) with claspers and found a complete female reproductive system in each. None of the seven sharks had any internal male sex organs. Six were pregnant. Barnes, of the Dakshin Foundation, shared her findings June 25 at the 5th International Marine Conservation Congress in Kuching, Sarawak, Malaysia. Barnes stumbled upon these hermaphrodite sharks at a port in Odhisa in eastern India in 2017. She was surveying local fishers to see if changes in their practices might explain a decline in hauls of sharks and rays. When she checked what the fishing vessels brought in, Barnes noticed two oddities. Male bigeye houndsharks greatly outnumbered females. And though males of this deepwater species are smaller than females, she saw immature males as large as female adults. Sensing something amiss, she took some sharks back to her lab for dissection. “I was amazed,” says Barnes, who admits she squealed during the dissections. Even before opening the fish, she had pressed on the bellies of the "male" sharks and felt the pups inside. |© Society for Science & the Public 2000 - 2018.

Keyword: Sexual Behavior
Link ID: 25195 - Posted: 07.12.2018

Amy Maxmen Legal hurdles to exploring marijuana’s medicinal properties might soon fall in the wake of the US Food and Drug Administration’s (FDA) first approval of a cannabis-derived drug. On 25 June, the FDA announced its approval of Epidiolex — a treatment for epileptic seizures that is based on a cannabis compound called cannabidiol (CBD). The US Drug Enforcement Administration (DEA) has until 24 September to re-classify Epidiolex so that it’s legal for doctors across the country to prescribe it. Many researchers hope that the agency will re-classify CBD itself, instead of just Epidiolex, so that they can more easily study this non-psychedelic component of marijuana. Now that the FDA has approved Epidiolex, “we have a clear recognition that this plant has more potential than people credited it for, and that has reverberations that are scientific as well as legal”, says Daniele Piomelli, director of a new centre for cannabis research at the University of California, Irvine. At the very least, he says, the DEA ought to grant researchers an exemption permitting them to study CBD — especially now that people consume it and other cannabis compounds, known as cannabinoids, in states where marijuana is legal. At this point, the limits on research seem irrational, he adds. Lessening restrictions on the study of CBD would also be good news for biotech startups that have been producing cannabinoids through genetic engineering. These products could be purer and more affordable than those obtained through older methods of extraction from marijuana plants or chemical synthesis. © 2018 Springer Nature Limited.

Keyword: Drug Abuse; Epilepsy
Link ID: 25194 - Posted: 07.11.2018

By Robert Martone We normally think that every cell in our body contains the same genome, the complete set of genetic information that makes up the biological core of our individuality. However, there are exceptions where the body contains cells that are genetically different. This happens in cancers, of course, which arise when mutations create genetically distinct cells. What most people do not realize, however, is that the brain has remarkable genetic diversity, with some studies suggesting there may be hundreds of mutations in each nerve cell. In the developing brain, mutations and other genetic changes that occur while brain cells divide are passed down to a cluster of daughter cells. As a result, the adult brain is composed of a mosaic of genetically distinct cell clusters. We know that the activity and organization of the brain changes in response to experience. Memories and learning are reflected in the number and strength of connections between nerve cells. We also know that the brain is genetically mosaic, but a new study makes a remarkable connection between experience and the genetic diversity of the brain. It suggests that experience can change the DNA sequence of the genome contained in brain cells. This is a fundamentally new and unexplored way in which experience can alter the brain. It is of great scientific interest because it reveals the brain to be pliable, to its genetic core, in response to the world. © 2018 Scientific America

Keyword: Epigenetics; Genes & Behavior
Link ID: 25193 - Posted: 07.11.2018