By Helen Briggs BBC News A mother's diet around the time of conception can permanently influence her baby's DNA, research suggests. Animal experiments show diet in pregnancy can switch genes on or off, but this is the first human evidence. The research followed women in rural Gambia, where seasonal climate leads to big differences in diet between rainy and dry periods. It emphasises the need for a well-balanced diet before conception and in pregnancy, says a UK/US team. Scientists followed 84 pregnant women who conceived at the peak of the rainy season, and about the same number who conceived at the peak of the dry season. Nutrient levels were measured in blood samples taken from the women; while the DNA of their babies was analysed two to eight months after birth. Lead scientist Dr Branwen Hennig, from the London School of Hygiene & Tropical Medicine, said it was the first demonstration in humans that a mother's nutrition at the time of conception can change how her child's genes will be interpreted for life. She told BBC News: "Our results have shown that maternal nutrition pre-conception and in early pregnancy is important and may have implications for health outcomes of the next generation. "Women should have a well-balanced food diet prior to conception and during pregnancy." BBC © 2014

Keyword: Epigenetics; Sexual Behavior
Link ID: 19556 - Posted: 04.30.2014

Guys, do you prefer more feminine faces? If so, chances are you grew up in a relatively healthy place. New research suggests that men raised in countries with higher average lifespans and lower child mortality more strongly prefer women with softer features than do men raised in less healthy nations. The finding bolsters the idea that years of human evolution have made men attracted to faces that could help them survive. Previous studies have found that women living in harsher conditions—such as communities with high homicide rates and low income—are more inclined to find more masculine men attractive. Urszula Marcinkowska, a biologist at the University of Turku in Finland, and her colleagues wanted to know whether culture also influenced males’ preferences for females, or whether men judged females in a more universal way. Using an online survey conducted in 16 different languages, the researchers presented 1972 heterosexual males between the ages of 18 and 24 from 28 different countries with 20 pairs of Caucasian female faces. Each pair contained one face with more feminine traits—such as larger eyes, fuller lips, and a less angular jaw—as well as a more androgynous face, with thinner lips and a wider chin. Participants were asked to select which face in each pair they found more sexually attractive. While men across all cultures generally preferred a more feminine face, the strength of that preference varied between countries. The difference couldn’t be explained by the ratio of men to women in a country, its gross national income, or the race of the participants, but it did correlate with the national health index of the men’s countries—a measure of overall well-being. Those from countries like Japan, with high national health index scores, chose the more feminine face more than three-quarters of the time, the authors report online today in Biology Letters. Men from countries such as Nepal, which has a lower health rating, selected the more feminine face in only slightly more than half of the cases, on average. © 2014 American Association for the Advancement of Science

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 19555 - Posted: 04.30.2014

THAT health and beauty are linked is not in doubt. But it comes as something of a surprise that who is perceived as beautiful depends not only on the health of the person in question but also on the average level of health in the place where she lives. This, though, is the conclusion of a study just published in Biology Letters by Urszula Marcinkowska of the University of Turku, in Finland, and her colleagues—for Ms Marcinkowska has found that men in healthy countries think women with the most feminine faces are the prettiest whilst those in unhealthy places prefer more masculine-looking ones. Ms Marcinkowska came to this conclusion by showing nearly 2,000 men from 28 countries various versions of the same female faces, modified to look less or more feminine, and thus reflect the effects of different levels of oestrogen and testosterone. Oestrogen promotes features, such as large eyes and full lips, that are characteristically feminine. Testosterone promotes masculine features, such as wide faces and strong chins. As the chart shows, the correlation is remarkable—and statistical analysis shows it is unconnected with a country’s wealth or its ratio of men to women and thus the amount of choice available to men. The cause, though, is unclear. Previous studies have shown that women with feminine features are more fertile. A man’s preference for them is thus likely to enhance his reproductive success. Ms Marcinkowska speculates that testosterone-induced behavioural characteristics like dominance, which might be expected to correlate with masculine-looking faces even in women (they certainly do in men), help in the competition for resources needed to sustain children once they are born. But why that should be particularly important in an unhealthy country is unclear.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 19554 - Posted: 04.30.2014

by Bethany Brookshire When you are waiting with a friend to cross a busy intersection, car engines running, horns honking and the city humming all around you, your brain is busy processing all those sounds. Somehow, though, the human auditory system can filter out the extraneous noise and allow you to hear what your friend is telling you. But if you tried to ask your iPhone a question, Siri might have a tougher time. A new study shows how the mammalian brain can distinguish the signal from the noise. Brain cells in the primary auditory cortex can both turn down the noise and increase the gain on the signal. The results show how the brain processes sound in noisy environments, and might eventually help in the development of better voice recognition devices, including improvements to cochlear implants for those with hearing loss. Not to mention getting Siri to understand you on a chaotic street corner. Nima Mesgarani and colleagues at the University of Maryland in College Park were interested in how mammalian brains separate speech from background noise. Ferrets have an auditory system that is extremely similar to humans. So the researchers looked at the A1 area of the ferret cortex, which corresponds to our auditory A1 region. Equipped with carefully implanted electrodes, the alert ferrets listened to both ferret sounds and parts of human speech. The ferret sounds and speech were presented alone, against a background of white noise, against pink noise (noise with equal energy at all octaves that sounds lower in pitch than white noise) and against reverberation. Then they took the neural signals recorded from the electrodes and used a computer simulation to reconstruct the sounds the animal was hearing. In results published April 21 in Proceedings of the National Academy of Sciences, the researchers show the ferret brain is quite good at detecting both ferrets sounds and speech in all three noisy conditions. “We found that the noise is drastically decreased, as if the brain of the ferret filtered it out and recovered the cleaned speech,” Mesgarani says. © Society for Science & the Public 2000 - 2013.

Keyword: Attention; Hearing
Link ID: 19553 - Posted: 04.30.2014

Combining the estrogen hormone estriol with Copaxone, a drug indicated for the treatment of patients with relapsing forms of multiple sclerosis (MS), may improve symptoms in patients with the disorder, according to preliminary results from a clinical study of 158 patients with relapsing remitting multiple sclerosis (RRMS). The findings were presented today by Rhonda Voskuhl, M.D., from the University of California, Los Angeles, at the American Academy of Neurology Annual Meeting in Philadelphia. The study was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health; and the National Multiple Sclerosis Society. “While these results are encouraging, the results of this Phase II study should be considered preliminary as a larger study would be needed to know whether benefits outweigh the risks for persons affected by MS. At present, we cannot recommend estrogen as part of standard therapy for MS. We encourage patients to talk with their doctors before making any changes to their treatment plans,” said Walter Koroshetz, M.D., deputy director of NINDS. MS is an autoimmune disorder in which immune cells break down myelin, a protective covering that wraps around nerve cells. Loss of myelin results in pain, movement and balance problems as well as changes in cognitive ability. RRMS is the most common form of the disorder. Patients with RRMS experience relapses, or flare-ups, of neurological symptoms, followed by recovery periods during which the symptoms improve.

Keyword: Multiple Sclerosis; Hormones & Behavior
Link ID: 19552 - Posted: 04.30.2014

Intelligence is hard to test, but one aspect of being smart is self-control, and a version of the old shell game that works for many species suggests that brain size is very important. When it comes to animal intelligence, says Evan MacLean, co-director of Duke University’s Canine Cognition Center, don’t ask which species is smarter. “Smarter at what?” is the right question. Many different tasks, requiring many different abilities, are given to animals to measure cognition. And narrowing the question takes on particular importance when the comparisons are across species. So Dr. MacLean, Brian Hare and Charles Nunn, also Duke scientists who study animal cognition, organized a worldwide effort by 58 scientists to test 36 species on a single ability: self-control. This capacity is thought to be part of thinking because it enables animals to override a strong, nonthinking impulse, and to solve a problem that requires some analysis of the situation in front of them. The testing program, which took several international meetings to arrange, and about seven years to complete, looked at two common tasks that are accepted ways to judge self-control. It then tried to correlate how well the animals did on the tests with other measures, like brain size, diet and the size of their normal social groups. Unsurprisingly, the great apes did very well. Dogs and baboons did pretty well. And squirrel monkeys, marmosets and some birds were among the worst performers. Surprisingly, absolute brain size turned out to be a much better predictor of success than relative brain size, which has been thought to be a good indication of intelligence. Social group size was not significant, but variety of diet was. The paper, published last week in the journal Proceedings of the National Academy of Sciences, is accompanied online by videos showing the animals doing what looks for all the world like the shell game in which a player has to guess where the pea is. © 2014 The New York Times Company

Keyword: Attention; Intelligence
Link ID: 19551 - Posted: 04.29.2014

Jeffrey Mogil’s students suspected there was something fishy going on with their experiments. They were injecting an irritant into the feet of mice to test their pain response, but the rodents didn’t seem to feel anything. “We thought there was something wrong with the injection,” says Mogil, a neuroscientist at McGill University in Montreal, Canada. The real culprit was far more surprising: The mice that didn’t feel pain had been handled by male students. Mogil’s group discovered that this gender distinction alone was enough to throw off their whole experiment—and likely influences the work of other researchers as well. “This is very important work with wide-ranging implications,” says M. Catherine Bushnell, a neuroscientist and the scientific director of the Division of Intramural Research at the National Center for Complementary and Alternative Medicine (NCCAM) in Bethesda, Maryland, who was not involved in the study. “Many people doing research have never thought of this.” Mogil has studied pain for 25 years. He’s long suspected that lab animals respond differently to the sensation when researchers are present. In 2007, his lab observed that mice spend less time licking a painful injection—a sign that they’re hurting—when a person is nearby, even if that “person” is a cardboard cutout of Paris Hilton. Other scientists began to wonder if their own data were biased by the same effect. “There were whisperings at meetings that this was confounding research results,” Mogil says. So he decided to take a closer look. In the new study, Mogil told the researchers in his lab to inject an inflammatory agent into the foot of a rat or mouse and then take a seat nearby and read a book. A video camera trained on the rodent’s face assessed the animal’s pain level, based on a 0- to 2-point “grimace scale” developed by the team. The results were mixed. Sometimes the animals showed pain when an experimenter was present, and sometimes they seemed just fine. So, on a hunch, Mogil and colleagues recrunched the data, this time controlling for whether a male or a female experimenter was present. “We were stunned by the results,” he says. © 2014 American Association for the Advancement of Science.

Keyword: Stress; Sexual Behavior
Link ID: 19550 - Posted: 04.29.2014

|By Christof Koch Quantum physicist Wolfgang Pauli expressed disdain for sloppy, nonsensical theories by denigrating them as “not even wrong,” meaning they were just empty conjectures that could be quickly dismissed. Unfortunately, many remarkably popular theories of consciousness are of this ilk—the idea, for instance, that our experiences can somehow be explained by the quantum theory that Pauli himself helped to formulate in the early 20th century. An even more far-fetched idea holds that consciousness emerged only a few thousand years ago, when humans realized that the voices in their head came not from the gods but from their own internal spoken narratives. Not every theory of consciousness, however, can be dismissed as just so much intellectual flapdoodle. During the past several decades, two distinct frameworks for explaining what consciousness is and how the brain produces it have emerged, each compelling in its own way. Each framework seeks to explain a vast storehouse of observations from both neurological patients and sophisticated laboratory experiments. One of these—the Integrated Information Theory—devised by psychiatrist and neuroscientist Giulio Tononi, which I have described before in these pages [see “Ubiquitous Minds”; Scientific American Mind, January/February 2014], uses a mathematical expression to represent conscious experience and then derives predictions about which circuits in the brain are essential to produce these experiences. [Full disclosure: I have worked with Tononi on this theory.] In contrast, the Global Workspace Model of consciousness moves in the opposite direction. Its starting point is behavioral experiments that manipulate conscious experience of people in a very controlled setting. It then seeks to identify the areas of the brain that underlie these experiences. © 2014 Scientific American

Keyword: Consciousness
Link ID: 19549 - Posted: 04.29.2014

By Sandra G. Boodman, As the jet hurtled toward New York’s John F. Kennedy International Airport on New Year’s Day 2013, the clinical psychologist watched her 16-year-old daughter warily, praying there would be no recurrence of the girl’s inexplicable and bizarre behavior. The previous night, while walking down a street in Spain where the family had spent Christmas, the teenager suddenly began yelling that the traditional New Year’s Eve fireworks were actually bombs. On the flight home, the girl seemed entirely normal. Her mother thought the high school junior might have had a panic attack, stressed by her upcoming college search and impending wisdom teeth extraction. But the uneventful flight brought a short-lived relief. Five days later, the teenager was hospitalized for treatment of what appeared to be a severe psychotic break. And for the next six weeks, the news seemed to get worse as a more ominous diagnosis emerged — and with it the specter of death. “Every day seemed like a horror story,” said Carmen, a psychoanalyst who practices in New York and whose last name, along with that of her daughter, Mia, is being withheld at her request to protect her professional privacy. For Lara Marcuse, a neurologist at Mount Sinai Hospital in Manhattan who treated Mia during her hospitalization, those weeks were filled with tension and anxiety that deepened as she worried that the teenager might not survive her sudden illness. “If she was my age,” said Marcuse, who is 44, “Mia would either be dead, in a coma or in a state psychiatric center.” Instead Mia, now 18, has fully recovered. She recently had a part in her high school play, is anticipating graduation and looking forward to entering college in September. © 1996-2014 The Washington Post

Keyword: Schizophrenia
Link ID: 19548 - Posted: 04.29.2014

The hormone oxytocin appears to increase social behaviors in newborn rhesus monkeys, according to a study by researchers at the National Institutes of Health, the University of Parma in Italy, and the University of Massachusetts, Amherst. The findings indicate that oxytocin is a promising candidate for new treatments for developmental disorders affecting social skills and bonding. Oxytocin, a hormone produced by the pituitary gland, is involved in labor and birth and in the production of breast milk. Studies have shown that oxytocin also plays a role in parental bonding, mating, and in social dynamics. Because of its possible involvement in social encounters, many researchers have suggested that oxytocin might be useful as a treatment for conditions affecting social behaviors, such as autism spectrum disorders. Although oxytocin has been shown to increase certain social behaviors in adults, before the current study it had not been shown to do so in primate infants of any species. Working with infant rhesus monkeys, the NIH researchers found that oxytocin increased two facial gestures associated with social interactions— one used by the monkeys themselves in certain social situations, the other in imitation of their human caregivers. “It was important to test whether oxytocin would promote social behaviors in infants in the same respects as it appears to promote social interaction among adults,” said the study’s first author, Elizabeth A. Simpson, Ph.D., postdoctoral fellow of the University of Parma, conducting research in the Comparative Behavioral Genetics Section of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. “Our results indicate that oxytocin is a candidate for further studies on treating developmental disorders of social functioning.” The study was published online in Proceedings of the National Academy of Sciences.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 19547 - Posted: 04.29.2014

By JAN HOFFMAN How well can computers interact with humans? Certainly computers play a mean game of chess, which requires strategy and logic, and “Jeopardy!,” in which they must process language to understand the clues read by Alex Trebek (and buzz in with the correct question). But in recent years, scientists have striven for an even more complex goal: programming computers to read human facial expressions. We all know what it’s like to experience pain that makes our faces twist into a grimace. But can you tell if someone else’s face of pain is real or feigned? The practical applications could be profound. Computers could supplement or even replace lie detectors. They could be installed at border crossings and airport security checks. They could serve as diagnostic aids for doctors. Researchers at the University of California, San Diego, have written software that not only detected whether a person’s face revealed genuine or faked pain, but did so far more accurately than human observers. While other scientists have already refined a computer’s ability to identify nuances of smiles and grimaces, this may be the first time a computer has triumphed over humans at reading their own species. “A particular success like this has been elusive,” said Matthew A. Turk, a professor of computer science at the University of California, Santa Barbara. “It’s one of several recent examples of how the field is now producing useful technologies rather than research that only stays in the lab. We’re affecting the real world.” People generally excel at using nonverbal cues, including facial expressions, to deceive others (hence the poker face). They are good at mimicking pain, instinctively knowing how to contort their features to convey physical discomfort. © 2014 The New York Times Company

Keyword: Emotions; Robotics
Link ID: 19546 - Posted: 04.29.2014

By Lenny Bernstein FILE - In this Oct. 7, 2013 file photo, workers collect red grapes in the vineyards of the famed Chateau Haut Brion, a Premier Grand Cru des Graves, during the grape harvest in Pessac-Leognan, near Bordeaux, southwestern France. Global warming makes feeding the world harder and more expensive, a United Nations scientific panel said. A warmer world will push food prices higher, trigger Red wine gets all the good press for the cardiovascular benefits of the flavonoids it contains, but U.S. Department of Agriculture researchers are reporting that one white wine grape has the reds beat when it comes to slowing weight gain and lowering cholesterol, at least in laboratory animals. The researchers put hamsters on a high-fat diet supplemented by flour made from the seeds of grapes used for chardonnay, syrah and cabernet sauvignon wines. They found that the white grapes easily beat the reds in slowing the hamsters’ weight gain and limiting production of cholesterol. They believe the higher levels of flavonoids in the chardonnay grape seeds altered the work of genes related to fat metabolism. They also had an anti-inflammatory effect, according to a study the USDA scientists published in the Journal of Agricultural and Food Chemistry in February. In part, the researchers say in another paper yet to be published, the anti-oxidant compounds in the chardonnay grape seeds may work with bacteria in the gut to produce beneficial effects. The flour production also provides grape-growers a way to use seeds that currently are discarded and dumped during the chardonnay production. The Mayo Clinic has begun human trials to determine whether the same results can be achieved, said Wally Yokoyama, a research chemist for the USDA in Albany, Calif., and one of the authors of the two studies. The innovation is one of many in a new USDA report released this week. © 1996-2014 The Washington Post

Keyword: Obesity
Link ID: 19545 - Posted: 04.29.2014

By LAURENCE STEINBERG I’M not sure whether it’s a badge of honor or a mark of shame, but a paper I published a few years ago is now ranked No. 8 on a list of studies that other psychologists would most like to see replicated. Good news: People find the research interesting. Bad news: They don’t believe it. The paper in question, written with my former student Margo Gardner, appeared in the journal Developmental Psychology in July 2005. It described a study in which we randomly assigned subjects to play a video driving game, either alone or with two same-age friends watching them. The mere presence of peers made teenagers take more risks and crash more often, but no such effect was observed among adults. I find my colleagues’ skepticism surprising. Most people recall that as teenagers, they did far more reckless things when with their friends than when alone. Data from the Federal Bureau of Investigation indicate that many more juvenile crimes than adult crimes are committed in groups. And driving statistics conclusively show that having same-age passengers in the car substantially increases the risk of a teen driver’s crashing but has no similar impact when an adult is behind the wheel. Then again, I’m aware that our study challenged many psychologists’ beliefs about the nature of peer pressure, for it showed that the influence of peers on adolescent risk taking doesn’t rely solely on explicit encouragement to behave recklessly. Our findings also undercut the popular idea that the higher rate of real-world risk taking in adolescent peer groups is a result of reckless teenagers’ being more likely to surround themselves with like-minded others. My colleagues and I have replicated our original study of peer influences on adolescent risk taking several times since 2005. We have also shown that the reason teenagers take more chances when their peers are around is partly because of the impact of peers on the adolescent brain’s sensitivity to rewards. In a study of people playing our driving game, my colleague Jason Chein and I found that when teens were with people their own age, their brains’ reward centers became hyperactivated, which made them more easily aroused by the prospect of a potentially pleasurable experience. This, in turn, inclined teenagers to pay more attention to the possible benefits of a risky choice than to the likely costs, and to make risky decisions rather than play it safe. Peers had no such effect on adults’ reward centers, though. © 2014 The New York Times Company

Keyword: Attention; Emotions
Link ID: 19544 - Posted: 04.28.2014

One of our most mysterious and intriguing states of consciousness is the dream. We lose consciousness when we enter the deep waters of sleep, only to regain it as we emerge into a series of uncanny private realities. These air pockets of inner experience have been difficult for psychologists to study scientifically and, as a result, researchers have mostly resorted to measuring brain activity as the sleeper lies passive. But interest has recently returned to a technique that allows real-time communication from within the dream world. The rabbit hole between these worlds of consciousness turns out to be the lucid dream, where people become aware that they are dreaming and can influence what happens within their self-generated world. Studies suggest that the majority of people have had a lucid dream at some point in their life but that the experience is not common. As a result, there is now a minor industry in technologies and training techniques that claim to increase your chance of having a lucid dream although a recent scientific review estimated that the effect of any particular strategy is moderate at best. Some people, however, can reliably induce lucid dreams and it's these people who are allowing us to conduct experiments inside dreams. When trying to study an experience or behaviour, cognitive scientists usually combine subjective reports, what people describe about their experience, with behavioural experiments, to see what effect a particular state has on how people reason, act or remember. But both are difficult in dreamers, because they can't tell you much until they wake up and active participation in experiments is difficult when you are separated from the world by a blanket of sleep-induced paralysis. This paralysis is caused by neurons in the brainstem that block signals from the action-generating areas in the brain to the spinal nerves and muscles. The shutdown happens when Rapid Eye Movement or REM sleep starts, meaning that dreaming of even the most energetic actions results in no more than a slight twitch. One of the few actions that are not paralysed, however, is eye movement. This is where REM sleep gets its name from and this window of free action provides the lucid dreamer a way of signalling to the outside world. © 2014 Guardian News and Media Limited

Keyword: Sleep
Link ID: 19543 - Posted: 04.28.2014

By Julie Steenhuysen CHICAGO (Reuters) - International teams of researchers using advanced gene sequencing technology have uncovered a single genetic mutation responsible for a rare brain disorder that may have stricken families in Turkey for some 400 years. The discovery of this genetic disorder, reported in two papers in the journal Cell, demonstrates the growing power of new tools to uncover the causes of diseases that previously stumped doctors. Besides bringing relief to affected families, who can now go through prenatal genetic testing in order to have children without the disorder, the discovery helps lend insight into more common neurodegenerative disorders, such as ALS, also known as Lou Gehrig's disease, the researchers said. The reports come from two independent teams of scientists, one led by researchers at Baylor College of Medicine and the Austrian Academy of Sciences, and the other by Yale University, the University of California, San Diego, and the Academic Medical Center in the Netherlands. Both focused on families in Eastern Turkey where marriage between close relatives, such as first cousins, is common. Geneticists call these consanguineous marriages. In this population, the researchers focused specifically on families whose children had unexplained neurological disorders that likely resulted from genetic defects. Both teams identified a new neurological disorder arising from a single genetic variant called CLP1. Children born with this disorder inherit two defective copies of this gene, which plays a critical role in the health of nerve cells. Babies with the disorder have small and malformed brains, they develop progressive muscle weakness, they do not speak and they are increasingly prone to seizures.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 19542 - Posted: 04.28.2014

Epigenetics is one of the hottest fields in the life sciences. It’s a phenomenon with wide-ranging, powerful effects on many aspects of biology, and enormous potential in human medicine. As such, its ability to fill in some of the gaps in our scientific knowledge is mentioned everywhere from academic journals to the mainstream media to some of the less scientifically rigorous corners of the Internet. Epigenetics is essentially additional information layered on top of the sequence of letters (strings of molecules called A, C, G, and T) that makes up DNA. If you consider a DNA sequence as the text of an instruction manual that explains how to make a human body, epigenetics is as if someone's taken a pack of highlighters and used different colours to mark up different parts of the text in different ways. For example, someone might use a pink highlighter to mark parts of the text that need to be read the most carefully, and a blue highlighter to mark parts that aren't as important. There are different types of epigenetic marks, and each one tells the proteins in the cell to process those parts of the DNA in certain ways. For example, DNA can be tagged with tiny molecules called methyl groups that stick to some of its C letters. Other tags can be added to proteins called histones that are closely associated with DNA. There are proteins that specifically seek out and bind to these methylated areas, and shut it down so that the genes in that region are inactivated in that cell. So methylation is like a blue highlighter telling the cell "you don't need to know about this section right now." Methyl groups and other small molecular tags can attach to different locations on the histone proteins, each one having a different effect. Some tags in some locations loosen the attachment between the DNA and the histone, making the DNA more accessible to the proteins that are responsible for activating the genes in that region; this is like a pink highlighter telling the cell "hey, this part's important". © 2014 Guardian News and Media Limited

Keyword: Genes & Behavior; Development of the Brain
Link ID: 19541 - Posted: 04.28.2014

by Helen Thomson A 22-year-old man has been instantaneously transported to his family's pizzeria and his local railway station – by having his brain zapped. These fleeting visual hallucinations have helped researchers pinpoint places where the brain stores visual location information. Pierre Mégevand at the Feinstein Institute for Medical Research in Manhasset, New York, and his colleagues wanted to discover just where in the brain we store and retrieve information about locations and places. They sought the help of a 22-year-old man being treated for epilepsy, because the treatment involved implanting electrodes into his brain that would record his neural activity. Mégevand and his colleagues scanned the volunteer's brain using functional MRI while he looked at pictures of different objects and scenes. They then recorded activity from the implanted electrodes as he looked at a similar set of pictures. In both situations, a specific area of the cortex around the hippocampus responded to images of places, but not to images of other kinds of objects, such as body parts or tools. "There are these little spots of tissues that seem to care about houses and places more than any other class of object," says research team member Ashesh Mehta, also at the Feinstein Institute. Next, the team used the implanted electrodes to stimulate the brain in this area – a move that the volunteer said triggered a series complex visual hallucinations. First he described seeing a railway station in the neighbourhood where he lives. Stimulation of a nearby area elicited another hallucination, this time of a staircase and a blue closet in his home. When stimulation of these areas was repeated, the same scenes arose. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Vision
Link ID: 19540 - Posted: 04.26.2014

by Laura Sanders When a baby cries at night, exhausted parents scramble to figure out why. He’s hungry. Wet. Cold. Lonely. But now, a Harvard scientist offers more sinister explanation: The baby who demands to be breastfed in the middle of the night is preventing his mom from getting pregnant again. This devious intention makes perfect sense, says evolutionary biologist David Haig, who describes his idea in Evolution, Medicine and Public Health. Another baby means having to share mom and dad, so babies are programmed to do all they can to thwart the meeting of sperm and egg, the theory goes. Since babies can’t force birth control pills on their mothers, they work with what they’ve got: Nighttime nursing liaisons keep women from other sorts of liaisons that might lead to another child. And beyond libido-killing interruptions and extreme fatigue, frequent night nursing also delays fertility in nursing women. Infant suckling can lead to hormone changes that put the kibosh on ovulation (though not reliably enough to be a fail-safe birth control method, as many gynecologists caution). Of course, babies don’t have the wherewithal to be interrupting their mothers’ fertility intentionally. It’s just that in our past, babies who cried to be nursed at night had a survival edge, Haig proposes. The timing of night crying seems particularly damning, Haig says. Breastfed babies seem to ramp up their nighttime demands around 6 months of age and then slowly improve — precisely the time when a baby would want to double down on its birth control efforts. © Society for Science & the Public 2000 - 2013

Keyword: Sexual Behavior; Evolution
Link ID: 19539 - Posted: 04.26.2014

By LAWRENCE K. ALTMAN Douglas L. Coleman, a Canadian-born scientist who upset scientific dogma by discovering that genes — not willpower, eating habits or other behaviors — could cause obesity in some people, died on April 16 at his home in Lamoine, Me. He was 82. The cause was aggressive basal cell cancer, said a spokeswoman for the Jackson Laboratory in Bar Harbor, Me., where Dr. Coleman spent his entire research career. Beginning in the 1960s, Dr. Coleman’s research showed that a blood-borne substance could curb hunger. In the 1990s, his findings led Dr. Jeffrey M. Friedman’s team at the Rockefeller University in Manhattan to identify the gene that produces the appetite suppressant leptin, which is released by fat cells. For their work, Dr. Coleman and Dr. Friedman shared the prestigious Lasker Award for basic medical research in 2010. Their discoveries upended the conventional wisdom that fat cells are simply energy storage bins, and demonstrated that fat tissue is an endocrine organ required for normal development. Scientists have learned from their research and others’ that fat produces a variety of hormones, cytokines and other chemicals in the body’s natural weight-control system. Douglas Leonard Coleman was born on Oct. 6, 1931, in Stratford, Ontario. Influenced by his father, Leonard, who repaired radios and refrigerators for a living, Douglas spent much of his youth investigating how things worked by taking them apart. He earned a chemistry degree from McMaster University in Hamilton, Ontario, and a doctorate in biochemistry from the University of Wisconsin. In 1958, facing poor employment prospects in academia or industry in Canada, he became a research scientist at the Jackson Laboratory, which studies mouse genetics to learn about human disease. He intended to spend a year or two there to gain experience in genetics and immunology, but stayed until he retired in 1991. After retiring, he turned a tract of land he owned into a nature preserve. © 2014 The New York Times Company

Keyword: Obesity; Genes & Behavior
Link ID: 19538 - Posted: 04.26.2014

Scientists have bioengineered, in neurons cultured from rats, an enhancement to a cutting edge technology that provides instant control over brain circuit activity with a flash of light. The research funded by the National Institutes of Health adds the same level of control over turning neurons off that, until now, had been limited to turning them on. “What had been working through a weak pump can now work through a highly responsive channel with many orders of magnitude more impact on cell function,” explained Karl Deisseroth, M.D., Ph.D., It is like going from a squirt to a gushing hose. Deisseroth and colleagues report on what is being hailed as a marvel of genetic engineering in the April 25, 2014 issue of the journal Science. Deisseroth’s team had pioneered the use of light pulses to control brain circuitry in animals genetically engineered to be light-responsive — optogenetics. Genes that allow the sun to control light-sensitive primitive organisms like algae, melded with genes that make fluorescent marker proteins, are fused with a deactivated virus that delivers them to specific types of neurons which they become part of — allowing pulses of light to similarly commandeer brain cells.

Keyword: Brain imaging
Link ID: 19537 - Posted: 04.26.2014