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By Sarah C. P. Williams The next time you forget where you left your car keys, you might be able blame an immune protein that builds up in your blood as you age. The protein impairs the formation of new brain cells and contributes to age-related memory loss—at least in mice, according to a new study. Blocking it could help prevent run-of-the-mill memory decline or treat cognitive disorders, the researchers say. “The findings are really exciting,” says neurologist Dena Dubal of the University of California, San Francisco (UCSF), who was not involved in the study. “The importance of this work cannot be underestimated as the world’s population is aging rapidly.” Multiple groups of scientists have shown that adding the blood of older mice to younger animals’ bodies makes them sluggish, weaker, and more forgetful. Likewise, young blood can restore the memory and energy of older mice. Neuroscientist Saul Villeda of UCSF homed in on one actor he thought might be responsible for some of that effect: β2 microglobulin (B2M), an immune protein normally involved in distinguishing one’s own cells from invading pathogens. B2M has also been found at increased levels in patients with Alzheimer’s disease and other cognitive disorders. Villeda and his colleagues first measured B2M levels in the blood of both people and mice of different ages; they found that those levels increased with age. When the researchers injected B2M into 3-month-old mice, the young animals suddenly had trouble remembering how to complete a water maze, making more than twice as many errors after they’d already been trained to navigate the maze. Moreover, their brains had fewer new neurons than other mice. Thirty days later, however, when the protein had been cleared from their bodies, the animals' memory troubles were gone as well, and the number of newly formed brain cells was back to normal. © 2015 American Association for the Advancement of Science

Keyword: Learning & Memory; Alzheimers
Link ID: 21144 - Posted: 07.07.2015

By Michael T. Ullman and Mariel Y. Pullman The human brain possesses an incredible capacity to adapt to new conditions. This plasticity enables us not only to constantly learn but also to overcome brain injury and loss of function. Take away one capability, and little by little we often compensate for these deficits. Our brain may be especially well suited to overcome limitations in the case of psychiatric or neurological conditions that originate early in life, what clinicians call neurodevelopmental disorders. Given the brain's considerable plasticity during early years, children with these disorders may have particular advantages in learning compensatory strategies. It now appears that a single brain system—declarative memory—can pick up slack for many kinds of problems across multiple neurodevelopmental disorders. This system, rooted in the brain's hippocampus, is what we typically refer to when we think of learning and memory. It allows us to memorize facts and names or recall a first grade teacher or a shopping list. Whereas other memory systems are more specialized—helping us learn movements or recall emotional events, for instance—declarative memory absorbs and retains a much broader range of knowledge. In fact, it may allow us to learn just about anything. Given declarative memory's powerful role in learning, one might expect it to help individuals acquire all kinds of compensatory strategies—as long as it remains functional. Indeed, research suggests that it not only remains largely intact but also compensates for diverse impairments in five common conditions that are rarely studied in conjunction: autism spectrum disorder, obsessive-compulsive disorder (OCD), Tourette's syndrome, dyslexia and developmental language disorder (which is often referred to as specific language impairment, or SLI). © 2015 Scientific American

Keyword: Learning & Memory
Link ID: 21143 - Posted: 07.07.2015

by Jessica Griggs Manoeuvring the colourful tiles of Tetris can help block flashbacks of traumatic events, even after the memory has fixed itself in your mind. Playing the game could be an easy way to reduce the risk of post-traumatic stress disorder (PTSD). After any event, there is a window of about six hours where memories are consolidated and cemented in the mind, says Emily Holmes at the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, UK. Sleeping on the memory strengthens it further. If an event is particularly traumatic, vivid memories of it can reoccur. These intrusive flashbacks are distressing for anyone, but in a proportion of cases they can persist and contribute to PTSD. For example, about half of people who have been raped go on to develop PTSD, as do a number of asylum seekers and people who have been tortured. About 20 per cent of people who have been in a serious car accident are affected by the condition. There are effective treatments for people who are diagnosed with PTSD, but nothing currently exists to help prevent people from developing it in the days and weeks after the initial trauma. Holmes and her colleagues think a dose of Tetris could be the answer. In 2009, they showed that playing the game four hours after being exposed to trauma reduced the number of subsequent flashbacks. But getting the game into a person's hands immediately after they have been raped, for example, won't always be practical, so the team tested whether it could still work a day later – after the memory had been consolidated and slept on. © Copyright Reed Business Information Ltd.

Keyword: Stress; Learning & Memory
Link ID: 21142 - Posted: 07.07.2015

By JAMES GORMAN Call it the case of the homing lizards. It’s a small mystery. No one of any species is murdered. But the central question is one that has prompted plenty of scientific research: How do animals find their way home? The lizards in this case are anoles — abundant, mostly small reptiles that thrive in the Caribbean. The species is Anolis gundlachi. The lead detective is Manuel Leal, a biologist at the University of Missouri. He has been studying the behavior of anoles for more than 20 years. For about three years, Dr. Leal has been trying to understand how the anole finds its way back to its own territory after being carried into the rain forest. And as he told an audience in June at the annual meeting of the Animal Behavior Society in Anchorage, the case is far from closed. First, a bit of background. Anoles are particularly abundant in the dense vegetation of the rain forests in Puerto Rico, where Dr. Leal studies them. Each species is tied to a very specific environment. For instance, many live on tree trunks, but only a particular part of the trunk. Trunk-ground anoles live only in the space from the ground up to six feet or so. Trunk-crown anoles live above them, up to the crown of the tree. Twig anoles live way up high. Several years ago, Dr. Leal was studying competition between two species. If he removed all of the trunk-ground anoles, he wondered, would the trunk-crown lizards extend their territory farther down the tree? He ran into a problem, however. He would take the trunk-ground lizards far from their home territory to make room for their upstairs neighbors, and then release them. But in a reptilian version of the children’s song, “The Cat Came Back,” the lizards wouldn’t stay away. “Lizards kept showing up in the territory that had just been scoured for lizards,” he said. Dr. Leal wondered whether new anoles were appearing in empty territory or the old ones were returning. But how could a lizard that had never left home find its way back through 25 yards or so of dense rain forest? © 2015 The New York Times Company

Keyword: Animal Migration
Link ID: 21141 - Posted: 07.07.2015

By Sabrina Imbler To our knowledge, there’s no correlation between a man’s singing ability and his care and attentiveness as a father. But any Pavarotti among the nightingales will serenade his mate while she sits on her eggs. And after they hatch he will visit the nest about 16 times each hour to feed their offspring. Because, among nightingales at least, the best singers also make the best fathers. So finds a study in the journal BMC Evolutionary Biology. [Conny Bartsch, Michael Weiss and Silke Kipper, Multiple song features are related to paternal effort in common nightingales] Some 80 percent of birds practice biparental care, meaning both the male and female rear their offspring together. So it’s crucial for a female bird to pick as a mate the most promising father—both genetically and behaviorally. Female birds look for signs of fitness that range from the flamboyant plumage of the peacock to the bizarre dances of birds of paradise. And for nightingales, it’s the most elaborate song that apparently wins the day. The average male has some 180 tunes in his repertoire. These avian Sinatras vocalize highly variable song types including buzzes, whistles and trills. And such virtuoso singing seems to signal the female that this is a guy she can count on. That is, when it’s time to help raise the kids, he’s not a flight risk. © 2015 Scientific American

Keyword: Sexual Behavior; Evolution
Link ID: 21140 - Posted: 07.07.2015

By DACHER KELTNER and PAUL EKMAN FIVE years ago, the writer and director Pete Docter of Pixar reached out to us to talk over an idea for a film, one that would portray how emotions work inside a person’s head and at the same time shape a person’s outer life with other people. He wanted to do this all in the mind of an 11-year-old girl as she navigated a few difficult days in her life. As scientists who have studied emotion for decades, we were delighted to be asked. We ended up serving as scientific consultants for the movie, “Inside Out,” which was recently released. Our conversations with Mr. Docter and his team were generally about the science related to questions at the heart of the film: How do emotions govern the stream of consciousness? How do emotions color our memories of the past? What is the emotional life of an 11-year-old girl like? (Studies find that the experience of positive emotions begins to drop precipitously in frequency and intensity at that age.) “Inside Out” is about how five emotions — personified as the characters Anger, Disgust, Fear, Sadness and Joy — grapple for control of the mind of an 11-year-old girl named Riley during the tumult of a move from Minnesota to San Francisco. (One of us suggested that the film include the full array of emotions now studied in science, but Mr. Docter rejected this idea for the simple reason that the story could handle only five or six characters.) Riley’s personality is principally defined by Joy, and this is fitting with what we know scientifically. Studies find that our identities are defined by specific emotions, which shape how we perceive the world, how we express ourselves and the responses we evoke in others. © 2015 The New York Times Company

Keyword: Emotions
Link ID: 21139 - Posted: 07.07.2015

By VIRGINIA HUGHES An extraterrestrial dropping into a modern-day hospital might be forgiven for thinking it was run by machines. Against a techno soundtrack of whirs and beeps, sleep-deprived doctors file in and out of exam rooms. They ask patients a series of standard questions, and make a few clicks on a computer to order a blood test or chest X-ray or pain meds. Then they hustle out the door to repeat the protocol on the impossibly large number of other patients under their watch. When their shifts end, some 12 or 18 or even 28 hours later, these zombies in blue scrubs are replaced by others, while the unflappable computers ease the handoff. The tech-centric approach to medicine has its benefits, to be sure. Imaging machines and genetic screening give doctors biological clues otherwise hidden. Computers can make hospitals more efficient, and prevent dumb mistakes. But the practice of medicine cannot be reduced to algorithms, pixels and protocols, as the neurologist Dr. Allan H. Ropper subtly argues in his entertaining book, “Reaching Down the Rabbit Hole.” (Read excerpt.) To Dr. Ropper, medicine is a craft — an art — that depends on the human interaction between doctor and patient. Like an episode of the popular television series “House,” the book presents mysterious medical cases from the behemoth Brigham and Women’s Hospital in Boston. The 10th floor holds the neurology inpatient ward, a place where, as Dr. Ropper and his co-author, Brian David Burrell, put it, “the strangest and most challenging cases are sent to be sorted out.” © 2015 The New York Times Company

Keyword: Miscellaneous
Link ID: 21138 - Posted: 07.07.2015

By David Robson William’s internal clock is eternally jammed at 13:40 on 14 March 2005 – right in the middle of a dentist appointment. A member of the British Armed Forces, he had returned to his post in Germany the night before after attending his grandfather’s funeral. He had gym in the morning, where he played volleyball for 45 minutes. He then entered his office to clear a backlog of emails, before heading to the dentist’s for root-canal surgery. “I remember getting into the chair and the dentist inserting the local anaesthetic,” he tells me. After that? A complete blank. It is as if all new memories are being written in invisible ink that slowly disappears. Since then, he has been unable to remember almost anything for longer than 90 minutes. So while he can still tell me about the first time he met the Duke of York for a briefing at the Ministry of Defence, he can’t even remember where he’s living now; he wakes up every morning believing he is still in Germany in 2005, waiting to visit the dentist. Without a record of new experiences, the passing of time means nothing to him. Today, he only knows that there is a problem because he and his wife have written detailed notes on his smartphone, in a file labelled “First thing – read this”. It is as if all new memories are being written in invisible ink that slowly disappears. How could minor dental work have affected his brain in such a profound way? This real-life medical mystery offers a rare glimpse at the hidden depths of the brain’s workings. © 2015 BBC.

Keyword: Learning & Memory
Link ID: 21137 - Posted: 07.06.2015

Gretchen Cuda Kroen When Kate Klein began working as a nurse in the Cleveland Clinic's Neurointensive Care Unit, one of the first things she noticed was that her patients spent a lot of time in bed. She knew patients with other injuries benefitted from getting up and moving early on, and she wondered why not patients with brain injuries. "I asked myself that question. I asked my colleagues that question," Klein says. "Why aren't these patients getting out of bed? Is there something unique about patients with neurologic injury?" Doctors have long encouraged their surgical patients to get out of bed as soon as it's safe to do so. Movement increases circulation, reduces swelling, inflammation and the risk of blood clots, and it speeds healing. But that wasn't the thinking with brain injuries, explains Edward Manno, director of the Neurointensive Care Unit at the Cleveland Clinic and one of the neurologists who works with Klein. "The predominant thinking was that rest was better suited for the brain," Manno says. Often the damaged brain is susceptible to lack of blood flow. Increased activity may make things worse if initiated too quickly, Manno says. "So many of us thought for quite some time that we needed to put the brain to rest after the initial insult of stroke or other neurologic injury." © 2015 NPR

Keyword: Brain Injury/Concussion
Link ID: 21136 - Posted: 07.06.2015

CONCORD, N.H. — Can an algorithm pass for an author? Can a robot rock the house? A series of contests at Dartmouth College is about to find out. Dartmouth is seeking artificial intelligence algorithms that create "human-quality" short stories, sonnets and dance music sets that will be pitted against human-produced literature, poetry and music selections. The judges won't know which is which. The goal is to determine whether people can distinguish between the two, and whether they might even prefer the computer-generated creativity. "Historically, often when we have advances in artificial intelligence, people will always say, 'Well, a computer couldn't paint a sunset,' or 'a computer couldn't write a beautiful love sonnet,' but could they? That's the question," said Dan Rockmore, director of the Neukom Institute for Computational Science at Dartmouth. Rockmore, a mathematics and computer science professor, spun off the idea for the contests from his experience riding a stationary bike. He started thinking about how the music being played during his spin class helped him pedal at the right the pace, and he was surprised when the instructor told him he selected the songs without the help of computer software. "I left there thinking, 'I wonder if I could write a program that did that, or somebody could?'" he said. "Because that is a creative act — a good spin instructor is a total artist. It sort of opened my mind to thinking about whether a computer or algorithm could produce something that was indistinguishable from or even perhaps preferred over what the human does." The competitions are variations of the "Turing Test," named for British computer scientist Alan Turing, who in 1950 proposed an experiment to determine if a computer could have humanlike intelligence. The classic Turing test involves intelligent computer programs that can fool a person carrying on a conversation with it, and there have been many competitions over the years, said Manuela Veloso, professor of computer science and robotics at Carnegie Mellon University and past president of the Association for the Advancement of Artificial Intelligence. © 2015 The New York Times Company

Keyword: Robotics
Link ID: 21135 - Posted: 07.06.2015

Taunya English What do we know about the power of food to rev up sex drive? Not much. "Really, science has not figured out what determines sexual motivation and sexual attraction. If we knew the answer to that, we'd probably be richer than Pfizer after they invented Viagra," says Dolores Lamb, director of the Center for Reproductive Medicine at Baylor College of Medicine. She hasn't seen any compelling evidence that any particular food can intensify desire. Lamb is a men's health researcher and knows a lot about the intricacies of male plumbing, but she says desire is largely psychological. Even medicines that treat erectile dysfunction can't create enthusiasm. "So the trigger still has to be up in the brain," Lamb says. Still, the idea persists that ginger stirs up lust, or that hot peppers make you hot. "Probably for some folks they do, and it's certainly fun to try," Lamb says. Some legendary aphrodisiacs do have a chemical here or a nutrient there that might support sexual health, but not enough of it to make an immediate difference in the bedroom. Red, juicy watermelon, for example, contains the amino acid citrulline, and that plant nutrient is healthy for erectile tissue in both men and women. But most of the amino acid is found in the rind of the fruit. Consider chili peppers. Capsaicin, which is what provides the heat in a jalapeno, also raises your metabolism and releases feel-good endorphins. "You get kind of a chill down the back of your neck and kind of a tingly, good sensation," Lamb says. "Gets blood flowing better." © 2015 NPR

Keyword: Sexual Behavior
Link ID: 21134 - Posted: 07.06.2015

By Adrian Cho Whether they're from humans, whales, or elephants, the brains of many mammals are covered with elaborate folds. Now, a new study shows that the degree of this folding follows a simple mathematical relationship—called a scaling law—that also explains the crumpling of paper. That observation suggests that the myriad forms of mammalian brains arise not from subtle developmental processes that vary from species to species, but rather from the same simple physical process. In biology, it rare to find a mathematical relationship that so tightly fits all the data, say Georg Striedter, a neuroscientist at the University of California, Irvine. "They've captured something," he says. Still, Striedter argues that the scaling law describes a pattern among fully developed brains and doesn't explain how the folding in a developing brain happens. The folding in the mammalian brain serves to increase the total area of the cortex, the outer layer of gray matter where the neurons reside. Not all mammals have folded cortices. For example, mice and rats have smooth-surfaced brains and are "lissencephalic." In contrast, primates, whales, dogs, and cats have folded brains and are "gyrencephalic." For decades, scientists have struggled to relate the amount of folding in a species' brain to some other characteristic. For example, although animals with tiny brains tend to have smooth ones, there is no clean relationship between the amount of folding—measured by the ratio of the total area of the cortex to the exposed outer surface of the brain—and brain mass. Make a plot of folding versus brain mass for various species and the data points fall all over and not on a unified curve. Similarly, there is no clean relationship between the amount of folding and the number of neurons, the total area of the cortex, or the thickness of the cortex. © 2015 American Association for the Advancement of Science

Keyword: Development of the Brain; Evolution
Link ID: 21133 - Posted: 07.04.2015

By BARRY MEIER and DANIELLE IVORY In a small brick building across the street from a Taco Bell in Marrero, La., patients enter a clear plastic capsule and breathe pure oxygen. The procedure, known as hyperbaric oxygen therapy, uses a pressurized chamber to help scuba divers overcome the bends and to aid people sickened by toxic gases. But Dr. Paul G. Harch, who operates the clinic there on the outskirts of New Orleans, offers it as a concussion treatment. One patient, Rashada Parks, said that she had struggled with neck pain, mood swings and concentration problems ever since she fell and hit her head more than three years ago. Narcotic painkillers hadn’t helped her, nor had antidepressants. But after 40 hourlong treatments, or dives, in a hyperbaric chamber, her symptoms have subsided. “I have hope now,” Ms. Parks said. “It’s amazing.” Three studies run at a taxpayer cost of about $70 million have all come to a far different conclusion. They found that the benefits of hyperbaric oxygen reported by patients like Ms. Parks may have resulted from a placebolike effect, not the therapy’s supposed ability to repair and regenerate brain cells. But undeterred, advocates of the treatment recently persuaded lawmakers to spend even more public money investigating whether the three studies were flawed. A growing industry has developed around concussions, with entrepreneurs, academic institutions and doctors scrambling to find ways to detect, prevent and treat head injuries. An estimated 1.7 million Americans are treated every year after suffering concussions from falls, car accidents, sports injuries and other causes. While the vast majority quickly recover with rest, a small percentage of patients experience lingering effects a year or longer afterward. Along with memory issues, symptoms can include headaches, dizziness and vision and balance problems. © 2015 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 21132 - Posted: 07.04.2015

By Kelly Servick How many times would you give your neighbor an electric shock to earn a few extra bucks? Your answer could be more malleable than you think. A new study finds that two common drugs—an antidepressant and a treatment for Parkinson’s disease—can influence moral decisions, a discovery that could help unravel specific mechanisms behind aggression and eventually help researchers design treatments for antisocial behavior. Previous research has linked two neurotransmitters, the brain’s signaling molecules, to our willingness to inflict harm. Serotonin appears to help keep us civil; it’s reduced in the brains of violent offenders, for example. Dopamine, meanwhile, has been shown to prompt aggression in animals, and it’s elevated in a certain part of the brain in people with psychopathic behavior. But measuring how these neurotransmitters contribute to moral decision-making is hard to do in the lab. Many studies rely on theoretical questions like the so-called trolley dilemma, which asks a person whether they would redirect an oncoming train to kill someone if it would save the lives of several others in its path. A person’s answer might not always reflect how they would behave in real life, however. So neuroscientist Molly Crockett of the University of Oxford in the United Kingdom and her colleagues developed a lab test with real consequences. They asked subjects to make a series of decisions about how many moderately painful electric shocks to deliver to themselves or to others. Half the questions gave volunteers a chance to earn money by inflicting self-harm. (For example: “Would you rather endure seven shocks to earn $10 or 10 shocks to earn $15?”) The other half offered the same type of decision, except that someone else stood to be shocked. At the end of the experiment, one of these choices was randomly selected and carried out: The decision-maker got paid, and either they or another person—waiting in a different room—got a series of painful zings on the wrist. Any answer could be the one with real consequences, so “people have to sort of put their money where their mouth is,” Crockett says. © 2015 American Association for the Advancement of Science

Keyword: Emotions
Link ID: 21131 - Posted: 07.04.2015

Spider-like cells inside the brain, spinal cord and eye hunt for invaders, capturing and then devouring them. These cells, called microglia, often play a beneficial role by helping to clear trash and protect the central nervous system against infection. But a new study by researchers at the National Eye Institute (NEI) shows that they also accelerate damage wrought by blinding eye disorders, such as retinitis pigmentosa. NEI is part of the National Institutes of Health. “These findings are important because they suggest that microglia may provide a target for entirely new therapeutic strategies aimed at halting blinding eye diseases of the retina,” said NEI Director, Paul A. Sieving, M.D. “New targets create untapped opportunities for preventing disease-related damage to the eye, and preserving vision for as long as possible.” The findings were published in the journal EMBO Molecular Medicine. Retinitis pigmentosa, an inherited disorder that affects roughly 1 in 4,000 people, damages the retina, the light-sensitive tissue at the back of the eye. Research has shown links between retinitis pigmentosa and several mutations in genes for photoreceptors, the cells in the retina that convert light into electrical signals that are sent to the brain via the optic nerve. In the early stages of the disease, rod photoreceptors, which enable us to see in low light, are lost, causing night blindness. As the disease progresses, cone photoreceptors, which are needed for sharp vision and seeing colors, can also die off, eventually leading to complete blindness.

Keyword: Vision; Glia
Link ID: 21130 - Posted: 07.04.2015

By SINDYA N. BHANOO It may be possible to diagnose autism by giving children a sniff test, a new study suggests. Most people instinctively take a big whiff when they encounter a pleasant smell and limit their breathing when they encounter a foul smell. Children with autism spectrum disorder don’t make this natural adjustment, said Liron Rozenkrantz, a neuroscientist at the Weizmann Institute of Science in Israel and one of the researchers involved with the study. She and her colleagues report their findings in the journal Current Biology. They presented 18 children who had an autism diagnosis and 18 typically developing children with pleasant and unpleasant odors and measured their sniff responses. The pleasant smells were rose and soap, and the unpleasant smells were sour milk and rotten fish. Typically developing children adjusted their sniffing almost immediately — within about 305 milliseconds. Children with autism did not respond as rapidly. As they were exposed to the smells, the children were watching a cartoon or playing a video game. “It’s a semi-automated response,” Ms. Rozenkrantz said. “It does not require the subject’s attention.” Using the sniff test alone, the researchers, who had not been told which children had autism, were able to correctly identify those with autism 81 percent of the time. They also found that the farther removed an autistic child’s sniff response was from the average for typically developing children, the more severe the child’s social impairments were. © 2015 The New York Times Company

Keyword: Autism; Chemical Senses (Smell & Taste)
Link ID: 21129 - Posted: 07.04.2015

By Victoria Gill Science reporter, BBC News Cat v mouse: it is probably the most famous predator-prey pairing, enshrined in idioms and a well-known cartoon. And cats, it turns out, even have chemical warfare in their anti-mouse arsenal - contained in their urine. Researchers found that when very young mice were exposed to a chemical in cat urine, they were less likely to avoid the scent of cats later in life. The findings were presented at the Society for Experimental Biology's annual meeting in Prague. The researchers, from the AN Severtov Institute of Ecology and Evolution in Moscow, had previously found that the compound - aptly named felinine - causes pregnant mice to abort. Dr Vera Voznessenskaya explained that mice have a physiological response to this cat-specific compound. Chemical-sensing mouse neurons in the mouse's brain pick up the scent, triggering a reaction which includes an increase in the levels of stress hormones. "It's something that has existed in cats and mice for thousands of years," said Dr Voznessenskaya. This new study revealed that baby mice exposed to the compound during a "critical period" in their development would, as adults, react quite differently to their arch enemy's smell. The team exposed one-month-old mice to the chemical over two weeks. When they were tested later for their reaction, they were much less likely to flee the same scent. The interaction between cats and mice has a long history "Their physical sensitivity [to the chemical] was actually actually much higher," Dr Voznessenskaya explained. "More of their receptors detect the compound and they produce higher levels of stress hormone." Despite this though, mice raised around the unmistakable scent of cat pee are less inclined to show signs of fear, or to flee when they sniff it out. © 2015 BBC.

Keyword: Chemical Senses (Smell & Taste); Hormones & Behavior
Link ID: 21128 - Posted: 07.04.2015

by Sarah Zielinski Seabirds called shearwaters manage to navigate across long stretches of open water to islands where the birds breed. It’s not been clear how the birds do this, but there have been some clues. When scientists magnetically disturbed Cory’s shearwaters, the birds still managed to find their way. But when deprived of their sense of smell, the shearwaters had trouble homing in on their final destination. Smell wouldn’t seem to be all that useful out over the ocean, especially with winds and other atmospheric disturbances playing havoc on any scents wafting through the air. But now researchers say they have more evidence that shearwaters are using olfactory cues to navigate. Andrew Reynolds of Rothamsted Research in Harpenden, England, and colleagues make their case June 30 in the Proceedings of the Royal Society B. Messing with Cory’s shearwaters or other seabirds, like researchers did in earlier studies, wasn’t a good option, the researchers say, because there are conservation concerns when it comes to these species. Instead, they attached tiny GPS loggers to 210 shearwaters belonging to three species: Cory’s shearwaters, Scopoli’s shearwaters and Cape Verde shearwaters. But how would the birds’ path reveal how they were navigating? If they were using olfactory cues, the team reasoned, the birds wouldn’t take a straight path to their target. Instead, they would fly straight for a time, guided in that direction by a particular smell. When they lost that scent, their direction would change, until they picked up another scent that could guide them. And only when a bird got close would it use landmarks, other birds and the odor of the breeding colony as guides. If the birds were using some other method of navigation — or randomly searching for where to go — their paths would look much different. © Society for Science & the Public 2000 - 2015

Keyword: Chemical Senses (Smell & Taste); Animal Migration
Link ID: 21127 - Posted: 07.04.2015

By SINDYA N. BHANOO Learning can be traced back to individual neurons in the brain, according to a new study. “What we wanted to do was see if we could actually create a new association — a memory — and see if we would be able to see actual change in the neurons,” said Matias Ison, a neuroscientist at the University of Leicester in England and one of the study’s authors. He and his colleagues were able to monitor the brain activity of neurosurgical patients at UCLA Medical Center. The patients already had electrodes implanted in their medial temporal lobes for clinical reasons. The patients were first presented with images of notable people — like Jennifer Aniston, Clint Eastwood and Halle Berry. Then, they were shown images of the same people against different backdrops — like the Eiffel Tower, the Leaning Tower of Pisa and the Sydney Opera House. The same neurons that fired for the images of each of the actors also fired when patients were shown the associated landmark images. In other words, the researchers were able to watch as the patients’ neurons recorded a new memory — not just of a particular person, but of the person at a particular place. © 2015 The New York Times Company

Keyword: Learning & Memory
Link ID: 21126 - Posted: 07.02.2015

Jon Hamilton If you run into an old friend at the train station, your brain will probably form a memory of the experience. And that memory will forever link the person you saw with the place where you saw them. For the first time, researchers have been able to see that sort of link being created in people's brains, according to a study published Wednesday in the journal Neuron. The process involves neurons in one area of the brain that change their behavior as soon as someone associates a particular person with a specific place. "This type of study helps us understand the neural code that serves memory," says Itzhak Fried, an author of the paper and head of the Cognitive Neurophysiology Laboratory at UCLA. It also could help explain how diseases like Alzheimer's make it harder for people to form new memories, Fried says. The research is an extension of work that began more than a decade ago. That's when scientists discovered special neurons in the medial temporal lobe that respond only to a specific place, or a particular person, like the actress Jennifer Aniston. The experiment used a fake photo of actor Clint Eastwood and Pisa's leaning tower to test how the brain links person and place. More recently, researchers realized that some of these special neurons would respond to two people, but only if the people were connected somehow. For example, "a neuron that was responding to Jennifer Aniston was also responding to pictures of Lisa Kudrow," [another actress on the TV series Friends], says Matias Ison of the University of Leicester in the U.K. © 2015 NPR

Keyword: Learning & Memory; Attention
Link ID: 21125 - Posted: 07.02.2015