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Nick Davis Mood disorders such as depression are devastating to sufferers, and hugely costly to treat. The most severe form of depression, often called clinical depression or major depressive disorder (MDD), increases the person’s likelihood of suicide and contributes significantly to a person’s disability-adjusted life years (DALYs), a measure of quality of life taking into account periods of incapacity. The healthcare burden of MDD is large in most countries, especially when the person requires a stay in hospital. Putting these factors together, it’s clear we need to develop effective treatments to combat depression. The mechanisms of depressive disorders are not well understood, and it seems likely that there is no single cause. Most modern therapies use drugs that target neurotransmitters – the chemicals that carry signals between neurons. For example, the class of drugs known as SSRIs, or selective serotonin reuptake inhibitors, prevent the neurotransmitter serotonin from being reabsorbed by a neuron; this means that more serotonin is available to wash around between the nerve cells, and is more likely to activate cells in the brain networks that area affected in MDD. But SSRIs and other drugs are not a pharmacological ‘free lunch’. Drug treatments for depression are ineffective for many people, cause side-effects, and may lose their therapeutic effect over time. For these reasons, many researchers are searching for alternative treatments for MDD that overcome these problems, and are more effective or less unpleasant. One potential treatment involves the use of pulses of magnetic energy over the head to target the brain’s mood circuits. This technique, called transcranial magnetic stimulation (TMS), may potentially address some of the problems of pharmaceutical treatments, but we still don’t know exactly how it works, or how effective it will be in treating MDD. © 2015 Guardian News and Media Limited
Link ID: 20946 - Posted: 05.18.2015
Jon Hamilton When Sam Swiller used hearing aids, his musical tastes ran to AC/DC and Nirvana – loud bands with lots of drums and bass. But after Swiller got a cochlear implant in 2005, he found that sort of music less appealing. "I was getting pushed away from sounds I used to love," he says, "but also being more attracted to sounds that I never appreciated before." So he began listening to folk and alternative music, including the Icelandic singer Bjork. There are lots of stories like this among people who get cochlear implants. And there's a good reason. A cochlear implant isn't just a fancy hearing aid. When his cochlear implant was first switched on, the world sounded different. "A hearing aid is really just an amplifier," says Jessica Phillips-Silver, a neuroscience researcher at Georgetown University. "The cochlear implant is actually bypassing the damaged part of the ear and delivering electrical impulses directly to the auditory nerve." As a result, the experience of listening to music or any other sound through the ear, with or without a hearing aid, can be completely unlike the experience of listening through a cochlear implant. "You're basically remapping the audio world," Swiller says. Swiller is 39 years old and lives in Washington, D.C. He was born with an inherited disorder that caused him to lose much of his hearing by his first birthday. That was in the 1970s, and cochlear implants were still considered experimental devices. So Swiller got hearing aids. They helped, but Swiller still wasn't hearing what other people were. © 2015 NPR
Backyard Brains. For 235 years we have been trying to isolate, understand, and analyze the elusive action potential, and here we tell the story that continues today. The progress of understanding Action Potentials can be classed into three main endeavors: 1. Amplification The amplifiers that gave us the first hint of the electrical impulses generated by neurons came from biological tissue itself! Scientists of the 18th and early 19th century used the contractions of muscles as "bioamplifiers" to indirectly measure neural firing. Using friction machines (spark generators), Leyden jars (primitive capacitors), or Voltaic Piles (the first batteries), electrical stimuli could be delivered to motor neurons that were still attached to muscles. The electrical stimulation would cause the nerve to fire action potentials (so people hypothesized), the muscle would then contract, and the force of contraction could be measured with a spring. With increasing electrical stimuli strength (thus more action potentials in the motor neurons), the muscle would contract with increasing force. This technique worked, but led to vigorous debates as to whether the neural tissue was actually generating its own action potentials at all, or whether the muscle contraction was just a direct result of electrical stimulation. By the mid-19th century, galvanometers had been invented, and it was possible to see that nerves were indeed generating their own action potentials. These galvanometers exploited the then new technology of electromagnets. For example, Emil de Bois-Reymond built by hand a type of galvanometer with 24,000 turns around an iron plate. When the nerve fired action potentials, a metal needle suspended by the plate would deflect. These devices worked, but the needle movement was not fast enough to separate the 1 ms individual action potentials, and the machines occupied a lot of time to construct. © 2009-2015 Backyard Brains
Link ID: 20944 - Posted: 05.18.2015
Andrew Griffin Evidence that ecigs help people stop smoking real ones is lacking, according to a new analysis. Electronic cigarettes seem to work for the first month, but there isn’t enough evidence to say that they work for longer periods, researchers said. "Until such data are available, there are a number of other smoking cessation aids available that have a more robust evidence base supporting their efficacy and safety,” said lead author of the study Riyad al-Leheb, from the University of Toronto. The analysis looked at four studies of how effective and safe ecigs were, which together had studied 1011 patients. It found that after one month, using ecigs had significantly improved the amount of people that had stopped smoking. But that effect appeared to have gone at three or six months. That included studies on people who had used a placebo against those who had used ecigarettes, as well as those who had used nicotine patches. As well as the apparent lack of permanent help, the analysis found that some studies had found people reported dry cough, throat irritation and shortness of breath. While those adverse effects weren’t any worse among those that used placebo ecigs, they were much less prevalent among those that had used nicotine patches.
Keyword: Drug Abuse
Link ID: 20943 - Posted: 05.18.2015
RACHEL MARTIN, HOST: For most of her life, Cole Cohen had a hard time with all kinds of things. She'd get lost all of the time. She couldn't do math to save her life. The whole concept of time was hard for her to grasp. Her parents took her to doctor after doctor, and there were all kinds of tests and experiments with medication, but no real diagnosis until she was 26 years old. Cole Cohen got her first MRI and finally, there was an explanation. There was a hole in her brain; a hole in her brain the size of a lemon. Her memoir, titled "Head Case," is a darkly funny exploration of what that discovery meant to her. Cole Cohen joins us now. Thanks so much for being with us. COLE COHEN: Thank you for having me, Rachel. MARTIN: Let's talk about what life was like before this revelation. I mentioned your propensity to get lost. We're not talking about being in a new place and getting confuses as a lot of us might do. You got lost in, like, big box stores that you had been to before. Can you describe that sensation, that feeling of not knowing where you are in a situation like that? COHEN: Yeah. I know that sensation every time I go grocery shopping. You know, you want to get a jar of peanut butter. You have a memory of where that jar of peanut butter is, and I just don't have that in my brain. I don't store that information. So it's like a discovery every time. MARTIN: I'd love for you to read an example of one of the symptoms. You have a hard time with numbers, even references to numbers. And you write about this in the book when you're taking driver's ed. Do you mind reading that bit? © 2015 NPR
Keyword: Learning & Memory
Link ID: 20942 - Posted: 05.18.2015
By Virginia Morell Like humans, dolphins, and a few other animals, North Atlantic right whales (Eubalaena glacialis) have distinctive voices. The usually docile cetaceans utter about half a dozen different calls, but the way in which each one does so is unique. To find out just how unique, researchers from Syracuse University in New York analyzed the “upcalls” of 13 whales whose vocalizations had been collected from suction cup sensors attached to their backs. An upcall is a contact vocalization that lasts about 1 to 2 seconds and rises in frequency, sounding somewhat like a deep-throated cow’s moo. Researchers think the whales use the calls to announce themselves and to “touch base” with others of their kind, they explained in a poster presented today at the Meeting of the Acoustical Society of America in Pittsburgh, Pennsylvania. After analyzing the duration and harmonic frequency of these upcalls, as well as the rate at which the frequencies changed, the scientists found that they could distinguish the voices of each of the 13 whales. They think their discovery will provide a new tool for tracking and monitoring the critically endangered whales, which number about 450 and range primarily from Florida to Newfoundland. © 2015 American Association for the Advancement of Science.
by Andy Coghlan When a fly escapes being swatted, what is going on in its head? Is it as terrified as we would be after a close shave with death? Or is buzzing away from assailantsMovie Camera a momentary inconvenience that flies shrug off? It now seems that flies do become rattled. "In humans, fear is something that persists on a longer timescale than a simple escape reflex," says William Gibson of the California Institute of Technology in Pasadena, California. "Our observations suggest flies have a persistent state of defensive arousal, which is not necessarily fear, but which has some similarities to it." This doesn't mean that flies share the same emotional responses to fear as humans, but they do seem to have the same behavioural building blocks of fear as us. Evasive action Gibson and his colleagues exposed fruit flies to overhead shadows resembling aerial predators, such as birds. The more shadows they were exposed to, the more the flies resorted to evasive behaviour, such as hopping, jumping or freezing. When the shadow passed over once per second, by the time the shadow had fallen 10 times, the average running speed of the flies had doubled, for example. Their average number of hops trebled after just two passes. They also offered starved flies food, and part way through the meal threatened them with shadows. The more often the meal was interrupted, the longer the flies took to return to their meal after flying away. © Copyright Reed Business Information Ltd.
By JIM DWYER The real world of our memory is made of bits of true facts, surrounded by holes that we Spackle over with guesses and beliefs and crowd-sourced rumors. On the dot of 10 on Wednesday morning, Anthony O’Grady, 26, stood in front of a Dunkin’ Donuts on Eighth Avenue in Manhattan. He heard a ruckus, some shouts, then saw a police officer chase a man into the street and shoot him down in the middle of the avenue. Moments later, Mr. O’Grady spoke to a reporter for The New York Times and said the wounded man was in flight when he was shot. “He looked like he was trying to get away from the officers,” Mr. O’Grady said. Another person on Eighth Avenue then, Sunny Khalsa, 41, had been riding her bicycle when she saw police officers and the man. Shaken by the encounter, she contacted the Times newsroom with a shocking detail. “I saw a man who was handcuffed being shot,” Ms. Khalsa said. “And I am sorry, maybe I am crazy, but that is what I saw.” At 3 p.m. on Wednesday, the Police Department released a surveillance videotape that showed that both Mr. O’Grady and Ms. Khalsa were wrong. Contrary to what Mr. O’Grady said, the man who was shot had not been trying to get away from the officers; he was actually chasing an officer from the sidewalk onto Eighth Avenue, swinging a hammer at her head. Behind both was the officer’s partner, who shot the man, David Baril. And Ms. Khalsa did not see Mr. Baril being shot while in handcuffs; he is, as the video and still photographs show, freely swinging the hammer, then lying on the ground with his arms at his side. He was handcuffed a few moments later, well after he had been shot. © 2015 The New York Times Company
Keyword: Learning & Memory
Link ID: 20939 - Posted: 05.16.2015
By Tina Hesman Saey A man who had been blind for 50 years allowed scientists to insert a tiny electrical probe into his eye. The man’s eyesight had been destroyed and the photoreceptors, or light-gathering cells, at the back of his eye no longer worked. Those cells, known as rods and cones, are the basis of human vision. Without them, the world becomes gray and formless, though not completely black. The probe aimed for a different set of cells in the retina, the ganglion cells, which, along with the nearby bipolar cells, ferry visual information from the rods and cones to the brain. No one knew whether those information-relaying cells still functioned when the rods and cones were out of service. As the scientists sent pulses of electricity to the ganglion cells, the man described seeing a small, faint candle flickering in the distance. That dim beacon was a sign that the ganglion cells could still send messages to the brain for translation into images. That 1990s experiment and others like it sparked a new vision for researcher Zhuo-Hua Pan of Wayne State University in Detroit. He and his colleague Alexander Dizhoor wondered if, instead of tickling the cells with electricity, scientists could transform them to sense light and do what rods and cones no longer could. The approach is part of a revolutionary new field called optogenetics. Optogeneticists use molecules from algae or other microorganisms that respond to light or create new molecules to do the same, and insert them into nerve cells that are normally impervious to light. By shining light of certain wavelengths on the molecules, researchers can control the activity of the nerve cells. © Society for Science & the Public 2000 - 2015
Link ID: 20938 - Posted: 05.16.2015
by Rachel Ehrenberg It was the dress that launched a million tweets. In February, a mother-in-law-to-be sent a picture of a dress she was considering wearing to her daughter’s Grace’s wedding to Grace and her fiancé. The couple couldn’t agree on the dress’s color: was it blue and black or white and gold? (White and gold, obviously.) The disagreement prompted the daughter to post the picture on social media, recruiting other opinions. That post caused such a stir that BuzzFeed picked it up, asking the masses to weigh in. And then the Internet went haywire. Within a few days, the original BuzzFeed article had more than 37 million hits. Serious news outlets interviewed neuroscientists and psychologists about color perception and optical illusions. Bevil Conway, a neuroscientist at Wellesley College, was one of those scientists. At the time, he thought the hullabaloo was interesting mostly because it showed how passionately people feel about color (as in, insanely riled-up and deeply offended by alternative views). He joked with NPR’s Robert Siegel, off air, that the story was “fluff,” Conway told me. Well, there’s nothing like a little research to turn fluff into gold (or blue or black). Conway, coauthor of a study appearing online May 14 in Current Biology that explores people’s perceptions of the dress, now calls the phenomenon “profound.” “I think it will go down as one of the most important discoveries in color vision in the last 10 years,” Conway says. “And all because of a crazy photograph.” In those February interviews, Conway (and some other scientists) explained the disparity of opinions on the dress in terms of “color constancy,” a feature of perception that allows us to identify colors under different lighting conditions. If we see a red poisonous snake or a red delicious apple, we need to be able to identify it as red (and dangerous or delicious), whether in bright sunlight or the gloom of clouds. © Society for Science & the Public 2000 - 2015
Link ID: 20937 - Posted: 05.16.2015
John Crace After over a year working in Westminster as this paper’s parliamentary sketchwriter, I thought I had learned a thing or two about bearpits. That was before I agreed to second Prof Allan Young in speaking against the motion that “This House believes that the long-term use of psychiatric medications is causing more harm than good”. It turned out that politicians are almost models of decency compared to psychiatrists fighting their own corner. I had wondered why I had been invited. I have no scientific knowledge of the subject under discussion; all I had to offer was my own personal experience of living with episodes of depression and acute anxiety for more than 20 years. For me, a combination of medication and therapy has proved effective; not so effective as to prevent recurrences of these mental health problems all together, but effective enough for me to have managed them without having to return as an in-patient at the psychiatric hospital I wound up in 20 years earlier. I could perhaps have done more to look after myself, I suppose. I could have given up my Spurs season ticket. But apart from that … Having raised concerns about my credentials, I was assured that it was important to have a patient’s voice heard. I thought so, too. So I agreed. But on the way home from the debate last night, I did wonder if the reason I had been asked was because everyone else had turned them down. Things didn’t get off to a great start, when there was a pre-debate vote in the packed theatre at King’s College’s Institute of Psychiatry, Psychology and Neuroscience, which had apparently sold out within hours of the tickets being made available in March. 126 people – a mixture of mental health practitioners, students and members of the public – believed the motion to be correct; 28 abstained, and only 64 were on my side. © 2015 Guardian News and Media Limited
Link ID: 20936 - Posted: 05.16.2015
Barbara J. King Last Friday in the Washington Post, Charles Krauthammer asked which contemporary practices will be deemed "abominable" in the future, in the way that we today think of human enslavement. He then offered his own opinion: "I've long thought it will be our treatment of animals. I'm convinced that our great-grandchildren will find it difficult to believe that we actually raised, herded and slaughtered them on an industrial scale — for the eating." Krauthammer goes on to predict that meat-eating will become "a kind of exotic indulgence," because "science will find dietary substitutes that can be produced at infinitely less cost and effort." I don't often agree with Krauthammer's views, and his animal column is no exception. His breezy attitude on animal biomedical testing does animals no favors. (It's perhaps only fair to note that I have similar concerns about Alva's conclusions on animal testing from his 13.7 post published that same day.) But, still, Krauthammer does a terrific job of awakening people to many issues related to animals' suffering. And he's not alone. On April 17, I joined other scientists and activists on the radio show To the Point hosted by Warren Olney, to discuss this question: Is Animal Liberation Going Mainstream? In the 34-minute segment, we discussed the public outcry against SeaWorld's treatment of orcas, Ringling Bros.' plan to retire elephants from the circus in three years, and the rightness or wrongness of keeping animals in zoos — all issues brought up by Krauthammer in his column. © 2015 NPR
Keyword: Animal Rights
Link ID: 20935 - Posted: 05.16.2015
By Virginia Morell Hyenas long ago mastered one of the keys to Facebook success: becoming the friend of a friend. The most common large carnivore in Africa, spotted hyenas (Crocuta crocuta), are known for their socially sophisticated behaviors. They live in large, stable clans (as pictured above), which can include as many as 100 individuals. They can tell clan members apart, discriminating among their maternal and paternal kin. They’re also choosy about their pals and form tight bonds only with specific members—the friends of their friends, researchers report in the current issue of Ecology Letters. And it’s this ability to form lasting friendships—or “cohesive clusters,” as the scientists describe a triad of friends—that is most important in maintaining the animals’ social structure. To reach this conclusion, the scientists analyzed more than 50,000 observations of social interactions among spotted hyenas in Kenya’s Maasai Mara National Reserve over 20 years. They found that individual traits, including the hyena’s sex and social rank, as well as environmental factors such as the amount of rainfall and prey abundance, all play a role in the animals’ social dynamics. But the most consistently influential factor was the ability of individual hyenas to form and maintain those tight friendships. The study used a new modeling method, which the researchers say can help other scientists better understand the sociality of other species. And that includes the human animal, who, the scientists note, are also prone to “cohesive clusters,” whether living as hunter-gatherers or as users of social media. © 2015 American Association for the Advancement of Science.
Link ID: 20934 - Posted: 05.16.2015
By Jonathan Webb Science reporter, BBC News A cluster of cells in the brain of a fly can track the animal's orientation like a compass, a study has revealed. Fixed in place on top of a spherical treadmill, a fruit fly walked on the spot while neuroscientists peered into its brain using a microscope. Watching the neurons fire inside a donut-shaped brain region, they saw activity sweep around the ring to match the direction the animal was headed. Mammals have similar "head direction cells" but this is a first for flies. The findings are reported in the journal Nature. Crucially, the compass-like activity took place not only when the animal was negotiating a virtual-reality environment, in which screens gave the illusion of movement, but also when it was left in the dark. "The fly is using a sense of its own motion to pick up which direction it's pointed," said senior author Dr Vivek Jayaraman, from the Howard Hughes Medical Institute's Janelia Research Campus. In some other insects, such as monarch butterflies and locusts, brain cells have been observed firing in a way that reflects the animal's orientation to the pattern of polarised light in the sky - a "sun compass". But the newly discovered compass in the fly brain works more like the "head directions cells" seen in mammals, which rapidly set up a directional system for the animal based on landmarks in the surrounding scene. "A key thing was incorporating the fly's own movement," Dr Jayaraman told the BBC. "To see that its own motion was relevant to the functioning of this compass - that was something we could only see if we did it in a behaving animal." © 2015 BBC
Keyword: Learning & Memory
Link ID: 20933 - Posted: 05.14.2015
Thomas R. Clandinin & Lisa M. Giocomo An analysis reveals that fruit-fly neurons orient flies relative to cues in the insects' environment, providing evidence that the fly's brain contains a key component for drawing a cognitive map of the insect's surroundings. See Article p.186 Animals need accurate navigational skills as they go about their everyday lives. Many species, from ants to rodents, navigate on the basis of visual landmarks, and this is complemented by path integration, in which neuronal cues about the animal's own motion are used to track its location relative to a starting point. In mammals, these different types of navigation are integrated by neurons called head-direction cells1. In this issue, Seelig and Jayaraman2 (page 186) provide the first evidence that certain neurons in fruit flies have similar properties to head-direction cells, encoding information that orients the insects relative to local landmarks. Head-direction cells act as a neuronal compass that generates a cognitive map of an animal's environment. The activity of each head-direction cell increases as the animal faces a particular direction, with different cells preferentially responding to different directions1, 3. Rather than certain cells always responding to north, south and so on, the direction in which the cells fire is set up arbitrarily when the animal encounters new visual landmarks. The signals are then updated by self-motion cues as the animal navigates. Studying head-direction cells in mammals is challenging because of the complexity of the mammalian brain. By contrast, the small fly brain is a good model for studying neuronal activity. © 2015 Macmillan Publishers Limited.
Keyword: Learning & Memory
Link ID: 20932 - Posted: 05.14.2015
Anya Kamenetz Are you a pen-clicker? A hair-twirler? A knee-bouncer? Did you ever get in trouble for fidgeting in class? Don't hang your head in shame. All that movement may be helping you think. A new study suggests that for children with attention disorders, hyperactive movements meant better performance on a task that requires concentration. The researchers gave a small group of boys, ages 8 to 12, a sequence of random letters and numbers. Their job: Repeat back the numbers in order, plus the last letter in the bunch. All the while, the kids were sitting in a swiveling chair. For the subjects with ADHD, moving and spinning in the chair were correlated with better performance. For typically developing kids, however, it was the opposite: the more they moved, the worse they did on the task. Dustin Sarver at the University of Mississippi Medical Center is the lead author of this study. ADHD is his field, and he has a theory as to why fidgeting helps these kids. "We think that part of the reason is that when they're moving more they're increasing their alertness." That's right — increasing. The prevailing scientific theory on attention disorders holds that they are caused by chronic underarousal of the brain. That's why stimulants are prescribed as treatment. Sarver believes that slight physical movements "wake up" the nervous system in much the same way that Ritalin does, thus improving cognitive performance. © 2015 NPR
Link ID: 20931 - Posted: 05.14.2015
by Jessica Hamzelou Painful needle heading your way? A sharp intake of breath might be all that is needed to make that injection a little more bearable. When you are stressed, your blood pressure rises to fuel your brain or limbs should you need to fight or flee. But your body has a natural response for calming back down. Pressure sensors on blood vessels in your lungs can tell your brain to bring the pressure back down, and the signals from these sensors also make the brain dampen the nervous system, leaving you less sensitive to pain. This dampening mechanism might be why people with higher blood pressures appear to have higher pain thresholds. Gustavo Reyes del Paso at the University of Jaén in Spain wondered whether holding your breath – a stress-free way of raising blood pressure and triggering the pressure sensors – might also raise a person's pain threshold. To find out, he squashed the fingernails of 38 people for 5 seconds while they held their breath. Then he repeated the test while the volunteers breathed slowly. Both techniques were distracting, but the volunteers reported less pain when breath-holding than when slow breathing. Reyes del Paso thinks holding your breath might be a natural response to the expectation of pain. "Several of our volunteers told us they already do this when they are in pain," he says. But he doesn't think the trick will work for a stubbed toe or unexpected injury. You have to start before the pain kicks in, he says, for example, in anticipation of an injection. © Copyright Reed Business Information Ltd
Keyword: Pain & Touch
Link ID: 20930 - Posted: 05.14.2015
Robinson Meyer Brett Redding felt like he was out of options. “It started with little things—having trouble making eye contact,” he told me. Soon it got worse. Redding, a 28-year-old salesman in Seattle, found himself freaking out during normal, everyday conversations. He worried any time his boss wanted to talk. He would dread his regular sales calls, and the city’s booming housing market—he works in construction—seemed to make his ever-increasing meetings all the more crushing. He was suffering social anxiety, a common but debilitating mental illness. “I was afraid of losing my job because I couldn’t do it,” he says. His meetings with a therapist weren’t working, and he didn’t “want to mess with antidepressants.” “I’ve always been so social—I’ve never had issues with looking people in the eye and talking with people,” he says. That’s when Redding’s girlfriend saw an ad on Craigslist that promised an online program could help treat Redding’s social anxiety through methods proven by science. “I had nothing to lose,” he says—so he signed up. That service is now called Joyable. I first saw Joyable when an ad for it appeared in Facebook on my phone. “90 percent of our clients see their anxiety decline,” said the ad, next to a sun-glinted, bokeh-heavy photo of a blonde woman. I clicked on. Joyable’s website, full of affable sans serifs and cheery salmon rectangles, looks Pinterest-esque, at least in its design. Except its text didn’t discuss eye glasses or home decor but “evidence-based” methods shown to reduce social anxiety. I knew those phrases: “Evidence-based” is the watchword of cognitive behavioral therapy, or CBT, the treatment now considered most effective for certain anxiety disorders. Joyable dresses a psychologists’s pitch in a Bay Area startup’s clothes. © 2015 by The Atlantic Monthly Group.
Link ID: 20929 - Posted: 05.14.2015
Haroon Siddique Long-term depression in people over 50 could more than double their risk of suffering a stroke, with the risk remaining significantly higher even after the depression allays, research suggests. The US study of more than 16,000 people, which documented 1,192 strokes, found that onset of recent depression was not associated with higher stroke risk, suggesting the damage is done by depressive symptoms accumulating over time. The study’s lead author, Paola Gilsanz, from Harvard University’s TH Chan School of Public Health, said: “Our findings suggest that depression may increase stroke risk over the long term. Looking at how changes in depressive symptoms over time may be associated with strokes allowed us to see if the risk of stroke increases after elevated depressive symptoms start or if risk goes away when depressive symptoms do. We were surprised that changes in depressive symptoms seem to take more than two years to protect against or elevate stroke risk.” The research, published on Wednesday in the Journal of the American Heart Association, used data from between 1998 and 2010 from the Health and Retirement Study, which interviews a panel of representative Americans aged over 50 every two years, on their depressive symptoms, history of stroke, and stroke risk factors. Gilsanz, with colleagues from universities in Washington, California and Minnesota, and Bronx Partners for Healthy Communities, found that people with high depressive symptoms at two consecutive interviews had a 114% higher risk of suffering a first stroke, compared with people without depression at either interview. Those who had depressive symptoms at one interview but not at the next had a 66% higher risk. © 2015 Guardian News and Media Limited
Jon Hamilton When the brain needs to remember a phone number or learn a new dance step, it creates a circuit by connecting different types of neurons. But scientists still don't know how many types of neurons there are or exactly what each type does. "How are we supposed to understand the brain and help doctors figure out what schizophrenia is or what paranoia is when we don't even know the different components," says Christof Koch, president and chief scientific officer of the Allen Institute for Brain Science, a nonprofit research center in Seattle. So the institute is creating a freely available online database that will eventually include thousands of nerve cells. For now, the Allen Cell Types Database has detailed information on 240 mouse cells, including their distinctive shapes. More than 100 years ago, Golgi staining on nerve cells opened the gates to modern neuroscience. Scientists recently developed the Technicolor version of Golgi staining, Brainbow, allowing more detailed reconstructions of brain circuits. "They look like different trees," Koch says. "Some fan out at the top. Some are like a Christmas tree; they fan out at the bottom. Others are like three-dimensional fuzz balls." The database also describes each cell by the electrical pattern it generates. And eventually it will include information about which genes are expressed. Once researchers have a complete inventory of details about the brain's building blocks, they'll need to know which combinations of blocks can be connected, Koch says. After all, he says, it is these connections that make us who we are. © 2015 NPR
Keyword: Brain imaging
Link ID: 20927 - Posted: 05.14.2015