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Few genes have made the headlines as much as FOXP2. The first gene associated with language disorders , it was later implicated in the evolution of human speech. Girls make more of the FOXP2 protein, which may help explain their precociousness in learning to talk. Now, neuroscientists have figured out how one of its molecular partners helps Foxp2 exert its effects.
The findings may eventually lead to new therapies for inherited speech disorders, says Richard Huganir, the neurobiologist at Johns Hopkins University School of Medicine in Baltimore, Maryland, who led the work. Foxp2 controls the activity of a gene called Srpx2, he notes, which helps some of the brain's nerve cells beef up their connections to other nerve cells. By establishing what SRPX2 does, researchers can look for defective copies of it in people suffering from problems talking or learning to talk.
Until 2001, scientists were not sure how genes influenced language. Then Simon Fisher, a neurogeneticist now at the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, and his colleagues fingered FOXP2 as the culprit in a family with several members who had trouble with pronunciation, putting words together, and understanding speech. These people cannot move their tongue and lips precisely enough to talk clearly, so even family members often can?t figure out what they are saying. It “opened a molecular window on the neural basis of speech and language,” Fisher says.
Photo credit: Yoichi Araki, Ph.D.
Regina Nuzzo Gene therapy delivered to the inner ear can help shrivelled auditory nerves to regrow — and in turn, improve bionic ear technology, researchers report today in Science Translational Medicine1. The work, conducted in guinea pigs, suggests a possible avenue for developing a new generation of hearing prosthetics that more closely mimics the richness and acuity of natural hearing. Sound travels from its source to ears, and eventually to the brain, through a chain of biological translations that convert air vibrations to nerve impulses. When hearing loss occurs, it’s usually because crucial links near the end of this chain — between the ear’s cochlear cells and the auditory nerve — are destroyed. Cochlear implants are designed to bridge this missing link in people with profound deafness by implanting an array of tiny electrodes that stimulate the auditory nerve. Although cochlear implants often work well in quiet situations, people who have them still struggle to understand music or follow conversations amid background noise. After long-term hearing loss, the ends of the auditory nerve bundles are often frayed and withered, so the electrode array implanted in the cochlea must blast a broad, strong signal to try to make a connection, instead of stimulating a more precise array of neurons corresponding to particular frequencies. The result is an ‘aural smearing’ that obliterates fine resolution of sound, akin to forcing a piano player to wear snow mittens or a portrait artist to use finger paints. To try to repair auditory nerve endings and help cochlear implants to send a sharper signal to the brain, researchers turned to gene therapy. Their method took advantage of the electrical impulses delivered by the cochlear-implant hardware, rather than viruses often used to carry genetic material, to temporarily turn inner-ear cells porous. This allowed DNA to slip in, says lead author Jeremy Pinyon, an auditory scientist at the University of New South Wales in Sydney, Australia. © 2014 Nature Publishing Group
by Michael Slezak Could preventing the brain shrinkage associated with depression be as simple as blocking a protein? Post-mortem analysis of brain tissue has shown that the dendrites that relay messages between neurons are more shrivelled in people with severe depression than in people without the condition. This atrophy could be behind some of the symptoms of depression, such as the inability to feel pleasure. As a result, drugs that help repair the neuronal connections, like ketamine, are under investigation. But how this shrinkage occurs has remained a mystery, limiting researchers' ability to find ways of stopping it. Ronald Duman at Yale University wondered whether a protein called REDD1, which was recently shown to reduce myelin, the fatty material that protects neurons, was the key. To find out, his team bred rats unable to produce REDD1 and exposed them to a prolonged period of unpredictable stress. In normal rats, this stress resulted in depressive-like behaviour and brain shrinkage, but Duman's rats were unaffected. In contrast, rats engineered to overproduce REDD1 became depressed and had brain shrinkage, even without being stressed. What's more, injecting normal rats with a stress hormone boosted levels of REDD1 in the brain. Giving them a drug that blocked the production of stress hormones stopped them producing the protein, even when they were externally stressed. Taken together, the experiments show that REDD1 is necessary to produce the brain shrinkage seen in stressed rats, and that stress hormones are involved in its production – offering a possible way to prevent the shrinkage. © Copyright Reed Business Information Ltd
Link ID: 19532 - Posted: 04.24.2014
Here to stay. The Y chromosome is small compared with the X, but is required to keep levels of some genes high enough for mammals to survive. The small, stumpy Y chromosome—possessed by male mammals but not females, and often shrugged off as doing little more than determining the sex of a developing fetus—may impact human biology in a big way. Two independent studies have concluded that the sex chromosome, which shrank millions of years ago, retains the handful of genes that it does not by chance, but because they are key to our survival. The findings may also explain differences in disease susceptibility between men and women. “The old textbook description says that once maleness is determined by a few Y chromosome genes and you have gonads, all other sex differences stem from there,” says geneticist Andrew Clark of Cornell University, who was not involved in either study. “These papers open up the door to a much richer and more complex way to think about the Y chromosome.” The sex chromosomes of mammals have evolved over millions of years, originating from two identical chromosomes. Now, males possess one X and one Y chromosome and females have two Xs. The presence or absence of the Y chromosome is what determines sex—the Y chromosome contains several genes key to testes formation. But while the X chromosome has remained large throughout evolution, with about 2000 genes, the Y chromosome lost most of its genetic material early in its evolution; it now retains less than 100 of those original genes. That’s led some scientists to hypothesize that the chromosome is largely indispensable and could shrink away entirely. © 2014 American Association for the Advancement of Science.
Keyword: Sexual Behavior
Link ID: 19531 - Posted: 04.24.2014
By Linda Carroll A college education may do a lot more than provide better job opportunities — it may also make brains more resilient to trauma, a new study suggests. The more years of education people have, the more likely they will recover from a traumatic brain injury, according to the study published Wednesday in Neurology. In fact, one year after a traumatic brain injury, people with a college education were nearly four times as likely as those who hadn’t finished high school to return to work or school with no disability. Earlier studies had shown that education might have a protective effect when it comes to degenerative brain diseases like Alzheimer’s. Scientists have theorized that education leads to greater “cognitive reserve,” which allows people to overcome or compensate for brain damage. So if there are two people with the same degree of damage from Alzheimer’s, the more highly educated one will show fewer symptoms. The assumption is that education changes and expands the brain, leaving it better able to cope with challenges. “Added capacity allows us to either work around the damaged areas or to adapt,” said Eric B. Schneider, an assistant professor of surgery at the Johns Hopkins School of Medicine. Schneider and his colleagues suspected that cognitive reserve might play an equally important role in helping people rehab from acute brain damage that results from falls, car crashes and other accidents as it does in Alzheimer’s disease.
By Brady Dennis, The Food and Drug Administration will for the first time regulate the booming market of electronic cigarettes, as well as cigars, pipe tobacco and hookahs, under a proposal to be released Thursday. The move would begin to place restrictions on e-cigarettes, a nearly $2 billion industry that for years has operated outside the reach of federal regulators. If adopted, the government’s plan would force manufacturers to curb sales to minors, stop handing out free samples, place health warning labels on their products and disclose the ingredients. Makers of e-cigarettes also would be banned from making health-related claims without scientific evidence. The FDA’s proposal stops short of broader restrictions sought by many tobacco-control advocates. Regulators at this point are not seeking to halt online sales of e-cigarettes, curb television advertising, or ban the use of flavorings such as watermelon, grape soda and piña colada — all tactics that critics say are aimed at attracting young smokers and that have been banned for traditional cigarettes. Those restrictions might come eventually, FDA officials said, but not before more rigorous research can establish a scientific basis for tougher rules. “Right now, for something like e-cigarettes, there are far more questions than answers,” said Mitch Zeller, director of the FDA’s Center for Tobacco Products. Thursday’s action is about expanding FDA’s authority to products that have been “rapidly evolving with no regulation whatsoever,” in order to create a foundation for broader regulation in the future, he said. “It creates the framework. We’re calling this the first step. . . . For the first time, there will be a science-based, independent regulatory agency playing a vital gate-keeping function.” © 1996-2014 The Washington Post
Keyword: Drug Abuse
Link ID: 19529 - Posted: 04.24.2014
I am a sociologist by training. I come from academic world, reading scholarly articles on topics of social import, but they're almost always boring, dry and quickly forgotten. Yet I can't count how many times I've gone to a movie, a theater production or read a novel and been jarred into seeing something differently, learned something new, felt deep emotions and retained the insights gained. I know from both my research and casual conversations with people in daily life that my experiences are echoed by many. The arts can tap into issues that are otherwise out of reach and reach people in meaningful ways. This realization brought me to arts-based research (ABR). Arts-based research is an emergent paradigm whereby researchers across the disciplines adapt the tenets of the creative arts in their social research projects. Arts-based research, a term first coined by Eliot Eisner at Stanford University in the early 90s, is based on the assumption that art can teach us in ways that other forms cannot. Scholars can take interview or survey research, for instance, and represent it through art. I've written two novels based on sociological interview research. Sometimes researchers use the arts during data collection, involving research participants in the art-making process, such as drawing their response to a prompt rather than speaking. The turn by many scholars to arts-based research is most simply explained by my opening example of comparing the experience of consuming jargon-filled and inaccessible academic articles to that of experiencing artistic works. While most people know on some level that the arts can reach and move us in unique ways, there is actually science behind this. ©2014 TheHuffingtonPost.com, Inc
Associated Press Diagnosed with retinitis pigmentosa as a teenager, Pontz has been almost completely blind for years. Now, thanks to a high-tech procedure that involved the surgical implantation of a "bionic eye," he has regained enough of his eyesight to catch small glimpses of his wife, grandson and cat. "It's awesome. It's exciting - seeing something new every day," Pontz said during a recent appointment at the University of Michigan Kellogg Eye Center. The 55-year-old former competitive weightlifter and factory worker is one of four people in the U.S. to receive an artificial retina since the Food and Drug Administration signed off on its use last year. The facility in Ann Arbor has been the site of all four such surgeries since FDA approval. A fifth is scheduled for next month. Retinitis pigmentosa is an inherited disease that causes slow but progressive vision loss due to a gradual loss of the light-sensitive retinal cells called rods and cones. Patients experience loss of side vision and night vision, then central vision, which can result in near blindness. Not all of the 100,000 or so people in the U.S. with retinitis pigmentosa can benefit from the bionic eye. An estimated 10,000 have vision low enough, said Dr. Brian Mech, an executive with Second Sight Medical Products Inc., the Sylmar (Los Angeles County) company that makes the device. Of those, about 7,500 are eligible for the surgery. The artificial implant in Pontz's left eye is part of a system developed by Second Sight that includes a small video camera and transmitter housed in a pair of glasses. © 2014 Hearst Communications, Inc.
It takes a lot to deter a male from wanting sex. A new study has found that male mice keep trying to copulate even when they are in pain, whereas females engage in less sex. But when given drugs that target pleasure centers in the human brain, the females again became interested. The findings could shed light on the nature of libido across various animal species. To assess how pain influences sexual desire, researchers first identified pairs of mice that wanted to have sex. “What we found early on was not all mice will mate with each other,” says clinical psychologist Melissa Farmer, who led the study while earning her Ph.D. at McGill University in Montreal, Canada. The team set up the rodents on a series of “dates,” during which a male and female were paired together for 30 minutes. Couples that copulated for most of the session were deemed compatible and moved into a cage with separate rooms. A small doorway allowed a female mouse to freely cross over from her chamber, but the male—which is larger—could not. The scientists then induced pain in males or females by applying a small dose of inflammatory compounds to the cheek, tail, foot, or genitals. The sensation would primarily be soreness, like a bad sunburn, says Farmer, who now works at Northwestern University’s Feinberg School of Medicine in Chicago, Illinois. Female mice that were in pain, whether genital or nongenital, spent 50% less time with their male partners, implying a decrease in sexual motivation. Even when they did visit their paramours, females wouldn’t allow males to mount them with the same frequency, the team reports online today in The Journal of Neuroscience. © 2014 American Association for the Advancement of Science.
|By Stephen L. Macknik and Susana Martinez-Conde The Best Illusion of the Year Contest brings scientific and popular attention to perceptual oddities. Anyone can submit an illusion to next year's contest at http://illusionoftheyear.com/submission-instructions for the rules Decked out in a mask, cape and black spandex, a fit young man leaps onto the stage, one hand raised high, and bellows, “I am Japaneeeese Bat-Maaaaaan!” in a thick accent. The performer is neither actor nor acrobat. He is a mathematician named Jun Ono, hailing from Meiji University in Japan. Ono's single bound, front and center, at the Philharmonic Center for the Arts in Naples, Fla. (now called Artis-Naples), was the opening act of the ninth Best Illusion of the Year Contest, held May 13, 2013. Four words into the event, we knew Ono had won. Aside from showcasing new science, the contest celebrates our brain's wonderful and mistaken sense that we can accurately see, smell, hear, taste and touch the world around us. In reality, accuracy is not the brain's forte, as the illusion creators competing each year will attest. Yes, there is a real world out there, and you do perceive (some of) the events that occur around you, but you have never actually lived in reality. Instead your brain gathers pieces of data from your sensory systems—some of which are quite subjective or frankly wrong—and builds a simulation of the world. This simulation, which some call consciousness, becomes the universe in which you live. It is the only thing you have ever perceived. Your brain uses incomplete and flawed information to build this mental model and relies on quirky neural algorithms to often—but not always—obviate the flaws. Let us take a spin through some of the world's top illusions and their contributions to the science of perception. (To see videos of these illusions, see ScientificAmerican.com/may2014/illusions.) © 2014 Scientific American
Victoria Colliver, Erin Allday Women who gain too much or too little weight during pregnancy can greatly increase their baby's risk of being overweight or obese as a young child, according to a study by Kaiser Permanente researchers. Researchers examined the health records from 4,145 Northern California Kaiser members who filled out a health survey between 2007 and 2009 and subsequently gave birth. They found that women who exceeded the Institute of Medicine's revised 2009 guidelines for weight gain during pregnancy were 46 percent more likely than women who met the guidelines to have an obese or overweight child between the ages of 2 and 5 years old. Under the new guidelines, women who are obese - defined as those with a body mass index, or BMI, of 30 or higher - should gain 11 to 20 pounds. Overweight women - with BMIs between 25 and 29 - can gain 15 to 25 pounds. And normal-weight women are recommended to gain between 25 and 35 pounds. Those who are underweight - with BMIs under 18.5 - are to gain 28 to 40 pounds. Women who had a healthy BMI before their pregnancy but gained less weight than recommended were 63 percent more likely than those who met the guidelines to have an obese or overweight child. Meanwhile, healthy-weight women who exceeded the guidelines were 79 percent more likely to have an overweight child. Researchers suggested gaining too little or too much weight may permanently affect the body's mechanisms that manage energy balance and metabolism. The study, which is considered the largest to examine the new guidelines in relationship to childhood obesity, was published April 14 in the American Journal of Obstetrics and Gynecology. © 2014 Hearst Communications, Inc.
Chelsea Wald The sailfish’s sword-like bill looks as if it was made to slash at prey. But a study published today in Proceedings of the Royal Society B1 reveals that the bill is actually a multifunctional killing tool, enabling the fish to perform delicate, as well as swashbuckling, manoeuvres. By following throngs of predatory birds off the coast of Cancún, Mexico, the study’s authors were able to track Atlantic sailfish (Istiophorus albicans) hunting sardines, says co-author Alexander Wilson, a behavioural ecologist now at Carleton University in Ottawa, Canada. He and his colleagues made high-speed, high-resolution films in the open ocean over six days in 2012. Sailfish hunt in groups, taking turns to approach the ball of schooling fish. Their bodies darken and sometimes flash stripes and spots, perhaps to confuse the prey, or to signal to each other. “It’s a very orderly process,” Wilson says. “They don’t want to risk breaking their bills.” Although sailfish are among the fastest creatures in the ocean — they have been documented to swim at more than 110 kilometres per hour, or 60 knots — the new research shows that their strategy is to approach their prey slowly from behind and gently insert their bills into the school, without eliciting an evasive manoeuvre from the sardines. Then, by whipping their heads in powerful, sudden jerks, they can slash their bills left and right, with their upright fins providing stability. In fact, their bill tips slash with about the same acceleration as the tip of a swinging baseball bat, even in the water, says co-author Paolo Domenici, an environmental physiologist at the Institute for the Marine and Coastal Environment of Italy's National Research Council in Torregrande, on the island of Sardinia. The result is a scene of fishy carnage, as the surrounding water fills with iridescent fragments of sardine skin. © 2014 Nature Publishing Group,
Keyword: Pain & Touch
Link ID: 19523 - Posted: 04.23.2014
By David Grimm “We did one study on cats—and that was enough!” Those words effectively ended my quest to understand the feline mind. I was a few months into writing Citizen Canine: Our Evolving Relationship With Cats and Dogs, which explores how pets are blurring the line between animal and person, and I was gearing up for a chapter on pet intelligence. I knew a lot had been written about dogs, and I assumed there must be at least a handful of studies on cats. But after weeks of scouring the scientific world for someone—anyone—who studied how cats think, all I was left with was this statement, laughed over the phone to me by one of the world’s top animal cognition experts, a Hungarian scientist named Ádám Miklósi. We are living in a golden age of canine cognition. Nearly a dozen laboratories around the world study the dog mind, and in the past decade scientists have published hundreds of articles on the topic. Researchers have shown that Fido can learn hundreds of words, may be capable of abstract thought, and possesses a rudimentary ability to intuit what others are thinking, a so-called theory of mind once thought to be uniquely human. Miklósi himself has written an entire textbook on the canine mind—and he’s a cat person. I knew I was in trouble even before I got Miklósi on the phone. After contacting nearly every animal cognition expert I could find (people who had studied the minds of dogs, elephants, chimpanzees, and other creatures), I was given the name of one man who might, just might, have done a study on cats. His name was Christian Agrillo, and he was a comparative psychologist at the University of Padova in Italy. When I looked at his website, I thought I had the wrong guy. A lot of his work was on fish. But when I talked to him he confirmed that, yes, he had done a study on felines. Then he laughed. “I can assure you that it’s easier to work with fish than cats,” he said. “It’s incredible.” © 2014 The Slate Group LLC.
Josh Fischman Dogs and cats, historically, have been people’s property like a couch or a toaster. But as they’ve moved into our houses and our hearts, courts of law have begun to treat them as something more. They can inherit your estate, get an appointed lawyer if your relatives challenge that inheritance and are protected from cruel acts. Your toaster can’t do any of that. As these animals inch closer to citizens' rights, the trend is being watched with worried eyes by biomedical researchers who fear judges could extend these rights to lab animals like monkeys and rats, thereby curbing experimentation. It also disturbs veterinarians who fear a flood of expensive malpractice suits if pets are worth more than their simple economic value. David Grimm, deputy news editor for Science magazine, explores this movement in his book Citizen Canine: Our Evolving Relationship with Cats and Dogs (PublicAffairs Books, 2014), published this month. He explained to Scientific American why scientists and animal doctors have good reason to be concerned. An edited transcript of the interview follows. In what way have dogs and cats moved beyond the status of property? They can inherit money, for one thing. And since property cannot inherit property, that makes them different. Legal scholars say that is the biggest change. About 25 US states have adopted the Uniform Trust Code, which allows animals to inherit.* Also judges have granted owners of slain animals awards of emotional damages. You cannot get emotional damages from the loss of a toaster. In 2004 a California jury awarded a man named Marc Bluestone $39,000 for the loss of his dog Shane; $30,000 of that was for Shane’s special and unique value to Bluestone. © 2014 Nature Publishing Group
Keyword: Animal Rights
Link ID: 19521 - Posted: 04.23.2014
By JAMES GORMAN SAN DIEGO — Dr. Karl Deisseroth is having a very early breakfast before the day gets going at the annual meeting of the Society for Neuroscience. Thirty thousand people who study the brain are here at the Convention Center, a small city’s worth of badge-wearing, networking, lecture-attending scientists. For Dr. Deisseroth, though, this crowd is a bit like the gang at Cheers — everybody knows his name. He is a Stanford psychiatrist and a neuroscientist, and one of the people most responsible for the development of optogenetics, a technique that allows researchers to turn brain cells on and off with a combination of genetic manipulation and pulses of light. He is also one of the developers of a new way to turn brains transparent, though he was away when some new twists on the technique were presented by his lab a day or two earlier. “I had to fly home to take care of the kids,” he explained. He went home to Palo Alto to be with his four children, while his wife, Michelle Monje, a neurologist at Stanford, flew to the conference for a presentation from her lab. Now she was home and, here he was, back at the conference, looking a bit weary, eating eggs, sunny side up, and talking about the development of new technologies in science. A year ago, President Obama announced an initiative to invest in new research to map brain activity, allocating $100 million for the first year. The money is a drop in the bucket compared with the $4.5 billion the National Institutes of Health spends annually on neuroscience, but it is intended to push the development of new techniques to investigate the brain and map its pathways, starting with the brains of small creatures like flies. Cori Bargmann of Rockefeller University, who is a leader of a committee at the National Institutes of Health setting priorities for its piece of the brain initiative, said optogenetics was a great example of how technology could foster scientific progress. © 2014 The New York Times Company
Keyword: Brain imaging
Link ID: 19520 - Posted: 04.22.2014
by Bethany Brookshire Many of us have experienced that depressing sight: The bottom of the ice cream pint. You get to the end of your favorite movie and suddenly realize the ice cream is gone — and you’re far too full for comfort. We’re left wondering why we did it. But when it comes to forgetting ourselves and bingeing on the pint, the power of habit can be strong. It could be that our previous eating experiences make us helpless to our habits. A new study in rats, published April 2 in the Journal of Neuroscience, shows that long-term exposure to bursts of sweet, fatty foods produces animals that appear to seek food not out of hunger, but out of habit. And neural changes associated with habit formation accompany the behavioral changes. The results suggest that repeated binges on sugar and fat could tilt the neural balance from taking a few scoops of Cherry Garcia toward mindlessly reaching the bottom of the bowl. But while the results show us the power of habit, bad habits don’t necessarily make us food addicts. Teri Furlong and her colleagues at the University of Sydney in Australia were interested in how animals control behaviors. Some behaviors are goal-directed, while others are more efficiently taken care of with habits. Furlong describes habits as “behaviors where we are not thinking about the consequences as we do them.” Many habits can be useful things to develop — eating breakfast daily or brushing your teeth, for example. But other habits can become maladaptive, such as drug abuse — or binge eating. © Society for Science & the Public 2000 - 2013.
It looks like a standardized test question: Is the sum of two numbers on the left or the single number on the right larger? Rhesus macaques that have been trained to associate numerical values with symbols can get the answer right, even if they haven’t passed a math class. The finding doesn’t just reveal a hidden talent of the animals—it also helps show how the mammalian brain encodes the values of numbers. Previous research has shown that chimpanzees can add single-digit numbers. But scientists haven’t explained exactly how, in the human or the monkey brain, numbers are being represented or this addition is being carried out. Now, a new study helps begin to answer those questions. Neurobiologist Margaret Livingstone of Harvard Medical School in Boston and her colleagues had already taught three rhesus macaques (Macaca mulatta) in the lab to associate the Arabic numbers 0 through 9 and 15 select letters with the values zero through 25. When given the choice between two symbols, monkeys reliably chose the larger to get a correspondingly larger number of droplets of water, apple juice, or orange soda as a reward. To test whether the monkeys could add these values, the researchers began giving them a choice between a sum and a single symbol rather than two single symbols. Within 4 months, the monkeys had learned how the task worked and were able to effectively add two symbols and compare the sum to a third, single symbol. To ensure that the monkeys hadn’t simply memorized every possible combination of symbols and associated a value with the combination—this wouldn’t be true addition—Livingstone’s team next taught the animals an entirely new set of symbols —Tetris-like blocks rather than letters and numbers. With the new symbols, the monkeys were again able to add—this time calculating the value of combinations they’d never seen before and confirming the ability to do basic addition, the team reports online today in the Proceedings of the National Academy of Sciences. © 2014 American Association for the Advancement of Science.
Link ID: 19518 - Posted: 04.22.2014
Muscle weakness from long-term alcoholism may stem from an inability of mitochondria, the powerhouses of cells, to self-repair, according to a study funded by the National Institutes of Health. In research conducted with rats, scientists found evidence that chronic heavy alcohol use affects a gene involved in mitochondrial repair and muscle regeneration. “The finding gives insight into why chronic heavy drinking often saps muscle strength and it could also lead to new targets for medication development,” said Dr. George Koob, director of the National Institute on Alcohol Abuse and Alcoholism, the NIH institute that funded the study. The study is available online in the April issue of the Journal of Cell Biology. It was led by Dr. Gyorgy Hajnoczky, M.D., Ph.D., director of Thomas Jefferson University’s MitoCare Center, Philadelphia, and professor in the Department of Pathology, Anatomy and Cell Biology. Mitochondria are cellular structures that generate most of the energy needed by cells. Skeletal muscle constantly relies on mitochondria for power. When mitochondria become damaged, they can repair themselves through a process called mitochondrial fusion — joining with other mitochondria and exchanging material such as DNA. Although well known in many other tissues, the current study is the first to show that mitochondria in skeletal muscle are capable of undergoing fusion as a repair mechanism. It had been thought that this type of mitochondrial self-repair was unlikely in the packed fibers of the skeletal muscle cells, as mitochondria have little opportunity to interact in the narrow space between the thread-like structures called myofilaments that make up muscle.
By Floyd Skloot, March 27, 2009. I was fine the night before. The little cold I’d had was gone, and I’d had the first good night’s sleep all week. But when I woke up Friday morning at 6:15 and got out of bed, the world was whirling counterclockwise. I knocked against the bookcase, stumbled through the bathroom doorway and landed on my knees in front of the sink. It was as though I’d been tripped by a ghost lurking beside the bed. Even when I was on all fours, the spinning didn’t stop. Lightheaded, reaching for solid support, I made it back to bed and, showing keen analytical insight, told my wife, Beverly, “Something’s wrong.” The only way I could put on my shirt was to kneel on the floor first. I teetered when I rose. Trying to keep my head still, moving only my eyes, I could feel my back and shoulders tightening, forming a shell. Everything was in motion, out of proportion, unstable. I barely made it downstairs for breakfast, clutching the banister, concentrating on each step and, when I finally made it to the kitchen, feeling too aswirl to eat anyway. I didn’t realize it at the time, but those stairs would become my greatest risk during this attack of relentless, intractable vertigo. Vertigo — the feeling that you or your surroundings are spinning — is a symptom, not a disease. You don’t get a diagnosis of vertigo; instead, you present with vertigo, a hallmark of balance dysfunction. Or with dizziness, a more generalized term referring to a range of off-kilter sensations including wooziness, faintness, unsteadiness, spatial disorientation, a feeling akin to swooning. It happens to almost everyone: too much to drink or standing too close to the edge of a roof or working out too hard or getting up too fast. © 1996-2014 The Washington Post
Link ID: 19516 - Posted: 04.22.2014
By JAMES GORMAN As the Brain Initiative announced by President Obama a year ago continues to set priorities and gear up for what researchers hope will be a decade-long program to understand how the brain works, two projects independent of that effort reached milestones in their brain mapping work. Both projects, one public and one private, are examples of the widespread effort in neuroscience to create databases and maps of brain structure and function that can serve as a foundation for research. While the Obama initiative is concentrating on the development of new tools, that research will build on and use the data being acquired in projects like these. One group of 80 researchers, working as part of a consortium of institutions funded by the National Institute of Mental Health, reported that it had mapped the genetic activity of the human fetal brain. Among other initial findings, the map, the first installment of an atlas of the developing human brain called BrainSpan, confirmed the significance of areas thought to be important in the development of autism. A group of 33 researchers, all but one at the Allen Institute for Brain Science, announced an atlas of the mouse brain showing the connections among 295 different regions. Ed Lein, an investigator at Allen, was the senior author on the fetal brain paper. He said the research required making sections only 20 microns thick, up to 3,500 for each of four brains, two from fetuses at 15 weeks of development and two from about 21 weeks. The researchers measured the activity of 20,000 genes in 300 different brain structures. One interesting finding, Dr. Lein said, was that “95 percent of the genome was used,” meaning almost all of the genes were active during brain development, significantly more than in adult brains. The team also found many differences from the mouse brain, underscoring the findings that, despite the many similarities in all mammalian brains, only so much can be extrapolated to humans from other animals. © 2014 The New York Times Company
Forget cellphones; rambunctious friends may be the riskiest driver distraction for teens, according to a new study. Researchers installed video and G-force recorders in the vehicles of 52 newly licensed high school students for 6 months. They found that certain distractions, such as fiddling with the car’s controls and eating, were not strongly related to serious incidents, which included collisions and evasive maneuvers. However, when passengers in the car were engaged in loud conversation, teen drivers were six times more likely to have a serious incident. What’s more, horseplay increased risk by a factor of three whereas cellphone use only doubled it, the team reported online this week in the Journal of Adolescent Health. Forty-three states restrict newly licensed drivers from having more than one other teen in the car, and the study authors say their data suggest that's good policy. © 2014 American Association for the Advancement of Science.