Chapter 16. None
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by Douglas Heaven Got a memory like a fish? The first study to visualise live memory retrieval in the whole brain has not only debunked the "three-second memory" myth, but also sheds light on the brain processes involved in forming long-term memories. Even the haziest recollections have a physical basis in the brain, but the mechanisms behind the formation and retrieval of memories are not well understood. By working with zebrafish, which are small and partially transparent, Hitoshi Okamoto at the RIKEN Brain Science Institute in Wako, Japan, and colleagues were able to study the whole brain at once. This allowed them to observe the roles played by different brain regions as a memory was retrieved. The team used fish with a genetically engineered fluorescent protein in the brain that glows less brightly when calcium levels increase – which occurs when neurons fire. They were able to study the activity of these proteins under a microscope. First, the team trained a group of fish to respond to a visual cue to avoid a small electric shock. Each fish was placed in a tank containing two compartments. When a red light shone in one compartment the fish had to swim to the other to avoid the shock. The researchers then selected the fish that had learned to perform the avoidance task successfully at least 80 per cent of the time and looked at the activity in their brains while a red light was switched on and off. © Copyright Reed Business Information Ltd.
Keyword: Learning & Memory
Link ID: 18167 - Posted: 05.18.2013
By CARL ZIMMER Imagine a wolf catching a Frisbee a dozen times in a row, or leading police officers to a stash of cocaine, or just sleeping peacefully next to you on your couch. It’s a stretch, to say the least. Dogs may have evolved from wolves, but the minds of the two canines are profoundly different. Dog brains, as I wrote last month in The New York Times, have become exquisitely tuned to our own. Scientists are now zeroing in on some of the genes that were crucial to the rewiring of dog brains. Their results are fascinating, and not only because they can help us understand how dogs turned into man’s best friend. They may also teach us something about the evolution of our own brains: Some of the genes that evolved in dogs are the same ones that evolved in us. To trace the change in dog brains, scientists have first had to work out how dog breeds are related to one another, and how they’re all related to wolves. Ya-Ping Zhang, a geneticist at the Chinese Academy of Sciences, has led an international network of scientists who have compared pieces of DNA from different canines. They’ve come to the conclusion that wolves started their transformation into dogs in East Asia. Those early dogs then spread to other parts of the world. Many of the breeds we’re most familiar with, like German shepherds and golden retrievers, emerged only in the past few centuries. © 2013 The New York Times Company
Keyword: Aggression; Aggression
Link ID: 18166 - Posted: 05.18.2013
By Tina Hesman Saey COLD SPRING HARBOR, N.Y. – Taming foxes changes not only the animals’ behavior but also their brain chemistry, a new study shows. The finding could shed light on how the foxes’ genetic cousins, wolves, morphed into man’s best friend. Lenore Pipes of Cornell University presented the results May 10 at the Biology of Genomes conference. The foxes she worked with come from a long line started in 1959 when a Russian scientist named Dmitry Belyaev attempted to recreate dog domestication, but using foxes instead of wolves. He bred silver foxes (Vulpes vulpes), which are actually a type of red fox with white-tipped black fur. Belyaev and his colleagues selected the least aggressive animals they could find at local fox farms and bred them. Each generation, the scientists picked the tamest animals to mate, creating ever friendlier foxes. Now, more than 50 years later, the foxes act like dogs, wagging their tails, jumping with excitement and leaping into the arms of caregivers for caresses. At the same time, the scientists also bred the most aggressive foxes on the farms. The descendents of those foxes crouch, flatten their ears, growl, bare their teeth and lunge at people who approach their cages. The foxes’ tame and aggressive behaviors are rooted in genetics, but scientists have not found DNA changes that account for the differences. Rather than search for changes in genes themselves, Pipes and her colleagues took an indirect approach, looking for differences in the activity of genes in the foxes’ brains. © Society for Science & the Public 2000 - 2013
Keyword: Genes & Behavior
Link ID: 18164 - Posted: 05.16.2013
by Michael Balter From the human perspective, few events in evolution were more momentous than the split among primates that led to apes (large, tailless primates such as today's gorillas, chimpanzees, and humans) and Old World monkeys (which today include baboons and macaques). DNA studies of living primates have estimated that the rift took place between 25 million and 30 million years ago, but the earliest known fossils of both groups date no earlier than 20 million years ago. Now, a team working in Tanzania has found teeth and partial jaws from what it thinks are 25-million-year-old ancestors of both groups. If the interpretations hold up, the finds would reconcile the molecular and fossil evidence and possibly provide insights into what led to the split in the first place. Researchers have long been frustrated by a paucity of fossils from this key period in evolution, which sits at the borderline between two major geological epochs: the Miocene (about 23 million to 5 million years ago) and the Oligocene (about 34 million to 23 million years ago). The earliest known fossils of early apes and Old World monkeys date from the early Miocene and have been found in just a handful of sites in Kenya, Uganda, and North Africa. Meanwhile, molecular studies of existing primates consistently suggest that these two groups arose during the Oligocene, leading scientists to wonder whether the molecular dates are wrong or if paleontologists have been looking in the wrong places. For more than a decade, researchers from the United States and Tanzania have been combing Tanzania's Rukwa Rift Basin, searching for fossils of all kinds. During the 2011 and 2012 seasons, a team led by Nancy Stevens, a vertebrate paleontologist at Ohio University in Athens, discovered fossils that it identified as belonging to two previously unknown species of primates: one, an apparent ape ancestor the team has named Rukwapithecus fleaglei; the other, a claimed Old World monkey ancestor dubbed Nsungwepithecus gunnelli. © 2010 American Association for the Advancement of Science.
Keyword: Evolution
Link ID: 18163 - Posted: 05.16.2013
By Jason G. Goldman There is a rich tradition in psychology and neuroscience of using animals as models for understanding humans. Humans, after all, are enormously complicated creatures to begin even from a strictly biological perspective. Tacking on the messiness that comes with culture makes the study of the human mind tricky, at best. So, just as biomedical scientists have relied upon the humble mouse, psychological and cognitive scientists have too turned to our evolutionary cousins in the animal kingdom as a means of better understanding ourselves. In her new book Animal Wise, journalist Virginia Morrell recounts a conversation with one researcher who pointed out that decades of research were built upon “rats, pigeons, and college sophomores, preferably male.” The college undergrads stood in for all of humanity, the rats served as representatives of all other mammals, and pigeons served as a model for the rest of the animal kingdom. The silly part isn’t that non-human animals can be used effectively as a means of understanding more about our own species. The idea is simple: understand how a simple system works, and you can make careful inferences about the way that complex systems work. That is (or should be) obvious. In his interview with CNN today, memory research pioneer and Nobel Prize winner Eric Kandel said as much: “Rather than studying the most complex form of memory in a very complicated animal, we had to take the most simple form — an implicit form of memory — in a very simple animal.” © 2013 Scientific American
Keyword: Learning & Memory; Aggression
Link ID: 18161 - Posted: 05.16.2013
by Meera Senthilingam Malaria parasites give mosquitoes a keener sense of smell, it seems. A small-scale study in the lab finds that mosquitoes infected by the parasite are three times as likely as uninfected mosquitoes to respond to human odours. If the same results are seen in malaria-carrying mosquitoes in the wild, it could lead to new ways to combat the disease. Female anopheles mosquitoes are attracted to the chemicals in human odours, which help them find the source of blood they need to grow their eggs. When these mosquitoes carry Plasmodium falciparum – the most lethal form of malaria parasite – the likelihood that they will target humans rises. "We knew already that mosquitoes bite more often when they're infected. They probe the skin more frequently," says James Logan from the London School of Hygiene and Tropical Medicine. To quantify the effect – and try to work out its cause – Logan and his colleagues infected some lab-grown Anopheles gambiae mosquitoes with Plasmodium parasites, while leaving others uninfected. They then tested how both groups were attracted to human smells. Mosquitoes are particularly attracted to foot odours, so Logan's team used nylon stockings containing the volatile chemicals produced by our feet. Over a period of three minutes, Plasmodium-infected mosquitoes landed and attempted to bite the stockings around 15 times on average. By contrast, the uninfected mosquitoes attempted to bite only around five times on average during that time. © Copyright Reed Business Information Ltd.
Keyword: Chemical Senses (Smell & Taste)
Link ID: 18160 - Posted: 05.16.2013
Brian Owens The gut is home to innumerable different bacteria — a complex ecosystem that has an active role in a variety of bodily functions. In a study published this week in Proceedings of the National Academy of Sciences1, a team of researchers finds that in mice, just one of those bacterial species plays a major part in controlling obesity and metabolic disorders such as type 2 diabetes. The bacterium, Akkermansia muciniphila, digests mucus and makes up 3–5% of the microbes in a healthy mammalian gut. But the intestines of obese humans and mice, and those with type 2 diabetes, have much lower levels. A team led by Patrice Cani, who studies the interaction between gut bacteria and metabolism at the Catholic University of Louvain in Belgium, decided to investigate the link. Mice that were fed a high-fat diet, the researchers found, had 100 times less A. muciniphila in their guts than mice fed normal diets. The researchers were able to restore normal levels of the bacterium by feeding the mice live A. muciniphila, as well as 'prebiotic' foods that encourage the growth of gut microbes. The effects of this treatment were dramatic. Compared with untreated animals, the mice lost weight and had a better ratio of fat to body mass, as well as reduced insulin resistance and a thicker layer of intestinal mucus. They also showed improvements in a host of other indicators related to obesity and metabolic disorders. “We found one specific common factor between all the different parameters that we have been investigating over the past ten years,” says Cani. © 2013 Nature Publishing Group
Keyword: Obesity
Link ID: 18156 - Posted: 05.14.2013
Linda Carroll TODAY contributor We all get lost or disoriented once in a while, but for Sharon Roseman, being lost is a way of life. A little quirk in her brain makes it impossible to recognize landmarks and find her way around neighborhoods that should have become familiar long ago. “I can literally see my house out the car window, but I have no clue that it’s my house,” Roseman told NBC’s Kristen Dahlgren. Roseman, 64, suffers from developmental topographical disorientation, or DTD, a disorder that had flown under brain researchers’ radar until very recently. DTD was first described as a single case study in a paper published online in 2008 in the journal Neuropsychologia. At the time, it was thought to be extremely rare, says the study’s lead author, Giuseppe Iaria, professor of cognitive neuroscience at the University of Calgary. But since then, Iaria has discovered nearly 1,000 other people with DTD and he thinks there may be a lot more. He currently estimates that about 2 percent of the population may be constantly coping with orientation and navigation problems caused by the disorder. DTD is a profound and disabling deficit. Nothing, not even the layout of a house you’ve lived in for decades, ever becomes familiar. And for Roseman that has made life very trying. When her kids would cry in the night, she would struggle to find her way to them.
Keyword: Attention
Link ID: 18155 - Posted: 05.14.2013
Zoe Cormier A study of two ancient hominins from South Africa suggests that changes in the shape and size of the middle ear occurred early in our evolution. Such alterations could have profoundly changed what our ancestors could hear — and perhaps how they could communicate. Palaeoanthropologist Rolf Quam of Binghamton University in New York state and his colleagues recovered and analysed a complete set of the three tiny middle-ear bones, or ossicles, from a 1.8-million-year-old specimen of Paranthropus robustus and an incomplete set of ossicles from Australopithecus africanus, which lived from about 3.3 million to around 2.1 million years ago. The ossicles are the smallest bones in the human body, and are rarely preserved intact in hominin fossils, Quam says. In both specimens, the team found that the malleus (the first in the chain of the three middle-ear bones) was human-like — smaller in proportion compared to the ones in our ape relatives. Its size would also imply a smaller eardrum. The similarity between the two species points to a “deep and ancient origin” of this feature, Quam says. “This could be like bipedalism: a defining characteristic of hominins.” It is hard to draw conclusions about hearing just from the shape of the middle-ear bones because the process involves so many different ear structures, as well as the brain itself. However, some studies have shown that the relative sizes of the middle-ear bones do affect what primates can hear2. Genomic comparisons with gorillas have indicated that changes in the genes that code for these structures might also demarcate humans from apes3. © 2013 Nature Publishing Group
Keyword: Hearing; Aggression
Link ID: 18151 - Posted: 05.14.2013
by Michael Balter Researchers debate when language first evolved, but one thing is sure: Language requires us not only to talk but also to listen. A team of scientists now reports recovering the earliest known complete set of the three tiny middle ear bones—the malleus ("hammer"), incus ("anvil"), and stapes ("stirrup")—in a 2.0-million-year-old skull of Paranthropus robustus, a distant human relative found in South Africa (see photo). Reporting online today in the Proceedings of the National Academy of Sciences, the researchers found that the malleus of P. robustus, as well one found earlier in the early human relative Australopithecus africanus, is similar to that of modern humans, whereas the two other ear bones most closely resemble existing African and Asian great apes. The team is not entirely sure what this precocious appearance of a human-like malleus means. But since the malleus is attached directly to the eardrum, the researchers suggest that it might be an early sign of the high human sensitivity to middle-range acoustic frequencies between 2 and 4 kilohertz—frequencies critical to spoken language, but which apes and other primates are much less sensitive to. © 2010 American Association for the Advancement of Science
Keyword: Hearing; Aggression
Link ID: 18150 - Posted: 05.14.2013
By DAVID DOBBS In the autistic person, it seems, hums a vital and distinctive essence — but one whose nature is obscured by thick layers of behavior and perception. Or, as Temple Grandin puts it, “two panes of glass.” For a quarter century, Dr. Grandin — the brainy, straight-speaking, cowboy-shirt-wearing animal scientist and slaughterhouse designer who at 62 is perhaps the world’s most famous autistic person — has been helping people break through the barriers separating autistic from nonautistic experience. Like Dr. Sacks, who made her famous as the title figure in his 1995 collection “An Anthropologist on Mars,” Dr. Grandin has helped us understand autism not just as a phenomenon, but as a different but coherent mode of existence that otherwise confounds us. In her own books and public appearances, she excels at finding concrete examples that reveal the perceptual and social limitations of autistic and “neurotypical” people alike. In “The Autistic Brain,” her latest book, written with the science author Richard Panek, she shows this talent most vividly in a middle chapter that looks at the sensory world of autism. It is a world filled with anomalies, in which everyday sensations can be overwhelming: A school bell can feel like a dentist’s drill, a scratchy shirt like a swarm of fire ants. In other cases the autistic person may feel so little sensation that she’ll try to fill the vacuum and create some sort of order — hence the rocking, twirling, hand-flapping, noisemaking behaviors that can discomfit and alienate onlookers. © 2013 The New York Times Company
Keyword: Autism
Link ID: 18149 - Posted: 05.14.2013
By ANDREW C. REVKIN Twenty-two months ago, I interrupted my nonstop reporting about paths toward a sustainable future for our species to focus on sustaining myself. The hiatus was not by choice, but was mandated by a stroke — the out-of-the-blue variant, the rare kind of “brain attack” (the term preferred by some neurologists) that is most often seen in otherwise healthy, youngish middle-aged people. It’s Fourth of July weekend, 2011 — a beautiful, if hot, morning for a run in the Hudson Valley woods with my son Daniel, back from brief service in the Israeli army. I’m eager to be pushed hard. I’m not even a lapsed middle-aged athlete; I’m truly negligent when it comes to exercise. We’re jogging up a steep path, and my breathing gets deeper and faster. At a particularly tough turn, I pause, hands on knees. “Come on, keep it up, Dad.” I’m panting but don’t want to disappoint. We press on. But I stop again, this time insisting that Daniel run ahead. I rest in the mottled shade and sunlight of the woods until he returns. Then I realize that through my left eye, the world appears paisley — as if I were looking through a patterned curtain. Something is really wrong. We make it back to the car. Daniel takes the wheel. Back home, I take a shower, thinking that cooling off will help. For the first time, a thought flickers. Could this be a stroke? Almost unconsciously, I take half a dozen baby aspirin. I know enough about aspirin’s blood-thinning properties to think this can’t hurt. Copyright 2013 The New York Times Company
Keyword: Stroke
Link ID: 18147 - Posted: 05.14.2013
By ANAHAD O'CONNOR The nation’s largest cardiovascular health organization has a new message for Americans: Owning a dog may protect you from heart disease. The unusual message was contained in a scientific statement published on Thursday by the American Heart Association, which convened a panel of experts to review years of data on the cardiovascular benefits of owning a pet. The group concluded that owning a dog, in particular, was “probably associated” with a reduced risk of heart disease. People who own dogs certainly have more reason to get outside and take walks, and studies show that most owners form such close bonds with their pets that being in their presence blunts the owners’ reactions to stress and lowers their heart rate, said Dr. Glenn N. Levine, the head of the committee that wrote the statement. But most of the evidence is observational, which makes it impossible to rule out the prospect that people who are healthier and more active in the first place are simply more likely to bring a dog or cat into their home. “We didn’t want to make this too strong of a statement,” said Dr. Levine, a professor at the Baylor College of Medicine. “But there are plausible psychological, sociological and physiological reasons to believe that pet ownership might actually have a causal role in decreasing cardiovascular risk.” Nationwide, Americans keep roughly 70 million dogs and 74 million cats as pets. Copyright 2013 The New York Times Company
Keyword: Emotions; Aggression
Link ID: 18146 - Posted: 05.11.2013
By Puneet Kollipara Identical twin mice sharing the same mazelike environment develop distinct personalities based on how much they explore their surroundings, researchers report in the May 10 Science. After death, those differences were reflected in the animals’ brains. The study “highlights something for which we had some intuition before, but actually quantifies it,” says Fred Gage, a neuroscientist at the Salk Institute for Biological Studies in La Jolla, Calif. Some character and biological differences between identical twins may originate as early as pregnancy. But twins become more and more different as life goes on, even when they grow up together. Scientists have recognized that having distinct experiences within the same environment might boost such personality differences, but that’s difficult to test in humans. Studying it in animals has multiple benefits. “You can keep the genes constant and also keep the environment constant,” says Gerd Kempermann of the Center for Regenerative Therapies Dresden in Germany. “It’s much more controlled than in a human situation.” Researchers led by Kempermann put 40 genetically identical female mice in an elaborate cage and observed their behavior. The cage had multiple levels linked together by tubes and contained toys and other features that the animals could explore. The researchers equipped each mouse with a microchip that tracked its location, using the animals’ movements as a measure of exploratory behavior. Initially, the mice differed only slightly in their tendency to roam. As they grew older, all tended to explore more often, but the differences among the mice grew more pronounced. © Society for Science & the Public 2000 - 2013
Keyword: Epigenetics; Aggression
Link ID: 18145 - Posted: 05.11.2013
Heidi Ledford Nassir Ghaemi, director of the Mood Disorders Program at Tufts Medical Center in Boston, Massachusetts, has felt shackled by the Diagnostic and Statistical Manual of Mental Disorders (DSM), often called the bible of psychiatry. Some of his depressed patients occasionally show manic behaviour but do not fulfil the DSM’s criteria for a diagnosis of bipolar disorder. Ghaemi is interested in whether such patients might respond better to drugs for bipolar disorder than for depression. But his colleagues warned him against straying from the DSM when he applied for funding at the US National Institute of Mental Health (NIMH), because peer reviewers tended to insist on research that hewed to DSM categories. Ghaemi held off from applying. If NIMH director Thomas Insel has his way, Ghaemi and other mental-health researchers will no longer feel the weight of the DSM. “NIMH will be re-orienting its research away from DSM categories,” Insel wrote in a blog entry on 29 April. The latest edition, the DSM-5, will be unveiled on 22 May at the annual meeting of the American Psychiatric Association in San Francisco, California. Like many psychiatrists, Insel questions whether the DSM’s categories accurately reflect the way the brain works. He is pushing a project that aims to create a new framework that classifies mental-health disorders according to their biological roots. “Going forward, we will be supporting research projects that look across current categories — or sub-divide current categories — to begin to develop a better system,” Insel wrote. The blog post made waves in the media and rattled some psychiatric clinicians and researchers. But Insel says that he has been talking about the issue since 2008. “The word was just still not out there,” he says. Insel says that he has increasingly received complaints from grant applicants who have tried to follow his guidance, only to be shot down by peer reviewers for eschewing DSM scripture. © 2013 Nature Publishing Group
Keyword: Schizophrenia; Aggression
Link ID: 18144 - Posted: 05.11.2013
by Claudia M Gold It seems that the National Institute of Mental Health (NIMH) may have dealt a death blow to the recently published Diagnostic and Statistical Manual of Mental Disorders (DSM 5) when the organization declared they would no longer fund research based on the DSM system of diagnosis. The views of NIMH director Thomas Insel were referenced in the recent New York Times article on the subject. His goal was to reshape the direction of psychiatric research to focus on biology, genetics and neuroscience so that scientists can define disorders by their causes, rather than their symptoms. I am no fan of the DSM system, which reduces complex experience to lists of symptoms; focusing on the "what" rather than the "why." However, the NIMH model has limits as well. There seems to be a wish to study mental illness in the same way we study cancer or diabetes. While I certainly have great respect for the complexity of the pancreas, or the process of malignant transformation of cells, trying to understand the brain/mind in an analogous way seems to be an unnecessary and even undesirable reduction of human experience. What is missing from both paradigms is recognition of the relational and historical context of being human. Fortunately there seems to be awareness that neither paradigm is complete. The Times article goes on to say: Dr. Insel is one of a growing number of scientists who think that the field needs an entirely new paradigm for understanding mental disorders, though neither he nor anyone else knows exactly what it will look like. © 2013 NY Times Co.
Keyword: Schizophrenia; Aggression
Link ID: 18143 - Posted: 05.11.2013
by Helen Thomson "I was sitting on the toilet. I suddenly felt an explosion in the left side of my head and ended up on the floor. I think the only thing that kept me conscious was that I didn't want to be found with my pants down. Then the other side of my head went bang! I woke up in hospital and looked out of the window to see the tree was sprouting numbers. 3, 6, 9. Then I started talking in rhyme…" Ten days after having a subarachnoid haemorrhage – a stroke caused by bleeding in and around the brain – Tommy McHugh, an ex-con who'd been in his fair share of scraps, became a new man, with a personality that nobody recognised. When he was a young man, Tommy did time in prison. But after his stroke at age 51, everything changed. "I could taste the femininity inside of myself," he said. "My head was full of rhymes and images and pictures." Not only did he feel a sudden urge to write poetry, but he also began to paint and draw obsessively for up to 19 hours a day. He was never artistic before – in fact, he joked that he'd never even been in an art gallery "except to maybe steal something". Desperate to find out what was going on, Tommy wrote to several neuroscientists and end up working closely with Alice Flaherty at Harvard Medical School and Mark Lythgoe at University College London. © Copyright Reed Business Information Ltd.
Keyword: Laterality; Aggression
Link ID: 18142 - Posted: 05.11.2013
By Bruce Bower Provocative evidence that certain memory exercises make people smarter has sparked the rise of online brain-training programs such as Lumosity. But at least one type of brain training may not work as advertised, a new study finds. As expected, practicing improved volunteers’ performance on tests of memory and the ability to locate items quickly in busy scenes, say psychologist Thomas Redick of Indiana University Purdue University Columbus and his colleagues. That improvement did not, however, translate into higher scores on tests of intelligence and multitasking, the researchers report in the May Journal of Experimental Psychology: General. Redick’s investigation is part of a growing scientific debate about brain training, which is promoted by some companies as having a variety of mental benefits. Some researchers say that extensive instruction and training on memory tasks can indeed fortify reasoning and problem solving. Others are skeptical that vigorous memory sessions produce such wide-ranging effects. The dispute feeds into a longstanding scientific controversy about whether enriched environments can increase intelligence, as measured on IQ tests. What’s not up for debate is that many people feel smarter after brain training. In the new study, 10 of 23 individuals who completed memory sessions said that the program helped them to think, multitask and focus better in daily life. But the scientists say that even if some participants performed daily tasks better after memory training, they may simply have tried harder or felt better about their efforts due to a belief that training had strengthened their minds. © Society for Science & the Public 2000 - 2013
Keyword: Learning & Memory
Link ID: 18140 - Posted: 05.11.2013
Ed Yong Many moths have evolved sensitive hearing that can pick up the ultrasonic probes of bats that want to eat them. But one species comes pre-adapted for anything that bats might bring to this evolutionary arms race. Even though its ears are extremely simple — a pair of eardrums on its flanks that each vibrate four receptor cells — it can sense frequencies up to 300 kilohertz, well beyond the range of any other animal and higher than any bat can squeak. “A lot of previous work has suggested that some bats have evolved calls that are out of the hearing range of the moths they are hunting. But this moth can hear the calls of any bat,” says James Windmill, an acoustical engineer at the University of Strathclyde, UK, who discovered the ability in the greater wax moth (Galleria mellonella). His study is published in Biology Letters1. Windmill's collaborator Hannah Moir, a bioacoustician now at the University of Leeds, UK, played sounds of varying frequencies to immobilized wax moths. As the insects “listened”, Moir used a laser to measure the vibrations of their eardrums, and electrodes to record the activity of their auditory nerves. The moths were most sensitive to frequencies of around 80 kilohertz, the average frequency of their courtship calls. But when exposed to 300 kilohertz, the highest level that the team tested, the insects' eardrums still vibrated and their neurons still fired. © 2013 Nature Publishing Group
Keyword: Hearing; Aggression
Link ID: 18137 - Posted: 05.09.2013
By Ingrid Wickelgren I have seen the invisible arms of multiple sclerosis, a potentially devastating disease of the nervous system, touch friends, relatives and acquaintances. They perturbed the personality of a father of a close friend and left him unable to keep a job and support the family. They forced a young woman I met years ago to walk tentatively, watching her step. They put one beloved member of my extended family with two small children in a wheelchair and took away his voice. Nowadays, many people with MS find that new medications can mitigate the progression of their disease (see “New Treatments Tackle Multiple Sclerosis,” by James D. Bowen, Scientific American Mind, July/August 2013). But many mysteries remain about the cause of the disorder and no one knows how to prevent or cure it. About a decade ago, a technology entrepreneur named Art Mellor, who was diagnosed with MS in 2000, founded an organization called Accelerated Cure Project based in Waltham, Massachusetts to help speed progress on solving these mysteries, in part through greater collaboration among scientists. In one of its efforts, it maintains a repository of thousands of blood samples from patients who visited any of 10 U.S. clinics. The samples are made available to anyone willing to share their data with the Project. Scientists have used these samples in more than 70 different studies into the causes of MS and how to diagnose and treat it. A number of these experiments involve trying to identify molecular signs of the disease in the blood, in hopes of developing a simple blood test for the disorder. Such a test might reduce the time and cost of an MS diagnosis. The primary tool for spotting MS today is magnetic resonance imaging (MRI), which can reveal inflammation in the brain characteristic of the disorder. © 2013 Scientific American
Keyword: Multiple Sclerosis
Link ID: 18132 - Posted: 05.08.2013




