Chapter 5. The Sensorimotor System

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by Flora Graham This glowing blue web of neurons is usually what researchers examine when searching for a cure for Parkinson's. But a new study, part-funded by Parkinson's UK, hones in on the tiny yellow dots. These are the connections between brain cells known as synapses, has discovered a killer that targets these links, potentially paving the way for new treatments. Soledad Galli at University College London and her colleagues have found that the death of synapses in mice may be due to malfunctioning proteins called Wnt proteins. "If we confirm that Wnt is involved in the early stages of Parkinson's, this throws up exciting possibilities, not just for new treatment targets, but also for new ways to identify people with Parkinson's early on in their condition," says Galli. Most patients currently depend on the drug levodopa, which is over 50 years old and can have severe side-effects, in addition to becoming less effective over time. Moreover, it only masks the symptoms: there is no cure for Parkinson's and no way to stop its progression. Journal reference: Nature Communications, DOI: 10.1038/ncomms5992 © Copyright Reed Business Information Ltd

Keyword: Parkinsons; Aggression
Link ID: 20214 - Posted: 10.18.2014

|By Amy Yee Pouring a bucket of ice water over one’s head may seem like a distant summer memory. But although the “ice bucket challenge” craze has died down, public awareness of amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig’s disease, has never been stronger. The viral video campaign raised $115 million from more than 3 million donors for the ALS Association. In one month, from July 29 to August 29, donors raised $100.9 million, compared with $2.8 million during the same period the previous year. In early October, the ALS Association began spending that money. It approved $21.7 million of funding for six programs and initiatives by groups that include the academic-industry partnership ALS Accelerated Therapeutics, the New York Genome Center, three California labs that form the Neuro Collaborative, and Project MinE, which will map the genomes of 15,000 people with ALS (about 10 percent of ALS patients have a family member with the disease). The grants focus on developing gene therapies for common ALS genes and exploring approaches to counter two major contributors to the disease, the inflammation of nervous tissue and misfolded proteins in brain cells that control movement. These efforts may not only someday lead to new treatments, but may also point to the cause of ALS. At the level of basic research, scientists do not have a dominant theory from which to work, notes Tom Jessell, a neuroscientist and co-director of Columbia University’s new Zuckerman Mind Brain Behavior Institute. Jessell is also the chair of the research advisory board of Project ALS, a nonprofit that identifies and funds ALS research. © 2014 Scientific American

Keyword: ALS-Lou Gehrig's Disease
Link ID: 20213 - Posted: 10.18.2014

By Carl T. Hall Even Clayton Kershaw, the Los Angeles Dodgers’ pitching ace, makes mistakes now and then. And although very few of his mistakes seemed to do Giants hitters much good this season, a team of San Francisco scientists found a way to take full advantage. A new study by UCSF researchers revealed a tendency of the brain’s motion-control system to run off track in a predictable way when we try to perform the same practiced movement over and over. The scientists found the phenomenon first in macaque monkeys, then documented exactly the same thing in Kershaw’s game video. Although he struggled in a playoff appearance last week, the left-hander’s pitching performance during the regular season was among the best on record. It included a minuscule 1.77 earned run average, a nearly flawless no-hitter in June, 239 strikeouts and only 31 walks. He led the major leagues with 10.85 strikeouts per nine innings pitched. In what turned out to be an early warm-up to the playoffs, UCSF scientists Kris Chaisanguanthum, Helen Shen and Philip Sabes delved into the motor-control system of the primate brain. Their study, published in the Journal of Neuroscience, could help design better prosthetic limbs — or make robots that move less like robots and more like Kershaw. Unlike most machines, our brains seem to never stop trying to adapt to new information, making subtle adjustments each time we repeat a particular movement no matter how practiced. This trial-by-trial form of learning has obvious advantages in a fast-changing world, but also seems prone to drift away from spot-on accuracy as those small adjustments go too far.

Keyword: Learning & Memory
Link ID: 20193 - Posted: 10.11.2014

by Andy Coghlan Ten years after the death of everyone's favourite Superman, Christopher Reeve, his son Matthew Reeve is pushing ahead with a spine-tingling clinical trial You're planning a large study of a paralysis treatment that has already helped four young men. What will it entail? This study will include 36 people with spinal cord injuries who will be treated with epidural stimulation – a technique in which a device is used to apply electrical current to the spinal cord. If we see the same results as we did in the first four, this therapy could have a profound impact on thousands of people living with paralysis. It has the potential to become as commonplace as the pacemaker is for cardiac patients. How well has the treatment worked for the four men who have already received it? Prior to epidural stimulation, they had all suffered chronic injuries caused by completely severed spinal cords. All four have seen dramatic improvements, including the ability to voluntarily move their toes, feet, ankles and legs, and even stand at times, when the device is on. One unexpected bonus has been the return of autonomic function, such as bladder and bowel control and sexual function. From a quality-of-life point of view, this is the biggest improvement. Also unexpectedly, these autonomic functions continue in all four men even when the device is switched off, although they still need it to stand, move their legs and do exercises. © Copyright Reed Business Information Ltd.

Keyword: Movement Disorders; Aggression
Link ID: 20190 - Posted: 10.11.2014

Posted by Rachel Dolhun, MD, The ability to quit smoking, especially “cold turkey” or on the first attempt, has been heralded as a marker of strong willpower and determination. But could the ease with which one eschews cigarettes also serve as an early sign of Parkinson’s disease (PD)? This is the conclusion drawn by Beate Ritz, MD, PhD, and colleagues from the University of California, Los Angeles in a recent study published in Neurology. Researchers compared lifelong tobacco use, use of nicotine substitutes, and individual’s rating of their difficulty in trying to quit tobacco among 1,808 Danish people with PD and 1,876 control volunteers. They found that those with PD were less inclined to ever pick up the smoking habit, but, even if they did, they were less likely to need nicotine replacement therapies and able to more effortlessly stop smoking cigarettes. Therefore, ease of quitting smoking may be a sign of early PD. This joins a short list of other symptoms — smell loss, constipation and REM sleep behavior disorder — that usually predate diagnosis and are strongly associated with PD. Physicians rely heavily on such information to help confirm the diagnosis of Parkinson’s, given that biomarkers, objective measurements of disease, are currently lacking. Research led by The Michael J. Fox Foundation is ongoing to identify biological markers of PD, which could help diagnose and treat people earlier. In the meantime, doctors must look for symptoms and behaviors to help identify Parkinson’s. Researchers have long known that tobacco use was linked to a lower risk of PD. An ongoing Foundation-funded study is investigating whether nicotine might guard against or slow the progression of PD.

Keyword: Parkinsons; Aggression
Link ID: 20189 - Posted: 10.11.2014

By Elizabeth Pennisi Four years ago, Igor Spetic lost his right arm in an industrial accident. Doctors outfitted him with a prosthetic arm that restored some function, but they couldn't restore his sense of touch. Without it, simple tasks like picking up a glass or shaking hands became hit-or-miss propositions. The lack of touch also robs Spetic of basic pleasures. “I would love to feel my wife’s hand,” he says. In time, he may regain that pleasure: Two independent research teams have now equipped artificial hands with sensors that send signals to the wearer’s nerves to recreate this missing sense. The sensing technologies work only in the lab, but they have proved durable, and amputees who have tried them, including Spetic, say that they are effective. One technology advances the range of touch sensations available, while the other promises to enable touch through a better way to attach the prosthesis. “All of these results are very positive,” says Mandayam Srinivasan, a neuroengineer at the Massachusetts Institute of Technology in Cambridge, who was not involved in either project. “Each of them fills a piece of the puzzle in terms of [prosthesis] development.” Almost 40 years ago, researchers tried to provide sensory feedback by adding pressure sensors to prostheses that relayed the sensation through electrodes attached to nerves. But for the most part, they just made it seem like the hand was tingling. And durability has been an issue in such efforts, too. In February, Silvestro Micera, a neuroengineer at the Sant'Anna School of Advanced Studies in Pisa, Italy, and the Swiss Federal Institute of Technology in Lausanne and his team showed that it was possible for sensor-equipped prosthetic arms to gently or powerfully grab objects and even to distinguish a round from a square object. But the study lasted just 4 weeks, in part because of the delicate interface with the body. © 2014 American Association for the Advancement of Science.

Keyword: Pain & Touch; Aggression
Link ID: 20187 - Posted: 10.09.2014

by Colin Barras LOCKED in but not shut out: for the first time people who have lost the ability to move or talk because of a stroke may be able to communicate with their loved ones using a brain-computer interface. Brain injuries can leave people aware but almost completely paralysed, a condition called locked-in syndrome. Brain-computer interfaces (BCIs) can help some people communicate by passing signals from electrodes attuned to their brain activity as they watch a screen displaying letters. Subtle changes in neural activity let researchers know when a person wishes to select a particular on-screen item, allowing them to spell out messages by thought alone. Until now, BCIs have only been tested on healthy volunteers and people with amyotrophic lateral sclerosis, a neurodegenerative disease that leads to muscle wasting. But no one had tested whether the technology could help people locked in after a brain stem stroke. Now Eric Sellers and his colleagues at East Tennessee State University in Johnson City have tested the technique on a 68-year-old man. After more than a year of training he learned to communicate reliably via the BCI. He took the opportunity to thank his wife for her hard work, and to give his thoughts on gift purchases for his children (Science Translational Medicine, DOI: 10.1126/scitranslmed.3007801). © Copyright Reed Business Information Ltd.

Keyword: Stroke; Aggression
Link ID: 20185 - Posted: 10.09.2014

|By Tara Haelle The first step to treating or preventing a disease is often finding out what drives it. In the case of neurodegenerative disorders, the discovery two decades ago of what drives them changed the field: all of them—including Alzheimer's, Parkinson's, Huntington's and amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)—involve the accumulation of misfolded proteins in brain cells. Typically when a protein misfolds, the cell destroys it, but as a person ages, this quality-control mechanism starts to fail and the rogue proteins build up. In Huntington's, for example, huntingtin protein—used for many cell functions—misfolds and accumulates. Symptoms such as muscular difficulties, irritability, declining memory, poor impulse control and cognitive deterioration accompany the buildup. Mounting evidence suggests that not only does the accumulation of misfolded proteins mark neurodegenerative disease but that the spread of the proteins from one cell to another causes the disease to progress. Researchers have seen misfolded proteins travel between cells in Alzheimer's and Parkinson's. A series of experiments reported in Nature Neuroscience in August suggests the same is true in Huntington's. In their tests, researchers in Switzerland showed that mutated huntingtin protein in diseased brain tissue could invade healthy brain tissue when the two were placed together. And when the team injected the mutated protein into a live mouse's brain, it spread through the neurons within a month—similar to the way prions spread, says Francesco Paolo Di Giorgio of the Novartis Institutes for BioMedical Research in Basel, who led the research. Prions are misfolded proteins that travel through the body and confer their disease-causing characteristics onto other proteins, as seen in mad cow disease. But it is not known if misfolded proteins involved in Huntington's convert other proteins as true prions do, according to Di Giorgio. © 2014 Scientific American

Keyword: Huntingtons
Link ID: 20181 - Posted: 10.08.2014

|By Tori Rodriguez Imagining your tennis serve or mentally running through an upcoming speech might help you perform better, studies have shown, but the reasons why have been unclear. A common theory is that mental imagery activates some of the same neural pathways involved in the actual experience, and a recent study in Psychological Science lends support to that idea. Scientists at the University of Oslo conducted five experiments investigating whether eye pupils adjust to imagined light as they do to real light, in an attempt to see whether mental imagery can trigger automatic neural processes such as pupil dilation. Using infrared eye-tracking technology, they measured the diameter of participants' pupils as they viewed shapes of varying brightness and as they imagined the shapes they viewed or visualized a sunny sky or a dark room. In response to imagined light, pupils constricted 87 percent as much as they did during actual viewing, on average; in response to imagined darkness, pupils dilated to 56 percent of their size during real perception. Two other experiments ruled out the possibility that participants were able to adjust their pupil size at will or that pupils were changing in response to mental effort, which can cause dilation. The finding helps to explain why imagined rehearsals can improve your game. The mental picture activates and strengthens the very neural circuits—even subconscious ones that control automated processes like pupil dilation—that you will need to recruit when it is time to perform. © 2014 Scientific American

Keyword: Learning & Memory
Link ID: 20176 - Posted: 10.08.2014

By Julie Rehmeyer Eight years ago, collapsed on a neurologist’s examining table, I asked a naive question that turned out to be at the center of a long-running controversy: “So what is chronic fatigue syndrome?” I had just been diagnosed with the illness, which for six years had been gradually overtaking me. A week earlier, I had woken up barely able to walk. Fatigue hardly described what I felt. Paralysis was more like it. My legs seemed to have been amputated and replaced with tubes of liquid concrete, and just shifting them on the table made me grunt like an Olympic weightlifter. My bones hurt; my brain felt like a swollen mass. Speaking required tracking down and spearing each word individually as it scampered away from me. I felt as capable of writing an article about science — my job — as of killing a rhino with my teeth. “We don’t understand it very well,” my neurologist said, his face blank. He could recommend no tests, no treatments, no other doctors. I came to understand that, for him, the term chronic fatigue syndrome meant “I can’t help you.” My neurologist’s understanding of the illness mirrored that of many doctors, who believe two things about CFS: that it’s probably psychosomatic and that there’s nothing doctors can do for it. One survey found that nearly half of doctors thought that CFS was or might be psychosomatic, and 58 percent said there wasn’t enough information available to help them diagnose it. An examination of medical textbooks found that CFS was underrepresented, even compared with less-prevalent illnesses.

Keyword: Movement Disorders; Aggression
Link ID: 20175 - Posted: 10.08.2014

By Gretchen Reynolds Encourage young boys and girls to run, jump, squeal, hop and chase after each other or after erratically kicked balls, and you substantially improve their ability to think, according to the most ambitious study ever conducted of physical activity and cognitive performance in children. The results underscore, yet again, the importance of physical activity for children’s brain health and development, especially in terms of the particular thinking skills that most affect academic performance. The news that children think better if they move is hardly new. Recent studies have shown that children’s scores on math and reading tests rise if they go for a walk beforehand, even if the children are overweight and unfit. Other studies have found correlations between children’s aerobic fitness and their brain structure, with areas of the brain devoted to thinking and learning being generally larger among youngsters who are more fit. But these studies were short-term or associational, meaning that they could not tease out whether fitness had actually changed the children’s’ brains or if children with well-developed brains just liked exercise. So for the new study, which was published in September in Pediatrics, researchers at the University of Illinois at Urbana-Champaign approached school administrators at public elementary schools in the surrounding communities and asked if they could recruit the school’s 8- and 9-year-old students for an after-school exercise program. This group was of particular interest to the researchers because previous studies had determined that at that age, children typically experience a leap in their brain’s so-called executive functioning, which is the ability to impose order on your thinking. Executive functions help to control mental multitasking, maintain concentration, and inhibit inappropriate responses to mental stimuli. © 2014 The New York Times Company

Keyword: ADHD; Aggression
Link ID: 20174 - Posted: 10.08.2014

Aaron E. Carroll For a drug to be approved by the Food and Drug Administration, it must prove itself better than a placebo, or fake drug. This is because of the “placebo effect,” in which patients often improve just because they think they are being treated with something. If we can’t compare a new drug with a placebo, we can’t be sure that the benefit seen from it is anything more than wishful thinking. But when it comes to medical devices and surgery, the requirements aren’t the same. Placebos aren’t required. That is probably a mistake. At the turn of this century, arthroscopic surgery for osteoarthritis of the knee was common. Basically, surgeons would clean out the knee using arthroscopic devices. Another common procedure was lavage, in which a needle would inject saline into the knee to irrigate it. The thought was that these procedures would remove fragments of cartilage and calcium phosphate crystals that were causing inflammation. A number of studies had shown that people who had these procedures improved more than people who did not. However, a growing number of people were concerned that this was really no more than a placebo effect. And in 2002, a study was published that proved it. A total of 180 patients who had osteoarthritis of the knee were randomly assigned (with their consent) to one of three groups. The first had a standard arthroscopic procedure, and the second had lavage. The third, however, had sham surgery. They had an incision, and a procedure was faked so that they didn’t know that they actually had nothing done. Then the incision was closed. The results were stunning. Those who had the actual procedures did no better than those who had the sham surgery. They all improved the same amount. The results were all in people’s heads. © 2014 The New York Times Company

Keyword: Pain & Touch
Link ID: 20167 - Posted: 10.07.2014

By Lisa Sanders, M.D. On Thursday, we challenged Well readers to solve the mystery of a 62-year-old man with severe neck pain that spread down his arm, a facial droop, and numbness on his torso. Nearly 200 of you wrote in, and 20 of you correctly diagnosed the patient. The correct diagnosis is… Lyme disease. And more precisely, the early disseminated form of Lyme disease with neurological involvement The first person with the correct answer was Dr. Arielle Hay, a pediatric rheumatologist in Miami, who nailed it just half an hour after the case was posted. Dr. Hay said that the biggest clue was the UConn letterhead. When combined with the odd neurological symptoms, this reminder of where the case took place brought Lyme disease to mind. Lyme disease is one of those diseases that hardly needs an explanation. It was first described in 1977, in a case series of 51 children and parents who had mysterious episodes of joint pain and swelling. The children were initially diagnosed with juvenile rheumatoid arthritis, but the clustering of cases eventually led the investigators, Dr. Allen Steere and Dr. Stephen Malawista, to consider an infectious disease. The illness was named after the Connecticut town where most of the initial cases were located. The disease is caused by a spirochete, a spiral shaped bacterium carried by the Ixodes tick, and usually presents first with a distinctive, expanding red rash (called erythema migrans) that appears at the site of the bite in the early, localized stage of the disease. It is thought that the rash appears in up to 80 percent of Lyme infections. © 2014 The New York Times Company

Keyword: Pain & Touch; Aggression
Link ID: 20166 - Posted: 10.07.2014

By Kevin Hartnett You may have seen that deliberately annoying “View of the World from Ninth Avenue” map featured on the cover of the New Yorker a while back. It shows the distorted way geography appears to a Manhattanite: 9th and 10th avenues are the center of the world, New Jersey appears, barely, and everywhere else is just a blip if it registers at all. As it turns out, a similar kind of map exists for the human body — with at least some basis in neuroscience. In August I wrote a story for Ideas on the rise of face transplants and spoke to Michael Sims, author of the book, “Adam’s Navel: A Natural and Cultural History of the Human Form.” During our conversation Sims mentioned an odd diagram published in 1951 by a neurosurgeon named Wilder Penfield. The diagram is known as “Homunculus” (a name taken from a weird and longstanding art form that depicts small human beings); it shows the human body scaled according to the amount of brain tissue dedicated to each part, and arranged according to the locations in the brain that control them. In the diagram, the eyes, lips, nose, and tongue appear grotesquely large, indicating that we devote an outsized amount of brain tissue to operating and receiving sensation from these parts of the body. (Sims’s point was that we devote a lot of processing power to the face, and for that reason find it biologically disorienting that faces could be changeable.) The hand is quite large, too, while the toes, legs, trunks, shoulders, and arms are tiny, the equivalents of Kansas City and Russia on the New Yorker map. “Homunculus” seems like the kind of thing that would have long since been superseded by modern brain science, but it actually continues to have a surprising amount of authority, and often appears in neuroscience textbooks.

Keyword: Pain & Touch
Link ID: 20158 - Posted: 10.04.2014

James Hamblin Mental exercises to build (or rebuild) attention span have shown promise recently as adjuncts or alternatives to amphetamines in addressing symptoms common to Attention Deficit Hyperactivity Disorder (ADHD). Building cognitive control, to be better able to focus on just one thing, or single-task, might involve regular practice with a specialized video game that reinforces "top-down" cognitive modulation, as was the case in a popular paper in Nature last year. Cool but still notional. More insipid but also more clearly critical to addressing what's being called the ADHD epidemic is plain old physical activity. This morning the medical journal Pediatrics published research that found kids who took part in a regular physical activity program showed important enhancement of cognitive performance and brain function. The findings, according to University of Illinois professor Charles Hillman and colleagues, "demonstrate a causal effect of a physical program on executive control, and provide support for physical activity for improving childhood cognition and brain health." If it seems odd that this is something that still needs support, that's because it is odd, yes. Physical activity is clearly a high, high-yield investment for all kids, but especially those attentive or hyperactive. This brand of research is still published and written about as though it were a novel finding, in part because exercise programs for kids remain underfunded and underprioritized in many school curricula, even though exercise is clearly integral to maximizing the utility of time spent in class. The improvements in this case came in executive control, which consists of inhibition (resisting distraction, maintaining focus), working memory, and cognitive flexibility (switching between tasks). The images above show the brain activity in the group of kids who did the program as opposed to the group that didn't. It's the kind of difference that's so dramatic it's a little unsettling. The study only lasted nine months, but when you're only seven years old, nine months is a long time to be sitting in class with a blue head. © 2014 by The Atlantic Monthly Group.

Keyword: ADHD
Link ID: 20152 - Posted: 10.02.2014

By CATHERINE SAINT LOUIS Driven by a handful of reports of poliolike symptoms in children, federal health officials have asked the nation’s physicians to report cases of children with limb weakness or paralysis along with specific spinal-cord abnormalities on a magnetic resonance imaging test. As a respiratory illness known as enterovirus 68 is sickening thousands of children from coast to coast, officials are trying to figure out if the weakness could be linked to the virus. The emergence of several cases of limb weakness among children in Colorado put doctors on alert in recent months. The Centers for Disease Control and Prevention issued an advisory on Friday, and this week, other cases of unexplained muscle weakness or paralysis came to light in Michigan, Missouri and Massachusetts. The C.D.C. is investigating the cases of 10 children hospitalized at Children’s Hospital Colorado with unexplained arm or leg weakness since Aug. 9. Some of the children, who range in age from 1 to 18, also developed symptoms like facial drooping, double vision, or difficulty swallowing or talking. Four of them tested positive for enterovirus 68, also known as enterovirus D68, which has recently caused severe respiratory illness in children in 41 states and the District of Columbia. One tested positive for rhinovirus, which can cause the common cold. Two tested negative. Two patients’ specimens are still being processed; another was never tested. It is unclear whether the muscle weakness is connected to the viral outbreak. “It’s one possibility we are looking at, but certainly not the only possibility,” said Mark Pallansch, director of the C.D.C.’s division of viral diseases. © 2014 The New York Times Company

Keyword: Movement Disorders
Link ID: 20150 - Posted: 10.02.2014

By Gretchen Reynolds Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice. The findings may have broad implications for anyone whose stress levels threaten to become emotionally overwhelming. Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. Working out somehow makes people and animals emotionally resilient, studies have shown. But precisely how exercise, a physical activity, can lessen someone’s risk for depression, a mood state, has been mysterious. So for the new study, which was published last week in Cell, researchers at the Karolinska Institute in Stockholm delved into the brains and behavior of mice in an intricate and novel fashion. Mouse emotions are, of course, opaque to us. We can’t ask mice if they are feeling cheerful or full of woe. Instead, researchers have delineated certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it’s available — because, presumably, they no longer experience normal pleasures — or give up trying to escape from a cold-water maze and just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but intermittent, low-level stress, such as being restrained or lightly shocked, mice displayed exactly those behaviors. They became depressed. The scientists could then have tested whether exercise blunts the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they knew it would. They wanted to parse how. So they bred pre-exercised mice. © 2014 The New York Times Company

Keyword: Depression
Link ID: 20145 - Posted: 10.01.2014

|By Tanya Lewis and LiveScience Dolphins can now add magnetic sense to their already impressive resume of abilities, new research suggests. When researchers presented the brainy cetaceans with magnetized or unmagnetized objects, the dolphins swam more quickly toward the magnets, the new study found. The animals may use their magnetic sense to navigate based on the Earth's magnetic field, the researchers said. A number of different animals are thought to possess this magnetic sense, called "magnetoreception," including turtles, pigeons, rodents, insects, bats and even deer (which are related to dolphins), said Dorothee Kremers, an animal behavior expert at the University of Rennes, in France, and co-author of the study published today (Sept. 29) in the journal Naturwissenschaften. "Inside the ocean, the magnetic field would be a very good cue to navigate," Kremers told Live Science. "It seems quite plausible for dolphins to have a magnetic sense." Some evidence suggests both dolphin and whale migration routes and offshore live strandings may be related to the Earth's magnetic field, but very little research has investigated whether these animals have a magnetic sense. Kremers and her colleagues found just one study that looked at how dolphins reacted to magnetic fields in a pool; that study found dolphins didn't show any response to the magnetic field. But the animals in that study weren't free to move around, and were trained to give certain responses. © 2014 Scientific American

Keyword: Animal Migration
Link ID: 20140 - Posted: 10.01.2014

By Bec Crew Mike meet everyone, everyone meet Mike. No, no, don’t wave. He can’t see, you’re just making this awkward. Also known as Miracle Mike, Mike the Headless Chicken was a plump, five-year-old cockerel when he was unceremoniously beheaded on 10 September 1945. Farmer Lloyd Olsen of Fruita in Colorado did the deed because his wife Clara was having her mother over for dinner that night, and Olsen knew she’d always enjoyed a bit of roast chicken neck. With that in mind, Olsen tried to save most of Mike’s neck as he lopped his head off, but in doing so, he accidentally made his axe miss Mike’s jugular vein, plus one ear and most of his brain stem, and to his surprise, Mike didn’t die. In fact, Mike stuck around for a good 18 months without his head. Immediately after it happened, Mike reeled around like any headless chicken would, but soon settled down. He even started pecking at the ground for food with his newly minted stump, and made preening motions. His crows had become throaty gurglings. Olsen, bewildered, left him to it. The next morning, when Olsen found Mike asleep in the barn, having attempted to tuck his head under his wing as he always had, the farmer took it upon himself to figure out how to feed this unwitting monstrosity. Mike had earned that much. All Olsen had to do was deposit food and water into Mike’s exposed oesophagus via a little eyedropper. He even got small grains of corn sometimes as a treat. © 2014 Scientific American

Keyword: Miscellaneous
Link ID: 20126 - Posted: 09.29.2014

By Rachel Feltman With the help of electrical stimulation, a paralyzed rat is "walking" again. It's actually being controlled by a computer that monitors its gait and adjusts it to keep the rat balanced. When a spinal cord is severed, the electrical pulses sent out by the brain to control limb movement are interrupted. With this method of treatment, the rat's leg movements are driven by electrical pulses shot directly into the spinal cord (which has unfortunately been severed in the name of science). Scientists have been working on this method in humans for awhile, but have only had moderate success — some subjects have regained sensation and movement in their legs, but haven't walked on their own. In the experiment described in the video above, published Wednesday in Science Translational Medicine, researchers tweaked this use of electrical stimulation: They primed the rats with a drug to boost their ability to respond to the electrical signal. Then, while the rats were placed in treadmill harnesses to support their weight, the researchers trained a camera on their subjects. The camera tracked the rats as they took electrically stimulated steps, and corrected their movement in real time. This instant feedback made the system precise enough to get the rats up tiny sets of stairs. MIT Technology Review reports that the team hopes to use a human volunteer within the next year. If the system works on humans, doctors can prescribe its use in rehabilitation therapy. You can watch the actual experiment in the video below:

Keyword: Regeneration; Aggression
Link ID: 20122 - Posted: 09.27.2014