Chapter 5. The Sensorimotor System

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By Laura Sanders Some nerve fibers seem to love a good rubdown. These tendrils, which spread across skin like upside-down tree roots, detect smooth, steady stroking and send a feel-good message to the brain, researchers report in the Jan. 31 Nature. Although the researchers found these neurons in mice, similar cells in people may trigger massage bliss. The results are the latest to emphasize the strong and often underappreciated connection between emotions and the sensation of touch, says study coauthor David Anderson, a Howard Hughes Medical Institute investigator at Caltech. “It may seem frivolous to be studying massage neurons in mice, but it raises a profound issue — why do certain stimuli feel a certain way?” he says. It’s no surprise that many people find a caress pleasant. Earlier studies in people suggested that a particular breed of nerve fibers detects a caress and carries that signal to the brain. But scientists hadn’t been able to directly link this type of neuron to good feelings, either in people or in animals. “The beauty of this paper is that it goes one step further and adds behavioral elements,” says cognitive neuroscientist Francis McGlone of Liverpool John Moores University in England. Directly linking these neurons with pleasure clarifies the importance of touch, McGlone says. “Skin is a social organ,” he says. A growing number of studies show that the sensation of touch, particularly early in life, profoundly sculpts the brain. Young animals deprived of touch grow up with severe behavioral abnormalities. Babies fare better when they are held and touched frequently. And touch sensation can be altered in certain disorders. People with autism, for instance, often dislike caresses. © Society for Science & the Public 2000 - 2013

Keyword: Pain & Touch; Aggression
Link ID: 17741 - Posted: 02.02.2013

Voluntary movements involve the coordinated activation of two brain pathways that connect parts of deep brain structures called the basal ganglia, according to a study in mice by researchers at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. The findings, which challenge the classical view of basal ganglia function, were published online in Nature on Jan. 23. “By improving our understanding of how the basal ganglia control movements, these findings could aid in the development of treatments for disorders in which these circuits are disrupted, such as Parkinson’s disease, Huntington’s disease and addiction,” says NIAAA Acting Director Kenneth R. Warren, Ph.D. The predominant model of basal ganglia function proposes that direct and indirect pathways originating in a brain region called the striatum have opposing effects on movement. Activity of neurons in the direct pathway is thought to promote movement, while activity in the indirect pathway is thought to inhibit movement. Newer models, however, suggest that co-activation of these pathways is necessary to synchronize basal ganglia circuits during movement. “Testing these models has been difficult due to the lack of methods to measure specific neurons in the direct and indirect pathways in freely moving animals,” explains first author Guohong Cui, Ph.D., of the NIAAA Laboratory for Integrated Neuroscience (LIN). To overcome these difficulties, Dr. Cui and colleagues devised a new approach for measuring the activity of neurons deep within the brain during complex behaviors. Their technique uses fiber optic probes implanted in the mouse brain striatum to measure light emissions from neurons engineered to glow when activated.

Keyword: Movement Disorders
Link ID: 17729 - Posted: 01.29.2013

By Sandra G. Boodman Still clutching his discharge instructions from a suburban Maryland emergency room, Brian Harms struggled to make sense of what the neurosurgeon was saying. The ER staff had told Harms, admitted hours earlier, that his diagnoses were headache and vertigo and that he should go home and rest. A CT scan had found a benign cyst in his brain, but the staff didn’t convey any urgency about treating it. As the 29-year-old College Park resident was gathering his things, a neurosurgeon rushed in, telling Harms he would not be going home. “I need to get this information to you quickly,” Harms remembers the specialist telling him on the morning of Sept. 28, 2011. “You are in a lot of trouble, and you need surgery as soon as possible.” The neurosurgeon had been trying to arrange a transfer to Johns Hopkins Hospital in Baltimore, but doctors were worried that he might die en route. “I highly suggest you trust me and let me do this procedure here,” Harms remembers the surgeon telling him, but the decision was his. For Harms, who had seen several doctors for headaches and other symptoms during the previous 18 months, the news was beyond shocking. “It felt like the floor dropped out beneath me,” he recalled. “I was scared witless.” Only later would Harms, a University of Maryland doctoral candidate in geochemistry, learn how lucky he was to have survived both a series of misdiagnoses and a test, performed hours before his emergency surgery, that could have killed him. © 1996-2013 The Washington Post

Keyword: Pain & Touch
Link ID: 17727 - Posted: 01.29.2013

by Gretchen Cuda Kroen A day in the life of a male dung beetle goes something like this: Fly to a heap of dung, sculpt a clump of it into a large ball, then roll the ball away from the pile as fast as possible. However, it turns out that the beetles, who work at night, need some sort of compass to prevent them from rolling around in circles. New research in Current Biology suggests that the insects use starlight to guide their way. Birds, seals, and humans also use starlight to navigate, but this is the first time it's been shown in an insect. The whole point of rolling dung is to impress the female beetle with provisions—i.e., excrement—for her future progeny and entice her to mate. She then lays an egg in the ball and buries it in a network of tunnels more than a meter deep, where it serves as food for the developing larvae inside. But rolling dung balls in a straight line is also key to the male dung beetle's reproductive success. Rival males have been known to overtake a slower moving insect and claim the hard-earned treasure as their own. Competition is fiercest near the dung heap, so making a quick and efficient getaway is crucial for mating success. The discovery that dung beetles use starlight "was an accident more than anything," explains study author Eric Warrant, professor of zoology at the Lund University in Sweden. His research group was studying how the beetles used the polarized light patterns of the moon to stay on their paths, when one moonless night they made a surprising observation—the beetles maintained straight trajectories. "Even without the moon—just with the stars—they were still able to navigate," Warrant says. "We were just flabbergasted." © 2010 American Association for the Advancement of Science

Keyword: Animal Migration; Aggression
Link ID: 17714 - Posted: 01.26.2013

By Ashutosh Jogalekar G Protein-Coupled Receptors (GPCRs) are the messengers of the human body, key proteins whose ubiquitous importance was validated by the 2012 Nobel Prize in chemistry. As I mentioned in a post written after the announcement of the prize, GPCRs are involved in virtually every physiological process you can think of, from sensing colors, flavors and smells to the action of neurotransmitters and hormones. In addition they are of enormous commercial importance, with something like 30% of marketed drugs binding to these proteins and regulating their function. These drugs include everything from antidepressants to blood-pressure lowering medications. But GPCRs are also notoriously hard to study. They are hard to isolate from their protective lipid cell membrane, hard to crystallize and hard to coax into giving up their molecular secrets. One reason the Nobel Prize was awarded was because the two researchers – Robert Lefkowitz and Brian Kobilka – perfected techniques to isolate, stabilize, crystallize and study these complex proteins. But there’s still a long way to go. There are almost 800 GPCRs, out of which ‘only’ 16 have been crystallized during the past decade or so. In addition all the studied GPCRs are from the so-called Class A family. There’s still five classes left to decipher, and these contain many important receptors including the ones involved in smell. Clearly it’s going to be a long time before we can get a handle on the majority of these important proteins. Fortunately there’s something important that GPCR researchers have realized; it’s the fact that many of these GPCRs have amino acid sequences that are similar. If you know what experimental conditions work for one protein, perhaps you can use the same conditions for another similar GPCR. © 2013 Scientific American

Keyword: Miscellaneous
Link ID: 17692 - Posted: 01.17.2013

By Christine Gorman In the January 2013 issue of Scientific American, D. Kacy Cullen and Douglas H. Smith of the University of Pennsylvania reported on their work using stretch-grown axons (the long thin "arm" of a nerve cell) to some day connect prosthetic devices to the peripheral nervous systems of people who had to have part of their arm amputated. There wasn't enough room to talk about it in the article, but there is another way that these "living bridges" could be used to help people with devastating injuries. The stretch-grown axons could also be used to treat people with major nerve damage that does not necessarily require amputation. The biohybrid bridge provides a conduit for the undamaged part of the peripheral nervous system to bypass the injured nerve and regrow its own axons all the way to the end of the affected limb. If such bridges could be implanted within a few days to weeks of the injury, they would benefit from the fact that neural support cells are still active throughout the length of the limb (these cells usually take a few months to disappear after nerve death) and could guide the regrowing nerve fiber to its final destination. Cullen and Smith hope to begin testing their stretch-grown axons soon in a few U.S. soldiers who were injured while fighting overseas. Cullen described their efforts in a recent email: Peripheral nerve injury (PNI) is a major source of warfighter morbidity. Indeed, only 50% of patients achieve good to normal restoration of function following surgical repair, regardless of the strategy. Moreover, failure of nerve regeneration may necessitate amputation of an otherwise salvaged limb. This stems from the inadequacy of current PNI repair strategies, where even the “gold-standard“ treatment – the nerve autograft – is largely ineffective for major nerve trauma. © 2013 Scientific American

Keyword: Regeneration
Link ID: 17682 - Posted: 01.15.2013

Fran Lowry Salivary gland biopsy appears to be a diagnostic test for Parkinson's disease, a new study suggests. A biopsy of the submandibular gland that shows the presence of the abnormal protein alpha-synuclein is highly indicative of Parkinson's, as distinct from other neurodegenerative disorders that can mimic the disease, said lead study author, Charles Adler, MD, PhD, from the Mayo Clinic Arizona, Scottsdale, Arizona. "There is currently no diagnostic test for Parkinson's disease in living patients. The only way to make the diagnosis is at autopsy, when you can see an abnormal protein, alpha-synuclein, in certain brain regions," Dr. Adler, a fellow of the American Academy of Neurology, told Medscape Medical News. Their preliminary findings were released January 10; full results will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego. Dr. Adler and his team have been working on determining whether there is evidence of alpha-synuclein in other organs of the body so that they could develop a diagnostic test in living patients. "We previously published the fact that the submandibular gland has one of the densest concentrations of alpha-synuclein in an organ outside the brain. When we tested this in an autopsy study of 28 Parkinson's disease patients, we found that all 28 of them had alpha-synuclein in the submandibular gland," he said. The discovery led the researchers to biopsy the submandibular gland in living patients with Parkinson's disease to see whether this protein was present. If it was, then the biopsy could potentially be used as a diagnostic test, they reasoned. © 1994-2013 by WebMD LLC

Keyword: Parkinsons
Link ID: 17671 - Posted: 01.12.2013

By KENNETH CHANG Mosquito bite? Poison ivy? Dry skin? Fuzzy sweater? Everyone has an itch to scratch. Why we and other animals itch remains something of a mystery. But now researchers at Johns Hopkins and Yale in the United States and several universities in China have found a key piece of the puzzle, identifying sensory neurons in mice that are dedicated to relaying itchy sensations from the top layers of skin to the spinal cord. “Our study, for the first time, shows the existence of itch-specific nerves,” said Xinzhong Dong, a professor of neuroscience at the Johns Hopkins University School of Medicine and the senior author of a paper about the findings in the journal Nature Neuroscience. Scientists have debated for decades whether separate circuitry existed for itchiness or whether its signals passed through the same nerves used to transmit pain. Earlier data — suppressing pain with morphine can cause chronic itching, for example — indicated some overlap between the two sensations. But the fact that evolution also produced dedicated itch nerves in mice — and almost certainly in people as well — suggests that itching serves an important role in survival and is not just a byproduct of the pain nerves. © 2013 The New York Times Company

Keyword: Pain & Touch
Link ID: 17660 - Posted: 01.08.2013

A strong family history of seizures could increase the chances of having severe migraines, says a study in Epilepsia journal. Scientists from Columbia University, New York, analysed 500 families containing two or more close relatives with epilepsy. Their findings could mean that genes exist that cause both epilepsy and migraine. Epilepsy Action said it could lead to targeted treatments. Previous studies have shown that people with epilepsy are substantially more likely than the general population to have migraine headaches, but it was not clear whether that was due to a shared genetic cause. The researchers found that people with three or more close relatives with a seizure disorder were more than twice as likely to experience 'migraine with aura' than patients from families with fewer individuals with seizures. Migraine with aura is a severe headache preceded by symptoms such as seeing flashing lights, temporary visual loss, speech problems or numbness of the face. Dr Melodie Winawer, lead author of the study from Columbia University Medical Centre, said the findings had implications for epilepsy patients. "Our study demonstrates a strong genetic basis for migraine and epilepsy, because the rate of migraine is increased only in people who have close (rather than distant) relatives with epilepsy." BBC © 2013

Keyword: Epilepsy; Aggression
Link ID: 17657 - Posted: 01.07.2013

By Alexandra Witze Quietly, on the top floor of a nondescript commercial building overlooking Boston Harbor, the future is being born. Rows of young scientists tap intently in front of computer monitors, their concentration unbroken even as the occasional plane from Logan Airport buzzes by. State-of-the-art lab equipment hums away in the background. This office, in Boston’s Marine Industrial Park, is what California’s Silicon Valley was four decades ago — the vanguard of an industry that will change your life. Just as researchers from Stanford provided the brains behind the semiconductor revolution, so are MIT and Harvard fueling the next big transformation. Students and faculty cross the Charles River not to build computer chips, but to re-engineer life itself. Take Reshma Shetty, one of the young minds at work in the eighth-floor biological production facility. After receiving her doctorate at MIT in 2008, she, like many new graduates, decided she wanted to make her mark on the world. She got together with four colleagues, including her Ph.D. adviser Tom Knight, to establish a company that aims “to make biology easy to engineer.” Place an order with Ginkgo BioWorks and its researchers will make an organism to do whatever you want. Need to suck carbon dioxide out of the atmosphere? They can engineer the insides of a bacterium to do just that. Want clean, biologically based fuels to replace petroleum taken from the ground? Company scientists will design a microbe to poop those out. © Society for Science & the Public 2000 - 2013

Keyword: Robotics
Link ID: 17650 - Posted: 01.05.2013

By GRETCHEN REYNOLDS Anyone whose resolve to exercise in 2013 is a bit shaky might want to consider an emerging scientific view of human evolution. It suggests that we are clever today in part because a million years ago, we could outrun and outwalk most other mammals over long distances. Our brains were shaped and sharpened by movement, the idea goes, and we continue to require regular physical activity in order for our brains to function optimally. The role of physical endurance in shaping humankind has intrigued anthropologists and gripped the popular imagination for some time. In 2004, the evolutionary biologists Daniel E. Lieberman of Harvard and Dennis M. Bramble of the University of Utah published a seminal article in the journal Nature titled “Endurance Running and the Evolution of Homo,” in which they posited that our bipedal ancestors survived by becoming endurance athletes, able to bring down swifter prey through sheer doggedness, jogging and plodding along behind them until the animals dropped. Endurance produced meals, which provided energy for mating, which meant that adept early joggers passed along their genes. In this way, natural selection drove early humans to become even more athletic, Dr. Lieberman and other scientists have written, their bodies developing longer legs, shorter toes, less hair and complicated inner-ear mechanisms to maintain balance and stability during upright ambulation. Movement shaped the human body. But simultaneously, in a development that until recently many scientists viewed as unrelated, humans were becoming smarter. Their brains were increasing rapidly in size. Copyright 2012 The New York Times Company

Keyword: Evolution; Aggression
Link ID: 17635 - Posted: 12.27.2012

By Rachel Ehrenberg Outfitted with a bionic eye, arm, legs and fantastic ’70s hair, Steve Austin was a cyborg whose implants allowed him to recover stolen atomic weapons, fight aliens and protect cryptographers in distress. Finally, real life is starting to catch up with the Six Million Dollar Man. In one of this year’s bionic breakthroughs, a paralyzed woman carried out her own superhuman feat: Using an implanted brain chip, she controlled a robotic arm with her mind (SN: 6/16/12, p. 5). She used the arm to grasp a cuppa joe and take a long, satisfying sip of coffee through a straw, an act she hadn’t done on her own for nearly 15 years. “We’re entering a really exciting area where we can develop all sorts of very complicated technologies that can actually have biomedical applications and improve the quality of life for people,” says bioengineer Grégoire Courtine of the Swiss Federal Institute of Technology in Lausanne. “It’s a revolution.” After her groundbreaking sip, Cathy Hutchinson, who had been paralyzed years earlier by a stroke, smiled and then laughed. A roomful of scientists burst into applause. This was a big year for prosthetic parts, both in and out of the lab. Athletes in London for the Paralympics and the Olympics sprinted on high-tech carbon blades and hurled javelins while balancing on the microprocessor-controlled C-Leg. People in wheelchairs used battery-powered robotic suits to keep their lower limbs in shape. A young man who lost his right leg in a motorcycle accident climbed the 103 flights of stairs in Chicago’s Willis Tower with a thought-controlled limb. That technology is still in development. But some bionic add-ons are starting to come out of the lab and into the clinic for the first time, though costs remain prohibitive for many potential users. © Society for Science & the Public 2000 - 2012

Keyword: Robotics
Link ID: 17634 - Posted: 12.27.2012

Cannabis makes pain more bearable rather than actually reducing it, a study from the University of Oxford suggests. Using brain imaging, researchers found that the psychoactive ingredient in cannabis reduced activity in a part of the brain linked to emotional aspects of pain. But the effect on the pain experienced varied greatly, they said. The researchers' findings are published in the journal Pain. The Oxford researchers recruited 12 healthy men to take part in their small study. Participants were given either a 15mg tablet of THC (delta-9-tetrahydrocannabinol) - the ingredient that is responsible for the high - or a placebo. The volunteers then had a cream rubbed into the skin of one leg to induce pain, which was either a dummy cream or a cream that contained chilli - which caused a burning and painful sensation. Each participant had four MRI scans which revealed how their brain activity changed when their perception of the pain reduced. Dr Michael Lee, lead study author from Oxford University's Centre for Functional Magnetic Resonance Imaging of the Brain, said: "We found that with THC, on average people didn't report any change in the burn, but the pain bothered them less." BBC © 2012

Keyword: Pain & Touch; Aggression
Link ID: 17633 - Posted: 12.22.2012

By Liz Kowalczyk Health officials investigating the national fungal meningitis outbreak caused by tainted steroid injections had thought that the worst was over. The number of new cases was dwindling. Then came patients like Anna Adair. An avid gardener and dog-breeder, Adair was rolled into a Michigan emergency room in a wheelchair Nov. 15. She had been bedridden for days, and that morning a bolt of pain in her lower back had caused her to tumble to the bathroom floor. Doctors quickly reached a disturbing realization: An infection caused by black mold had infiltrated her spine, near where she had received an injection made by a Massachusetts pharmacy, and spread into the bone. It was not the ­meningitis that sickened hundreds of others in late summer and early fall, but part of a frightening second wave of ­fungal infections caused by contaminated drugs. Dozens more people have now been diagnosed with excruciating abscesses or inflamed nerves in their backs that are proving formidable to cure. In a health alert issued Thursday, the federal Centers for Disease Control and Prevention said it is worried that some patients with spinal infections may not even be aware of their condition because the symptoms mimic the very back pain they originally sought to treat with steroids. The agency is now recommending that doctors consider performing MRI scans to screen all patients who have persistent back pain and received steroids from one of three contaminated batches. Previously, it advised scanning just those with new or worsening pain. © 2012 NY Times Co.

Keyword: Pain & Touch
Link ID: 17631 - Posted: 12.22.2012

By Sandra G. Boodman, For the first decade of his life, every doctor who saw Jack DeWitt inevitably zeroed in on the harrowing circumstances of his premature birth. Delivered by emergency Caesarean section in December 1999, doctors universally ascribed his developmental problems to his being born six weeks early, said his mother, Ruth DeWitt. “It always came back to that.” When Jack’s walking became odd at age 5, doctors chalked it up to a mild form of cerebral palsy that can occur in children born too soon. “We were okay with it,” his mother said, because mild cerebral palsy would not “affect the length of his life or his enjoyment of it.” Jack’s parents were also reassured by his ability to catch up; with help, he mastered various skills: jumping, walking and writing in cursive. But by age 10, when his ability to walk badly deteriorated, a reevaluation by his doctors resulted in a very different diagnosis and prognosis. “We had all those years of feeling that he was a normal, healthy kid with some challenges,” his mother recalled. Discovering what was really wrong has been a heavy blow, magnified by Jack’s perceptive awareness of its implications. Ruth DeWitt, who lives with her family in Howell, Mich., outside Ann Arbor, was in the hospital undergoing a test for preeclampsia, or pregnancy-induced hypertension, when she began hemorrhaging, a sign of placental abruption. The life-threatening condition occurs when the placenta prematurely detaches from a woman’s uterus. Rushed into surgery, Jack was born weighing 3 pounds, 9 ounces, and was transferred to the neonatal intensive care unit at the University of Michigan Medical Center. Small but strong, he needed oxygen but no ventilator, and he came home 15 days later. © 1996-2012 The Washington Post

Keyword: Movement Disorders; Aggression
Link ID: 17615 - Posted: 12.18.2012

By ANAHAD O'CONNOR Chronic sleep loss has many downsides, among them weight gain, depression and irritability. But now scientists have found a new one: It also weakens your tolerance for pain. In recent studies, researchers have shown that losing sleep may disrupt the body’s pain signaling system, heightening sensitivity to painful stimuli. Though it is not clear why, one theory is that sleep loss increases inflammation throughout the body. Catching up on sleep if you are behind may reduce inflammation. Scientists believe this could have implications for people with chronic pain. It could also have an impact on the effects of painkillers, which appear to be blunted after chronic sleep loss. In one study published in the journal Sleep, scientists at the sleep disorders and research center at Henry Ford Hospital in Detroit recruited 18 healthy adults and split them into two groups. One was allowed to sleep for an average of nine hours, while the other averaged two fewer hours of sleep each night. To assess pain thresholds, the researchers measured how long the subjects were able to hold a finger to a source of radiant heat. After four nights, the group that was allowed to sleep the longest was able to withstand the painful stimuli much longer, by about 25 percent on average. Several studies in the past have had similar findings, including one in 2006 that showed that one night of cutting sleep in half could significantly reduce a person’s threshold for physical pain. Copyright 2012 The New York Times Company

Keyword: Sleep; Aggression
Link ID: 17612 - Posted: 12.18.2012

By James Gallagher Health and science reporter, BBC News Unrivalled control of a robotic arm has been achieved using a paralysed woman's thoughts, a US study says. Jan Scheuermann, who is 53 and paralysed from the neck down, was able to deftly grasp and move a variety of objects just like a normal arm. Brain implants were used to control the robotic arm, in the study reported in the Lancet medical journal. Experts in the field said it was an "unprecedented performance" and a "remarkable achievement". Jan was diagnosed with spinocerebellar degeneration 13 years ago and progressively lost control of her body. She is now unable to move her arms or legs. She was implanted with two sensors - each four millimetres by four millimetres - in the motor cortex of her brain. A hundred tiny needles on each sensor pick up the electrical activity from about 200 individual brain cells. "The way that neurons communicate with each other is by how fast they fire pulses, it's a little bit akin to listening to a Geiger counter click, and it's that property that we lock onto," said Professor Andrew Schwartz from the University of Pittsburgh. The pulses of electricity in the brain are then translated into commands to move the arm, which bends at the elbow, wrist and could grab an object. BBC © 2012

Keyword: Robotics
Link ID: 17611 - Posted: 12.17.2012

by Christian Jarrett, Ph.D in Brain Myths Back in the 1990s neuroscientists at the University of Parma identified cells in the premotor cortex of monkeys that had an unusual response pattern. They were activated when the monkeys performed a given action and, mirror-like, when they saw another individual perform that same movement. Since then, the precise function and influence of these neurons has become perhaps the most hyped topic in neuroscience. In 2000, Vilayanur Ramachandran, the charismatic neuroscientist, made a bold prediction: “mirror neurons will do for psychology what DNA did for biology.” He's at the forefront of a frenzy of excitement that has followed these cells ever since their discovery. For many, they have came to represent all that makes us human. Perhaps, in those early heady years, Ramachandran was just getting a little carried away? Not at all. For his 2011 book, The Tell-Tale Brain, Ramachandran took his claims further. In the chapter “The neurons that shaped civilisation”, he argues that mirror neurons underlie empathy, allow us to imitate other people, that they accelerated the evolution of the brain, that they help explain the origin of language, and most impressively of all, that they prompted the great leap forward in human culture that happened about 60,000 years ago. “We could say mirror neurons served the same role in early hominin evolution as the Internet, Wikipedia, and blogging do today,” he concludes. “Once the cascade was set in motion, there was no turning back from the path to humanity.” © Copyright 2002-2012 Sussex Directories, Inc

Keyword: Vision; Aggression
Link ID: 17591 - Posted: 12.11.2012

By LISA SANDERS, M.D. On Thursday, we challenged Well readers to puzzle their way through the case of a 25-year-old elephant trainer who developed “the worst headache of his life.” The case was made more confusing by the fact that he had been head-butted by a zebra several years earlier. Turns out the zebra was a bit of a red herring – for the doctors at the time, and for many of you. The correct diagnosis is… Herpes zoster, commonly known as shingles The internist assigned to the case, Dr. Bilal Ahmed, was able to make the diagnosis because when he examined the patient the next day, he saw the characteristic zoster rash above the patient’s right eye that had developed overnight. Nearly 200 people wrote in with their thoughts on what Dr. Ahmed might have seen to reveal the diagnosis when he looked at the patient. The first person to guess the correct diagnosis was Lotty Fulkerson of Massachusetts, a licensed practical nurse who has seen a lot of zoster. It was the combination of the patient’s terrible pain and the fact that the doctor saw something that told him the diagnosis that made her think it was probably shingles. Only three other readers guessed correctly. Herpes zoster, also known as shingles, is caused by the re-emergence of the herpes virus that is the source of the childhood illness chickenpox. The term “shingles” comes from the Latin word “cingulum,” which means belt or girdle; the rash of herpes zoster often appears in a band or belt-like pattern. When the original chickenpox infection resolves, the virus doesn’t die but instead takes refuge in branches of the nerves just outside the spinal cord, where it will reside for decades. In up to a third of patients who have had chickenpox, it re-emerges, causing pain and a rash and sometimes more. Why these survivor viruses re-emerge is unclear, but it may be linked to a weakened immune system. Copyright 2012 The New York Times Company

Keyword: Pain & Touch
Link ID: 17556 - Posted: 12.01.2012

by Jessica Hamzelou A single session of nerve stimulation has improved the movement of people with spinal cord injuries. Mimicking the passage of nerve signals by stimulating a muscle as well as the brain has boosted recovery and helped people to regain better control of their movements. Voluntary movement requires a signal from the brain, which is passed down the spinal cord and then to neurons in muscles. Damage to the spinal cord can interrupt this pathway, resulting in paralysis. To improve the control of movement in people with these injuries, Monica Perez and Karen Bunday at the University of Pittsburgh in Pennsylvania used electrical and magnetic stimulation to strengthen the connection between two nerves involved in voluntary movement of the index finger. The pair used transcranial magnetic stimulation (TMS), a non-invasive technique in which a magnetic field alters brain activity, to target the corticospinal tract. This bundle of nerves connects movement-associated parts of the brain with the spinal cord. "The corticospinal tract plays a major role in the recovery of motor function in spinal cord injury," says Perez. Just 1 to 2 milliseconds after stimulating the brain, they used an electrode to stimulate a nerve that innervates an index-finger muscle – mimicking normal brain-to-muscle nerve signalling. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 17554 - Posted: 12.01.2012