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by Robert F. Service According to George Bernard Shaw: "The most intolerable pain is produced by prolonging the keenest pleasure." Not to be picky George, but actually both sensations result from the activity of a diverse family of proteins on the surface of cells. This year's Nobel Prize in chemistry was awarded to two Americans—Robert Lefkowitz of Duke University in Durham, North Carolina, and Brian Kobilka of Stanford University School of Medicine in Palo Alto, California—who revealed the inner workings of these proteins, which also orchestrate a variety of things such as the way we see, smell, taste, feel, and fight infections. The notion that a single family of proteins was responsible for so many different physiological processes was far from evident early on. One hint came at the end of the 19th century, when scientists studying the effects of the hormone adrenaline discovered that it had different effects in various parts of the body. It made heart rate and blood pressure increase, but it decreased digestive activity and caused pupils to relax. One idea was that proteins called receptors on different cells somehow captured adrenaline molecules and either ferried the hormone into cells or transferred a message inside to trigger a response. In the 1940s, an American biologist named Raymond Ahlquist made enough progress to conclude that there must be two types of adrenaline receptors, one that caused smooth muscle cells to contract, and the other that stimulated the heart. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 10: Vision: From Eye to Brain; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 5: The Sensorimotor System
Link ID: 17354 - Posted: 10.11.2012

By Katherine Harmon A bite from the black mamba snake (Dendroaspis polylepis) can kill an adult human within 20 minutes. But mixed in with that toxic venom is a new natural class of compound that could be used to help develop new painkillers. Named “mambalgins,” these peptides block acute and inflammatory pain in mice as well as morphine does, according to a new study. Researchers, led by Sylvie Diochot, of the Institute of Molecular and Cellular Pharmacology at Nice University, Sophia Antipolis in France, purified the peptides from the venom and profiled the compounds’ structure. They then were able to test the mambalgins in strains of mice with various genetic tweaks to their pain pathways. Diochot and her colleagues determined that the mambalgins work by blocking an as-yet untargeted set of neurological ion channels associated with pain signals. The findings were published online October 3 in Nature (Scientific American is part of Nature Publishing Group). As a bonus, mambalgins did not have the risky side effect of respiratory depression that morphine does. And the mice developed less tolerance to them over time than is typical with morphine. Experimenting with the newfound compounds should also help researchers learn more about the mechanisms that drive pain. As the researchers noted in their paper, “It is essential to understand pain better to develop new analgesics. The black mamba peptides discovered here have the potential to address both of these aims.” © 2012 Scientific American,

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 17333 - Posted: 10.04.2012

By PAULINE W. CHEN, M.D. Recounting her father’s struggle with cancer was difficult for the young woman, even several years after his death. He’d endured first surgery and then chemotherapy and radiation, she told me, and the cancer had gone into remission. He was thrilled, but the aggressive treatment left him with chronic, debilitating pain. Once active, he struggled to get around in his own home. “It wasn’t the cancer that got him,” the daughter said. “It was the pain.” Her father had turned to all of his doctors, with little relief. His surgeon had looked at his operative wounds, pronounced them well healed, then stated that they were in no way responsible for his disability. Both his cancer doctor and his radiation doctor congratulated him on being in remission but then declined to prescribe pain medications since they were no longer treating him and couldn’t provide ongoing follow-up and dosing guidance. His primary care doctor listened intently to his descriptions of his limitations, but then prescribed only small amounts of pain meds that offered fleeting relief at best. “I’ll never forget what my father had to go through,” she said, weeping. “I wouldn’t wish this on anyone.” I wish I could have reassured her that her father’s case was unusual. Sadly, according to a new study in The Journal of Clinical Oncology, a significant percentage of cancer patients continue to suffer from pain as her father did. Copyright 2012 The New York Times Company

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 17300 - Posted: 09.26.2012

By James Gallagher Health and science reporter, BBC News Up to a million people in the UK have "completely preventable" severe headaches caused by taking too many painkillers, doctors have said. They said some were trapped in a "vicious cycle" of taking pain relief, which then caused even more headaches. The warning came as part of the National Institute for Health and Clinical Excellence's (NICE) first guidelines for treating headaches. It is also recommending acupuncture in some circumstances. "Medication overuse headaches" feel the same as other common headaches or migraines. There is no definitive UK data on the incidence of the condition, but studies in other countries suggest 1-2% of people are affected, while the World Health Organization says figures closer to 5% have been reported. While painkillers would be many people's instant response, they could be making sufferers feel even worse. Prof Martin Underwood, from Warwick Medical School, who led the NICE panel, said: "This can end up getting into a vicious cycle where your headache gets worse, so you take more painkillers, so your headache gets worse and this just becomes worse and worse and worse. BBC © 2012

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17277 - Posted: 09.19.2012

In May, my six-year-old daughter, Julia, smashed into our front door handle and got a deep, bloody gash in her forehead. We rushed her, head wrapped like a tiny mummy, to the medical center at MIT, where we generally go for pediatric care. Julia wept while the nurse cleaned and examined her lacerated skin. After a short exam, she sent us to the emergency department at Children’s Hospital Boston for stitches. “How bad is that, generally?” I asked, having never experienced suturing either for myself or my cautious, risk-averse, older daughter. “It can be traumatic,” the nurse said. Julia cried, “I don’t want stitches.” It’s a large needle, but Julia is too busy coloring to notice. So I braced myself for the worst: an endless wait and nerve-wracking bustle; screaming, germ-laden children and brusque, end-of-shift staff. But more than anything, I dreaded the inevitable pain in store for my small child with the deep cut. (I know, kids get banged up on the path to adulthood and some pain is unavoidable. Still, when bloody heads are involved, I tend to overreact.) Indeed, I was in full Mama Bear mode when into our exam room strode Dr. Baruch Krauss, the attending physician that evening. Copyright Trustees of Boston University

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 14: Attention and Consciousness
Link ID: 17276 - Posted: 09.19.2012

By Jorge Cham and Dwayne Godwin [Graphic novel format.] Dwayne Godwin is a neuroscientist at the Wake Forest University School of Medicine. Jorge Cham draws the comic strip Piled Higher and Deeper at www.phdcomics.com. © 2012 Scientific American,

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17264 - Posted: 09.17.2012

Daniel Cressey Rabbits are the latest focus of work seeking to measure animal discomfort by assessing facial expressions. Researchers working with animals often find it difficult to scientifically assess when their study subjects are in pain. Traditional methods rely on after-the-fact measurements involving weight loss or food and water consumption, or on subjective judgements such as how an animal moves. In an attempt to make pain assessment more scientific, geneticist Jeffrey Mogil at McGill University in Montreal, Canada, and his colleagues developed the 'mouse grimace scale', which was published in Nature Methods1 in May 2010 (see 'Mice pull pained expressions'). The scale relies on the scoring of five ‘action units’ — such as narrowing of the eyes and bulging of the cheeks — between zero (not present) and two (obviously present), with the combined score indicating total pain. The scale rapidly caught on among veterinarians to assess post-operative pain. “I’m surprised how quickly it was adopted as a practical thing to use in real-time for animal care,” says Mogil. Matthew Leach, who researches animal welfare at Newcastle University, UK, and led the work in rabbits, has been working on facial expressions of pain in various animals since the original mouse grimace scale came out. "The only way you can alleviate pain is to be able to identify it, and to understand how much pain an animal is in," he says. "There is a broad interest in grimace scales,” he notes, adding that compared with traditional models, “I would argue it’s potentially better and faster in many circumstances”. © 2012 Nature Publishing Group

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17238 - Posted: 09.10.2012

by Colin Barras ON THE face of it, the placebo effect makes no sense. Someone suffering from a low-level infection will recover just as nicely whether they take an active drug or a simple sugar pill. This suggests people are able to heal themselves unaided - so why wait for a sugar pill to prompt recovery? New evidence from a computer model offers a possible evolutionary explanation, and suggests that the immune system has an on-off switch controlled by the mind. It all starts with the observation that something similar to the placebo effect occurs in many animals, says Peter Trimmer, a biologist at the University of Bristol, UK. For instance, Siberian hamsters do little to fight an infection if the lights above their lab cage mimic the short days and long nights of winter. But changing the lighting pattern to give the impression of summer causes them to mount a full immune response. Likewise, those people who think they are taking a drug but are really receiving a placebo can have a response which is twice that of those who receive no pills (Annals of Family Medicine, doi.org/cckm8b). In Siberian hamsters and people, intervention creates a mental cue that kick-starts the immune response. There is a simple explanation, says Trimmer: the immune system is costly to run - so costly that a strong and sustained response could dangerously drain an animal's energy reserves. In other words, as long as the infection is not lethal, it pays to wait for a sign that fighting it will not endanger the animal in other ways. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17231 - Posted: 09.07.2012

By Stephani Sutherland Ice cream headache is a familiar summertime sensation, but the pain's source has been mysterious until now. A team led by Jorge Serrador of Harvard Medical School produced brain scans of “second-by-second changes” in blood flow while subjects sipped iced water through a straw pressed against the roof of the mouth, which caused the brain's major artery to widen. “Blood flow changes actually preceded the pain” that subjects reported, Serrador says. As the vessel narrowed again, the discomfort ebbed. He suspects that the influx of blood is meant to protect the brain from extreme cold and that increased pressure inside the skull could cause the pain. Serrador presented the results at Experimental Biology 2012 in April in San Diego. © 2012 Scientific American

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17205 - Posted: 08.27.2012

by Catherine de Lange A potential new treatment to prevent morphine addiction is at hand. Researchers have identified an immune receptor involved in addiction to the drug, and found a way to block this receptor without affecting pain relief. The discovery offers hope that morphine can be used to relieve pain without running the risk of addiction. Opioid drugs such as morphine are known to target opioid receptors in the central nervous system, which block pain signals to the brain and flood it with the "feel-good" chemical dopamine. This reward response is what makes opioids so addictive. Morphine is a widely used pain killer, but its addictiveness means it has to be administered with caution, and often cannot be used for protracted periods of chronic pain. Mark Hutchinson from the University of Adelaide, Australia, and colleagues have now discovered that as well as working through the central nervous system, opioid drugs like heroin and morphine trigger an immune response, which seems to boost their addictive effects. Blocking this immune response in animals inhibits their addiction. Hutchinson's team previously observed that opioids bind to TLR-4 – immune system receptors in the cell membrane – which are responsible for identifying foreign bodies. However, the team did not know how this binding affected the body. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 17169 - Posted: 08.15.2012

by Carol Cruzan Morton Migraines are a battle of the sexes that women might prefer not winning. Each year, roughly three times more women than men—up to 18% of all women—suffer from the debilitating headaches, as tallied by epidemiological surveys in Europe and the United States. A new brain imaging study may explain the divide: The brains of women with migraines appear to be built differently than those of their male counterparts. To conduct the study, researchers headed by David Borsook, a neurologist and neurobiologist of Boston Children’s Hospital and Harvard Medical School, recruited 44 men and women, half of whom were migraine sufferers. The women who had migraines rated them as being as intense as the men did, but they tended to find them more unpleasant. Borsook says the distinction is analogous to the loudness of fingernails scratching on a chalkboard versus the torment of hearing the sound. The team then scanned the brains of the volunteers. The researchers gathered two kinds of data sets, one that captured brain shapes and features, and one that measured brain activity. Female migraine sufferers showed slightly thicker gray matter in two regions: one, the posterior insula, is well-known in pain processing; the other, the precuneus, has been recently linked to migraines but is more widely known as a fundamental brain hub that may house a person's consciousness or sense of self. The other volunteers, including the male migraine sufferers, did not show this thickening. All of the scans were done when people did not have a migraine. To figure out what those structural changes meant, lead author Nasim Maleki, a medical physicist at Boston Children's Hospital and Harvard Medical School, returned to the MRI scans of only those men and women with episodic migraines. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 8: Hormones and Sex
Link ID: 17160 - Posted: 08.14.2012

by Krystnell A. Storr Imagine feeling like you’re lifting a 50-kilogram weight just by pulling at thin air. That’s just one of the possible applications of new "smart fingertips" created by a team of nanoengineers. The electronic fingers mold to the shape of the hand, and so far the researchers have shown that they can transmit electric signals to the skin. The team hopes to one day incorporate the devices into a smart glove that creates virtual sensations, fooling the brain into feeling everything from texture to temperature. Scientists have already developed circuits that stimulate our sense of touch. Some are used in Braille readers that allow blind people to browse the Internet. The devices work by sending electric currents to receptors in the skin, which interpret them as real sensations. However, most of these circuits are built on flat, rigid surfaces that can’t bend, stretch, or fold, says Darren Lipomi, a nanoengineer at the University of California, San Diego, who was not involved in the new study. Hoping to create circuits with the flexibility of skin, materials scientist John Rogers of the University of Illinois, Urbana-Champaign, and colleagues cut up nanometer-sized strips of silicon; implanted thin, wavy strips of gold to conduct electricity; and mounted the entire circuit in a stretchable, spider web-type mesh of polymer as a support. They then embedded the circuit-polyimide structure onto a hollow tube of silicone that had been fashioned in the shape of a finger. Just like turning a sock inside out, the researchers flipped the structure so that the circuit, which was once on the outside of the tube, was on the inside where it could touch a finger placed against it. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17152 - Posted: 08.13.2012

By ANAHAD O'CONNOR THE FACTS Certain regions of the human brain are dedicated to the various senses. The visual cortex handles vision, for example, while the auditory cortex processes sound. But what happens if one of the senses is lost? Do the neurons in the auditory cortex of a deaf person atrophy and go to waste, for instance, or are they put to work processing vision and other senses? In studies, scientists have shown that when one sense is lost, the corresponding brain region can be recruited for other tasks. Researchers learned this primarily by studying the blind. Brain imaging studies have found that blind subjects can locate sounds using both the auditory cortex and the occipital lobe, the brain’s visual processing center. But recently a similar phenomenon was discovered in the deaf. In a study financed by the National Institutes of Health and published in The Journal of Neuroscience, researchers recruited 13 deaf volunteers and a dozen volunteers with normal hearing and looked at what happened in their brains when touch and vision responses were stimulated. They found that both senses were processed in Heschl’s gyrus, where the auditory cortex is situated, suggesting that this part of the brain had been dedicated to other senses. Other studies have shown that structural changes in the auditory cortex are noticeable in the brains of deaf children from a very early age. THE BOTTOM LINE Losing one sense can cause the brain to become rewired. Copyright 2012 The New York Times Company

Related chapters from BP7e: Chapter 10: Vision: From Eye to Brain; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 5: The Sensorimotor System
Link ID: 17133 - Posted: 08.07.2012

By Jessica Gross An amiable joke can be much more effective than darker humor at improving mood, according to recent research from Stanford University. In the study, led by psychologist Andrea Samson and James Gross and published in February in Cognition & Emotion, 40 people in Switzerland and 37 people in the U.S. looked at photographs of upsetting things such as car accidents, corpses and dangerous animals. They were instructed to either say nothing about the images, use good-natured humor focusing on the absurdity of life or the human condition, or use mean-spirited humor. The experimenters offered examples of each type of response to help coach the subjects; given a picture of a snake with its prey, for instance, “Looks like someone's bitten off more than they can chew” exhibits positive humor, whereas “Nourishing my future handbag” has a negative spin. In both countries, those who made benevolent jokes about the images had more positive emotions and fewer negative emotions afterward than those who laughed mockingly at the pictures, although both groups who used humor fared better than those who simply looked silently. The upshot: when something upsets you, humor can help. The next time you try to laugh off a grim situation, reflect on whether your jokes skew negative (“My boss isn't just dumb; he has terrible body odor, too!”) or positive (“No matter what happens at work, I've got it better than a politician these days …”). You might find tweaking your comedic style could give more of a boost. © 2012 Scientific American,

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17074 - Posted: 07.21.2012

by Sarah C. P. Williams The vast majority of adults have had a sore back at some point in their lives. If they're lucky, the pain subsides after a few days or weeks. But for some, whose initial injuries appear no different than the fortunate ones, back pain lasts for years. Now, researchers have discovered a difference in brain scans between the two groups of patients that appears early in the course of the pain. The finding could lead to not only ways of identifying patients who are the most at risk for long-term pain but to new treatments or preventions for chronic pain. "This is the very first time we can say that if we have two subjects who have the same type of injury for the same amount of time, we can predict who will become a chronic pain patient versus who will not," says neuroscientist Vania Apkarian of Northwestern University, Chicago, who led the new work. Over the past 2 decades, Apkarian's lab has run many studies comparing the brains of patients with chronic back pain with those of healthy people, finding differences in brain anatomy or the function of certain regions. But the study designs made it hard to sort out which brain changes were consequences of the chronic pain—or the patients' painkillers or altered lifestyles—versus those that drove the pain's chronic nature. Apkarian and colleagues have now tracked the brains of back pain patients over time rather than comparing single neural snapshots. His team began with 39 people who had experienced moderate back pain—a five or six on a self-described scale of 10—for 1 to 4 months. Over the next year, the team scanned the patients' brains four times and followed their pain. By year's end, 20 of the patients had recovered, while 19 continued to hurt, meeting the criteria for chronic pain. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 16988 - Posted: 07.02.2012

By Deborah Kotz, Globe Staff I get occasional migraines, and the only good thing about the throbbing pain, nausea, and depressed mood is the sense of euphoria that comes when the pain finally lifts. For some headache sufferers, however, the pain never goes away -- for months, years, or even decades. I received a call recently from a relative whose teenage son developed a headache one day that’s lasted two months and counting, causing him to miss his final months of high school. His diagnosis: new daily persistent headache, a wastebasket term given when everything else has been ruled out. Dr. Elizabeth Loder, chief of the division of headache and pain at Brigham and Women’s/Faulkner Hospital, estimated that about 5 percent of the patients she sees at her clinic have new daily persistent headache. More commonly, patients come in with chronic migraines that result from medication overuse or because a particular drug isn’t working for them or has been prescribed at too low a dose. With new daily persistent headache, or NDPH, however, none of the array of migraine medications seems to work, even when prescribed at optimal doses. There’s no known cause such as a head injury, tumor, or seizure condition. And, unlike the typical headache sufferer, those with NDPH can name the exact day when their headache began -- even what they were doing when it started -- because they’ve never before had a problem with headaches and suddenly they’re in pain all the time with no relief in sight. © 2012 NY Times Co.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16953 - Posted: 06.23.2012

by Helen Thomson EVER wanted to know what an invisible hand looks like? Well, it is slightly wider than a real hand, and it has shorter fingers too. For the first time, the perceived shape of a phantom limb has been measured. This should make it possible to learn more about how the brain represents what we look like. The illusion of a phantom limb can kick in after an amputation or in people missing limbs from congenital disease. The result is the sensation that the limb is, in fact, present. One theory suggests people with phantom limbs take cues from those around them to work out what their missing body part looks like. Another theory is that the sensation of an invisible limb reflects brain activity in regions that map our body in space. To clarify the sensory origins of phantom limbs, Matthew Longo at Birkbeck, University of London, and colleagues enlisted the help of CL - a 38-year-old woman born without a left arm, who periodically feels she has a phantom hand. They asked her to place her right hand beneath a board and indicate where she believed her fingertips and knuckles were. She then repeated the exercise imagining that her phantom left hand was beneath the board instead. Previous studies have shown that we tend to underestimate our finger length increasingly from thumb to little finger. This mirrors differences in the sensitivity and size of areas in the brain's somatosensory cortex that are thought to represent each digit, probably by making use of visual, mechanical and tactile feedback. The thumb is represented by a larger area of the cortex than the little finger. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16917 - Posted: 06.16.2012

By Rachel Ehrenberg Among a small number of related families from northern Pakistan, some individuals never feel pain in any part of their bodies. Scientists studying six such children found that by the age of 4, they all had injuries to the lips or tongue from repeatedly biting themselves. Bruises, cuts and broken bones were common, though fractures were diagnosed only long after the fact, when weird, painless limping or the inability to use a limb called attention to the injury. Tests showed that the pain-free children perceived sensations of warm and cold, tickling and pressure. They could feel the prick of a needle, but it didn’t hurt. Two had been scalded — painlessly — by hot liquids. And one boy who performed street theater by putting knives through his arms and walking on hot coals died after jumping off a roof on his 14th birthday. Besides their inability to feel pain, the Pakistani individuals studied by the scientists had something else in common: mutations in a gene called SCN9A. That gene encodes the instructions for a protein that forms a passageway for letting sodium ions into nerve cells. Known as Nav1.7, this particular ion channel sits on pain-sensing nerves; when a nerve is stimulated enough to warrant sending a signal to the brain, a flood of sodium ions rush into the cell. Among the pain-free Pakistanis, various mutations in SCN9A altered the blueprints for Nav1.7 in different ways, but with the same result: The channel didn’t work. Muted nerve cells could no longer alert the brain when the body encountered something painful. © Society for Science & the Public 2000 - 2012

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 16916 - Posted: 06.16.2012

By Keith Seinfeld If you came face to face with a great whale, you might find a few surprises in its chin: Like whiskers, if you look closely at the surface. And, hidden inside the chin, lies a mysterious sensory organ, unknown to centuries of whalers and biologists. You just need the right tools to find it: a high-tech, oversized x-ray machine, and the right saws to slice it into thin pieces that fit in a microscope. A group of scientists based at the University of British Columbia, in Vancouver, BC, have done all that looking—and they discovered an organ that serves a crucial purpose and answers a longstanding mystery. Here is a graphic from the science study, published in Nature (expand the graphic to full screen to for best browsing of the information and images): How do great whales, such as humpbacks and blues, drive their jaws so wide open and then snap them shut, while swimming at full speed? “These heads are five meters long and weigh close to ten tons,” says Nick Pyenson, first author of the new study, published in the journal Nature. He’s now the curator of fossil marine mammals at the Smithsonian Institution. “What we found in the course of our investigation into the jaw and skull anatomy was this surprising structure in the chin. We had no idea what it was.” KPLU is a service of Pacific Lutheran University | ©2012

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16847 - Posted: 05.29.2012

By Stephani Sutherland Amputees who experience phantom limb pain can sometimes get relief from an optical illusion. This trick involves looking in a mirror at the reflection of a healthy limb from a certain angle, which causes it to appear where the missing limb should be. Seeing the limb move freely fools the brain into relieving the pain. Now a study suggests this technique might also work for arthritis pain. Cognitive scientist Laura Case, working in the lab of Vilayanur S. Ramachandran (a member of Scientific American Mind’s board of advisers) at the University of California, San Diego, used a modified version of the mirror technique to superimpose a researcher’s healthy hand over a subject’s arthritic hand, which was painfully constricted or contorted. Subjects mimicked the slow, purposeful movements of the researcher’s hand with their own unseen hand. After experiencing the illusion of their hand moving smoothly, subjects rated their arthritis pain slightly lower than before and had an increased range of motion. The result suggests that the toxic soup of inflammatory molecules bathing an arthritic joint is not the only source of painful sensations. “The brain has learned to associate movement with pain,” says Case, who presented her results at the Society for Neuroscience meeting last November in Washington, D.C. The illusion provides the brain with a way to disconnect the sight from the sensation. Next, the group will investigate whether this type of mirror therapy might provide long-term benefits for arthritis, a condition that affects about 50 million Americans. © 2012 Scientific American,

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16836 - Posted: 05.24.2012