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By Krystnell A. Storr Can you tell the difference between high – and low –thread-count sheets just by touching them? Thank usherin, a protein found in a mysterious structure in your fingertips. Usherin also helps us see and hear, suggesting a deep molecular connection among our most important senses. “The work is surprising,” says Ellen Lumpkin, a neuroscientist at the University of California (UC), Berkeley, who was not involved in the study. The study, she says, points to a single protein being used over and over again in distinct ways to help us monitor the outside world. Scientists already had some hints that usherin is important for our sense of touch. A mutation in the gene that codes for it, USH2A, causes Usher syndrome—a rare, inherited disease that leads to blindness, deafness, and an inability to feel faint vibrations in the fingertips. To further explore usherin’s role in touch, researchers recruited 13 patients with a form of Usher syndrome that specifically affects touch. The team—led by Gary Lewin, a neuroscientist at the Max Delbrück Center for Molecular Medicine—measured how well each person sensed pain, temperature changes, and tiny vibrations at 10 and 125 hertz (Hz), mimicking the sensation of moving a fingertip across a rough surface. The scientists then compared the patients’ results against those of 65 healthy volunteers. People with Usher syndrome did just as well as their counterparts at sensing temperature changes and mild pain, the team found. But they were four times less likely to pick up on the 125-Hz vibrations and 1.5 times less likely to detect the 10-Hz vibrations. © 2020 American Association for the Advancement of Science.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27623 - Posted: 12.12.2020

By Veronique Greenwood The ibis and the kiwi are dogged diggers, probing in sand and soil for worms and other buried prey. Sandpipers, too, can be seen along the shore excavating small creatures with their beaks. It was long thought that these birds were using trial and error to find their prey. But then scientists discovered something far more peculiar: Their beaks are threaded with cells that can detect vibrations traveling through the ground. Some birds can feel the movements of their distant quarry directly, while others pick up on waves bouncing off buried shells — echolocating like a dolphin or a bat, in essence, through the earth. There’s one more odd detail in this story of birds’ unusual senses: Ostriches and emus, birds that most definitely do not hunt this way, have beaks with a similar interior structure. They are honeycombed with pits for these cells, though the cells themselves are missing. Now, scientists in a study published Wednesday in Proceedings of the Royal Society B report that prehistoric bird ancestors dating nearly as far back as the dinosaurs most likely were capable of sensing vibrations with their beaks. The birds that use this remote sensing today are not closely related to one another, said Carla du Toit, a graduate student at the University of Cape Town in South Africa and an author of the paper. That made her and her co-authors curious about when exactly this ability evolved, and whether ostriches, which are close relatives of kiwis, had an ancestor that used this sensory ability. “We had a look to see if we could find fossils of early birds from that group,” Ms. du Toit said. “And we’re very lucky.” There are very well-preserved fossils of birds called lithornithids dating from just after the event that drove nonavian dinosaurs to extinction. © 2020 The New York Times Company

Related chapters from BN: 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: 27605 - Posted: 12.05.2020

Linda Geddes Many of the side-effects attributed to statins could be down to the “nocebo effect”, which occurs when someone expects to experience negative symptoms – even if the drug is a placebo – a study suggests. Statins are one of the most widely prescribed drugs in the UK, taken by nearly eight million people to reduce their risk of cardiovascular disease by lowering cholesterol levels. Yet, despite their effectiveness, up to a fifth of people stop taking them because of side-effects, such as fatigue, muscle aches, joint pain and nausea. Clinical studies have suggested, however, the incidence of side-effects is far lower. Researchers led by Frances Wood and Dr James Howard at Imperial College London recruited 60 patients who had been on statins, but stopped taking them owing to adverse effects. They were persuaded to resume treatment, and given four bottles containing atorvastatin, four bottles containing identical-looking placebo pills and four empty bottles, to be taken in a randomly prescribed order over the course of a year – including four months taking no pills. Each day, they recorded any side-effects on a smartphone, ranking their intensity from zero to 100. The researchers found 90% of symptoms experienced by the patients were present when they took placebo tablets. Also, 24 patients stopped taking tablets for at least one month of the trial, citing intolerable side-effects – amounting to 71 stoppages in total. Of these, 31 occurred during placebo months and 40 were during statin months. The results were published in the New England Journal of Medicine. © 2020 Guardian News & Media Limited

Related chapters from BN: 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 Higher Cognition
Link ID: 27582 - Posted: 11.16.2020

By Carolyn Wilke Fish fins aren’t just for swimming. They’re feelers, too. The fins of round gobies can detect textures with a sensitivity similar to that of the pads on monkeys’ fingers, researchers report November 3 in the Journal of Experimental Biology. Compared with landlubbers, little is known about aquatic animals’ sense of touch. And for fish, “we used to only think of fins as motor structures,” says Adam Hardy, a neuroscientist at the University of Chicago. “But it’s really becoming increasingly clear that fins play important sensory roles.” Studying those sensory roles can hint at ways to mimic nature for robotics and provide a window into the evolution of touch. The newfound parallels between primates and fish suggest that limbs that sense physical forces emerged early, before splits in the vertebrate evolutionary tree led to animals with fins, arms and legs, says Melina Hale, a neurobiologist and biomechanist also at the University of Chicago. “These capabilities arose incredibly early and maybe set the stage for what we can do with our hands now and what fish can do with their fins in terms of touch.” Hardy and Hale measured the activity of nerves in the fins of bottom-dwelling round gobies (Neogobius melanostomus) to get a sense of what fish learn about texture from their fins. In the wild, round gobies brush against the bottom surface and rest there on their large pectoral fins. “They’re really well suited to testing these sorts of questions,” Hardy says. Working with fins from six euthanized gobies, the researchers recorded electrical spikes from their nerves as a bumpy plastic ring attached to a motor rolled lightly above each fin. A salt solution keeps the nerves functioning as they would if the nerves were in a live fish, Hardy says. © Society for Science & the Public 2000–2020

Related chapters from BN: 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: 27564 - Posted: 11.04.2020

By Lisa Sanders, M.D. The 61-year-old woman put on her reading glasses to try to decipher the tiny black squiggles on the back of the package of instant pudding. Was it two cups of milk? Or three? The glasses didn’t seem to help. The fuzzy, faded marks refused to become letters. The right side of her head throbbed — as it had for weeks. The constant aggravation of the headache made everything harder, and it certainly wasn’t helping her read this label. She rubbed her forehead, then brought her hand down to cover her right eye. The box disappeared into darkness. She could see only the upper-left corner of the instructions. Everything else was black. She quickly moved her hand to cover her left eye. The tiny letters sprang into focus. She moved back to the right: blackness. Over to the left: light and letters. That scared her. For the past few months, she’d had one of the worst headaches she had ever experienced in her lifetime of headaches. One that wouldn’t go away no matter how much ibuprofen she took. One that persisted through all the different medications she was given for her migraines. Was this terrible headache now affecting her vision? The neurologists she saw over the years always asked her about visual changes. She’d never had them, until now. “Should I take you to the hospital?” her husband asked anxiously when she told him about her nearly sightless left eye. “This could be serious.” She thought for a moment. No, tomorrow was Monday; her neurologist’s office would be open, and the doctor would see her right away. She was always reliable that way. The patient had bad headaches for most of her adult life. They were always on the right side. They were always throbbing. They could last for days, or weeks, or sometimes months. Loud noises were always bothersome. With really bad headaches, her eye would water and her nose would run, just on that side. Bending over was agony. For the past few weeks, her headache had been so severe that if she dropped something on the floor, she had to leave it there. When she bent down, the pounding was excruciating. © 2020 The New York Times Company

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 7: Vision: From Eye to Brain
Link ID: 27553 - Posted: 10.28.2020

By Perri Klass, M.D. In a new report on pediatric pain in the British medical journal The Lancet, a commission of experts, including scientists, doctors, psychologists, parents and patients, challenged those who take care of children to end what they described as the common undertreatment of pain in children, starting at birth. Isabel Jordan, of Squamish, British Columbia, took part as a parent partner, along with her son Zachary, 19, who has a genetic condition, and lives with chronic pain. “Pain matters with every child and at every intersection with the health care system,” she said. But for her son, “it didn’t matter with many providers, doctors, nurses, phlebotomists, and that made for worse outcomes.” “The professionals had a wealth of knowledge and experience, but what they lacked was the knowledge of what was really impacting patients in day-to-day life, they didn’t know how impactful poorly managed procedural pain was to patients,” especially children like her son who have ongoing medical issues, Ms. Jordan said. “He’s got a rare disease and has had a lifetime of chronic pain and also procedure pain.” Although we often pride ourselves, in pediatrics, on taking a kinder and gentler approach to our patients, pain experts feel that children’s pain is often taken for granted, and that simple and reliable strategies to mitigate it are disregarded; such as, for example, the 2015 World Health Organization recommendations that infants should be held by parents and perhaps breastfed during immunizations, and that distraction techniques should be used with older children. Christopher Eccleston, a professor of pain science and medical psychology at the University of Bath, where he directs the Centre for Pain Research, was the lead author on the report. He became interested in pediatric pain through working with adults with chronic pain, he said, and realizing that many of them had pain going back into adolescence, which had not been treated. © 2020 The New York Times Company

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27548 - Posted: 10.26.2020

By Lisa Sanders, M.D. The pain woke the 52-year-old physician from a dead sleep. It was as if all the muscles in his right leg, from those in the buttock down his thigh to the very bottom of his calf, were on fire. He shifted slightly to see if he could find a more comfortable position. There was a jag of pain, and he almost cried out. He glanced at the clock: 4 a.m. In just three hours he would have to get up. He had a full day of patients to see. Massage didn’t help. He couldn’t get comfortable lying flat, so finally he moved to the living room, to a recliner. Only then, and only by lying completely still, did he manage to get the pain to abate. He drifted off, but never for long. The searing pain in his leg and buttock slowly eased, and by the time his alarm went off, he could stand and walk — though his muscles still ached and he had to baby his right leg, causing a limp. Between patients, he arranged to see his own doctor. He’d had pain off and on in his buttocks, one side or the other, for more than a year. The pain was in the middle of each cheek and was worse when he was sitting and at the end of the day. Walking to and from his car on the way home was brutal. And then, as mysteriously as it came, it would disappear — only to come back a week or two later. When he first told his doctor about his pain, the exam didn’t show much. He was a little tender at the bottom of the bones you sit on, called the ischia. His doctor thought it was ischial bursitis. Between the tips of the ischia and the largest muscles of the buttocks, there are little pads called bursae. Sometimes these pads become inflamed. The man’s doctor recommended stretching exercises for the muscles around the bursae. He did them regularly, though he wasn’t sure they helped. The pain he had that night, though, was different, and a whole lot worse. Again, his doctor couldn’t find much. Maybe it was a kind of nerve pain, like sciatica, the patient suggested. The doctor agreed and ordered an M.R.I. to look for a pinched nerve. The result was normal. © 2020 The New York Times Company

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 27474 - Posted: 09.16.2020

By Amanda Loudin Last summer while out on a bike ride, 35-year-old Andrew Bernstein of Boulder, Colo., was hit by a van that knocked him off the road and kept on going. A passing driver spotted Bernstein lying, unmoving, in a ditch and called 911. Bernstein’s injuries were life threatening. After multiple surgeries, 10 weeks recovering in the hospital and more than three weeks in inpatient rehab, Bernstein has spent the better part of every week since then working with a number of practitioners to help him progress to where he is today — in a wheelchair and walking with the assistance of a full-length leg brace and crutches. But almost all of that effort came to a complete halt when the coronavirus pandemic hit in March and all of his physical therapy facilities either closed or dramatically reduced their patient contact. “I typically worked with a variety of therapists nine or 10 times a week at four different facilities,” Andrew Bernstein says. He was given a home-based plan but “the disruptions to my therapies was challenging. It was frustrating to do without supervision, because my condition changes from one week to the next, something my therapists might notice even if I don’t.”“I typically worked with a variety of therapists nine or 10 times a week at four different facilities,” Andrew Bernstein says. He was given a home-based plan but “the disruptions to my therapies was challenging. It was frustrating to do without supervision, because my condition changes from one week to the next, something my therapists might notice even if I don’t.”

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27460 - Posted: 09.09.2020

Abby Carney Shortly after relocating to Texas from California three years ago, Cheryl Webster started hosting a game night at her home as a way of meeting new people. They stopped meeting due to Covid-19, and Webster has only heard from one person in the group in the months since they were able to play. Eventually, she decided to pick up the phone herself – but nobody called back. “I think that’s the hardest part about loneliness,” she said. “Is it my fault? Am I not a very nice person? Or is there something wrong with me?” End of the office: the quiet, grinding loneliness of working from home Read more Webster, 65, is a proactive doer who volunteers regularly and has even helped finance the education of several friends’ children. She sits on the board of the Austin housing authority and the chamber of commerce, and is sure the Christian business leaders’ group she meets with monthly would say flattering things about her. Though divorced and childless, Webster is not a Havisham spinster – putting herself “out there” comes naturally. And so she supposes many people in her life would be surprised to learn that she’s lonely. Despite following the advice of experts to ward off the feeling, her heart still aches. Advertisement Webster is not alone. A growing number of people share her affliction – so much so that some governments are incorporating loneliness into their health public policy. To help people like her, a number of scientists are researching medical solutions, such as pills and nasal sprays. But will treating loneliness like a disease, rather than an existential question, work to ease their pain? © 2020 Guardian News & Media Limited

Related chapters from BN: 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: 27405 - Posted: 08.06.2020

By Abdul-Kareem Ahmed “He doesn’t look like himself,” his wife said. It was midnight, and I was consulting on a patient in the emergency room. He was 48 years old and complaining of a headache. Ten years ago my attending had partially removed a benign tumor growing in his cerebellum, part of the hindbrain that controls movement, coordination and speech. Our team had also placed a shunt in his brain. The brain is buoyed and bathed by cerebrospinal fluid. This clear fluid is made in large cavities, called ventricles, and is eventually absorbed by veins. The tumor’s inoperable remnant had blocked the fluid’s natural escape, causing it to build up, a condition known as hydrocephalus. A shunt is a thin rubber tube that is placed in the ventricles of the brain and tunneled under the skin, into the abdomen. It can have a programmable pressure valve, a gauge that sits under the scalp. His shunt had been siphoning excess fluid to his abdomen for years where it was absorbed, preventing life-threatening high pressure in the brain. Today, however, something was wrong, and I thought it was revealed on his new head CT. His ventricles were very large, suggesting high pressure. “I get a bad headache when I sit up,” he mumbled. “Sometimes I vomit. I feel better when I lie flat.” His wife, a strong and kindhearted woman, corroborated his complaint. “He’s also having memory problems, and he’s losing his balance when he walks,” she added. His symptoms were the opposite of what I expected. He was describing a low-pressure headache. He was relieved by lying down but worsened when sitting up.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 27397 - Posted: 08.03.2020

Ewen Callaway Despite their rough and tumble existence, Neanderthals had a biological predisposition to a heightened sense of pain, finds a first-of-its kind genome study published in Current Biology on 23 July1. Evolutionary geneticists found that the ancient human relatives carried three mutations in a gene encoding the protein NaV1.7, which conveys painful sensations to the spinal cord and brain. They also showed that in a sample of British people, those who had inherited the Neanderthal version of NaV1.7 tend to experience more pain than others. “It’s a first example, to me, about how we begin to perhaps get an idea about Neanderthal physiology by using present-day people as transgenic models,” says Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the work with Hugo Zeberg at the Karolinska Institute in Stockholm. Pain-sensing protein Researchers have access to only a few Neanderthal genomes, and most of those have been sequenced at a low resolution. This has made it hard to identify mutations that evolved after their lineage split from that of humans some 500,000–750,000 years ago. But in the past few years, Pääbo and his team have generated three high-quality Neanderthal genomes from DNA found in caves in Croatia and Russia. This allows them to confidently identify mutations that were probably common in Neanderthals, yet very rare in humans. Mutations in a gene called SCN9A — which encodes the NaV1.7 protein — stood out because all of the Neanderthals had three mutations that alter the shape of the protein. The mutated version of the gene was found on both sets of chromosomes in all three Neanderthals, hinting that it was common across their populations. © 2020 Springer Nature Limited

Related chapters from BN: 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: 27382 - Posted: 07.25.2020

By William Schwalbe More than three years ago, I came down with a mysterious illness I thought might be a flu, but turned out to be something entirely different. My blizzard of symptoms began innocuously in November 2016 with terribly cold feet. So cold that even when I got under the covers with a hot water bottle between them, and they were warm to the touch, they still felt like painful ice-blocks. At other times, I had the equally unpleasant sensation that my feet and shins were burning or already burnt. A few weeks later, I started to experience intense throbbing pain in all my toes, as if someone had seconds before stomped on them with heavy boots, which made walking or standing difficult. Often my legs were so heavy that I could barely move them. Occasionally, my feet turned bright red. And every few hours came shooting pains, electric shocks that traveled up my legs. In my 55 years on earth, I’d never felt pain like that — except when a dentist drilled without Novocain. All the symptoms increased at night, so sleep became elusive. I wound up sticking my feet outside the covers because even a sheet brushing against them proved too painful to bear. Before long, the same panoply of pains had moved to my hands and then arms — and occasionally my face and stomach. Heat made the symptoms worse; cold and damp made them much worse. But often these pains flared for no discernible reason. Totally unrelated, or so I thought, were other things that began to go wrong with me over the next few months: I often found myself pouring with sweat from my forehead, but became unable to sweat on my legs and arms; I lost all the hair on my lower legs; I was increasingly faint and dizzy, with my heart racing whenever I changed position or had a shower; and I was experiencing a fatigue and bone-pain so profound that every few hours I needed to stop whatever I was doing and lie down on the floor. © 1996-2020 The Washington Post

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27334 - Posted: 06.29.2020

Ashley Yeager It had been seven weeks since I’d touched another human being. Arms outstretched, I walked quickly toward my dad, craving his embrace. In the instant before we touched, we paused, our minds probably running quick, last-minute calculations on the risk of physical contact. But, after turning our faces away from each other and awkwardly shuffling closer, we finally connected. Wrapped in my dad’s bear hug, I momentarily forgot we were in the midst of the worst global crisis I have ever experienced. “Touch is the most powerful safety signal of togetherness,” says Steve Cole, a psychiatrist and biobehavioral scientist at the University of California, Los Angeles. Like more than 35 million other Americans, I live alone, and with the guidelines of physical distancing set by the Centers for Disease Control and Prevention, I hadn’t been getting close to anyone to avoid being infected with (or potentially spreading) SARS-CoV-2, the virus that causes COVID-19. I’d been working, thankfully, at home and staying connected with friends and family through Zoom and Skype, but those virtual interactions were no replacement for being with loved ones in person. “When we get lonely and isolated our brainstem recognizes that suddenly we are in insecure territory and flips on a bunch of fight-or-flight stress responses without us even knowing it,” Cole says. “There’s all sorts of things in our social world that lead us to calculate that we are either safe or unsafe. You can think of physical touch, supportive and affectionate touch, as the most fundamental signal that you’re with somebody who cares about you . . . a fundamental signal of safety and well-being.” © 1986–2020 The Scientist.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 5: The Sensorimotor System
Link ID: 27259 - Posted: 05.21.2020

By Kelly Servick The dark side of opioids’ ability to deaden pain is the risk that they might kill their user. The same brain receptors that blunt pain when drugs such as morphine or oxycodone bind to them can also signal breathing to slow down. It’s this respiratory suppression that causes most overdose deaths. So scientists have hoped to design opioids that are “biased” toward activating painkilling signals while leaving respiratory signaling alone. Several companies have cropped up to develop and test biased opioids. But two new studies in mice contest a key hypothesis underlying these efforts—that a signaling protein called beta-arrestin2 is fundamental to opioids’ effect on breathing. “It seems like the premise was wrong,” says Gaspard Montandon, a neuroscientist and respiratory physiologist at the University of Toronto. He and others doubt that the good and bad effects of opioids can be disentangled. Hopes first arose in the late 1990s and early 2000s, as neuroscientist Laura Bohn, biochemist Robert Lefkowitz, and colleagues at Duke University explored the cascades of signals triggered when a drug binds to muopioid receptors on a neuron. This binding changes the receptor’s structure and its interactions with two types of proteins inside the cell—signaling molecules known as G-proteins, and beta-arrestins, which, among other effects, inhibit G-protein signaling. It’s still not clear how the resulting signal cascades influence cells or brain circuits. But the researchers reported in 1999 that mice engineered to lack the gene for beta-arrestin2 got stronger and longer lasting pain relief from morphine. And in 2005, Bohn and her colleagues at Ohio State University found that two morphine-induced side effects, constipation and slowed breathing, were dramatically reduced in these “knockout” mice. The findings suggested that a drug able to nudge the mu-opioid receptors toward G-protein signaling and away from beta-arrestin2 signaling would prompt more pain relief with fewer risks. © 2020 American Association for the Advancement of Science

Related chapters from BN: 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 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 27083 - Posted: 02.28.2020

By Benedict Carey Soldiers with deep wounds sometimes feel no pain at all for hours, while people without any detectable injury live in chronic physical anguish. How to explain that? Over drinks in a Boston-area bar, Ronald Melzack, a psychologist, and Dr. Patrick Wall, a physiologist, sketched out a diagram on a cocktail napkin that might help explain this and other puzzles of pain perception. The result, once their idea was fully formed, was an electrifying theory that would become the founding document for the field of modern pain studies and establish the career of Dr. Melzack, whose subsequent work deepened medicine’s understanding of pain and how it is best measured and treated. Dr. Melzack died on Dec. 22 in a hospital near his home in Montreal, where he lived, his daughter, Lauren Melzack, said. He was 90, and had spent most of his professional life as a professor of psychology at McGill University. When Dr. Melzack and Dr. Wall, then at the Massachusetts Institute of Technology, met that day in 1959 or 1960 (accounts of their encounter vary), pain perception was thought to work something like a voltmeter, in which nerves send signals up to the brain that reflect the severity of the injury. But that model failed to explain not only battlefield experience but also a host of clinical findings and everyday salves. Most notably, rubbing a wound lessens its sting — and accounting for just that common sensation proved central to the new theory. Doctors knew that massaging the skin activated so-called large nerve fibers, which are specialized to detect subtle variations of touch; and that deeper, small fibers sounded the alarm of tissue damage. The two researchers reasoned that all these sensations must pass through a “gate” in the spinal cord, which adds up their combined signals before sending a message to the brain. In effect, activating the large fibers blocks signals from the smaller ones, by closing the gate. © 2020 The New York Times Company

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26950 - Posted: 01.13.2020

Amber Dance The girl tried hard to hold her arms and hands steady, but her fingers wriggled and writhed. If she closed her eyes, the squirming got worse. It wasn’t that she lacked the strength to keep her limbs still — she just didn’t seem to have control over them. Carsten Bönnemann remembers examining the teenager at a hospital in Calgary, Canada, in 2013. As a paediatric neurologist with the US National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, he often travelled to weigh in on puzzling cases. But he had never seen anything like this. If she wasn’t looking at her limbs, the girl didn’t seem to have any clue where they were. She lacked the sense of her body’s position in space, a crucial ability known as proprioception. “This is something that just doesn’t occur,” says Bönnemann. His team sequenced the girl’s genes, and those of another girl with similar symptoms1, and found mutations in a gene called PIEZO2. Their timing was fortunate: just a few years earlier, researchers looking for the mechanisms that cells use to sense touch had found that the gene encoded a pressure-sensitive protein2. The discovery of Piezo2 and a related protein, Piezo1, was a high point in a decades-long search for the mechanisms that control the sense of touch. The Piezos are ion channels — gates in the cell membrane that allow ions to pass through — that are sensitive to tension. “We’ve learned a lot about how cells communicate, and it’s almost always been about chemical signalling,” says Ardem Patapoutian, a molecular neurobiologist at Scripps Research in La Jolla, California, whose group identified the Piezos. “What we’re realizing now is that mechanical sensation, this physical force, is also a signalling mechanism, and very little is known about it.” © 2020 Springer Nature Limited

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26944 - Posted: 01.09.2020

By Jane E. Brody If you live with or work with someone who suffers from migraine, there’s something very important you should know: A migraine is not “just a headache,” as many seem to think. Nor is it something most sufferers can simply ignore and get on with their lives. And if you are a migraine sufferer, there’s something potentially life-changing that you should know: There are now a number of medications available that can either prevent or alleviate many attacks, as well as a newly marketed wearable nerve-stimulating device that can be activated by a smartphone to relieve the pain of migraine. Migraine is a neurological disorder characterized by recurrent attacks of severe, often incapacitating headache and dysfunction of the autonomic nervous system, which controls the body’s myriad automatic activities like digestion and breathing. The throbbing or pulsating pain of migraine is often accompanied by nausea and vomiting. Translation: Migraine is a headache, all right, but with body-wide effects because the brain converses with the rest of the body. It is often severe enough to exact a devastating toll on someone’s ability to work, interact with others, perform the tasks of daily life, or even be in a normal living environment. When in the throes of a migraine attack, sufferers may be unable to tolerate light, noise, smells or even touch. Dr. Stephen Silberstein, a neurologist at Thomas Jefferson University and director of the Jefferson Headache Center, told me “There are 47 million people in this country with migraine, and for six million, the condition is chronic, which means they have more than 15 headache days a month,” he said. “It’s time to destigmatize migraine and provide sufferers with effective treatment,” said Dr. David W. Dodick, neurologist at the Mayo Clinic in Scottsdale. “They’re not fakers, weak individuals who are trying to get out of work.” © 2020 The New York Times Company

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26936 - Posted: 01.07.2020

By Debbie Jackson BBC Scotland "Fluffing your son's hair, really hugging him, holding his hand." For someone who has been through what she has in the space of a year, Corinne Hutton doesn't need much to make her happy. Last January she got the double hand transplant she had been waiting more than five years for, and feared would never happen. This January, she will celebrate her "handiversary", a year since a surgeon handed her back her independence. Being able to do the simplest things for 11-year-old son Rory means the world to Finding Your Feet charity founder Cor. "From an emotional point of view to be able to do things for him - make the packed lunches or the washing, or do the ironing is great," she said. "But on top of that, being able to hold his hand, fluff his hair, little things that might not be hugely exciting to him - but they matter a lot to me. "People don't appreciate what it means to have lost them," she said. Cor became the first Scot to undergo a double hand transplant when, in a 12-hour procedure, Prof Simon Kay attached two donor hands to her arms at Leeds general Infirmary. The 48-year-old lost her hands and feet in 2013 after suffering acute pneumonia and sepsis, which almost killed her. After more than a dozen false alarms over the years, a match for her own blood group, skin tone and hand size had been found. Much celebration and wonder was made of the news that the transplant had finally happened, but the aftermath was far from easy. © 2019 BBC.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26922 - Posted: 12.30.2019

By Richard Sima Luke Miller, a cognitive neuroscientist, was toying with a curtain rod in his apartment when he was struck by a strange realization. When he hit an object with the rod, even without looking, he could tell where it was making contact like it was a sensory extension of his body. “That’s kind of weird,” Miller recalls thinking to himself. “So I went [to the lab], and we played around with it in the lab.” Sensing touch through tools is not a new concept, though it has not been extensively investigated. In the 17th century, philosopher René Descartes discussed the ability of blind people to sense their surroundings through their walking cane. While scientists have researched tool use extensively, they typically focused on how people move the tools. “They, for the most part, neglected the sensory aspect of tool use,” Miller says. In a 2018 Nature study, Miller and his colleagues at Claude Bernard Lyon 1 University in France reported that humans are actually quite good at pinpointing where an object comes into contact with a handheld tool using touch alone, as if the object were touching their own skin. A tool is not innervated like our skin, so how does our brain know when and where it is touched? Results in a follow-up study, published in December in Current Biology, reveal that the brain regions involved with sensing touch on the body similarly processes it on the tool. “The tool is being treated like a sensory extension of your body,” Miller says. In the initial experiment, the researchers asked 16 right-handed subjects to determine where they felt touches on a one-meter-long wooden rod. In a total of 400 trials, each subject compared the locations of two touches made on the rod: If they were felt in different locations, participants did not respond. If they were in the same location, the people in the study tapped a foot pedal to indicate whether the touches were close or far from their hand. Even without any experience with the rod or feedback on their performance, the participants were, on average, 96 percent accurate. © 2019 Scientific American,

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26914 - Posted: 12.26.2019

By Austin Frakt Some days I’m grumpy; other times, my head hurts or my feet or my arms do. Yet when I play the trumpet, my mood improves and the pain disappears. Why? Alternative medicine — including music therapy — is full of pain-relief claims. Although some are simply too good to be true, the oddities of pain can explain why others hold up, as well as why my trumpet playing helps. One thing we tend to believe about pain, but is wrong, is that it always stems from a single, fixable source. Another is that pain is communicated from that source to our brains by “pain nerves.” That’s so wrong it’s called “the naïve view” by neuroscientists. In truth, pain is in our brain. Or as the author and University of California, San Diego, neuroscientist V. S. Ramachandran put it, “Pain is an opinion.” We feel it because of how our brain interprets input transmitted to it from all our senses, not necessarily because of the inherent properties of the input itself. There are no nerves dedicated to sensing and transmitting pain. Anyone who has willed themselves to not feel a tickle as ticklish can appreciate the difference between stimulation and our perception of it. Pain can be experienced and relieved in phantom limbs. Discomfort and swelling increase when people believe a painful hand or knee is larger. They decrease when it seems smaller, for example in a distorted image or based on virtual reality technology. Injections are less painful when we don’t watch them. Using our brains, we can exert some control over it. © 2019 The New York Times Company

Related chapters from BN: 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: 26865 - Posted: 12.02.2019