Chapter 8. General Principles of Sensory Processing, Touch, and Pain

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Katharine Sanderson Researchers have developed an electronic skin that can mimic the same process that causes a finger, toe or limb to move when poked or scalded. The technology could lead to the development of a covering for prosthetic limbs that would give their wearers a sense of touch, or help to restore sensation in people whose skin has been damaged. The ‘e-skin’ was developed in the laboratory of chemical engineer Zhenan Bao at Stanford University in California. Her team has long been trying to make a prosthetic skin that is soft and flexible, but that can also transmit electrical signals to the brain to allow the wearer to ‘feel’ pressure, strain or changes in temperature. The latest work, published on 18 May in Science1, describes a thin, flexible sensor that can transmit a signal to part of the motor cortex in a rat’s brain that causes the animal’s leg to twitch when the e-skin is pressed or squeezed. “This current e-skin really has all the attributes that we have been dreaming about,” says Bao. “We have been talking about it for a long time.” In healthy living skin, mechanical receptors sense information and convert it into electrical pulses that are transmitted through the nervous system to the brain. To replicate this, an electronic skin needs sensors and integrated circuits, which are usually made from rigid semiconductors. Flexible electronic systems are already available, but they typically work only at high voltages that would be unsafe for wearable devices. To make a fully soft e-skin, Bao’s team developed a flexible polymer for use as a dielectric — a thin layer in a semiconductor device that determines the strength of the signal and the voltage needed to run the device. The researchers then used the dielectric to make stretchy, flexible arrays of transistors, combined into a sensor that was thin and soft like skin. © 2023 Springer Nature Limited

Keyword: Pain & Touch; Robotics
Link ID: 28790 - Posted: 05.21.2023

By Lucy Odling-Smee Philip Kass spends 90% of his day lying on a twin bed in a sparsely decorated room that used to belong to his niece. He takes most meals with a plate balanced on his chest, and he usually watches television because reading is too stressful. “I’m barely living,” he told me on a warm night in June last year. Ever since a back injury 23 years ago, pain has been eating away at Kass’s life. It has cost him his career, his relationships, his mobility and his independence. Now 55, Kass lives with his sister and her family in San Francisco, California. He occasionally joins them for dinner, which means he’ll eat while standing. And once a day he tries to walk four or five blocks around the neighbourhood. But he worries that any activity, walking too briskly or sitting upright for more than a few minutes, will trigger a fresh round of torment that can take days or weeks to subside. Philip Kass has dealt with pain for more than two decades. Some of what Kass describes is familiar. I have been pinned to the floor by spinal pain several times in my life. In my twenties, I was immobilized for three months. In my thirties and forties, each episode of severe pain lasted more than a year. I spent at least another half decade standing or pacing through meetings, meals and movies — for fear that even a few minutes spent sitting would result in weeks of disabling pain. For years, I read anything I could find to better understand why my pain persisted.

Keyword: Pain & Touch
Link ID: 28723 - Posted: 03.29.2023

Miryam Naddaf It is thanks to proteins in the nose called odour receptors that we find the smell of roses pleasant and that of rotting food foul. But little is known about how these receptors detect molecules and translate them into scents. Now, for the first time, researchers have mapped the precise 3D structure of a human odour receptor, taking a step forwards in understanding the most enigmatic of our senses. The study, published in Nature on 15 March1, describes an olfactory receptor called OR51E2 and shows how it ‘recognizes’ the smell of cheese through specific molecular interactions that switch the receptor on. “It’s basically our first picture of any odour molecule interacting with one of our odour receptors,” says study co-author Aashish Manglik, a pharmaceutical chemist at the University of California, San Francisco. Smell mystery The human genome contains genes encoding 400 olfactory receptors that can detect many odours. Mammalian odour-receptor genes were first discovered in rats by molecular biologist Richard Axel and biologist Linda Buck in 19912. Researchers in the 1920s estimated that the human nose could discern around 10,000 smells3, but a 2014 study suggests that we can distinguish more than one trillion scents4. Each olfactory receptor can interact with only a subset of smelly molecules called odorants — and a single odorant can activate multiple receptors. It is “like hitting a chord on a piano”, says Manglik. “Instead of hitting a single note, it’s a combination of keys that are hit that gives rise to the perception of a distinct odour.” Beyond this, little is known about exactly how olfactory receptors recognize specific odorants and encode different smells in the brain. Technical challenges in producing mammalian olfactory-receptor proteins using standard laboratory methods have made it difficult to study how these receptors bind to odorants. © 2023 Springer Nature Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 28710 - Posted: 03.18.2023

ByClaudia Lopez Lloreda Peanuts have a dark side. In some people, they can cause a dangerous and sometimes deadly allergic reaction marked by a sharp drop in body temperature and blood pressure, as well as difficulty breathing. This anaphylactic shock has typically been blamed on the immune system going into overdrive. But a new study in mice pegs an additional culprit: the nervous system. The findings, reported today in Science Immunology, “are line with what people thought but no one was actually able to demonstrate,” says Sebastien Talbot, a neuroimmunologist at Queen’s University who was not involved in the study. The work, he says, could open up new targets to treat severe allergic reactions in people. Anaphylaxis strikes about one in 50 individuals in the United States every year. Besides peanuts, bee stings and some medicines are common triggers. These allergens cause the immune system’s mast cells to release a barrage of histamine and other molecules that spread throughout the body, dilating blood vessels and narrowing airways. Body temperature can also drop, making people feel cold and clammy, though why this happens has been less clear. Mice experience anaphylaxis, too. When exposed to an allergen, they lie on their bellies and stretch out. Such behaviors are controlled by the central nervous system, which made Soman Abraham, an immunologist at Duke University, suspect nerves may also play a role in severe allergic reactions. To find out, he and colleagues gave the mice ovalbumin—the main protein found in egg whites and a known trigger of anaphylaxis—and used electrodes and microscopy to record and measure neuron activity. As in humans, the rodents’ body temperature dropped—about 10°C. But the mice’s brains didn’t register this as a sudden freeze; instead, brain areas that typically respond to heat had higher levels of activity. This false feeling of warmth explains why the animals stretch out as if they’re overheating even as their body temperature drops.

Keyword: Neuroimmunology
Link ID: 28706 - Posted: 03.18.2023

By Christina Jewett The Food and Drug Administration has approved a Pfizer nasal spray for treatment of migraines that uses a different therapy from other nasal products on the market for severe headache pain, the company said on Friday. The fast-acting treatment, which is called zavegepant and will be sold as Zavzpret, performed better than a placebo in relieving pain and patients’ most bothersome symptoms, according to clinical trial results published in the journal Lancet Neurology. Participants in the trial who took the medication were more likely to report returning to normal function 30 minutes to two hours after taking it. The gains, though, were not significant for every patient. A study tracked the experience of 1,269 patients — half on the drug and half on a placebo — focusing on how they reported feeling two hours after using either substance. About 24 percent on the medication reported freedom from pain, compared to about 15 percent who took a placebo, according to the study. Dr. Timothy A. Collins, chief of the headache division at Duke University Medical Center’s neurology department, said the product gave doctors a new option in a nasal spray format that patients with migraines tended to appreciate. He said the condition often comes with nausea, so swallowing a pill can be unpleasant. He also said the drug presented few side effects, like drowsiness, that had been reported with other products. “We’ve been waiting for this medication to come out,” Dr. Collins said. “It’s a really helpful addition to migraine management.” One additional upside of the medication is that it’s safe for patients who have had a heart attack or a stroke, he added. Pfizer said the medication would be available in pharmacies in July, but did not disclose the estimated price of the new spray. The company estimated that nearly 40 million people in the United States suffered from migraines each year. © 2023 The New York Times Company

Keyword: Pain & Touch
Link ID: 28701 - Posted: 03.15.2023

By Jack Tamisiea An elephant’s trunk has 40,000 muscles and weighs more than a Burmese python. The appendage is strong enough to uproot a tree, yet sensitive enough to suction up fragile tortilla chips. But how does an elephant’s brain help accomplish these feats of dexterity? That has been difficult to study, according to Michael Brecht, a neuroscientist at the Humboldt University of Berlin. Weighing in excess of 10 pounds, the elephant’s brain degrades quickly after death and is a hassle to store. “I tend to think that the big animals are a bit neglected because we don’t do enough work on big brains,” Dr. Brecht said. Dr. Brecht and his colleagues were fortunate enough to gain access to a trove of elephant brains from animals that had died of natural causes or were euthanized for health reasons and ended up either frozen or in a fixative substance at the Leibniz Institute for Zoo and Wildlife Research in Berlin. In a study published Wednesday in the journal Science Advances, Dr. Brecht and his colleagues reported that elephants had more facial neurons than any other land mammal, which might contribute to trunk dexterity and other anatomical abilities. The study also helped to pinpoint major differences between the neural wirings of African savanna elephants and Asian elephants. Using the brains of four Asian elephants and four African savanna elephants, the researchers homed in on the facial nucleus, a bundle of neurons concentrated in the brainstem and hooked up to facial nerves. In mammals, these neurons serve as the control center for facial muscles. They’re in command whenever you wrinkle your nose, purse your lips or raise your eyebrows. They also help elephants employ their trunks. The researchers divided the facial nucleus into regions of neurons that controlled the elephant’s ears, lips and trunk. African elephants sported 63,000 facial neurons, while their Asian cousins had 54,000. The only mammals with more are dolphins, which pack nearly 90,000 facial neurons into their sensitive snouts. While his team expected both African savanna and Asian elephants to possess massive stores of facial neurons, Dr. Brecht said the discrepancy between the two species was noteworthy. © 2022 The New York Times Company

Keyword: Evolution; Pain & Touch
Link ID: 28533 - Posted: 10.28.2022

By Jim Robbins Tens of thousands of bar-tailed godwits are taking advantage of favorable winds this month and next for their annual migration from the mud flats and muskeg of southern Alaska, south across the vast expanse of the Pacific Ocean, to the beaches of New Zealand and eastern Australia. They are making their journey of more than 7,000 miles by flapping night and day, without stopping to eat, drink or rest. “The more I learn, the more amazing I find them,” said Theunis Piersma, a professor of global flyway ecology at the University of Groningen in the Netherlands and an expert in the endurance physiology of migratory birds. “They are a total evolutionary success.” The godwit’s epic flight — the longest nonstop migration of a land bird in the world — lasts from eight to 10 days and nights through pounding rain, high winds and other perils. It is so extreme, and so far beyond what researchers knew about long-distance bird migration, that it has required new investigations. In a recent paper, a group of researchers said the arduous journeys challenge “underlying assumptions of bird physiology, orientation, and behavior,” and listed 11 questions posed by such migrations. Dr. Piersma called the pursuit of answers to these questions “the new ornithology.” The extraordinary nature of what bar-tailed and other migrating birds accomplish has been revealed in the last 15 years or so with improvements to tracking technology, which has given researchers the ability to follow individual birds in real time and in a detailed way along the full length of their journey. “You know where a bird is almost to the meter, you know how high it is, you know what it’s doing, you know its wing-beat frequency,” Dr. Piersma said. “It’s opened a whole new world.” The known distance record for a godwit migration is 13,000 kilometers, or nearly 8,080 miles. © 2022 The New York Times Company

Keyword: Animal Migration; Sleep
Link ID: 28484 - Posted: 09.21.2022

By Anil Oza Sitting alone in the cockpit of a small biplane, Martin Wikelski listens for the pings of a machine by his side. The sonic beacons help the ecologist stalk death’s-head hawkmoths (Acherontia atropos) fluttering across the dark skies above Konstanz, Germany — about 80 kilometers north of the Swiss Alps. The moths, nicknamed for the skull-and-crossbones pattern on their backs, migrate thousands of kilometers between northern Africa and the Alps during the spring and fall. Many migratory insects go where the wind takes them, says Ring Carde, an entomologist at the University of California, Riverside who is not a member of Wikelski’s team. Death’s-head hawkmoths appear to be anything but typical. “When I follow them with a plane, I use very little gas,” says Wikelski, of the Max Planck Institute of Animal Behavior in Munich. “That shows me that they are supposedly choosing directions or areas that are probably supported by a little bit of updraft.” A new analysis of data collected from 14 death’s-head hawkmoths suggest that these insects indeed pilot themselves, possibly relying in part on an internal compass attuned to Earth’s magnetic field. The moths not only fly along a straight path, they also stay the course even when winds change, Wikelski and colleagues report August 11 in Science. The findings could help predict how the moths’ flight paths might shift as the globe continues warming, Wikelski says. Like many animals, death’s-head hawkmoths will probably move north in search of cooler temperatures, he suspects. To keep tabs on the moths, Wikelski’s team glued radio transmitters to their backs, which is easier to do than one might expect. “Death’s-head hawkmoths are totally cool,” Wikelski says. They’re also huge. Weighing as much as three jellybeans, the moths are the largest in Europe. That makes attaching the tiny tags a cinch, though the moths don’t like it very much. “They talk to you, they shout at you a little bit,” he says. © Society for Science & the Public 2000–2022.

Keyword: Animal Migration
Link ID: 28451 - Posted: 08.27.2022

By Betsy Mason 08.05.2022 What is special about humans that sets us apart from other animals? Less than some of us would like to believe. As scientists peer more deeply into the lives of other animals, they’re finding that our fellow creatures are far more emotionally, socially, and cognitively complex than we typically give them credit for. A deluge of innovative research is revealing that behavior we would call intelligent if humans did it can be found in virtually every corner of the animal kingdom. Already this year scientists have shown that Goffin’s cockatoos can use multiple tools at once to solve a problem, Australian Magpies will cooperate to remove tracking devices harnessed to them by scientists, and a small brown songbird can sometimes keep time better than the average professional musician — and that’s just among birds. This pileup of fascinating findings may be at least partly responsible for an increase in people’s interest in the lives of other animals — a trend that’s reflected in an apparent uptick in books and television shows on the topic, as well as in legislation concerning other species. Public sentiment in part pushed the National Institutes of Health to stop supporting biomedical research on chimpanzees in 2015. In Canada, an outcry led to a ban in 2019 on keeping cetaceans like dolphins and orcas in captivity. And earlier this year, the United Kingdom passed an animal welfare bill that officially recognizes that many animals are sentient beings capable of suffering, including invertebrates like octopuses and lobsters. Many of these efforts are motivated by human empathy for animals we’ve come to see as intelligent, feeling beings like us, such as chimpanzees and dolphins. But how can we extend that concern to the millions of other species that share the planet with us?

Keyword: Vision; Hearing
Link ID: 28447 - Posted: 08.27.2022

By Chantel Prat I remember all too well that day early in the pandemic when we first received the “stay at home” order. My attitude quickly shifted from feeling like I got a “snow day” to feeling like a bird in a cage. Being a person who is both extraverted by nature and not one who enjoys being told what to do, the transition was pretty rough. But you know what? I got used to it. Though the pandemic undoubtedly affected some of your lives more than others, I know it touched every one of us in ways we will never forget. And now, after two years and counting, I am positive that every person reading this is fundamentally different from when the pandemic started. Because that’s how our brains work. They are molded by our experiences so that we can fit into all kinds of different situations—even the decidedly suboptimal ones. MOTHER TONGUE: Neuroscientist and psychologist Chantel Prat says the languages we speak play a huge role in shaping our minds and brains. Photo by Shaya Bendix Lyon. This is actually one of the most human things about all of our brains. In fact, according to some contemporary views of human evolution, our ancestors underwent a “cognitive revolution” precisely because they were forced to adapt. Based on evidence suggesting that the size of our ancestors’ brains increased following periods of extreme weather instability, one popular explanation for our remarkable flexibility is that the hominids who were not able to adapt to environmental changes didn’t survive. In other words, the brains of modern humans were selected for their ability to learn and adapt to changing environments. But one of the major costs of this remarkable flexibility is that humans are born without any significant preconceived notions about how things work. If you’ve ever had a conversation with someone about an event you both participated in that left you feeling like one of you was delusional because your stories were so different, you might have a hint about how much your experiences have shaped the way you understand the world around you. This can be insanely frustrating because—let’s face it—our own brains are really convincing when they construct our personal version of reality. Remember the Dress? Though it can feel like gaslighting when someone has a different reality from yours, it’s also entirely possible that you both were reporting your version of the truth. At the end of the day, the way people remember a story reflects differences in the way they experienced the original event. The scientific explanation for this boils down to differences in perspective. © 2022 NautilusThink Inc,

Keyword: Attention; Vision
Link ID: 28427 - Posted: 08.11.2022

By Betsy Mason What is special about humans that sets us apart from other animals? Less than some of us would like to believe. As scientists peer more deeply into the lives of other animals, they’re finding that our fellow creatures are far more emotionally, socially, and cognitively complex than we typically give them credit for. A deluge of innovative research is revealing that behavior we would call intelligent if humans did it can be found in virtually every corner of the animal kingdom. Already this year scientists have shown that Goffin’s cockatoos can use multiple tools at once to solve a problem, Australian Magpies will cooperate to remove tracking devices harnessed to them by scientists, and a small brown songbird can sometimes keep time better than the average professional musician — and that’s just among birds. This pileup of fascinating findings may be at least partly responsible for an increase in people’s interest in the lives of other animals — a trend that’s reflected in an apparent uptick in books and television shows on the topic, as well as in legislation concerning other species. Public sentiment in part pushed the National Institutes of Health to stop supporting biomedical research on chimpanzees in 2015. In Canada, an outcry led to a ban in 2019 on keeping cetaceans like dolphins and orcas in captivity. And earlier this year, the United Kingdom passed an animal welfare bill that officially recognizes that many animals are sentient beings capable of suffering, including invertebrates like octopuses and lobsters. Many of these efforts are motivated by human empathy for animals we’ve come to see as intelligent, feeling beings like us, such as chimpanzees and dolphins. But how can we extend that concern to the millions of other species that share the planet with us?

Keyword: Vision; Hearing
Link ID: 28420 - Posted: 08.06.2022

R. Douglas Fields Neuroscientists, being interested in how brains work, naturally focus on neurons, the cells that can convey elements of sense and thought to each other via electrical impulses. But equally worthy of study is a substance that’s between them — a viscous coating on the outside of these neurons. Roughly equivalent to the cartilage in our noses and joints, the stuff clings like a fishing net to some of our neurons, inspiring the name perineuronal nets (PNNs). They’re composed of long chains of sugar molecules attached to a protein scaffolding, and they hold neurons in place, preventing them from sprouting and making new connections. Given this ability, this little-known neural coating provides answers to some of the most puzzling questions about the brain: Why do young brains absorb new information so easily? Why are the fearful memories that accompany post-traumatic stress disorder (PTSD) so difficult to forget? Why is it so hard to stop drinking after becoming dependent on alcohol? And according to new research from the neuroscientist Arkady Khoutorsky and his colleagues at McGill University, we now know that PNNs also explain why pain can develop and persist so long after a nerve injury. Neural plasticity is the ability of neural networks to change in response to experiences in life or to repair themselves after brain injury. Such opportunities for effortless change are known as critical periods when they occur early in life. Consider how easily babies pick up language, but how difficult it is to learn a foreign language as an adult. In a way, this is what we’d want: After the intricate neural networks that allow us to understand our native language are formed, it’s important for them to be locked down, so the networks remain relatively undisturbed for the rest of our lives. All Rights Reserved © 2022

Keyword: Pain & Touch; Glia
Link ID: 28415 - Posted: 07.30.2022

ByVirginia Morell We swat bees to avoid painful stings, but do they feel the pain we inflict? A new study suggests they do, a possible clue that they and other insects have sentience—the ability to be aware of their feelings. “It’s an impressive piece of work” with important implications, says Jonathan Birch, a philosopher and expert on animal sentience at the London School of Economics who was not involved with the paper. If the study holds up, he says, “the world contains far more sentient beings than we ever realized.” Previous research has shown honey bees and bumble bees are intelligent, innovative, creatures. They understand the concept of zero, can do simple math, and distinguish among human faces (and probably bee faces, too). They’re usually optimistic when successfully foraging, but can become depressed if momentarily trapped by a predatory spider. Even when a bee escapes a spider, “her demeanor changes; for days after, she’s scared of every flower,” says Lars Chittka, a cognitive scientist at Queen Mary University of London whose lab carried out that study as well as the new research. “They were experiencing an emotional state.” To find out whether these emotions include pain, Chittka and colleagues looked at one of the criteria commonly used for defining pain in animals: “motivational trade-offs.” People will endure the pain of a dentist’s drill for the longer term benefits of healthy teeth, for example. Similarly, hermit crabs will leave preferred shells to escape an electric shock only when given a particularly high jolt—an experiment that demonstrated crabs can tell the difference between weak and strong painful stimuli, and decide how much pain is worth enduring. That suggests crabs do feel pain and don’t simply respond reflexively to an unpleasant stimulus. Partly as a result of that study, crabs (and other crustaceans, including lobsters and crayfish) are recognized as sentient under U.K. law. © 2022 American Association for the Advancement of Science

Keyword: Pain & Touch; Evolution
Link ID: 28410 - Posted: 07.30.2022

By Meghan Rosen A flexible electronic implant could one day make pain management a lot more chill. Created from materials that dissolve in the body, the device encircles nerves with an evaporative cooler. Implanted in rats, the cooler blocked pain signals from zipping up to the brain, bioengineer John Rogers and colleagues report in the July 1 Science. Though far from ready for human use, a future version could potentially let “patients dial up or down the pain relief they need at any given moment,” says Rogers, of Northwestern University in Evanston, Ill. Scientists already knew that low temperatures can numb nerves in the body. Think of frozen fingers in the winter, Rogers says. But mimicking this phenomenon with an electronic implant isn’t easy. Nerves are fragile, so scientists need something that gently hugs the tissues. And an ideal implant would be absorbed by the body, so doctors wouldn’t have to remove it. Made from water-soluble materials, the team’s device features a soft cuff that wraps around a nerve like toilet paper on a roll. Tiny channels snake down its rubbery length. When liquid coolant that’s pumped through the channels evaporates, the process draws heat from the underlying nerve. A temperature sensor helps scientists hit the sweet spot — cold enough to block pain but not too cold to damage the nerve. The researchers wrapped the implant around a nerve in rats and tested how they responded to having a paw poked. With the nerve cooler switched on, scientists could apply about seven times as much pressure as usual before the animals pulled their paws away. That’s a sign that the rats’ senses had grown sluggish, Rogers says. © Society for Science & the Public 2000–2022.

Keyword: Pain & Touch
Link ID: 28387 - Posted: 07.05.2022

Sofia Quaglia When they are in the deep, dark ocean, seals use their whiskers to track down their prey, a study has confirmed after observing the sea mammals in their natural habitat. It’s hard for light to penetrate the gloom of the ocean’s depths, and animals have come up with a variety of adaptations in order to live and hunt there. Whales and dolphins, for example, use echolocation – the art of sending out clicky noises into the water and listening to their echo as they bounce off possible prey, to locate them. But deep-diving seals who don’t have those same acoustic projectors must have evolutionarily learned to deploy another sensory technique. Scientists have long hypothesised that the secret weapons are their long, cat-like whiskers, conducting over 20 years of experiments with artificial whiskers or captive seals blindfolded in a pool, given the difficulties of directly observing the hunters in the tenebrous depths of the ocean. Now a study may have confirmed the hypothesis, according to Taiki Adachi, assistant project scientist of University of California, Santa Cruz, and one of the lead authors of the study published in Proceedings of the National Academy of Science. Adachi and his team positioned small video cameras with infrared night-vision on the left cheek, lower jaw, back and head of five free-ranging northern elephant seals, the Mirounga angustirostris, in Año Nuevo state park in California. They recorded a total of approximately nine and a half hours of deep sea footage during their seasonal migration. By analysing the videos the scientists noted that diving seals held back their whiskers for the initial part of their dives and, and once they reached a depth suitable for foraging, they rhythmically whisked their whiskers back and forth, hoping to sense any vibration caused by the slightest water movements of swimming prey. © 2022 Guardian News & Media Limited o

Keyword: Pain & Touch
Link ID: 28368 - Posted: 06.14.2022

By Maria Temming The Terminator may be one step closer to reality. Researchers at the University of Tokyo have built a robotic finger that, much like Arnold Schwarzenegger’s titular cyborg assassin, is covered in living human skin. The goal is to someday build robots that look like real people — albeit for more altruistic applications. Super realistic-looking robots could more seamlessly interact with humans in medical care and service industries, say biohybrid engineer Shoji Takeuchi and his colleagues June 9 in Matter. (Whether cyborgs masked in living tissue would be more congenial or creepy is probably in the eye of the beholder.) To cover the finger in skin, Takeuchi and colleagues submerged the robotic digit in a blend of collagen and human skin cells called dermal fibroblasts. The mixture settled into a base layer of skin, or dermis, covering the finger. The team then poured a liquid containing human keratinocyte cells onto the finger, which formed an outer skin layer, or epidermis. After two weeks, skin covering the finger measured a few millimeters thick — comparable to the thickness of human skin. The lab-made skin was strong and stretchy enough to withstand the robotic finger bending. It could also heal itself: When researchers made a small cut on the robotic finger and covered it with a collagen bandage, the skin’s fibroblast cells merged the bandage with the rest of the skin within a week. Researchers at the University of Tokyo covered this robotic finger in living human skin to pave the way for ultrarealistic cyborgs. “This is very interesting work and an important step forward in the field,” says Ritu Raman, an MIT engineer who also builds machines with living components. “Biological materials are appealing because they can dynamically sense and adapt to their environments.” For instance, she’d like to see a future version of the living robot skin embedded with nerve cells to make robots more aware of their surroundings. © Society for Science & the Public 2000–2022.

Keyword: Pain & Touch; Robotics
Link ID: 28365 - Posted: 06.11.2022

By Eiman Azim, Sliman Bensmaia, Lee E. Miller, Chris Versteeg Imagine you are playing the guitar. You’re seated, supporting the instrument’s weight across your lap. One hand strums; the other presses strings against the guitar’s neck to play chords. Your vision tracks sheet music on a page, and your hearing lets you listen to the sound. In addition, two other senses make playing this instrument possible. One of them, touch, tells you about your interactions with the guitar. Another, proprioception, tells you about your arms’ and hands’ positions and movements as you play. Together, these two capacities combine into what scientists call somatosensation, or body perception. Our skin and muscles have millions of sensors that contribute to somatosensation. Yet our brain does not become overwhelmed by the barrage of these inputs—or from any of our other senses, for that matter. You’re not distracted by the pinch of your shoes or the tug of the guitar strap as you play; you focus only on the sensory inputs that matter. The brain expertly enhances some signals and filters out others so that we can ignore distractions and focus on the most important details. How does the brain accomplish these feats of focus? In recent research at Northwestern University, the University of Chicago and the Salk Institute for Biological Studies in La Jolla, Calif., we have illuminated a new answer to this question. Through several studies, we have discovered that a small, largely ignored structure at the very bottom of the brain stem plays a critical role in the brain’s selection of sensory signals. The area is called the cuneate nucleus, or CN. Our research on the CN not only changes the scientific understanding of sensory processing, but it might also lay the groundwork for medical interventions to restore sensation in patients with injury or disease. © 2022 Scientific American

Keyword: Attention
Link ID: 28330 - Posted: 05.18.2022

By Gina Kolata The very treatments often used to soothe pain in the lower back, which the Centers for Disease Control and Prevention says is the most common type of pain, might cause it to last longer, according to a new study. Managing pain with steroids and nonsteroidal anti-inflammatory drugs, like ibuprofen, can actually turn a wrenched back into a chronic condition, the study found. Some medical experts urged caution in interpreting the results too broadly. The study did not use the gold standard for medical research, which would be a clinical trial in which people with back pain would be randomly assigned to take a nonsteroidal anti-inflammatory drug or a placebo and followed to see who developed chronic pain. Instead, it involved observations of patients, an animal study and an analysis of patients in a large database. “It’s intriguing but requires further study,” said Dr. Steven J. Atlas, director of primary care practice-based research and quality improvement at Massachusetts General Hospital. Dr. Bruce M. Vrooman, a pain specialist at Dartmouth Hitchcock Medical Center in New Hampshire, agreed, but also called the study “impressive in its scope” and said that if the results hold up in a clinical trial, it could “force reconsideration of how we treat acute pain.” Dr. Thomas Buchheit, director of the regenerative pain therapies program at Duke, had a different view. “People overuse the term ‘paradigm shift’, but this is absolutely a paradigm shift,” Dr. Buchheit said. “There is this unspoken rule: If it hurts, take an anti-inflammatory, and if it still hurts, put a steroid on it,” he added. “But,” he said, the study shows that “we have to think of healing and not suppression of inflammation.” Guidelines from professional medical societies already say that people with back pain should start with nondrug treatments like exercise, physical therapy, heat or massage. Those measures turn out to be as effective as pain-suppressing drugs, without the same side effects. © 2022 The New York Times Company

Keyword: Pain & Touch
Link ID: 28328 - Posted: 05.18.2022

Perspective by Susan Berger As I faced a prophylactic double mastectomy in hopes of averting cancer, I had many questions for my surgeons — one of which was about pain. I was stunned when both my breast surgeon and plastic surgeon said that a nerve block would leave me pain-free for about three days, after which the worst of the pain would be over. Pectoralis nerve (PECS) blocks were developed to provide analgesia or pain relief for chest surgeries, including breast surgery. That is what happened. I went through the mastectomy Dec. 1 after learning I had the PALB2 gene mutation that carried a sharply elevated risk of breast cancer as well as a higher risk of ovarian and pancreatic cancers. I also had my fallopian tubes and ovaries removed in July. I had learned about the gene mutation in April 2021, when one of my daughters found out she was a carrier. As a 24-year breast cancer survivor and longtime health reporter, I was astonished that I had heard nothing about this mutation. I researched it and wrote “This Breast Cancer Gene Is Less Well Known, but Nearly as Dangerous” in August. After the double mastectomy, I also wrote about it for The Washington Post. Just as my surgeons at NorthShore University HealthSystem predicted, I was released from the hospital the same day as my surgery and remarkably pain-free. I took one Tramadol (a step down from stronger medications containing codeine) when I got home — only because it was suggested I take one pill. As I recovered, I only took Advil and Tylenol. The opioid epidemic is a major public health issue in the United States and nerve blocks could be a solution. According to a study published in the Journal of Clinical Medicine in 2021, 1 in 20 surgical patients will continue to use opioids beyond 90 days. “There is no association with magnitude of surgery, major versus minor, and the strongest predictor of continued use is surgical exposure,” the study states. © 1996-2022 The Washington Post

Keyword: Pain & Touch; Drug Abuse
Link ID: 28316 - Posted: 05.07.2022

By Jim Robbins TUCSON, Ariz. — In a small room in a building at the Arizona-Sonora Desert Museum, the invertebrate keeper, Emma Califf, lifts up a rock in a plastic box. “This is one of our desert hairies,” she said, exposing a three-inch-long scorpion, its tail arced over its back. “The largest scorpion in North America.” This captive hairy, along with a swarm of inch-long bark scorpions in another box, and two dozen rattlesnakes of varying species and sub- species across the hall, are kept here for the coin of the realm: their venom. Efforts to tease apart the vast swarm of proteins in venom — a field called venomics — have burgeoned in recent years, and the growing catalog of compounds has led to a number of drug discoveries. As the components of these natural toxins continue to be assayed by evolving technologies, the number of promising molecules is also growing. “A century ago we thought venom had three or four components, and now we know just one type of venom can have thousands,” said Leslie V. Boyer, a professor emeritus of pathology at the University of Arizona. “Things are accelerating because a small number of very good laboratories have been pumping out information that everyone else can now use to make discoveries.” She added, “There’s a pharmacopoeia out there waiting to be explored.” It is a striking case of modern-day scientific alchemy: The most highly evolved of natural poisons on the planet are creating a number of effective medicines with the potential for many more. One of the most promising venom-derived drugs to date comes from the deadly Fraser Island funnel web spider of Australia, which halts cell death after a heart attack. Blood flow to the heart is reduced after a heart attack, which makes the cell environment more acidic and leads to cell death. The drug, a protein called Hi1A, is scheduled for clinical trials next year. In the lab, it was tested on the cells of beating human hearts. It was found to block their ability to sense acid, “so the death message is blocked, cell death is reduced, and we see improved heart cell survival,” said Nathan Palpant, a researcher at the University of Queensland in Australia who helped make the discovery. © 2022 The New York Times Company

Keyword: Pain & Touch; Neurotoxins
Link ID: 28315 - Posted: 05.04.2022