Links for Keyword: Pain & Touch

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.


Links 1 - 20 of 1016

By Alejandra Manjarrez People wear gloves when making a snowman for a reason: Handling cold stuff can hurt. A new mouse study reveals what may be a key player in this response: a protein already known to enable sensory neurons in worms to detect cold. New evidence published this week in Nature Neuroscience confirms that this protein has the same function in mammals. “The paper is exciting,” says Theanne Griffith, a neuroscientist at the University of California, Davis who was not involved in the research. She notes that the protein, called GluK2, is found in the brain and has “traditionally been thought to play a major role in learning and memory.” The new work shows that elsewhere in the body, it has an unsuspected and “completely divergent role.” We perceive touch, pain, and temperature thanks to a system of nerves that extends throughout our bodies. Researchers have identified skin sensors that detect hot and warm stimuli. Cold sensors, though, have proved more challenging to find. Researchers have proposed various candidates but found limited and contradictory evidence for their function. An ion channel named TRPM8 is the exception. Famous for detecting the “cool” sensation of menthol, it also detects cold temperatures and helped earn its discoverers the Nobel Prize in Physiology or Medicine in 2021. “Nobody questions that TRPM8 is a cold sensor,” says sensory neurobiologist Félix Viana of the Institute for Neuroscience in Alicante, Spain. But it could not be the whole story. It works most efficiently at temperatures above roughly 10°C, and mice lacking the gene for TRPM8 can still detect very cold temperatures. A few years ago, University of Michigan neuroscientists Shawn Xu and Bo Duan and their colleagues found another candidate: a protein on certain sensory neurons in the tiny roundworm Caenorhabditis elegans that causes the animals to avoid temperatures between 17°C and 18°C, which are colder than their preferred temperatures. Preliminary data from that study hinted that the equivalent protein in mammals, GluK2, also allowed mice to sense cold.

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: 29190 - Posted: 03.16.2024

By Regina G. Barber, Anil Oza, Ailsa Chang, Rachel Carlson Neuroscientist Nathan Sawtell has spent a lot of time studying a funky looking electric fish characterized by its long nose. The Gnathonemus petersii, or elephantnose fish, can send and decipher weak electric signals, which Sawtell hopes will help neuroscientists better understand how the brain pieces together information about the outside world. But as Sawtell studied these electric critters, he noticed a pattern he couldn't explain: the fish tend to organize themselves in a particular orientation. "There would be a group of subordinates in a particular configuration at one end of the tank, and then a dominant fish at the other end. The dominant fish would swim in and break up the group, and they would scatter. A few seconds later, the group would coalesce and it would stay there for hours at a time in this stationary configuration," Sawtell, who runs a lab at Columbia University's Zuckerman Institute says. Initially Sawtell and his team couldn't put together why the fish were always hanging out in this configuration. "What could they really be talking to each other about all of this time?" A new study released this week in Nature by Sawtell and colleagues at Columbia University could have one potential answer: the fish are creating an electrical network that is larger than any field an individual fish can muster alone. In this collective field, the whole school of fish get instantaneous information on changes in the water around them, like approaching predators. Rather than being confused by the flurry of electric signals from other fish, "these fish were clever enough to exploit the pulses of group members to sense their environment," Sawtell says. © 2024 npr

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: 29187 - Posted: 03.09.2024

By Simon Makin A new device makes it possible for a person with an amputation to sense temperature with a prosthetic hand. The technology is a step toward prosthetic limbs that restore a full range of senses, improving both their usefulness and acceptance by those who wear them. A team of researchers in Italy and Switzerland attached the device, called ”MiniTouch,” to the prosthetic hand of a 57-year-old man named Fabrizio, who has an above-the-wrist amputation. In tests, the man could identify cold, cool and hot bottles of liquid with perfect accuracy; tell the difference between plastic, glass and copper significantly better than chance; and sort steel blocks by temperature with around 75 percent accuracy, researchers report February 9 in Med. Thank you for being a subscriber to Science News! Interested in more ways to support STEM? Consider making a gift to our nonprofit publisher, Society for Science, an organization dedicated to expanding scientific literacy and ensuring that every young person can strive to become an engineer or scientist. “It’s important to incorporate these technologies in a way that prosthesis users can actually use to perform functional tasks,” says neuroengineer Luke Osborn of Johns Hopkins University Applied Physics Laboratory in Laurel, Md., who was not involved in the study. “Introducing new sensory feedback modalities could help give users more functionality they weren’t able to achieve before.” The device also improved Fabrizio’s ability to tell whether he was touching an artificial or human arm. His accuracy was 80 percent with the device turned on, compared with 60 percent with it off. “It’s not quite as good as with the intact hand, probably because we’re not giving [information about] skin textures,” says neuroengineer Solaiman Shokur of EPFL, the Swiss Federal Institute of Technology in Lausanne. © Society for Science & the Public 2000–2024.

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: 29144 - Posted: 02.10.2024

By Sandra G. Boodman His plane was coming in for a landing at Philadelphia International Airport when Allen M. Weiss, a marketing professor at the University of Southern California, felt a spasm of pain pierce his left cheek near his nose. “It was really weird,” recalled Weiss, then director of Mindful USC, a group of meditation-based programs at the Los Angeles university. “My face froze up.” Within minutes the pain disappeared and the final leg of Weiss’s December 2015 trip home to California was uneventful. But over the next few months the sensation recurred in the same spot. At first the unpredictable pain was fairly mild and merely bothersome; later it became an excruciating daily torment. Several years after the pain first occurred Weiss, who had consulted dentists, oral pain experts and an otolaryngologist, was given a diagnosis that ended up being correct. But his complicated medical history, a radiology report that failed to describe an important finding and a cryptic warning by one of his doctors delayed effective treatment for three more years. “It was completely confusing,” Weiss said. In June 2023 he underwent surgery that has significantly reduced his pain and improved the quality of his life. N. Nicole Moayeri, the Santa Barbara, Calif., neurosurgeon who operated on Weiss, said a protracted search for a diagnosis and treatment is not unusual for those suffering from Weiss’s uncommon malady. “I commonly see people who’ve had multiple dental procedures for years” when the problem was not in their mouths, Moayeri said. “It’s really shocking to me that so many people suffer” with this for so long. After three months of intermittent pain following the flight, Weiss consulted his internist. For reasons that are unclear, the doctor told Weiss the cause was probably psychological, not physical, and that it wasn’t serious. He sent Weiss to an ear, nose and throat specialist whom he saw in March 2016. She performed an exam and ordered a CT scan that revealed a deviated septum, a typically painless condition estimated to affect up to 80 percent of the population in which the bone or cartilage that divides the nostrils is off-center. A moderate or severe deviation can contribute to the development of sinus infections, headaches and breathing problems. But Weiss had none of these. And a deviated septum didn’t explain the spasms of pain.

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: 29054 - Posted: 12.19.2023

Nell Greenfieldboyce If you've got itchy skin, it could be that a microbe making its home on your body has produced a little chemical that's directly acting on your skin's nerve cells and triggering the urge to scratch. That's the implication of some new research that shows how a certain bacteria, Staphylococcus aureus, can release an enzyme that generates an itchy feeling. What's more, a drug that interferes with this effect can stop the itch in laboratory mice, according to a new report in the journal Cell. "That's exciting because it's a drug that's already approved for another condition, but maybe it could be useful for treating itchy skin diseases like eczema," says Isaac Chiu, a scientist at Harvard Medical School who studies interactions between microbes and nerve cells. He notes that eczema or atopic dermatitis is actually pretty common, affecting about 20% of children and 10% of adults. In the past, says Chiu, research on itchy skin conditions has focused on the role of the immune response and inflammation in generating the itch sensation. People with eczema often take medications aimed at immune system molecules. But scientists have also long known that people with eczema frequently have skin that's colonized by Staphylococcus aureus, says Chiu, even though it's never been clear what role the bacteria might play in this condition. Chiu's previous lab work had made him realize that bacteria can directly act on nerve cells to cause pain. "So this made us ask: Could certain microbes like Staphylococcus aureus also particularly be in some way linked to itch?" says Chiu. "Is there a role for microbes in talking to itch neurons?" He and his colleagues first found that putting this bacteria on the skin of mice resulted in vigorous scratching by these animals, leading to damaged skin that spread beyond the original exposure site. © 2023 npr

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: 29022 - Posted: 11.26.2023

By Veronique Greenwood When someone brushes a hand across your skin, it’s like a breeze blowing through a forest of countless small hairs. Nerves that surround your hair follicles detect that contact, and very far away in your brain, other cells fire. Some of the neurons responding to light contact might make you shiver and give you goose bumps. Some might tell you to move away. Or they might tell you to move closer. Scientists who study the sense of touch have explored which cells bear these messages, and they have made an intriguing discovery: Follicle cells triggered by hair movements release the neurotransmitters histamine and serotonin, chemical messengers linked to biological phenomena as varied as inflammation, muscle contraction and mood changes. The observation, reported in October in the journal Science Advances, lays the groundwork for tracing how gentle touch makes us feel the way it does. Studying hair follicles is challenging, because they begin to decay soon after being removed from the body, said Claire Higgins, a bioengineering professor at Imperial College London and an author of the study. So she and her colleagues went to a hair transplant clinic. There, they were able to look at freshly harvested follicles, which they gently prodded with a very small rod to simulate touch. The scientists knew from work done by other groups that the neurons in the skin surrounding hair follicles are capable of sensing movement. “When you brush your hair, you feel it because the sensory neurons are directly being stimulated,” Dr. Higgins said. But they were curious whether the cells of the follicle itself — the tube from which a hair sprouts — could be contributing to some of the feelings associated with more gentle touch. Not all of the follicle cells had movement sensors, but some did. The researchers identified these and watched them carefully as the rod touched them. “We found that when we stimulated our hair follicle cells, they actually released mood-regulating neurotransmitters serotonin and histamine,” Dr. Higgins said. © 2023 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: 28999 - Posted: 11.11.2023

Marlys Fassett Itching can be uncomfortable, but it’s a normal part of your skin’s immune response to external threats. When you’re itching from an encounter with poison ivy or mosquitoes, consider that your urge to scratch may have evolved to get you to swat away disease-carrying pests. However, for many people who suffer from chronic skin diseases like eczema, the sensation of itch can fuel a vicious cycle of scratching that interrupts sleep, reduces productivity and prevents them from enjoying daily life. This cycle is caused by sensory neurons and skin immune cells working together to promote itching and skin inflammation. But, paradoxically, some of the mechanisms behind this feedback loop also stop inflammation from getting worse. In our newly published research, my team of immunologists and neuroscientists and I discovered that a specific type of itch-sensing neuron can push back on the itch-scratch-inflammation cycle in the presence of a small protein. This protein, called interleukin-31, or IL-31, is typically involved in triggering itching. This negative feedback loop – like the vicious cycle – is only possible because the itch-sensing nerve endings in your skin are closely intertwined with the millions of cells that make up your skin’s immune system. The protein IL-31 is key to the connection between the nervous and immune systems. This molecule is produced by some immune cells, and like other members of this molecule family, it specializes in helping immune cells communicate with each other. © 2010–2023, The Conversation US, Inc.

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: 28961 - Posted: 10.14.2023

Regina G. Barber Ever had an itch you can't scratch? Maybe it's out of reach, or your hands are full, or you don't want to damage your skin. It can be deeply frustrating. And even though the itch response, or what scientists refer to simply as "itch," has a purpose — it's one of our bodies' alert systems — it can also go very wrong. The importance of a regular itch Itch is evolution's way of drawing our attention to something on our skin that needs removing. This could be a stinging bug, a nesting parasite or an irritating plant (poison ivy, anyone?!). All these things urge us to scratch, which generally removes the threat and soothes the itch. "We know that itch can activate sensory neurons and the signal will be transmitted to the brain. When we scratch the skin, somehow other neural circuits will be activated. And these neural circuits will suppress the itch circuits and alleviate the itch sensation," says Qin Liu, a neuroscientist at the Washington University School of Medicine in St. Louis. Because the itch sensation has separate neural circuitry from temperature, pressure and pain, applying pressure or ice or scratching can relieve an itch. They're effective neural distractions. Oftentimes, when someone experiences hives or an insect bite, histamine is involved, a chemical released by our immune system that can contribute to itchiness. So relieving that itch only requires antihistamine medication. "But most other forms of itch, like atopic dermatitis, eczema, other conditions, they don't actually have a pathway for histamine as the itch mediator," says Kwatra. © 2023 npr

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: 28929 - Posted: 09.27.2023

By Claudia López Lloreda When someone loses a hand or leg, they don’t just lose the ability to grab objects or walk—they lose the ability to touch and sense their surroundings. Prosthetics can restore some motor control, but they typically can’t restore sensation. Now, a preliminary studyposted to the preprint server bioRxiv this month—shows that by mimicking the activity of nerves, a device implanted in the remaining part of the leg helps amputees “feel” as they walk, allowing them to move faster and with greater confidence. “It's a really elegant study,” says Jacob George, neuroengineer at the University of Utah who was not involved with the research. Because the experiments go from a computational model to an animal model and then, finally humans, he says, “This work is really impactful, because it's one of the first studies that's done in a holistic way.” Patients with prosthetics often have a hard time adapting. One big issue is that they can’t accurately control the device because they can’t feel the pressure that they’re exerting on an object. Hand and arm amputees, for example, are more prone to drop or break things. As a result, some amputees refuse to use such prosthetics. In the past few years, researchers have been working on prosthetic limbs that provide more natural sensory feedback both to help control the device better and give them back a sense of agency over their robotic limb. In a critical study in 2019, George and his team showed that so-called biomimetic feedback, sensory information that aims to resemble the natural signals that occur with touch, allowed a patient who’d lost his hand to more precisely grip fragile objects such as eggs and grapes. But such studies have been limited to single patients. They’ve also left many questions unanswered about how exactly this feedback helps with motor control and improves the use of the prosthetic. So in the new work, researchers used a computer model that re-creates how nerves in the foot respond to different inputs, such as feeling pressure. The goal was to create natural patterns of neural activity that might occur when sensing something with the foot or walking. © 2023 American Association for the Advancement of Science.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 5: The Sensorimotor System
Link ID: 28863 - Posted: 08.02.2023

By Charlotte Stoddart Charlotte Stoddart: Can a sugar pill make you feel better? What about the rituals surrounding a visit to the doctor? Can the care of a doctor or your trust in them reduce the amount of pain you feel? I’m Charlotte Stoddart and this is Knowable. This episode is all about the placebo effect. We’re going to look in detail at one key paper to learn how the placebo effect has been used in medicine and how it’s been understood and misunderstood. The paper is called “The Powerful Placebo.” It was written by Henry Beecher and published in JAMA, the Journal of the American Medical Association, in 1955. I chose this paper because it’s often referred to as a classic, and it’s still one of the most frequently cited papers on the placebo effect. I’ve enlisted the help of Ted Kaptchuk, who knows the paper well. Ted Kaptchuk: I enjoyed rereading it, actually. It’s a remarkable paper. I’ve read it probably 15 times in my life. Charlotte Stoddart: Ted is director of the Program in Placebo Studies at the Beth Israel Deaconess Medical Center in Boston and a professor of medicine at Harvard Medical School, where Henry Beecher also held a professorship. Beecher also worked at Massachusetts General Hospital. Charlotte Stoddart: During the Second World War, Beecher served in the US Army, and there’s a story about how that experience got him interested in the placebo effect. It goes like this: Beecher was working at a military hospital. One day, a badly injured soldier needed surgery, but the hospital had run out of morphine. So Beecher injected the soldier with saline solution instead. The soldier relaxed and Beecher carried out the operation without any real anesthetic. This, so the story goes, is when Beecher realized the power of the mind over the body. There are several different versions of this story, but Ted says it’s likely some version of it is true. © 2023 Annual Reviews

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 28832 - Posted: 06.28.2023

By Laura Sanders Scientists can see chronic pain in the brain with new clarity. Over months, electrodes implanted in the brains of four people picked up specific signs of their persistent pain. This detailed view of chronic pain, described May 22 in Nature Neuroscience, suggests new ways to curtail the devastating condition. The approach “provides a way into the brain to track pain,” says Katherine Martucci, a neuroscientist who studies chronic pain at Duke University School of Medicine. Chronic pain is incredibly common. In the United States from 2019 to 2020, more adults were diagnosed with chronic pain than with diabetes, depression or high blood pressure, researchers reported May 16 in JAMA Network Open. Chronic pain is also incredibly complex, an amalgam influenced by the body, brain, context, emotions and expectations, Martucci says. That complexity makes chronic pain seemingly invisible to an outsider, and very difficult to treat. One treatment approach is to stimulate the brain with electricity. As part of a clinical trial, researchers at the University of California, San Francisco implanted four electrode wires into the brains of four volunteers with chronic pain. These electrodes can both monitor and stimulate nerve cells in two brain areas: the orbitofrontal cortex, or OFC, and the anterior cingulate cortex, or ACC. The OFC isn’t known to be a key pain influencer in the brain, but this region has lots of neural connections to pain-related areas, including the ACC, which is thought to be involved in how people experience pain. But before researchers stimulated the brain, they needed to know how chronic pain was affecting it. For about 3 to 6 months, the implanted electrodes monitored brain signals of these people as they went about their lives. During that time, the participants rated their pain on standard scales two to eight times a day. © Society for Science & the Public 2000–2023.

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 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 28795 - Posted: 05.23.2023

By Priyanka Runwal Researchers have for the first time recorded the brain’s firing patterns while a person is feeling chronic pain, paving the way for implanted devices to one day predict pain signals or even short-circuit them. Using a pacemaker-like device surgically placed inside the brain, scientists recorded from four patients who had felt unremitting nerve pain for more than a year. The devices recorded several times a day for up to six months, offering clues for where chronic pain resides in the brain. The study, published on Monday in the journal Nature Neuroscience, reported that the pain was associated with electrical fluctuations in the orbitofrontal cortex, an area involved in emotion regulation, self-evaluation and decision making. The research suggests that such patterns of brain activity could serve as biomarkers to guide diagnosis and treatment for millions of people with shooting or burning chronic pain linked to a damaged nervous system. “The study really advances a whole generation of research that has shown that the functioning of the brain is really important to processing and perceiving pain,” said Dr. Ajay Wasan, a pain medicine specialist at the University of Pittsburgh School of Medicine, who wasn’t involved in the study. About one in five American adults experience chronic pain, which is persistent or recurrent pain that lasts longer than three months. To measure pain, doctors typically rely on patients to rate their pain, using either a numerical scale or a visual one based on emojis. But self-reported pain measures are subjective and can vary throughout the day. And some patients, like children or people with disabilities, may struggle to accurately communicate or score their pain. “There’s a big movement in the pain field to develop more objective markers of pain that can be used alongside self-reports,” said Kenneth Weber, a neuroscientist at Stanford University, who was not involved in the study. In addition to advancing our understanding of what neural mechanisms underlie the pain, Dr. Weber added, such markers can help validate the pain experienced by some patients that is not fully appreciated — or is even outright ignored — by their doctors. © 2023 The New York Times Company

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 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 28794 - Posted: 05.23.2023

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

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: 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.

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: 28723 - Posted: 03.29.2023

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

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: 28701 - Posted: 03.15.2023

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

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 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
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

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: 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.

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: 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

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: 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.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 5: The Sensorimotor System
Link ID: 28365 - Posted: 06.11.2022