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

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Ever wonder why things that normally feel gentle, like putting on soft shirts, are painful after a sunburn? In a study of four patients with a rare genetic disorder, NIH researchers found that PIEZO2, a gene previously shown to control our sense of our bodies in space and gentle touch, may also be responsible for tactile allodynia: the skin’s reaction to injury that makes normally gentle touches feel painful. This and a second NIH-funded study, both published in Science Translational Medicine, used mice to show how the gene may play an essential role in the nervous system’s reaction to injury and inflammation, making PIEZO2 a target for developing precise treatments for relieving the pain caused by cuts, burns, and other skin injuries. “For years scientists have been trying to solve the mystery of how gentle touch becomes painful. These results suggest PIEZO2 is the gene for tactile allodynia. We hope that these results will help researchers develop better treatments for managing this form of pain,” said Alexander T. Chesler, Ph.D., a Stadtman Investigator at the National Center for Complementary and Integrative Health (NCCIH) and a senior author of one of the studies. The PIEZO2 gene encodes what scientists call a mechanosensitive protein which produces electrical nerve signals in response to changes in cell shape, such as when skin cells and neurons of the hand are pressed against a table. Since its discovery in mice by a team led by Ardem Patapoutian, Ph.D., Scripps Research, La Jolla, CA, the lead author of the second paper, scientists have proposed that PIEZO2 plays an important role in touch and pain in humans.

Keyword: Pain & Touch; Genes & Behavior
Link ID: 25563 - Posted: 10.11.2018

Jake Harper Months in prison didn't rid Daryl of his addiction to opioids. "Before I left the parking lot of the prison, I was shooting up, getting high," he says. Daryl has used heroin and prescription painkillers for more than a decade. Almost four years ago he became one of more than 200 people who tested positive for HIV in a historic outbreak in Scott County, Ind. After that diagnosis, he says, he went on a bender. But about a year ago, Daryl had an experience that made him realize he might be able to stay away from heroin and opioids. For several days, he says, he couldn't find drugs. He spent that time in withdrawal. "It hurts all over. You puke, you get diarrhea," Daryl says. His friend offered him part of a strip of Suboxone, a brand-name version of the addiction medication buprenorphine that is combined with naloxone. Buprenorphine is a long-acting opioid that is generally used to treat opioid addiction. It reduces cravings for the stronger opioids he had been taking, prevents physical withdrawal from those drugs and comes with a significantly lower risk of fatal overdose. Daryl injected the buprenorphine, and his opioid withdrawal symptoms disappeared. (Daryl is his middle name, which NPR is using to protect his identity because it is illegal to use buprenorphine without a prescription.) "At first it felt like I was high," Daryl says. "But I think that's what normal feels like now. I have not been normal in a long time." © 2018 npr

Keyword: Drug Abuse; Pain & Touch
Link ID: 25550 - Posted: 10.09.2018

Giorgia Guglielmi A study that claims to show that a homeopathic treatment can ease pain in rats has caused uproar after it was published in a peer-reviewed journal. Groups that promote homeopathy in Italy, where there is currently a debate about how to label homeopathic remedies, have held the study up as evidence that the practice works. But several researchers have cast doubt on its claims. The authors acknowledge some errors flagged in an analysis of the paper by a separate researcher, but stand by its overall conclusions. Senior author, pharmacologist Chandragouda Patil of the R. C. Patel Institute of Pharmaceutical Education and Research in Dhule, India, also says that the results are preliminary and cannot yet be applied to people, and that he hopes that the team’s findings will encourage other researchers to conduct clinical studies. Researchers have presented evidence in support of homeopathy before — famously, in a 1988 Nature paper2 by French immunologist Jacques Benveniste that was later discredited. This latest claim has attracted attention, in part, because it passed peer review at the journal Scientific Reports. (Nature’s news team is editorially independent of its publisher Springer Nature, which also publishes Scientific Reports). © 2018 Springer Nature Limited

Keyword: Pain & Touch
Link ID: 25549 - Posted: 10.09.2018

By Michael Mosley Horizon Could taking a placebo, a pill which contains nothing but ground rice, really help cure back pain? The placebo effect is well studied but at the same time something of a mystery. The word placebo comes from the Latin "I shall please" and is associated with images of quack doctors selling dodgy cures. Yet it is also an important part of modern clinical trials, where patients are given either a placebo (sometimes called a dummy pill) or an active drug (without knowing which is which) and researchers then look to see if the drug outperforms the placebo, or vice versa. But what if you decided to do a placebo-controlled trial on back pain, with a twist? The twist being that everyone, unknowingly, was getting placebo? Would people taking the pills get better anyway? That's what we set out to test for BBC2's Horizon programme, Can my brain cure my body? With the help of Dr Jeremy Howick. an expert on the placebo effect from University of Oxford, we set out to see if we could cure real back pain with fake pills. It would be the largest experiment of its kind ever carried out in the UK, with 100 people from Blackpool taking part. Some were asked to act as a "control" group. The rest were told that they were taking part in a study - where they might receive the placebo or a powerful new painkiller. What they weren't told was that they would all get placebos, capsules containing nothing but ground rice. The pills were authentic looking and based on years of research. They were blue-and-white-striped, because that has been shown to have a greatest painkilling effect. They came in bottles, carefully labelled, warning of potential side effects and sternly reminding patients to keep out of the hands of children. All very convincing. © 2018 BBC

Keyword: Pain & Touch
Link ID: 25525 - Posted: 10.04.2018

By Ersilia M. DeFilippis I felt a shake and opened my eyes. The clock read 1:30 a.m. “We need to go to the hospital,” my mother whispered in my ear, clutching her stomach. She knew; it was the same pain she had experienced many times before. We were in California, many miles from home, many miles from my father (a doctor), who always knew what to do. At the time, I was early in my medical school training, although I knew all the intricate details of my mother’s medical history and realized she needed to get medical attention. When we arrived at the local emergency room in an affluent neighborhood, my mother was placed in a wheelchair and taken to the waiting room. She curled up on the cold barren hospital floor, the only position she could find comfortable. Although my mother usually puts on lipstick and high heels to go to the grocery store, this time, her hair was unkempt and her pajamas worn out. Her knees were tucked into her chest and her belly was distended. It should have been clear to onlookers that she was in agonizing pain, but people were hesitant, skeptical even. “Ma’am,” someone yelled. “Ma’am, we can’t have you lying on the floor. Get up.” My mother lay still. “Get up, ma’am,” she was told again, again more forcibly. They helped her back into the wheelchair. “Help me,” she said. “The pain is unbearable.” Reluctantly, they put her in a stretcher and prepared to place an IV in her arm. To convince them the pain was real, we asked them to call my father, who could fill in all of the medical details: her multiple prior hospitalizations, surgeries and diagnoses. © 1996-2018 The Washington Post

Keyword: Pain & Touch
Link ID: 25511 - Posted: 10.01.2018

By Lisa Rein In my first Feldenkrais class, we lay on our backs with eyes closed and drifted our eyeballs left to right and back again. We shifted our heads from side to side as our eyes followed in their sockets. Then we changed it up, moving our eyes in the opposite direction from our heads. This may sound like a simple sequence. It’s deceptively challenging. And it continued for an hour, with sitting variations, eyes alternately open and shut, a brain workout that included tracking our thumbs as our bent arms moved at eye level from left to right and back again. These eye calisthenics were supposed to relieve my years of back pain. Yeah, right, I remember thinking that Sunday morning 18 months ago as I felt an odd exhaustion set in. Slow and subtle was harder than I thought. I fidgeted. My eyes grew tired. How was all of this commotion under my lids supposed to stop my right hip from unnecessary rotation when I walked and unfreeze my left shoulder and neck? I had tried the Feldenkrais Method under some duress. Although there aren’t a lot of good studies, my friend Jon told me it had reduced his lower back pain from excruciating to manageable. Too many chiropractors, osteopaths, yoga classes, trainers, acupuncturists and ibuprofen over 30 years of back pain. They had at best given me only temporary relief — or sometimes more pain. Feldenkrais sounded too nuanced, with its slow and subtle movements that were supposed to retrain how I walked, sat or held myself as I typed a story on my computer. © 1996-2018 The Washington Post

Keyword: Pain & Touch
Link ID: 25502 - Posted: 09.28.2018

By Nicholas Bakalar Consuming caffeine regularly may increase the ability to withstand pain, a small study suggests. Researchers recruited 62 men and women, ages 19 to 77, and had them record their daily caffeine intake from coffee, tea, soda, energy drinks and chocolate. They averaged 170 milligrams of caffeine a day, about the amount in two cups of coffee, although 15 percent of the group consumed more than 400 milligrams a day. The study is in Psychopharmacology. After seven days, they took the volunteers into a laboratory to test their pain tolerance using calibrated devices that gradually increased heat or pressure on a volunteer’s forearm or back. The people pressed a button on a hand-held device first when the sensation became painful, and then again when it became intolerable. The experiment controlled for sex and race, current tobacco use and alcohol consumption, among other variables that could affect pain sensation. Still, they found that the more caffeine consumed, the greater the tolerance for pain. “Diet can actually be a useful intervention for decreasing pain sensitivity,” said the lead author, Burel R. Goodin, an associate professor of psychology at the University of Alabama at Birmingham. “It’s not just caffeine. A study has shown, for example, that a plant-based diet can actually help increase pain tolerance.” © 2018 The New York Times Company

Keyword: Pain & Touch
Link ID: 25501 - Posted: 09.28.2018

Stephanie O'Neill Shirley Avedon, 90,­­ had never been a cannabis user. But carpal tunnel syndrome that sends shooting pains into both of her hands and an aversion to conventional steroid and surgical treatments is prompting her to consider some new options. "It's very painful, sometimes I can't even open my hand," Avedon says. So for the second time in two months, she's climbed on board a bus that provides seniors at the Laguna Woods Village retirement community in Orange County, Calif., with a free shuttle to a nearby marijuana dispensary. The retired manager of an oncology office says she's seeking the same relief she saw cancer patients get from smoking marijuana 25 years ago. "At that time (marijuana) wasn't legal, so they used to get it off their children," she says with a laugh. "It was fantastic what it did for them." Avedon, who doesn't want to get high from anything she uses, picked up a topical cream on her first trip that was sold as a pain reliever. It contained cannabidiol or CBD, but was formulated without THC, or tetrahydrocannabinol, marijuana's psychoactive ingredient. "It helped a little," she says. "Now I'm going back for the second time hoping they have something better." As more states legalize marijuana for medical or recreational use — 30 states plus the District of Columbia to date — the cannabis industry is booming. Among the fastest growing group of users: people over 50, with especially steep increases among those 65 and older. And some dispensaries are tailoring their pitches to seniors like Avedon who are seeking alternatives treatments for their aches, pains and other medical conditions. © 2018 npr

Keyword: Pain & Touch; Drug Abuse
Link ID: 25458 - Posted: 09.17.2018

By Erin Blakemore Janet Jay is a cyborg. No, she’s not RoboCop or Darth Vader. But she shares a similarity with those characters: Her all-too-human body has been upgraded with a machine. A next-generation implant deep in Jay’s back stimulates her spinal cord, overriding her body’s pain signals to give her some relief from the back pain that has plagued her for years. In an article on Popular Science’s website, Jay writes about her experience with pain and the next-generation way she’s finding relief. She is hardly alone in her suffering. According to the National Center for Health Statistics, an estimated 25.3 million Americans, or 11.2 percent of U.S. adults, experience chronic pain. It can interfere with work and home life and leave patients debilitated, disabled and depressed. So it makes sense that Jay jumped at the chance to experience long-term pain relief with the help of a spinal-cord stimulator. Jay lays out the hows and whys of spinal stimulation, and she paints a vivid picture of a life in agony, a journey that has included skeptical doctors, plenty of painkillers and unanswered questions about the future. She also describes her path to spinal stimulation, how the device works with the body to short-circuit pain, and the many roadblocks to relief that patients face. “Even for me, the battle is not over,” Jay writes. “Since this surgery I’ve actually had another disc herniate, complicating everything. My spine isn’t cured, and I still hurt all the time. But the pain is far more controlled, and I can function much better at my current level of discomfort.” © 1996-2018 The Washington Post

Keyword: Pain & Touch
Link ID: 25455 - Posted: 09.17.2018

Aimee Cunningham Certain brain and personality characteristics may help predict whether a sugar pill can provide relief to someone suffering from chronic pain. In a small study, patients with persistent back pain who responded to a placebo treatment benefitted from up to a 33 percent reduction in their pain intensity. These people had distinctive features in their brains and certain personality traits, researchers report online September 12 in Nature Communications. About 20 percent of U.S. adults, or about 50 million people, had chronic pain in 2016, according to new data released September 13 by the U.S. Centers for Disease Control and Prevention. Chronic pain was defined as feeling pain on most days, if not every day, over the previous six months. Being able to identify people who respond to a placebo might mean doctors could give these individuals the option of a pain reliever that’s cheap, free of side effects and — unlike opioids, which are often prescribed to treat persistent pain — not addictive. “We need to seriously think about placebo as a treatment option, especially in chronic pain patients,” says neuroscientist and study coauthor A. Vania Apkarian of Northwestern University Feinberg School of Medicine in Chicago. |© Society for Science & the Public 2000 - 2018

Keyword: Pain & Touch
Link ID: 25452 - Posted: 09.15.2018

By Stephani Sutherland With nearly 50,000 drug overdose deaths from opioids last year and an estimated two million Americans addicted, the opioid crisis continues to rage throughout the U.S. This statistic must be contrasted with another: 25 million Americans live with daily chronic pain, for which few treatment options are available apart from opioid medications. Opioid drugs like morphine and Oxycontin are still held as the gold standard when it comes to relieving pain. But it has become brutally obvious that opioids have dangerous side effects, including physical dependence, addiction and the impaired breathing that too often leads to death from an overdose. Researchers have long been searching for a drug that would relieve pain without such a heavy toll, with few results so far. Now a study in monkeys published in Science Translational Medicine shows a new type of opioid drug met all the criteria on drug developers’ wish list. The findings even suggest that instead of causing addiction, the new compound might be used to curb addiction and pain all at once. The study was led by Mei-Chuan (Holden) Ko, a researcher at Wake Forest University, and medical chemist Nurulain Zaveri, founder of California-based Astraea Therapeutics. “They’ve got something here that’s really important,” says William Schmidt, a pharmaceutical consultantbased in Davis, Calif., who was not involved in the work. “I think the chances of a compound with these properties moving forward are high, and simultaneously pretty exciting.” © 2018 Scientific American

Keyword: Drug Abuse; Pain & Touch
Link ID: 25422 - Posted: 09.07.2018

Shawna Williams Deciphering the communications of electric fish in their native streams is not for the faint of heart. “Once in a while, there is a thunderstorm ten kilometers away, then at some point the water level of those streams rises by one meter in one hour or so,” says Jan Benda, a computational neuroscientist at the University of Tübingen in Germany. “Then we are in big trouble with our equipment.” Even in the absence of extreme weather, given the normal heat and humidity levels at his team’s research sites in Panama and Columbia, “things break and then you sit there in the field and try to solder a wire back to something late at night,” he says, laughing. “You’re dreaming about your nice lab where everything is so easy.” To reach the study site with their equipment, researchers traveled by boat, and then on foot. Benda was driven from his comfortable lab a few years ago by a gaping hole in the body of scientific knowledge: weakly electric fish, which use electricity to communicate but not to stun prey, are popular subjects for neuroscientists who want to know how vertebrate brains process sensory information, but few if any researchers had ever eavesdropped on the animals zap-chatting in nature. Gaining this type of insight into the behavior of a species studied for decades in the lab is “a massively important undertaking,” says Malcolm MacIver, a neuroscientist and engineer researching animal behavior at Northwestern University in Illinois. © 1986 - 2018 The Scientist

Keyword: Animal Communication
Link ID: 25401 - Posted: 08.31.2018

Laurel Hamers A draft of the poppy’s genetic instruction book is providing clues to how the plant evolved to produce molecules such as morphine. Scientists pieced together the genome of the opium poppy (Papaver somniferum). Then, they identified a cluster of 15 close-together genes that help the plant synthesize a group of chemically related compounds that includes powerful painkillers like morphine as well as other molecules with potential medical properties (SN: 6/10/17, p. 22). A group of genes that help poppy plants produce some of these molecules, collectively known as benzylisoquinoline alkaloids, have been clustered together for tens of millions of years, researchers report online August 30 in Science. But the plant’s morphine production evolved more recently. Around 7.8 million years ago, the plant copied its entire genome. Some of the resulting surplus genes evolved new roles helping poppies produce morphine, because the plant already had at least one other copy of those genes carrying out their original jobs. It wasn’t a one-step process, though. An even earlier gene duplication event caused two genes to fuse into one. That hybrid gene is responsible for a key shape-shift in alkaloid precursors, directing those molecules down the chemical pathway toward morphinelike compounds instead of other benzylisoquinoline alkaloids (SN Online: 6/25/15). |© Society for Science & the Public 2000 - 2018.

Keyword: Pain & Touch; Drug Abuse
Link ID: 25399 - Posted: 08.31.2018

Jon Hamilton A new study suggests that ketamine, an increasingly popular treatment for depression, has something in common with drugs like fentanyl and oxycodone. The small study found evidence that ketamine's effectiveness with depression, demonstrated in many small studies over the past decade, comes from its interaction with the brain's opioid system. A Stanford University team reported their findings Wednesday in The American Journal of Psychiatry. "We think ketamine is acting as an opioid," says Alan Schatzberg, one of the study's authors and a professor of psychiatry and behavioral sciences at Stanford. "That's why you're getting these rapid effects." Until now, most researchers have attributed ketamine's success to its effect on the brain's glutamate system, which is involved in learning and memory. The opioid system, in contrast, controls pain, reward, and addictive behaviors. Ketamine is an anesthetic that is frequently given to children in the emergency room. It is also a popular but illicit party drug that can cause an out-of-body experience at high doses. And in the past few years, ketamine has seen increasing use as an off-label treatment that doctors prescribe for patients with severe depression that doesn't respond to other drugs. Unlike conventional antidepressants like Prozac, which can take weeks to work, an infusion or nasal administration of ketamine typically produces results in hours. © 2018 npr

Keyword: Depression; Drug Abuse
Link ID: 25397 - Posted: 08.29.2018

By Susana Martinez-Conde Research has shown that the experience of pain is highly subjective: people feel more or less pain, in identical physical situations, as a function of their mood and attention. This flexibility showcases the potential for cognitive manipulations to decrease the pain associated with a variety of pathologies. As an example, the virtual-reality game “Snow World” (in which game in which players shoot snowballs to defeat snowman Frosty and his penguins) reportedly works better than morphine at counteracting the pain of patients in burn units. Other studies have indicated that virtual reality manipulations of the patient’s own body can also help ameliorate pain: an experiment conducted by neuroscientist Maria Victoria Sanchez-Vives and her team at the University of Barcelona in Spain showed that heat applied to experimental participants’ wrists felt more painful when their virtual arms turned red than when they turned blue or green. Following on this tradition, a study published PeerJ last month showed that visuotactile illusions can help the pain experienced by patients suffering from knee osteoarthritis. According to lead author Tasha Stanton, from the University of South Australia, the idea for the study originated from her observation that “people with knee osteoarthritis have an altered perception of their own body. [Their affected knee] often feels too big, and they also have changes to the way that touch and movement information is represented in the brain.” She hypothesized that patients may “respond to illusions that change the way their knee looks.” © 2018 Scientific American,

Keyword: Pain & Touch; Attention
Link ID: 25390 - Posted: 08.28.2018

Sarah Boseley Health editor A new drug to relieve pain during labour works better than pethidine, which has been in widespread use since the 1950s even though it has long been known it does not help all women, say researchers. Pethidine is given as an injection, but a new study funded by the National Institute for Health Research shows that remifentanil, which women control by pressing a button when they feel pain, appears to be more effective. Women using remifentanil were half as likely to end up asking for an epidural, which blocks all pain and sensation and often leads to a forceps delivery. Pethidine was the first opioid drug that was allowed to be given by a midwife alone and was very widely adopted, said Dr Matthew Wilson, a senior lecturer at the University of Sheffield and the lead author of the study published in the Lancet medical journal. More than a quarter of a million women in labour are given pethidine each year in the UK, even though up to 40% do not find it helpful, he said. “Some women do not report any useful pain relief at all and it has significant side effects,” he said. That includes sedation and potentially affecting the baby. “There has been a longstanding need for something else,” he said. Epidurals are by far the most effective form of pain relief, but women who have them are more likely to end up with their baby having a forceps or vacuum delivery. That can sometimes cause damage to the mother and have long-term consequences, including sexual problems. © 2018 Guardian News and Media Limited

Keyword: Pain & Touch
Link ID: 25331 - Posted: 08.15.2018

Tina Hesman Saey Some snippets of RNA can be a real pain. A microRNA called miR-30c-5p contributes to nerve pain in rats and people, a new study finds. A different microRNA, miR-711, interacts with a well-known itch-inducing protein to cause itching, a second study concludes. Together, the research highlights the important role that the small pieces of genetic material can play in nerve cell function, and may help researchers understand the causes of chronic nerve pain and itch. MicroRNAs help regulate gene activity and protein production. The small molecules play a big role in controlling cancer (SN: 8/28/10, p. 18) and other aspects of health and disease (SN: 2/20/16, p. 18). Usually, microRNAs work by pairing up with bigger pieces of RNA called messenger RNAs, or mRNA. Messenger RNAs contain copies of genetic instructions that are read by cellular machinery to build proteins. When microRNAs glom onto the messengers, the mRNA can be degraded or the microRNAs can prevent the protein-building machinery from reading the instructions. Either way, the result is typically to dial down production of certain proteins. In the case of nerve pain, miR-30c-5p limits production of an important protein called TGF-beta that’s involved in controlling pain, María Hurlé, a pharmacologist at the University of Cantabria in Santander, Spain, and colleagues report August 8 in Science Translational Medicine. The researchers discovered the link in experiments with mice, rats and people. |© Society for Science & the Public 2000 - 2018.

Keyword: Pain & Touch
Link ID: 25329 - Posted: 08.14.2018

Michaeleen Doucleff My back hurts when I sit down. It's been going on for 10 years. It really doesn't matter where I am — at work, at a restaurant, even on our couch at home. My lower back screams, "Stop sitting!" To try to reduce the pain, I bought a kneeling chair at work. Then I got a standing desk. Then I went back to a regular chair because standing became painful. I've seen physical therapists, orthopedic surgeons and pain specialists. I've mastered Pilates, increased flexibility and strengthened muscles. At one point, my abs were so strong my husband nicknamed them "the plate." All these treatments helped a bit, at first. But the pain never really went away. So a few years ago, I decided to accept reality: Sitting down is — and will always be — painful for me. Then back in November, I walked into the studio of Jenn Sherer in Palo Alto, Calif. She is part of a growing movement on the West Coast to teach people to move and sit and stand as they did in the past — and as they still do in other parts of the world. I was interviewing Sherer for a story about bending. But she could tell I was in pain. So I told her my story. Her response left me speechless: "Sitting is a place where you can find heaven in your joints and in your back," she says. "It's not sitting that's causing the pain, it's how you're sitting. "Do you want me to show you how?" © 2018 npr

Keyword: Pain & Touch
Link ID: 25322 - Posted: 08.13.2018

Frances Perraudin Deaths caused by the drug fentanyl rose by nearly 30% last year, according to figures from the Office for National Statistics. While statistics show that the rate of deaths from drug poisoning in England and Wales has remained steady – 66.1 deaths per 1 million people (3,756 deaths) – fatalities involving the synthetic opioid fentanyl were up 29%. There were 75 deaths in 2017, up from 58 deaths in 2016. Fentanyl has been found mixed with street heroin, causing accidental overdose in users. The drug can up to 100 times stronger than heroin and is sometimes prescribed as a painkiller for the terminally ill. One type of fentanyl, carfentanyl, is 10,000 times stronger and is used as an elephant tranquilliser. It was first seen mentioned in death certificates in 2017 and accounted for 27 deaths, 87% of the 31 deaths related to types of fentanyl in 2017. In April 2017, after a spate of deaths linked to fentanyl in northern England, Public Health England issued a warning to heroin users to be extra careful when using the drug, urging them to test a small amount first and not to take it alone. The ONS statistics also show that deaths from cocaine were up for the sixth year in a row. There were 432 deaths related to the drug in 2017, compared with 371 deaths in 2016. In June a report by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) found that purity of street cocaine across Europe was at its highest level in a decade and the number of people seeking treatment for use of the drug was on the rise. © 2018 Guardian News and Media Limited

Keyword: Drug Abuse; Pain & Touch
Link ID: 25295 - Posted: 08.06.2018

By Elizabeth Gamillo Conservationists trying to restore the United States’s grasslands kept running into a problem: As soon as they planted the seeds meant to bring back native flora, hungry mice would gobble them up. In an effort to deter the rodents, biologists tried coating the seeds with capsaicin, the active ingredient that gives chili peppers their signature fiery taste. It worked: Dusting the seeds with chili powder reduced the number of seeds consumed by deer mice by 86%, researchers report in Restoration Ecology. The hot discovery required some trial and error. One big challenge was finding a chili powder that would deter the mice but not prevent the seeds from germinating. Another was finding a coating that wouldn’t weather away after a few months outdoors. After 4 years of laboratory and field experiments in Montana’s Missoula Valley, researchers found a workable recipe. A powder made from the Bhut jolokia, or ghost pepper, from India—considered to be one of the world’s hottest chilis—did the trick. The scientists suggest their findings demonstrate how nontoxic, natural plant defense compounds—such as capsaicin—can be used to aid restoration efforts. © 2018 American Association for the Advancement of Science

Keyword: Pain & Touch
Link ID: 25294 - Posted: 08.06.2018