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By Natalie Grover (Reuters) - A handful of drugmakers are taking their first steps toward developing marijuana-based painkillers, alternatives to opioids that have led to widespread abuse and caused the U.S. health regulator to ask for a withdrawal of a popular drug this month. The cannabis plant has been used for decades to manage pain and there are increasingly sophisticated marijuana products available across 29 U.S. states, as well as in the District of Columbia, where medical marijuana is legal. There are no U.S. Food and Drug Administration (FDA)-approved painkillers derived from marijuana, but companies such as Axim Biotechnologies Inc, Nemus Bioscience Inc and Intec Pharma Ltd have drugs in various stages of development. The companies are targeting the more than 100 million Americans who suffer from chronic pain, and are dependent on opioid painkillers such as Vicodin, or addicted to street opiates including heroin. Opioid overdose, which claimed celebrities including Prince and Heath Ledger as victims, contributed to more than 33,000 deaths in 2015, according to the Centers for Disease Control and Prevention. Earlier this month, the FDA asked Endo International Plc to withdraw its Opana ER painkiller from the market, the first time the agency has called for the removal of an opioid painkiller for public health reasons. The FDA concluded that the drug's benefits no longer outweighed its risks. Multiple studies have shown that pro-medical marijuana states have reported fewer opiate deaths and there are no deaths related to marijuana overdose on record.(http://reut.rs/2r74Sbe) © 2017 Scientific American

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 23774 - Posted: 06.26.2017

By Matthew Hutson The life of a sheep is not as cushy as it looks. They suffer injury and infection, and can’t tell their human handlers when they’re in pain. Recently, veterinarians have developed a protocol for estimating the pain a sheep is in from its facial expressions, but humans apply it inconsistently, and manual ratings are time-consuming. Computer scientists at the University of Cambridge in the United Kingdom have stepped in to automate the task. They started by listing several “facial action units” (AUs) associated with different levels of pain, drawing on the Sheep Pain Facial Expression Scale. They manually labeled these AUs—nostril deformation, rotation of each ear, and narrowing of each eye—in 480 photos of sheep. Then they trained a machine-learning algorithm by feeding it 90% of the photos and their labels, and tested the algorithm on the remaining 10%. The program’s average accuracy at identifying the AUs was 67%, about as accurate as the average human, the researchers will report today at the IEEE International Conference on Automatic Face and Gesture Recognition in Washington, D.C. Ears were the most telling cue. Refining the training procedure further boosted accuracy. Given additional labeled images, the scientists expect their method would also work with other animals. Better diagnosis of pain could lead to quicker treatment. © 2017 American Association for the Advancement of Science. A

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23694 - Posted: 06.02.2017

Laurel Hamers Last year, Joan Peay slipped on her garage steps and smashed her knee on the welcome mat. Peay, 77, is no stranger to pain. The Tennessee retiree has had 17 surgeries in the last 35 years — knee replacements, hip replacements, back surgery. She even survived a 2012 fungal meningitis outbreak that sickened her and hundreds of others, and killed 64. This knee injury, though, “hurt like the dickens.” When she asked her longtime doctor for something stronger than ibuprofen to manage the pain, he treated her like a criminal, Peay says. His response was frustrating: “He’s known me for nine years, and I’ve never asked him for pain medicine other than what’s needed after surgery,” she says. She received nothing stronger than over-the-counter remedies. A year after the fall, she still lives in constant pain. Just five years ago, Peay might have been handed a bottle of opioid painkillers for her knee. After all, opioids — including codeine, morphine and oxycodone — are some of the most powerful tools available to stop pain. Hitting opioid receptors in the peripheral nervous system keeps pain messages from reaching the brain. But opioids can cause problems by overstimulating the brain’s reward system and binding to receptors in the brain stem and gut. But an opioid addiction epidemic spreading across the United States has soured some doctors on the drugs. Many are justifiably concerned that patients will get hooked or share their pain pills with friends and family. And even short-term users risk dangerous side effects: The drugs slow breathing and can cause constipation, nausea and vomiting. |© Society for Science & the Public 2000 - 2017

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 23686 - Posted: 05.31.2017

Patients who are told their medication can have certain side-effects may report these symptoms more often than patients who aren't aware their treatment carries these risks, a study of popular cholesterol pills suggests. Researchers focused on what they dubbed the "nocebo" effect, or the potential for people to complain of treatment-related side-effects when they think they're taking a specific drug but are actually given a placebo, or dummy pill, without any active ingredients. "It has been recognized for many years that when patients are warned about possible adverse reactions to a drug, they are much more likely to complain of these side effects than when they are unaware of the possibility that such side-effects might occur," said senior study author Dr. Peter Sever, a researcher at Imperial College London. To test this "nocebo" effect, researchers first randomly assigned about 10,000 trial participants in the UK, Ireland and Scandinavia to take either a statin pill to lower cholesterol or a placebo, then followed people for around three years to see how often they complained of four known statin side-effects: Patients on statins and on placebo pills reported similar rates of muscle aches and erectile dysfunction, the study found. People taking placebo also reported higher rates of sleep difficulties than patients on statins. ©2017 CBC/Radio-Canada.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23665 - Posted: 05.27.2017

By Roman Liepelt and Jack Brooks An amputee struggles to use his new prosthetic limb. A patient with a frontal-lobe brain lesion insists that her left hand has a mind of its own. The alleged criminal claims in court that he did not fire the gun, even though several eyewitnesses watched him do it. Each of these individuals is grappling with two elements of the mind-body connection: ownership, or an ability to separate ourselves from the physical and social environments, and agency, a conviction that we have control over our limbs. We are quick to investigate a sticker placed on our forehead when looking in a mirror, recognizing the foreign object as abnormal. The human brain typically handles these phenomena by comparing neural signals encoding the intended action with those signals carrying sensory feedback. When we are born, we make erratic reaching and kicking movements to map our body and to calibrate our sensorimotor system. During infancy, these movements solidify our self-awareness, and around the time we first walk, we are quick to investigate a sticker placed on our forehead when looking in a mirror, recognizing the foreign object as abnormal. By the age of four, our brains are proficient at distinguishing self and other. In the amputee, the brain lesion patient, and the defendant on trial, the sense of self is disrupted due to discordance between sensory feedback from the limb and the brain’s expectations of how a movement should feel. © 1986-2017 The Scientist

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23625 - Posted: 05.17.2017

By Moheb Costandi Pain in infants is heartbreaking for new parents, and extremely difficult to treat effectively—if at all. Every year an estimated 15 million babies are born prematurely, most of whom will then undergo numerous lifesaving but painful procedures, such as heel pricking or insertion of a thin tube known as a cannula to deliver fluids or medicine. Preterm babies in the intensive care unit are subjected to an average of 11 such “skin-breaking” procedures per day, but analgesia is only used just over one third of the time. We know that repetitive, painful procedures in early infancy can impact brain development negatively—so why is pain in infants so undertreated? One reason is the lack of standard guidelines for administering the drugs. Some analgesics given to adults are unsuitable for infants, and those that can be used often have different effects in children, making dosing a problem. What is more, newborn babies are incapable of telling us how they feel, making it impossible to determine how effective any painkiller might be. Researchers at the University of Oxford may now have overcome this latter challenge, however. They report May 3 in Science Translational Medicine having identified a pain-related brain wave signal that responds to analgesics, and could be used to measure the drugs’ efficacy. Until as recently as the 1980s, it was assumed that newborn babies do not feel pain, and that giving them analgesics would do more harm than good. Although these misconceptions have been cleared up, we still have very little understanding of infant pain, and so treating it is a huge challenge for clinicians. © 2017 Scientific American

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 23576 - Posted: 05.05.2017

Laura Sanders An electrode on top of a newborn’s scalp, near the soft spot, can measure when the baby feels pain. The method, described online May 3 in Science Translational Medicine, isn’t foolproof, but it brings scientists closer to being able to tell when infants are in distress. Pain assessment in babies is both difficult and extremely important for the same reason: Babies don’t talk. That makes it hard to tell when they are in pain, and it also means that their pain can be more easily overlooked, says Carlo Bellieni, a pediatric pain researcher at the University Hospital Siena in Italy. Doctors rely on a combination of clues such as crying, wiggling and facial grimacing to guess whether a baby is hurting. But these clues can mislead. “Similar behaviors occur when infants are not in pain, for example if they are hungry or want a cuddle,” says study coauthor Rebeccah Slater of the University of Oxford. By relying on brain activity, the new method promises to be a more objective measurement. Slater and colleagues measured brain activity in 18 newborns between 2 and 5 days old. Electroencephalography (EEG) recordings from electrodes on the scalp picked up collective nerve cell activity as babies received a heel lance to draw blood or a low-intensity bop on the foot, a touch that’s a bit like being gently poked with a blunt pencil. One electrode in particular, called the Cz electrode and perched on the top of the head, detected a telltale neural spike between 400 and 700 milliseconds after the painful event. This brain response wasn’t observed when these same babies received a sham heel lance or an innocuous touch on the heel. |© Society for Science & the Public 2000 - 2017

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 23566 - Posted: 05.04.2017

Amber Dance Biologist Leo Smith held an unusual job while an undergraduate student in San Diego. Twice a year, he tagged along on a chartered boat with elderly passengers. The group needed him to identify two particular species of rockfish, the chilipepper rockfish and the California shortspine thornyhead. Once he’d found the red-orange creatures, the passengers would stab themselves in the arms with the fishes’ spines. Doing so, the seniors believed, would relieve their aching arthritic joints. Smith, now at the University of Kansas in Lawrence, didn’t think much of the practice at the time, but now he wonders if those passengers were on to something. Though there’s no evidence that anything in rockfish venom can alleviate pain — most fish stings are, in fact, quite painful themselves — some scientists suspect fish venom is worth a look. Studying the way venom molecules from diverse fishes inflict pain might help researchers understand how nerve cells sense pain and lead to novel ways to dull the sensation. Smith is one of a handful of scientists who are studying fish venoms, and there’s plenty to investigate. An estimated 7 to 9 percent of fishes, close to 3,000 species, are venomous, Smith’s work suggests. Venomous fishes are found in freshwater and saltwater, including some stingrays, catfishes and stonefishes. Some, such as certain fang blennies, are favorites in home aquariums. Yet stinging fishes haven’t gotten the same attention from scientists as snakes and other venomous creatures. |© Society for Science & the Public 2000 - 2017

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23515 - Posted: 04.20.2017

By STEPH YIN It’s a small fish, only a couple of inches long, and its bright colors make it pop in the Pacific coral reefs it calls home. The first thing that makes this fish peculiar is the striking pair of large lower canines it sports. But when attacked by a predator, this fish, part of a group called fang blennies,does something even more strange. A predator that puts this fang blenny in its mouth would experience a “violent quivering of the head,” according to George Losey, a zoologist who observed this species up close in a series of feeding experiments in the 1970s. Then the predator would open its jaws and gills. The little blenny would swim away, unscathed. A study published on Thursday in Current Biology now lays bare the details of the fish’s unusual defense mechanism: Unlike most venomous fish, which inject toxins through their fins, fang blennies deliver venom through their bite. Furthermore, fang blenny venom does not appear to produce potent pain, at least in mice. Instead, it causes a sudden drop in blood pressure, which might temporarily stupefy predators. “This is one of the most in-depth studies of how venom functions in any particular group of fish,” said Matthew Davis, an assistant professor of biology at St. Cloud State University in Minnesota, who did not participate in the research. A CT scan of Meiacanthus grammistes, a venomous fang blenny species. Anthony Romilio The authors of the study took a multipronged approach to studying venomous fang blennies. First, they imaged the jaws of fang blennies collected from around the Pacific and Indian Oceans to confirm what scientists long suspected: Not all fang blennies have venom glands at the base of their teeth. © 2017 The New York Times Company

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 23432 - Posted: 03.31.2017

by Laura Sanders Many babies born early spend extra time in the hospital, receiving the care of dedicated teams of doctors and nurses. For these babies, the hospital is their first home. And early experiences there, from lights to sounds to touches, may influence how babies develop. Touches early in life in the NICU, both pleasant and not, may shape how a baby’s brain responds to gentle touches later, a new study suggests. The results, published online March 16 in Current Biology, draw attention to the importance of touch, both in type and number. Young babies can’t see that well. But the sense of touch develops early, making it a prime way to get messages to fuzzy-eyed, pre-verbal babies. “We focused on touch because it really is some of the basis for communication between parents and child,” says study coauthor Nathalie Maitre, a neonatologist and neuroscientist at Nationwide Children’s Hospital in Columbus, Ohio. Maitre and her colleagues studied how babies’ brains responded to a light puff of air on the palms of their hands — a “very gentle and very weak touch,” she says. They measured these responses by putting adorable, tiny electroencephalogram, or EEG, caps on the babies. The researchers puffed babies’ hands shortly before they were sent home. Sixty-one of the babies were born early, from 24 to 36 weeks gestation. At the time of the puff experiment, they had already spent a median of 28 days in the hospital. Another group of 55 babies, born full-term, was tested in the three days after birth. |© Society for Science & the Public 2000 - 2017

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 23398 - Posted: 03.23.2017

By Jia Naqvi A drug frequently prescribed for pain is no more effective than a placebo at controlling sciatica, a common source of pain in the lower back and leg, according to a study published Wednesday in the New England Journal of Medicine. The researchers at the George Institute for Global Health in Australia followed 209 sciatica patients in Sydney who were randomly assigned to receive either the drug pregabalin, more commonly known as Lyrica, or a placebo. The results showed no significant differences in leg pain intensity between the group on the placebo and that on Lyrica after eight weeks taking the drug or during the rest of the year on follow-up exams. Similarly, there were no differences for other outcomes such as back pain, quality of life and degree of disability. After Lyrica was approved in 2004, it has become the most commonly prescribed medicine for neuropathic pain, which is caused by damage to the nervous system. The drug was ranked as the 19th-highest-earning pharmaceutical in 2015, with worldwide sales rising annually at a rate of 9 percent and sale revenue of more than $3 billion in 2015 in the United States. “We have seen a huge rise in the amount of prescriptions being written each year for patients suffering from sciatica. It’s an incredibly painful and disabling condition, so it’s no wonder people are desperate for relief and medicines such as pregabalin have been widely prescribed,” Christine Lin, one of the authors of the study and an associate professor at the George Institute for Global Health, said in a news release. © 1996-2017 The Washington Post

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23395 - Posted: 03.23.2017

By Daniel Barron It was 4 P.M., and Andrew* had just bought 10 bags of heroin. In his kitchen, he tugged one credit-card-sized bag from the rubber-banded bundle and laid it on the counter with sacramental reverence. Pain shot through his body as he pulled a cutting board from the cabinet. Slowly, deliberately, he tapped the bag's white contents onto the board and crushed it with the flat edge of a butter knife, forming a line of fine white powder. He snorted it in one pass and shuffled back to his armchair. It was bitter, but snorting heroin was safer than injecting, and he was desperate: his prescription pain medication was gone. I met Andrew the next day in the emergency room, where he told me about the previous day's act of desperation. I admitted him to control his swelling legs and joint pain. He was also detoxing from opioids. Andrew looked older than his 69 years. His face was wrinkled with exhaustion. A frayed, tangled mop of grizzled hair fell to his shoulders. Andrew had been a satellite network engineer, first for the military, more recently for a major telecommunications company. An articulate, soft-spoken fellow, he summed up his (rather impressive) career modestly: “Well, I'd just find where a problem was and then find a way to fix it.” Yet there was one problem he couldn't fix. “Doctor, I'm always in the most terrible pain,” he said, with closed eyes. “I had no other options. I started using heroin, bought it from my neighbor to help with the pain. I'm scared stiff.” © 2017 Scientific American

Related chapters from BP7e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 5: The Sensorimotor System
Link ID: 23378 - Posted: 03.20.2017

By Jia Naqvi Sixty percent of the calls to poison control centers for help with prescription opioid exposure involved children younger than 5. (Rich Pedroncelli/Associated Press) The phone rings once approximately every 45 minutes — that is how often poison control centers in the United States receive calls about children being exposed to prescription opioids, according to a study published Monday. Over a span of 16 years, from January 2000 until December 2015, about 188,000 calls were placed to poison control centers regarding pediatric and teenage exposure to opioids, the study published in the journal Pediatrics found. Sixty percent of the children exposed to opioids were younger than 5, while teenagers accounted for 30 percent. Pediatric exposure to opioids increased by 86 percent from 2000 to 2009 but decreased overall for all ages under 20 from 2009 until 2015, the study found. Increasing awareness among people with prescription drugs, physicians putting more thought into prescribing opioids, and prescription drug monitoring programs implemented by many states and efforts by different organizations could have contributed to the decrease in exposure, said Marcel Casavant, study author, medical director of the Central Ohio Poison Center and chief toxicologist at Nationwide Children’s Hospital in Columbus. “We are not quite sure, and so it would be good to try to sort out of all the things that we are trying, which ones are the most effective and how can we spend more time doing that,” Casavant said. © 1996-2017 The Washington Post

Related chapters from BP7e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 5: The Sensorimotor System
Link ID: 23377 - Posted: 03.20.2017

Susan Milius Catch sight of someone scratching and out of nowhere comes an itch, too. Now, it turns out mice suffer the same strange phenomenon. Tests with mice that watched itchy neighbors, or even just videos of scratching mice, provide the first clear evidence of contagious scratching spreading mouse-to-mouse, says neuroscientist Zhou-Feng Chen of Washington University School of Medicine in St. Louis. The quirk opens new possibilities for exploring the neuroscience behind the spread of contagious behaviors. For the ghostly itch, experiments trace scratching to a peptide nicknamed GRP and areas of the mouse brain better known for keeping the beat of circadian rhythms, Chen and colleagues found. They report the results in the March 10 Science. In discovering this, “there were lots of surprises,” Chen says. One was that mice, nocturnal animals that mostly sniff and whisker-brush their way through the dark, would be sensitive to the sight of another mouse scratching. Yet Chen had his own irresistible itch to test the “crazy idea,” he says. Researchers housed mice that didn’t scratch any more than normal within sight of mice that flicked and thumped their paws frequently at itchy skin. Videos recorded instances of normal mice looking at an itch-prone mouse mid-scratch and, shortly after, scratching themselves. In comparison, mice with not-very-itchy neighbors looked at those neighbors at about the same frequency but rarely scratched immediately afterward. |© Society for Science & the Public 2000 - 2017.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 23341 - Posted: 03.10.2017

By Joshua A. Krisch Alcian blue-stained skateUCSF/JULIUS LABSharks, rays, and skates can detect minute fluctuations in electric fields—signals as subtle as a small fish breathing within the vicinity—and rely on specialized electrosensory cells to navigate, and hunt for prey hidden in the sand. But how these elasmobranch fish separate signal from noise has long baffled scientists. In an environment full of tiny electrical impulses, how does the skate home in on prey? See “Sensory Biology Around the Animal Kingdom” In a study published this week (March 6) in Nature, researchers at the University of California, San Francisco (UCSF), have analyzed the electrosensory cells of the little skate (Leucoraja erinacea). They found that voltage-gated calcium channels within these cells appear to work in concert with calcium-activated potassium channels, both specifically tuned in the little skate to pick up on weak electrical signals. “We have elucidated a molecular basis for electrosensation, at least in the little skate, which accounts for this unusual and highly sensitive mechanism for detecting electrical fields,” said coauthor Nicholas Bellono, a postdoc at USCF. “How general it is, we don’t know. But this is really the first instance in which we’ve been able to drill down and ask what molecules could be involved in this kind of system.” © 1986-2017 The Scientist

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23330 - Posted: 03.09.2017

By NICHOLAS BAKALAR Acupuncture can relieve wrist pain, and researchers have tracked the brain and nervous system changes that may help explain why. Scientists randomized 80 people with mild or moderate carpal tunnel syndrome — pain caused by nerve compression at the wrist — to one of three groups. The first received acupuncture at the wrist and ankle. The second got acupuncture at the wrist alone. And the third received sham acupuncture, using “fake” needles near the affected wrist, as a placebo. Using functional M.R.I. and nerve conduction tests before and after the procedures, they measured the effect on brain and nerves. All three groups found relief from pain, but both of the true acupuncture groups showed measurable physiological improvements in pain centers in the brain and nerves, while sham acupuncture did not produce such changes. Improvement in brain measures predicted greater pain relief three months after the tests, a long-term effect that placebo did not provide. The study is in Brain. “What’s really interesting here is that we’re evaluating acupuncture using objective outcomes,” said the senior author, Vitaly Napadow, a researcher at Harvard. Sham acupuncture was good at relieving pain temporarily, he said, but true acupuncture had objective physiological — and enduring — effects. “Acupuncture is a safe, low-risk, low side-effect intervention,” he continued. “It’s perfect for a first-line approach, and it’s something patients should consider before trying more invasive procedures like surgery.” © 2017 The New York Times Company

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23299 - Posted: 03.02.2017

By Robert F. Service Scientists are chasing a new lead on a class of drugs that may one day fight both pain and opioid addiction. It’s still early days, but researchers report that they’ve discovered a new small molecule that binds selectively to a long-targeted enzyme, halting its role in pain and addiction while not interfering with enzymes critical to healthy cell function. The newly discovered compound isn’t likely to become a medicine any time soon. But it could jumpstart the search for other binders that could do the job. Pain and addiction have many biochemical roots, which makes it difficult to treat them without affecting other critical functions in cells. Today, the most potent painkillers are opioids, including heroin, oxycodone, and hydrocodone. In addition to interrupting pain, they inhibit enzymes known as adenylyl cyclases (ACs) that convert cells’ energy currency, ATP, into a molecule involved in intracellular chemical communication known as cyclic AMP (cAMP). Chronic opioid use can make cells increase the activity of ACs to compensate, causing cAMP levels to skyrocket. When opioid users try to stop using, their cAMP levels remain high, and drugs that reduce those levels—like buprenorphine—have unwanted side effects. A promising candidate for selectively reducing cAMP is one particular AC enzyme, known as AC1. Humans have 10 ACs, all of which convert ATP to cAMP. But they are expressed at different levels in different tissues, suggesting they serve disparate purposes. Over the last 15 years, experiments on mice without the gene for AC1 have shown they have reduced sensitivity to pain and fewer signs of opioid dependence. But the enzyme, along with its close relative AC8, also appears to be heavily involved in memory formation in a brain region known as the hippocampus. © 2017 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23291 - Posted: 02.28.2017

By Diana Kwon Neuroscientists have long debated how itch and pain overlap in the nervous system. Although itch was once thought to arise from the same neurons that generate pain, later observations disputing this theory led many to believe these sensations had distinct neural circuits. In a study published today (February 22) in Neuron, researchers report that a subset of “itch-specific” nerve cells in the murine spinal cord are also involved in sensing pain, bringing the specificity theory into question. “We were surprised that contrary to what the field believes, neurons [in the spinal cord] coded for both pain and itch sensations,” coauthor Shuhao Sun, a neuroscience graduate student at Johns Hopkins University, told The Scientist. “[This] means there can be some crosstalk between these two sensations in the central nervous system.” Historically, the observation that pain could quell itch led many neuroscientists to subscribe to the intensity theory, which suggested that, in the same neurons, weak stimulation generated itch, while strong activation led to pain. However, this theory was largely abandoned around the 1980s when several groups discovered that weak painful stimuli did not lead to itch and that strong itch stimuli did not lead to pain. Instead, many researchers adopted the labeled-line theory, which proposed that there were separate neurons dedicated to each sensation. © 1986-2017 The Scientist

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23273 - Posted: 02.24.2017

By Amitha Kalaichandran, When pain researcher Diane Gromala recounts how she started in the field of virtual reality, she seems reflective. She had been researching virtual reality for pain since the early 1990s, but her shift to focusing on how virtual reality could be used for chronic pain management began in 1999, when her own chronic pain became worse. Prior to that, her focus was on VR as entertainment. Gromala, 56, was diagnosed with chronic pain in 1984, but the left-sided pain that extended from her lower stomach to her left leg worsened over the next 15 years. "Taking care of my chronic pain became a full-time job. So at some point I had to make a choice — either stop working or charge full force ahead by making it a motivation for my research. You can guess what I chose," she said. Diane Gromala Pain researcher Diane Gromala found that taking care of her own chronic pain became 'a full-time job.' (Pain studies lab at Simon Fraser University) Now she's finding that immersive VR technology may offer another option for chronic pain, which affects at least one in five Canadians, according to a 2011 University of Alberta study. "We know that there is some evidence supporting immersive VR for acute pain, so it's reasonable to look into how it could help patients that suffer from chronic pain." Gromala has a PhD in human computer interaction and holds the Canada Research Chair in Computational Technologies for Transforming Pain. She also directs the pain studies lab and the Chronic Pain Research Institute at Simon Fraser University in Burnaby, B.C. ©2017 CBC/Radio-Canada.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 7: Vision: From Eye to Brain
Link ID: 23232 - Posted: 02.15.2017

By GINA KOLATA Dr. James Weinstein, a back pain specialist and chief executive of Dartmouth-Hitchcock Health System, has some advice for most people with lower back pain: Take two aspirin and don’t call me in the morning. On Monday, the American College of Physicians published updated guidelines that say much the same. In making the new recommendations for the treatment of most people with lower back pain, the group is bucking what many doctors do and changing its previous guidelines, which called for medication as first-line therapy. Dr. Nitin Damle, president of the group’s board of regents and a practicing internist, said pills, even over-the-counter pain relievers and anti-inflammatories, should not be the first choice. “We need to look at therapies that are nonpharmacological first,” he said. “That is a change.” The recommendations come as the United States is struggling with an epidemic of opioid addiction that often begins with a simple prescription for ailments like back pain. In recent years, a number of states have enacted measures aimed at curbing prescription painkillers. The problem has also led many doctors around the country to reassess prescribing practices. The group did not address surgery. Its focus was on noninvasive treatment.The new guidelines said that doctors should avoid prescribing opioid painkillers for relief of back pain and suggested that before patients try anti-inflammatories or muscle relaxants, they should try alternative therapies like exercise, acupuncture, massage therapy or yoga. Doctors should reassure their patients that they will get better no matter what treatment they try, the group said. The guidelines also said that steroid injections were not helpful, and neither was acetaminophen, like Tylenol, although other over-the-counter pain relievers like aspirin, naproxen or ibuprofen could provide some relief. © 2017 The New York Times Company

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 23231 - Posted: 02.15.2017