Chapter 5. The Sensorimotor System

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By THOMAS FULLER SANTA ROSA, Calif. — In the heart of Northern California’s wine country, a civil engineer turned marijuana entrepreneur is adding a new dimension to the art of matching fine wines with gourmet food: cannabis and wine pairing dinners. Sam Edwards, co-founder of the Sonoma Cannabis Company, charges diners $100 to $150 for a meal that experiments with everything from marijuana-leaf pesto sauce to sniffs of cannabis flowers paired with sips of a crisp Russian River chardonnay. “It accentuates the intensity of your palate,” Mr. Edwards, 30, said of the dinners, one of which was held recently at a winery with sweeping views of the Sonoma vineyards. “We are seeing what works and what flavors are coming out.” Sonoma County, known to the world for its wines, is these days a seedbed of cannabis experimentation. The approval of recreational cannabis use by California voters in November has spurred local officials here to embrace the pot industry and the tax income it may bring. “We’re making this happen,” said Julie Combs, a member of the Santa Rosa City Council, who is helping lead an effort to issue permits to cannabis companies. “This is an industry that can really help our region.” Of the many ways in which California is on a collision course with the Trump administration, from immigration to the environment, the state’s enthusiastic embrace of legalized and regulated marijuana may be one of the biggest tests of the federal government’s power. Attorney General Jeff Sessions has equated marijuana with heroin and, on Wednesday, mentioned cannabis in the context of the “scourge of drug abuse.” © 2017 The New York Times Compan

Keyword: Drug Abuse; Pain & Touch
Link ID: 23379 - Posted: 03.20.2017

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

Keyword: Pain & Touch; Drug Abuse
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

Keyword: Pain & Touch; Drug Abuse
Link ID: 23377 - Posted: 03.20.2017

Doctors who limit the supply of opioids they prescribe to three days or less may help patients avoid the dangers of dependence and addiction, a new study suggests. Among patients without cancer, a single day's supply of a narcotic painkiller can result in 6 per cent of patients being on an opioid a year later, the researchers said. The odds of long-term opioid use increased most sharply in the first days of therapy, particularly after five days of taking the drugs. The rate of long-term opioid use increased to about 13 per cent for patients who first took the drugs for eight days or more, according to the report. "Awareness among prescribers, pharmacists and persons managing pharmacy benefits that authorization of a second opioid prescription doubles the risk for opioid use one year later might deter overprescribing of opioids," said senior researcher Martin Bradley. He is from the division of pharmaceutical evaluation and policy at the University of Arkansas for Medical Sciences. "The chances of long-term opioid use, use that lasts one year or more, start increasing with each additional day supplied, starting after the third day, and increase substantially after someone is prescribed five or more days, and especially after someone is prescribed one month of opioid therapy," Bradley said. The odds of chronic opioid use also increase when a second prescription is given or refilled, he noted. ©2017 CBC/Radio-Canada.

Keyword: Drug Abuse; Pain & Touch
Link ID: 23373 - Posted: 03.19.2017

By Linda Geddes A gentle touch can make all the difference. Premature babies – who miss out on the sensory experiences of late gestation – show different brain responses to gentle touch from babies that stay inside the uterus until term. This could affect later physical and emotional development, but regular skin-to-skin contact from parents and hospital staff seem to counteract it. Infants who are born early experience dramatic events at a time when babies that aren’t born until 40 weeks are still developing in the amniotic fluid. Premature babies are often separated from their parents for long periods, undergo painful procedures like operations and ventilation, and they experience bigger effects of gravity on the skin and muscles. “There is substantial evidence that pain exposure during early life can cause long-term alterations in infant brain development,” says Rebeccah Slater at the University of Oxford. But it has been less clear how gentle touches shape the brains of babies, mainly because the brain’s response to light touch is about a hundredth of that it has to pain, so it’s harder to study. Nathalie Maitre of the Nationwide Children’s Hospital in Columbus, Ohio, and her colleagues have gently stretched soft nets of 128 electrodes over the heads of 125 preterm and full-term babies, shortly before they were discharged from hospital. These were used to record how their brains responded to a gentle puff of air on the skin. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Pain & Touch
Link ID: 23371 - Posted: 03.17.2017

By Catherine Offord A few years ago, UK composer and technology reporter LJ Rich participated in a music technology competition as part of a project with the BBC. The 24-hour event brought together various musicians, and entailed staying awake into the wee hours trying to solve technical problems related to music. Late into the night, during a break from work, Rich thought of a way to keep people’s spirits up. “At about four in the morning, I remember playing different tastes to people on a piano in the room we were working in,” she says. For instance, “to great amusement, during breakfast I played people the taste of eggs.” It didn’t take long before Rich learned, for the first time, that food’s association with music was not as universally appreciated as she had assumed. “You realize everybody else doesn’t perceive the world that way,” she says. “For me, it was quite a surprise to find that people didn’t realize that certain foods had different keys.” Rich had long known she had absolute pitch—the ability to identify a musical note, such as B flat, without any reference. But that night, she learned she also has what’s known as synesthesia, a little-understood mode of perception that links senses such as taste and hearing in unusual ways, and is thought to be present in around 4 percent of the general population. It’s a difficult phenomenon to get to the bottom of. Like Rich, many synesthetes are unaware their perception is atypical; what’s more, detecting synesthesia usually relies on self-reported experiences—an obstacle for standardized testing. But a growing body of evidence suggests that Rich is far from being alone in possessing both absolute pitch and synesthesia. © 1986-2017 The Scientist

Keyword: Hearing
Link ID: 23353 - Posted: 03.14.2017

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.

Keyword: Pain & Touch; Learning & Memory
Link ID: 23341 - Posted: 03.10.2017

By Colin Barras What a difference 1000 kilometres make. Neanderthals living in prehistoric Belgium enjoyed their meat – but the Neanderthals who lived in what is now northern Spain seem to have survived on an almost exclusively vegetarian diet. This is according to new DNA analysis that also suggests sick Neanderthals could self-medicate with naturally occurring painkillers and antibiotics, and that they shared mouth microbiomes with humans – perhaps exchanged by kissing. Neanderthals didn’t clean their teeth particularly well – which is lucky for scientific investigators. Over time, plaque built up into a hard substance called dental calculus, which still clings to the ancient teeth even after tens of thousands of years. Researchers have already identified tiny food fragments in ancient dental calculus to get an insight into the diets of prehistoric hominins. Now Laura Weyrich at the University of Adelaide, Australia, and her colleagues have shown that dental calculus also carries ancient DNA that can reveal both what Neanderthals ate and which bacteria lived in their mouths. The team focused on three Neanderthals – two 48,000-year-old specimens from a site called El Sidrón in Spain and a 39,000-year-old specimen from a site called Spy in Belgium. The results suggested that the Spy Neanderthal often dined on woolly rhinoceros, sheep and mushrooms – but no plants. The El Sidrón Neanderthals ate more meagre fare: moss, bark and mushrooms – and, apparently, no meat. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Pain & Touch
Link ID: 23331 - Posted: 03.09.2017

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

Keyword: Pain & Touch
Link ID: 23330 - Posted: 03.09.2017

By Timothy Revell A smartphone app that uses deep learning lets people with Parkinson’s disease test their symptoms at home in just 4 minutes. The app could help people monitor the disease’s progression more closely, and uncover how lifestyle factors may affect their symptoms. “There’s very little understanding as to how Parkinson’s arises, and patients say that every day the condition is different,” says George Roussos at Birkbeck, University of London. People report symptom changes related to everything from exercise to socialising to diet, but it’s not yet possible to build a solid picture of how these factors interact. “To understand these differences, we need to monitor the condition regularly, in a quick and easy way, over a long period of time,” says Roussos. People with Parkinson’s usually only see a specialist once or twice a year. This makes it hard to track the disease progression in an individual in detail, and means that side effects of medication such as deterioration of mood can go unnoticed. With their Android app, called CloudUPDRS, Roussos and his colleagues want to make it easier to track symptoms and flag potential problems earlier. Similar to how a clinician would conduct a Parkinson’s severity test, the app includes both self-assessment questions and physical tests using a smartphone’s sensors. © Copyright Reed Business Information Ltd.

Keyword: Parkinsons
Link ID: 23313 - Posted: 03.04.2017

By Alistair Steele, CBC News The opioid crisis that's claiming lives across the country has taken a particularly sinister turn in the nation's capital. Or so it appears. Much of the public discussion — and a good deal of the news coverage — surrounding the growing number of deaths by opioid overdose in Ottawa has concentrated on the cruel toll the drugs are taking on the city's teenagers, particularly those living in the western suburb of Kanata. The fake prescription pills they take recreationally are cheap and easy to find, but they can also be laced with potentially lethal doses of fentanyl. This tragic trend was given a fresh, young face when Grade 9 student Chloe Kotval, just 14, died from an overdose on Valentine's Day. Police later confirmed pills found near the girl's body contained fentanyl. In a statement released the day of their daughter's funeral, Kotval's parents wrote: "We are concerned about the epidemic nature of the use of high-grade pharmaceuticals amongst young people and their lack of knowledge about them — the consequences of using them are real and terrible." While families have every right to be concerned and to prepare for the worst, there's no evidence showing young people are any more susceptible to opioid overdoses than any other group of drug users in Ottawa. Sean O'Leary, whose own teenage daughter became addicted to counterfeit percocets, told CBC about coming home one night to find a 17-year-old boy who had overdosed in his garage. ©2017 CBC/Radio-Canada.

Keyword: Drug Abuse; Pain & Touch
Link ID: 23312 - Posted: 03.04.2017

By Matt Reynolds If you’re happy and you know it, clap someone else’s hands. A muscle stimulation system aims to evoke empathy by triggering involuntary hand gestures in one person in response to mood changes in another. “If you’re moving in the same way as another person you might understand that person better,” says Max Pfeiffer at the University of Hannover in Germany. Pfeiffer and his team wired up four people to an EEG machine that measured changes in the electrical activity in their brain as they watched film clips intended to provoke three emotional responses: amusement, anger and sadness. These people were the “emotion senders”. Each sender was paired with an “emotion recipient” who wore electrodes on their arms that stimulated their muscles and caused their arms and hands to move when the mood of their partner changed. The gestures they made were based on American Sign Language for amusement, anger and sadness. To express amusement, volunteers had their muscles stimulated to raise one arm, to express anger they raised an arm and made a claw gesture, and to express sadness they slowly slid an arm down their chest. These resemble natural movements associated with the feelings, so the team hypothesised that they would evoke the relevant emotion. Asked to rate how well the gestures corresponded to the emotions, the volunteers largely matched the gestures to the correct mood. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 23302 - Posted: 03.02.2017

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

Keyword: Pain & Touch
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.

Keyword: Pain & Touch
Link ID: 23291 - Posted: 02.28.2017

Allison Aubrey If you drink more alcohol than you want to or should, you're not alone. A nationwide survey by the National Institutes of Health found that 28 percent of adults in the U.S. are heavy drinkers or drink more than is recommended. Yet, most heavy drinkers don't get the help they need. "The biggest problem we have in the field is that less than 10 percent of individuals with an alcohol use disorder get any treatment whatsoever," says George Koob, director of the National Institute on Alcohol Abuse and Alcoholism. Part of the challenge, researchers say, is that many drinkers don't realize that a medicine long used to help people addicted to opioids quit their drug habit can help alcoholics and other heavy drinkers cut back, too. "I thought my only option was AA," John tells NPR. We've agreed to use only his middle name; disclosing his trouble with alcohol publicly, he says, would jeopardize his business. He's a 47-year-old professional who says he started out as a social drinker — a few beers with his softball team after a game. But he sank into a deep depression after several deaths in his family, and sought "solace the bottle," he says. "I wanted to numb my thoughts," says John. He'd often start with hard liquor in the morning, John says, and it wasn't uncommon to have eight drinks or more before the end of the day. © 2017 npr

Keyword: Drug Abuse; Pain & Touch
Link ID: 23286 - Posted: 02.27.2017

By Christine Vestal NEW YORK — After a 12-year battle with debilitating abdominal conditions that forced her to stop working, marijuana has helped Lynn Sabulski feel well enough to look for a job. Sabulski is among nearly 14,000 patients in New York state who are certified to use medical marijuana for one of 10 ­conditions, including her ­primary diagnosis, inflammatory bowel disease. Marijuana doesn’t address her underlying disease, but it does relieve her painful symptoms. Nationwide, an estimated 1.4 million patients in 28 states and the District of Columbia use legal medical marijuana for a varying list of conditions. A much smaller number of patients in 16 states use limited extracts of the plant, primarily to treat seizure disorders. In the midst of an opioid crisis, some medical practitioners and researchers say they think that greater use of marijuana for pain relief could result in fewer people using the highly addictive prescription painkillers that led to the epidemic. A 2016 study by researchers at Johns Hopkins Bloomberg School of Public Health found that states with medical marijuana laws had 25 percent fewer opioid overdose deaths than states that do not have medical marijuana laws. And another study published in Health Affairs last year found that prescriptions for opioid painkillers such as OxyContin, Vicodin and Percocet paid for by Medicare dropped substantially in states that adopted medical marijuana laws. © 1996-2017 The Washington Post

Keyword: Drug Abuse; Pain & Touch
Link ID: 23285 - Posted: 02.27.2017

By KATHRYN SHATTUCK After his short film screened at the Sundance Film Festival in 2008, a euphoric Simon Fitzmaurice was walking the snowy streets of Park City, Utah, when his foot began to hurt. Back home in Ireland that summer, by then dealing with a pronounced limp, he received a shattering diagnosis: motor neuron disease, or M.N.D. (more commonly known in the United States as A.L.S., or Lou Gehrig’s Disease), a neurological disorder that causes increasing muscle weakness and eventual paralysis and is, in most cases, fatal. The doctor gave Mr. Fitzmaurice, then 33, three or four years to live. That might have been the end of any normal existence. But Mr. Fitzmaurice, by his own measure a “bit of a stubborn bastard,” was determined to leave his wife, Ruth, and their two young sons — with a third on the way — a legacy other than self-pity. The result is Mr. Fitzmaurice’s first feature film, and perhaps his salvation — “My Name Is Emily.” The movie, which opened in limited release in the United States on Feb. 17, stars Evanna Lynch, the airy Luna Lovegood of “Harry Potter” fame, as a teenage outlier in both her Dublin foster home and high school who goes on the lam with her only friend (George Webster) to free her father (Michael Smiley) from a mental hospital. The film — with gorgeous scenes of Ms. Lynch plunged, nymphlike, into a cerulean sea or riding shotgun through the emerald countryside in a canary-yellow vintage Renault — won for best cinematography when it debuted at the Galway Film Fleadh in 2015. “I am not trying to prove anything,” Mr. Fitzmaurice wrote in an email, before quickly reconsidering. “Actually, I am trying to prove something. I remember thinking, ‘I must do this to show my children to never give up.’” Mr. Fitzmaurice was writing with his hands when he began the script for “My Name Is Emily.” By the time he was finished, he was writing with his eyes. © 2017 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 23275 - Posted: 02.24.2017

Laurel Hamers Clusters of a toxic bacterial protein have a surprising structure, differing from similar clumps associated with Alzheimer’s and Parkinson’s in humans, scientists report in the Feb. 24 Science. These clusters, called amyloids, are defined in part by their structure: straight regions of protein chains called beta strands, folded accordion-style into flat beta sheets, which then stack up to form a fiber. That definition might now need to be broadened. “All the amyloids that have been structurally looked at so far have certain characteristics,” says Matthew Chapman, a biologist at the University of Michigan in Ann Arbor who wasn’t part of the work. “This is the odd amyloid out right now.” In the human brain, misfolded proteins can form amyloids that trigger neurodegenerative diseases. But amyloids aren’t always a sign of something gone wrong — some bacteria make amyloids to help defend their turf. In Staphylococcus aureus, for example, the PSMα3 protein assembles into amyloids that help the bacteria kill other cells. Previous research suggested that PSMα3 clusters were like any other amyloid. But researchers using X-ray crystallography found that instead of straight beta strands, the PSMα3 fiber was made up of curly structures called alpha helices that resemble an old-fashioned phone cord. The helices still formed a familiar fiber shape just like the beta strands did, but the sheets making up that fiber were rippled instead of flat. |© Society for Science & the Public 2000 - 2017.

Keyword: Alzheimers
Link ID: 23274 - Posted: 02.24.2017

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

Keyword: Pain & Touch
Link ID: 23273 - Posted: 02.24.2017

Daqing Li and Ying Li In 1969 Geoffrey Raisman, who has died aged 77, introduced the term “plasticity” to describe the ability of damaged nerve tissue to form new synaptic connections. He discovered that damaged nerves in the central nervous system (CNS) could be repaired and developed the theory that white matter (nerve fibres and supporting cells) is like a pathway – when it is disrupted by injury, such as spinal cord injury, growth of the regenerating fibres is blocked. In 1985 he described how olfactory ensheathing cells (OECs) “open doors” for newly formed nerve fibres in the nose to enter the CNS. Believing that reconstruction of the damaged pathway is essential to repair of the injured CNS and using the unique door-opening capability of OECs, in 1997, together with colleagues, Geoffrey showed that transplantation of OECs into the damaged spinal cord in experimental models repairs the damaged pathway and results in the regeneration of severed nerve fibres and the restoration of lost functions. The study led to a joint clinical trial with Pawel Tabakow and his team at Wroclaw Medical University, Poland. In 2014 the first patient with a complete severance of the thoracic spinal cord received transplantation of his own OECs. The operation enabled the patient, Darek Fidyka, to gain significant neurological recovery of sensation and voluntary movement. He can now get out of his wheelchair and ride a tricycle. The wider application of OECs has also been investigated. In 2012, with his team at University College London, collaborating with the UCL Institute of Ophthalmology and Southwest hospital, at the Third Military Medical University in Chongqing, China, Geoffrey described the protective effect of OECs in an experimental glaucoma model. The discovery has led to a plan to translate this research to clinical application which, it is hoped, will help many sufferers regain sight.

Keyword: Regeneration; Glia
Link ID: 23266 - Posted: 02.22.2017