Chapter 5. The Sensorimotor System

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Andrew Orlowski Special Report If the fMRI brain-scanning fad is well and truly over, then many fashionable intellectual ideas look like collateral damage, too. What might generously be called the “British intelligentsia” – our chattering classes – fell particularly hard for the promise that “new discoveries in brain science” had revealed a new understanding of human behaviour, which shed new light on emotions, personality and decision making. But all they were looking at was statistical quirks. There was no science to speak of, the results of the experiments were effectively meaningless, and couldn’t support the (often contradictory) conclusions being touted. The fMRI machine was a very expensive way of legitimising an anecdote. This is an academic scandal that’s been waiting to explode for years, for plenty of warning signs were there. In 2005, Ed Vul, now a psychology professor at UCSD, and Hal Pashler – then and now at UCSD – were puzzled by a claim being made in a talk by a neuroscience researcher. He was explaining study that purported to report a high correlation between a test subject’s brain activity and the speed with which they left the room after the study. “It seemed unbelievable to us that activity in this specific brain area could account for so much of the variance in walking speed,” explained Vul. “Especially so, because the fMRI activity was measured some two hours before the walking happened. So either activity in this area directly controlled motor action with a delay of two hours — something we found hard to believe — or there was something fishy going on.” IT © 1998–2016

Keyword: Brain imaging
Link ID: 22410 - Posted: 07.08.2016

DAVID GREENE, HOST: Nearly one-quarter of all Americans reach for a bottle of acetaminophen every single week. Many of you might know this drug as Tylenol. It's a pain killer that can take the edge off a headache or treat you when you have a fever. It also might have another effect. And let's talk about this with NPR social science correspondent Shankar Vedantam. And, Shankar, straight out, is this going to make me not want to take Tylenol, what you're about to tell me? VEDANTAM: It might make you not want to take Tylenol when you're talking with me, David. GREENE: Oh, even more interesting. VEDANTAM: (Laughter) I was speaking with Dominik Mischkowski. He's currently a researcher at the National Institutes of Health. He recently conducted a couple of double blind experiments. These are experiments where the volunteers are given either sugar pills or Tylenol, but neither the volunteers nor the researchers know which volunteers are getting which pill. Mischkowski and his advisers at Ohio State University, Jennifer Crocker and Baldwin Way, they played loud noises for the volunteers. Not surprisingly, volunteers given Tylenol experienced less physical discomfort than volunteers given the placebo. © 2016 npr

Keyword: Pain & Touch
Link ID: 22403 - Posted: 07.07.2016

By Damian Garde, A boy in Pakistan became a local legend as a street performer in recent years by traversing hot coals and lancing his arms with knives without so much as a wince. A thousand miles away, in China, lived a family wracked by excruciating bouts of inexplicable pain, passed down generation after generation. Scientists eventually determined what the boy and the family had in common: mutations in a gene that functions like an on-off switch for agony. Now, a bevy of biotech companies, including Genentech and Biogen, are staking big money on the idea that they can develop drugs that toggle that switch to relieve pain without the risk of addiction. The gene in question is SCN9A, which is responsible for producing a pain-related protein called Nav1.7. In patients who feel nothing, SCN9A is pretty much broken. In those who feel searing random pain, the gene is cranking out far too much Nav1.7. That discovery raises an obvious question: Can blocking Nav1.7 provide relief for many types of pain—and someday, perhaps, replace dangerous opioid therapies? “That’s the dream,” said David Hackos, a senior scientist at Genentech, which has two Nav1.7 treatments in the first stage of clinical development. It’s too early make any sweeping predictions—and, indeed, a Pfizer pill targeting Nav1.7 has already stumbled—but the pharma industry clearly sees the potential for a blockbuster. © 2016 Scientific American

Keyword: Pain & Touch
Link ID: 22400 - Posted: 07.06.2016

By Jessica Hamzelou Imagine if each of the words in this article had their own taste, or the music you’re listening to played out as visual scene in your mind. For synaesthetes – a small proportion of people whose senses intertwine – this is the stuff of the every day. “Most people describe it as a gift,” says Jamie Ward, a neuroscientist at the University of Sussex in the UK. Now, he and his colleagues have found a new form of synaesthesia – one that moves beyond written language to sign language. It is the first time the phenomenon has been observed. “People with synaesthesia experience the ordinary world in extraordinary ways,” says Ward. In theory, any two senses can overlap. Some synaesthetes connect textures with words, while others can taste them. More commonly, written letters seem to have corresponding colours. An individual synaesthete may always associate the letter A with the colour pink, for instance. This type of synaesthesia has been found across many written languages, prompting Ward’s team to wonder if it can also apply to sign language. They recruited 50 volunteers with the type of synaesthesia that means they experience colours with letters, around half of whom were fluent in sign language too. All the participants watched a video of sign language and were asked if it triggered any colours. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 22390 - Posted: 07.02.2016

By Rachel Rabkin Peachman It began with a simple roller-skating accident three years ago. Taylor Aschenbrenner, then 8 years old, lost her balance amid a jumble of classmates, tumbled to the floor and felt someone else’s skate roll over her left foot. The searing pain hit her immediately. The diagnosis, however, would take much longer. An X-ray, M.R.I.s, a CT scan and blood tests over several months revealed no evidence of a break, sprain or other significant problem. Taylor’s primary symptom was pain — so severe that she could not put weight on the foot. “Our family doctor first told us to give it some time,” said Taylor’s mother, Jodi Aschenbrenner, of Hudson, Wis. But time didn’t heal the pain. After about a month, an orthopedist recommended physical therapy. That didn’t end the problem, either. “I couldn’t walk or play outside or do anything,” Taylor said. After she had spent a year and a half on crutches, her orthopedist suggested she see Dr. Stefan Friedrichsdorf, the medical director ofpain medicine, palliative care and integrative medicine at Children’s Hospitals and Clinics of Minnesota. He and his team promptly recognized Taylor’s condition as complex regional pain syndrome, a misfiring within the peripheral and central nervous systems that causes pain signals to go into overdrive and stay turned on even after an initial injury or trauma has healed. He came up with a treatment plan for Taylor that included cognitive behavioral therapy, physical therapy, mind-body techniques, stress-reduction strategies, topical pain-relief patches and a focus on returning to her normal life and sleep routine, among other things. © 2016 The New York Times Company

Keyword: Pain & Touch; Development of the Brain
Link ID: 22368 - Posted: 06.28.2016

Emily Conover Sharks have a sixth sense that helps them locate prey in murky ocean waters. They rely on special pores on their heads and snouts, called ampullae of Lorenzini, that can sense electric fields generated when nearby prey move. The pores were first described in 1678, but scientists haven’t been sure how they work. Now, the answer is a bit closer. The pores, which connect to electrosensing cells, are filled with a mysterious clear jelly. This jelly is a highly efficient proton conductor, researchers report May 13 in Science Advances. In the jelly, positively charged particles move and transmit current. Marco Rolandi of the University of California, Santa Cruz and colleagues squeezed jelly from the pores of one kind of shark and two kinds of skate and tested how well protons could flow through the substance. Good proton conductors, including a protein found in squid skin, occur in nature. But the jelly is the best biological proton conductor discovered so far. In fact, even humankind’s best technology isn’t wildly better. The most efficient proton conductor devised by people — a polymer known as Nafion — is a mere 40 times better than the stuff sharks are born with. Citations E.E. Josberger et al. Proton conductivity in ampullae of Lorenzini jelly. Science Advances. Published online May 13, 2016. doi:10.1126/sciadv.1600112. Further Reading |© Society for Science & the Public 2000 - 2016.

Keyword: Pain & Touch
Link ID: 22366 - Posted: 06.28.2016

By Eric Hand That many animals sense and respond to Earth’s magnetic field is no longer in doubt, and people, too, may have a magnetic sense. But how this sixth sense might work remains a mystery. Some researchers say it relies on an iron mineral, magnetite; others invoke a protein in the retina called cryptochrome. Magnetite has turned up in bird beaks and fish noses and even in the human brain, as Joe Kirschvink of the California Institute for Technology in Pasadena reported in 1992, and it is extremely sensitive to magnetic fields. As a result, Kirschvink and other fans say, it can tell an animal not only which way it is heading (compass sense) but also where it is. “A compass cannot explain how a sea turtle can migrate all the way around the ocean and return to the same specific stretch of beach where it started out,” says neurobiologist Kenneth Lohmann of the University of North Carolina, Chapel Hill. A compass sense is enough for an animal to figure out latitude, based on changes in the inclination of magnetic field lines (flat at the equator, plunging into the earth at the poles). But longitude requires detecting subtle variations in field strength from place to place—an extra map or signpost sense that magnetite could supply, Lohmann says. Except in bacteria, however, no one has seen magnetite crystals serving as a magnetic sensor. The crystals could be something else—say, waste products of iron metabolism, or a way for the body to sequester carcinogenic heavy metals. In the early 2000s, scientists found magnetite-bearing cells in the beaks of pigeons. But a follow-up study found that the supposed magnetoreceptors were in fact scavenger immune cells that had nothing to do with the neural system. And because there is no unique stain or marker for magnetite, false sightings are easy to make. © 2016 American Association for the Advancement of Science

Keyword: Pain & Touch
Link ID: 22357 - Posted: 06.24.2016

By Eric Hand Birds do it. Bees do it. But the human subject, standing here in a hoodie—can he do it? Joe Kirschvink is determined to find out. For decades, he has shown how critters across the animal kingdom navigate using magnetoreception, or a sense of Earth’s magnetic field. Now, the geophysicist at the California Institute of Technology (Caltech) in Pasadena is testing humans to see if they too have this subconscious sixth sense. Kirschvink is pretty sure they do. But he has to prove it. He takes out his iPhone and waves it over Keisuke Matsuda, a neuroengineering graduate student from the University of Tokyo. On this day in October, he is Kirschvink’s guinea pig. A magnetometer app on the phone would detect magnetic dust on Matsuda—or any hidden magnets that might foil the experiment. “I want to make sure we don’t have a cheater,” Kirschvink jokes. They are two floors underground at Caltech, in a clean room with magnetically shielded walls. In a corner, a liquid helium pump throbs and hisses, cooling a superconducting instrument that Kirschvink has used to measure tiny magnetic fields in everything from bird beaks to martian meteorites. On a lab bench lie knives—made of ceramic and soaked in acid to eliminate magnetic contamination—with which he has sliced up human brains in search of magnetic particles. Matsuda looks a little nervous, but he will not be going under the knife. With a syringe, a technician injects electrolyte gel onto Matsuda’s scalp through a skullcap studded with electrodes. He is about to be exposed to custom magnetic fields generated by an array of electrical coils, while an electroencephalogram (EEG) machine records his brain waves. © 2016 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 22356 - Posted: 06.24.2016

Jon Hamilton Researchers have identified a substance in muscles that helps explain the connection between a fit body and a sharp mind. When muscles work, they release a protein that appears to generate new cells and connections in a part of the brain that is critical to memory, a team reports Thursday in the journal Cell Metabolism. The finding "provides another piece to the puzzle," says Henriette van Praag, an author of the study and an investigator in brain science at the National Institute on Aging. Previous research, she says, had revealed factors in the brain itself that responded to exercise. The discovery came after van Praag and a team of researchers decided to "cast a wide net" in searching for factors that could explain the well-known link between fitness and memory. They began by looking for substances produced by muscle cells in response to exercise. That search turned up cathepsin B, a protein best known for its association with cell death and some diseases. Experiments showed that blood levels of cathepsin B rose in mice that spent a lot of time on their exercise wheels. What's more, as levels of the protein rose, the mice did better on a memory test in which they had to swim to a platform hidden just beneath the surface of a small pool. The team also found evidence that, in mice, cathepsin B was causing the growth of new cells and connections in the hippocampus, an area of the brain that is central to memory. But the researchers needed to know whether the substance worked the same way in other species. So they tested monkeys, and found that exercise did, indeed, raise circulating levels of cathepsin in the blood. © 2016 npr

Keyword: Muscles; Learning & Memory
Link ID: 22353 - Posted: 06.24.2016

By BARRY MEIER and ABBY GOODNOUGH A few months ago, Douglas Scott, a property manager in Jacksonville, Fla., was taking large doses of narcotic drugs, or opioids, to deal with the pain of back and spine injuries from two recent car accidents. The pills helped ease his pain, but they also caused him to withdraw from his wife, his two children and social life. “Finally, my wife said, ‘You do something about this or we’re going to have to make some changes around here,’” said Mr. Scott, 43. Today, Mr. Scott is no longer taking narcotics and feels better. Shortly after his wife’s ultimatum, he entered a local clinic where patients are weaned off opioids and spend up to five weeks going through six hours of training each day in alternative pain management techniques such as physical therapy, relaxation exercises and behavior modification. Mr. Scott’s story highlights one patient’s success. Yet it also underscores the difficulties that the Obama administration and public health officials face in reducing the widespread use of painkillers like OxyContin and Percocet. The use and abuse of the drugs has led to a national epidemic of overdose deaths, addiction and poor patient outcomes. In recent months, federal agencies and state health officials have urged doctors to first treat pain without using opioids, and some have announced plans to restrict how many pain pills a doctor can prescribe. But getting the millions of people with chronic pain to turn to alternative treatments is a daunting task, one that must overcome inconsistent insurance coverage as well as some resistance from patients and their doctors, who know the ease and effectiveness of pain medications. “We are all culpable,” said Dr. David Deitz, a former insurance industry executive and a consultant on pain treatment issues. “I don’t care whether you are a doctor, an insurer or a patient.” © 2016 The New York Times Compan

Keyword: Pain & Touch
Link ID: 22352 - Posted: 06.23.2016

Megan Scudellari Shinya Yamanaka looked up in surprise at the postdoc who had spoken. “We have colonies,” Kazutoshi Takahashi said again. Yamanaka jumped from his desk and followed Takahashi to their tissue-culture room, at Kyoto University in Japan. Under a microscope, they saw tiny clusters of cells — the culmination of five years of work and an achievement that Yamanaka hadn't even been sure was possible. Two weeks earlier, Takahashi had taken skin cells from adult mice and infected them with a virus designed to introduce 24 carefully chosen genes. Now, the cells had been transformed. They looked and behaved like embryonic stem (ES) cells — 'pluripotent' cells, with the ability to develop into skin, nerve, muscle or practically any other cell type. Yamanaka gazed at the cellular alchemy before him. “At that moment, I thought, 'This must be some kind of mistake',” he recalls. He asked Takahashi to perform the experiment again — and again. Each time, it worked. Over the next two months, Takahashi narrowed down the genes to just four that were needed to wind back the developmental clock. In June 2006, Yamanaka presented the results to a stunned room of scientists at the annual meeting of the International Society for Stem Cell Research in Toronto, Canada. He called the cells 'ES-like cells', but would later refer to them as induced pluripotent stem cells, or iPS cells. “Many people just didn't believe it,” says Rudolf Jaenisch, a biologist at the Massachusetts Institute of Technology in Cambridge, who was in the room. But Jaenisch knew and trusted Yamanaka's work, and thought it was “ingenious”. © 2016 Macmillan Publishers Limited,

Keyword: Stem Cells; Development of the Brain
Link ID: 22324 - Posted: 06.15.2016

By Teal Burrell Sociability may be skin deep. The social impairments and high anxiety seen in people with autism or related disorders may be partly due to a disruption in the nerves of the skin that sense touch, a new study in mice suggests. Autism spectrum disorders are primarily thought of as disorders of the brain, generally characterized by repetitive behaviors and deficits in communication skills and social interaction. But a majority of people with autism spectrum disorders also have an altered tactile sense; they are often hypersensitive to light touch and can be overwhelmed by certain textures. “They tend to be very wary of social touch [like a hug or handshake], or if they go outside and feel a gust of wind, it can be very unnerving,” says neuroscientist Lauren Orefice from Harvard Medical School in Boston. An appreciation for this sensory aspect of autism has grown in recent years. The newest version of psychiatry’s bible, the Diagnostic and Statistical Manual of Mental Disorders, includes the sensory abnormalities of autism as core features of the disease. “That was a big nod and a recognition that this is a really important aspect of autism,” says Kevin Pelphrey, a cognitive neuroscientist at The George Washington University in Washington, D.C., who was not involved in the work. The sensation of touch starts in the peripheral nervous system—in receptors at the surface of the skin—and travels along nerves that connect into the central nervous system. Whereas many autism researchers focus on the end of the pathway—the brain—Orefice and colleagues wondered about the first leg of the trip. So the group introduced mutations that silenced genes associated with autism spectrum disorders in mice, adding them in a way that restricted the effects to peripheral nerve cells, they report today in Cell. The team singled out the gene Mecp2, which encodes a protein that regulates the expression of genes that help forge connections between nerve cells. © 2016 American Association for the Advancement of Science

Keyword: Autism; Pain & Touch
Link ID: 22310 - Posted: 06.11.2016

By ALAN COWELL LONDON — When Muhammad Ali died last week, the memories spooled back inevitably to the glory days of the man who called himself the Greatest, a champion whose life intertwined with America’s traumas of race, faith and war. It was a chronicle of valor asserted in the most public of arenas scrutinized by an audience that spanned the globe. But there was another narrative, just as striking to some admirers, of a private courage beyond his klieg-lit renown. For the minority afflicted by Parkinson’s disease, Ali’s 30-year struggle with the same illness magnified the broader status he built from his boxing prowess as a black man who embraced radical Islam, refused to fight in Vietnam, earned the opprobrium of the establishment and yet emerged as an icon. “It was his longest bout, and one that ultimately he could not win,” the reporter Patrick Sawer wrote in The Telegraph, referring to Ali’s illness. Yet the affliction “only served to increase the worldwide admiration he had gained before the disease robbed him of his powers.” As a global superstar, Ali touched many lands, and Britain felt a particular bond. Boxing fans recalled his far-flung bouts — the “Rumble in the Jungle” against George Foreman in Zaire, as the Democratic Republic of Congo was then called, in 1974; “The Thrilla in Manila” in the Philippines against Joe Frazier a year later. But in Britain, his two defeats in the 1960s of Henry Cooper, a much-loved British heavyweight who died in 2011, and his feisty appearances in prime-time television interviews left an indelible mark. © 2016 The New York Times Company

Keyword: Parkinsons
Link ID: 22308 - Posted: 06.11.2016

By Esther Landhuis About 100 times rarer than Parkinson’s, and often mistaken for it, progressive supranuclear palsy afflicts fewer than 20,000 people in the U.S.—and two thirds do not even know they have it. Yet this little-known brain disorder that killed comic actor Dudley Moore in 2002 is quietly becoming a gateway for research that could lead to powerful therapies for a range of intractable neurodegenerative conditions including Alzheimer’s and chronic traumatic encephalopathy, a disorder linked to concussions and head trauma. All these diseases share a common feature: abnormal buildup of a protein called tau in the brains of patients. Progressive supranuclear palsy has no cure and is hard to diagnose. Although doctors may have heard of the disease, many know little about it. It was not described in medical literature until 1964 but some experts believe one of the earliest accounts of the debilitating illness appeared in an 1857 short story by Charles Dickens and his friend Wilke Collins: “A cadaverous man of measured speech. A man who seemed as unable to wink, as if his eyelids had been nailed to his forehead. A man whose eyes—two spots of fire—had no more motion than if they had been connected with the back of his skull by screws driven through them, and riveted and bolted outside among his gray hair. He had come in and shut the door, and he now sat down. He did not bend himself to sit as other people do, but seemed to sink bolt upright, as if in water, until the chair stopped him.” © 2016 Scientific American

Keyword: Parkinsons; Alzheimers
Link ID: 22304 - Posted: 06.09.2016

By ANNA FELS ONE of the most painful experiences of being a psychiatrist is having a patient for whom none of the available therapies or medications work. A while back, I was asked to do a consultation on just such a patient. This person had been a heroin addict in her early 20s. She had quit the opioid five years earlier, but her life was plagued with anxiety, apathy and self-doubt that prior treatments had not helped. At the end of the session, almost as an afterthought, she noted with irony that the only time in her adult life when she had been able to socialize easily and function at work was when she had been hooked on heroin. We are in the midst of a devastating and often lethal opioid epidemic, one of whose victims, we learned last week, was the pop star Prince. At such a time, it is hard to remember that there are multiple opioids naturally produced in our brains and required for our well-being. The neural circuitry utilizing these substances controls some of our most fundamental feelings of pain, stress and hopelessness, as well as pleasure and even euphoria. There is obviously a need for extreme caution, but research suggests that certain opioids may actually be useful in treating psychiatric diseases that have proved frustratingly unresponsive to current medications. It is the potentially addictive subset of opioids, whose natural ancestors were originally derived from poppies, that we associate with the word. These substances have been with us for most, if not all, of human civilization. Poppy seeds have been found at archaeological sites of Neolithic man. The Sumerians wrote about “the joy plant”; an Egyptian papyrus from the second millennium B.C. described the use of a product of poppies to stop the crying of children. Hippocrates suggested its use for female ailments, and a ninth-century Persian physician advocated the use of opium for melancholia. Millenniums later, during the American Civil War, the Union Army used 10 million opium pills to treat wounded soldiers. And then there were the two Opium Wars fought between China and Britain. Unquestionably, no other psychoactive substance has played such a central role in human affairs. © 2016 The New York Times Company

Keyword: Depression; Drug Abuse
Link ID: 22287 - Posted: 06.06.2016

By DENISE GRADY Muhammad Ali, who died on Friday after a long struggle with Parkinson’s disease, was given the diagnosis in 1984 when he was 42. The world witnessed his gradual decline over the decades as tremors and stiffness set in, replacing his athletic stride with a shuffle, silencing his exuberant voice and freezing his face into an expressionless mask. What is Parkinson’s disease? It is a progressive, incurable deterioration of the part of the brain that produces a chemical needed to carry signals to the regions that control movement. How common is Parkinson’s? About one million people in the United States, and between seven million and 10 million worldwide, are thought to have Parkinson’s, according to the Parkinson’s Disease Foundation. What causes it? Was boxing a factor for Ali? The exact cause is not known. As with many disorders, experts suspect a combination of genes and environment, meaning that people with a particular genetic makeup may be predisposed to the disease if they are exposed to certain environmental factors. Head injuries, such as those sustained repeatedly in boxing, are among the possible risk factors listed by the National Parkinson Foundation. So is exposure to certain pesticides. These factors have both been suggested as possible contributors in Muhammad Ali’s case. Can Parkinson’s disease be treated? Medication can ease the symptoms for a time, but the disease continues to progress. In some cases, implanted devices called deep-brain stimulators can also help with symptoms. But Parkinson’s is not curable. © 2016 The New York Times Company

Keyword: Parkinsons
Link ID: 22284 - Posted: 06.06.2016

By JOHN ELIGON and SERGE F. KOVALESKI Prince, the music icon who struggled with debilitating hip pain during his career, died from an accidental overdose of self-administered fentanyl, a type of synthetic opiate, officials in Minnesota said Thursday. The news ended weeks of speculation about the sudden death of the musician, who had a reputation for clean living but who appears to have developed a dependency on medications to treat his pain. Authorities have yet to discuss how he came to be in possession of the fentanyl and whether it had been prescribed by a doctor. Officials had waited several weeks for the results of a toxicology test undertaken as part of an autopsy performed after he was found dead April 21 in an elevator at his estate. He was preparing to enroll in an opioid treatment program when he died at 57, according to the lawyer for a doctor who was planning to treat him. The Midwest Medical Examiner’s Office, which conducted the autopsy, declined to comment beyond releasing a copy of its findings. The Carver County Sheriff’s Office is continuing to investigate the death with help from the federal Drug Enforcement Administration. The sheriff’s office had said it was looking into whether opioid abuse was a factor, and a law enforcement official had said that painkillers were found on Prince when investigators arrived. “The M.E. report is one piece of the whole thing,” said Jason Kamerud, the county’s chief deputy sheriff. Fentanyl is a potent but dangerous painkiller, estimated to be more than 50 times more powerful than heroin, according to the Centers for Disease Control and Prevention. The report did not list how much fentanyl was found in Prince’s blood. Last year, federal officials issued an alert that said incidents and overdoses with fentanyl were “occurring at an alarming rate throughout the United States.” © 2016 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 22283 - Posted: 06.04.2016

By Gretchen Reynolds A weekly routine of yoga and meditation may strengthen thinking skills and help to stave off aging-related mental decline, according to a new study of older adults with early signs of memory problems. Most of us past the age of 40 are aware that our minds and, in particular, memories begin to sputter as the years pass. Familiar names and words no longer spring readily to mind, and car keys acquire the power to teleport into jacket pockets where we could not possibly have left them. Some weakening in mental function appears to be inevitable as we age. But emerging science suggests that we might be able to slow and mitigate the decline by how we live and, in particular, whether and how we move our bodies. Past studies have found that people who run, weight train, dance, practice tai chi, or regularly garden have a lower risk of developing dementia than people who are not physically active at all. There also is growing evidence that combining physical activity with meditation might intensify the benefits of both pursuits. In an interesting study that I wrote about recently, for example, people with depression who meditated before they went for a run showed greater improvements in their mood than people who did either of those activities alone. But many people do not have the physical capacity or taste for running or other similarly vigorous activities. So for the new study, which was published in April in the Journal of Alzheimer’s Disease, researchers at the University of California, Los Angeles, and other institutions decided to test whether yoga, a relatively mild, meditative activity, could alter people’s brains and fortify their ability to think. © 2016 The New York Times Company

Keyword: Learning & Memory
Link ID: 22270 - Posted: 06.01.2016

By Kelly Servick There’s an unfortunate irony for people who rely on morphine, oxycodone, and other opioid painkillers: The drug that’s supposed to offer you relief can actually make you more sensitive to pain over time. That effect, known as hyperalgesia, could render these medications gradually less effective for chronic pain, leading people to rely on higher and higher doses. A new study in rats—the first to look at the interaction between opioids and nerve injury for months after the pain-killing treatment was stopped—paints an especially grim picture. An opioid sets off a chain of immune signals in the spinal cord that amplifies pain rather than dulling it, even after the drug leaves the body, the researchers found. Yet drugs already under development might be able to reverse the effect. It’s no secret that powerful painkillers have a dark side. Overdose deaths from prescription opioids have roughly quadrupled over 2 decades, in near lockstep with increased prescribing. And many researchers see hyperalgesia as a part of that equation—a force that compels people to take more and more medication, while prolonging exposure to sometimes addictive drugs known to dangerously slow breathing at high doses. Separate from their pain-blocking interaction with receptors in the brain, opioids seem to reshape the nervous system to amplify pain signals, even after the original illness or injury subsides. Animals given opioids become more sensitive to pain, and people already taking opioids before a surgery tend to report more pain afterward. © 2016 American Association for the Advancement of Scienc

Keyword: Pain & Touch; Drug Abuse
Link ID: 22268 - Posted: 05.31.2016

By Viviane Callier Bees don’t just recognize flowers by their color and scent; they can also pick up on their minute electric fields. Such fields—which form from the imbalance of charge between the ground and the atmosphere—are unique to each species, based on the plant’s distance from the ground and shape. Flowers use them as an additional way to advertise themselves to pollinators, but until now researchers had no idea how bees sensed these fields. In a new study, published online today in the Proceedings of the National Academy of Sciences, researchers used a laser vibrometer—a tiny machine that hits the bee hair with a laser—to measure how the hair on a bee’s body responds to a flower’s tiny electric field. As the hair moves because of the electric field, it changes the frequency of the laser light that hits it, allowing the vibrometer to keep track of the velocity of motion of the hair. When the bees buzzed within 10 centimeters of the flower, the electric field—like static electricity from a balloon—caused the bee’s hair to bend. This bending activates neurons at the base of bee hair sockets, which allows the insects to “sense” the field, the team found. Electric fields can only be sensed from a distance of 10 cm or so, so they’re not very useful for large animals like ourselves. But for small insects, this distance represents several body lengths, a relatively long distance. Because sensing such fields is useful to small animals, the team suspects this ability could be important to other insect species as well. © 2016 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 22263 - Posted: 05.31.2016