Links for Keyword: Pain & Touch

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by Helen Shen A thermometer is great for measuring a fever, but when it comes to pain, doctors must rely on the age-old question, "How bad is it?" Scientists have long struggled to find physiological signs that can reliably tell "ouch" from "@#%!" and everything in between. Now, a brain scanning study suggests that painful heat excites a specific pattern of neural activity that could hold the key to better diagnosis and treatment of all kinds of pain in the future. Functional magnetic resonance imaging (fMRI) studies have shown that certain areas of the brain—including the anterior cingulate cortex, somatosensory cortex, and thalamus—activate when people experience pain. But those same regions also light up in response to other experiences, such as painful thoughts or social rejection. In recent years, scientists have looked for a particular pattern of activity across these areas that single out the experience of physical pain. "What we're evolving towards is trying to predict quantitatively from patterns of brain activity how much an individual is feeling," says Tor Wager, a neuroscientist at the University of Colorado, Boulder. In the new study, Wager's group performed fMRI brain scans on a total of 114 healthy participants while delivering different amounts of heat to the volunteers' arms with a computer-controlled hot plate. In an initial experiment, the scientists used data from 20 people to find a brain-wide pattern of excitation and inhibition—a neural "signature"—that changed reliably as people experienced varying degrees of heat, ranging from painless to scalding. In the remainder of the study, Wager and his colleagues were able use the signature derived from the first group to predict pain responses in a completely different set of subjects—a promising sign for one day using such a model on patients suffering from unknown conditions, he says. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 18024 - Posted: 04.11.2013

by Sid Perkins The electric fields that build up on honey bees as they fly, flutter their wings, or rub body parts together may allow the insects to talk to each other, a new study suggests. Tests show that the electric fields, which can be quite strong, deflect the bees' antennae, which, in turn, provide signals to the brain through specialized organs at their bases. Scientists have long known that flying insects gain an electrical charge when they buzz around. That charge, typically positive, accumulates as the wings zip through the air—much as electrical charge accumulates on a person shuffling across a carpet. And because an insect's exoskeleton has a waxy surface that acts as an electrical insulator, that charge isn't easily dissipated, even when the insect lands on objects, says Randolf Menzel, a neurobiologist at the Free University of Berlin in Germany. Although researchers have suspected for decades that such electrical fields aid pollination by helping the tiny grains stick to insects visiting a flower, only more recently have they investigated how insects sense and respond to such fields. Just last month, for example, a team reported that bumblebees may use electrical fields to identify flowers recently visited by other insects from those that may still hold lucrative stores of nectar and pollen. A flower that a bee had recently landed on might have an altered electrical field, the researchers speculated. Now, in a series of lab tests, Menzel and colleagues have studied how honey bees respond to electrical fields. In experiments conducted in small chambers with conductive walls that isolated the bees from external electrical fields, the researchers showed that a small, electrically charged wand brought close to a honey bee can cause its antennae to bend. Other tests, using antennae removed from honey bees, indicated that electrically induced deflections triggered reactions in a group of sensory cells, called the Johnston's organ, located near the base of the antennae. In yet other experiments, honey bees learned that a sugary reward was available when they detected a particular pattern of electrical field. © 2010 American Association for the Advancement of Science

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: Language and Our Divided Brain
Link ID: 17963 - Posted: 03.28.2013

By Sandra G. Boodman, A year after her daughter’s stomach problems began, Margaret Kaplow began having pains of her own. When she sat down to dinner with her family, Kaplow’s gut would clench involuntarily as she waited to see if this was one of the nights Madeline would eat a few bites before putting down her fork, pushing away from the table and announcing, “I don’t feel good.” For nearly six years, Maddie Kaplow’s severe, recurrent abdominal pain, which began shortly before her 13th birthday, was attributed to a host of ailments. Specialists in the District, Maryland and Virginia decided at various times that she had a gluten intolerance, a ruptured ovarian cyst, a diseased appendix or irritable bowel syndrome (IBS). Some were convinced that her problem was psychological and that she was a high-strung teenaged girl seeking attention. “It was a freaking nightmare,” Kaplow recalled of those years. She said she never believed her daughter was exaggerating or faking her symptoms. And each time a new diagnosis was made, Kaplow said, she felt elated that a doctor had figured out the cause of Maddie’s pain, which would turn into crushing disappointment when it recurred. It was only after she landed in a college infirmary 400 miles from her Northern Virginia home that doctors finally determined what was wrong and treated Maddie for the illness that dominated her adolescence. © 1996-2013 The Washington Post

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 17948 - Posted: 03.26.2013

By LAURIE EDWARDS TO the list of differences between men and women, we can add one more: the drug-dose gender gap. Doctors and researchers increasingly understand that there can be striking variations in the way men and women respond to drugs, many of which are tested almost exclusively on males. Early this year, for instance, the Food and Drug Administration announced that it was cutting in half the prescribed dose of Ambien for women, who remained drowsy for longer than men after taking the drug. Women have hormonal cycles, smaller organs, higher body fat composition — all of which are thought to play a role in how drugs affect our bodies. We also have basic differences in gene expression, which can make differences in the way we metabolize drugs. For example, men metabolize caffeine more quickly, while women metabolize certain antibiotics and anxiety medications more quickly. In some cases, drugs work less effectively depending on sex; women are less responsive to anesthesia and ibuprofen for instance. In other cases, women are at more risk for adverse — even lethal — side effects. These differences are particularly important for the millions of women living with chronic pain. An estimated 25 percent of Americans experience chronic pain, and a disproportionate number of them are women. A review published in the Journal of Pain in 2009 found that women faced a substantially greater risk of developing pain conditions. They are twice as likely to have multiple sclerosis, two to three times more likely to develop rheumatoid arthritis and four times more likely to have chronic fatigue syndrome than men. As a whole, autoimmune diseases, which often include debilitating pain, strike women three times more frequently than men. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 8: Hormones and Sex
Link ID: 17910 - Posted: 03.18.2013

By Stephani Sutherland Treating the brain with magnets went mainstream a few years ago, when the technique proved successful at relieving major depression. Now the procedure, repetitive transcranial magnetic stimulation (rTMS), shows promise for another mysterious, hard-to-treat disorder: chronic pain. Until now, pain seemed out of reach for rTMS because the regions involved in pain perception lie very deep within the brain. The other disorders helped by rTMS all involve brain areas close to the skull. To treat depression, for example, a single magnetic coil directs a magnetic field at the dorsolateral prefrontal cortex, a region of the brain's outer folds. When aimed at different areas of these outer folds, rTMS improves the motor symptoms of Parkinson's disease, staves off the damage of stroke, lessens the discomfort that follows nerve injury and treats obsessive-compulsive disorder. The magnetic field affects the electrical signaling used by neurons to communicate, but how exactly it improves symptoms is unclear—scientists suspect rTMS may redirect the activity of select cells or even entire brain circuits. To extend the technique's reach, David Yeomans, a neuroscientist at Stanford University, and his colleagues used four magnets rather than one and employed high-level math to steer the resulting complex fields. Their target was an area called the anterior cingulate cortex (ACC), an area active in the experience of all types of pain, regardless of its source or nature. © 2013 Scientific American

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: 17909 - Posted: 03.18.2013

By Sandra G. Boodman, Ian Liu’s back was killing him — and no matter what he tried, it wasn’t getting better. The 39-year-old Coast Guard officer assumed he had wrenched his back caring for his infant son, not surprising given his long history of lower back problems. But this time, the pain was much more intense and persistent, and neither physical therapy nor painkillers seemed to help. For more than a month, Liu shuttled between two Washington area military hospitals, searching for an explanation and, especially, relief. “It was the worst pain I’d ever had,” Liu recalled. A series of tests failed to explain his deteriorating condition, which stumped the medical personnel who treated him. It was only after Liu’s wife confided that he sometimes seemed disoriented that a doctor looked beyond the obvious problem and discovered the source of Liu’s pain. The cause turned out to be unrelated to his orthopedic history — and far more serious than a bad back. Liu first noticed the pain on a Friday night, Dec. 3, 2004, after he finished bathing the youngest of his three sons. “I assumed it was just from bending over the tub,” recalled Liu, who figured it would improve with time, as such problems had in the past. But the next day, his pain was worse, and as he wheeled his shopping cart around a Northern Virginia commissary, Liu was glad he had something to lean on. © 1996-2013 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: 17823 - Posted: 02.19.2013

By Alan Boyle, Science Editor, NBC News BOSTON — Neuroscientists are following through on the promise of artificially enhanced bodies by creating the ability to "feel" flashes of light in invisible wavelengths, or building an entire virtual body that can be controlled via brain waves. "Things that we used to think were hoaxes or science fiction are fast becoming reality," said Todd Coleman, a bioengineering professor at the University of California at San Diego. Coleman and other researchers surveyed the rapidly developing field of neuroprosthetics in Boston this weekend at the annual meeting of the American Association for the Advancement of Science. One advance came to light just in the past week, when researchers reported that they successfully wired up rats to sense infrared light and move toward the signals to get a reward. "This was the first attempt … not to restore a function but to augment the range of sensory experience," said Duke University neurobiologist Miguel Nicolelis, the research team's leader. The project, detailed in the journal Nature Communications, involved training rats to recognize a visible light source and poke at the source with its nose to get a sip of water. Then electrodes were implanted in a region of the rats' brains that is associated with whisker-touching. The electrodes were connected to an infrared sensor on the rats' heads, which stimulated the target neurons when the rat was facing the source of an infrared beam. Then the visible lights in the test cage were replaced by infrared lights. © 2013 NBCNews.com

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 17816 - Posted: 02.18.2013

By Laura Sanders Some nerve fibers seem to love a good rubdown. These tendrils, which spread across skin like upside-down tree roots, detect smooth, steady stroking and send a feel-good message to the brain, researchers report in the Jan. 31 Nature. Although the researchers found these neurons in mice, similar cells in people may trigger massage bliss. The results are the latest to emphasize the strong and often underappreciated connection between emotions and the sensation of touch, says study coauthor David Anderson, a Howard Hughes Medical Institute investigator at Caltech. “It may seem frivolous to be studying massage neurons in mice, but it raises a profound issue — why do certain stimuli feel a certain way?” he says. It’s no surprise that many people find a caress pleasant. Earlier studies in people suggested that a particular breed of nerve fibers detects a caress and carries that signal to the brain. But scientists hadn’t been able to directly link this type of neuron to good feelings, either in people or in animals. “The beauty of this paper is that it goes one step further and adds behavioral elements,” says cognitive neuroscientist Francis McGlone of Liverpool John Moores University in England. Directly linking these neurons with pleasure clarifies the importance of touch, McGlone says. “Skin is a social organ,” he says. A growing number of studies show that the sensation of touch, particularly early in life, profoundly sculpts the brain. Young animals deprived of touch grow up with severe behavioral abnormalities. Babies fare better when they are held and touched frequently. And touch sensation can be altered in certain disorders. People with autism, for instance, often dislike caresses. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17741 - Posted: 02.02.2013

By Sandra G. Boodman Still clutching his discharge instructions from a suburban Maryland emergency room, Brian Harms struggled to make sense of what the neurosurgeon was saying. The ER staff had told Harms, admitted hours earlier, that his diagnoses were headache and vertigo and that he should go home and rest. A CT scan had found a benign cyst in his brain, but the staff didn’t convey any urgency about treating it. As the 29-year-old College Park resident was gathering his things, a neurosurgeon rushed in, telling Harms he would not be going home. “I need to get this information to you quickly,” Harms remembers the specialist telling him on the morning of Sept. 28, 2011. “You are in a lot of trouble, and you need surgery as soon as possible.” The neurosurgeon had been trying to arrange a transfer to Johns Hopkins Hospital in Baltimore, but doctors were worried that he might die en route. “I highly suggest you trust me and let me do this procedure here,” Harms remembers the surgeon telling him, but the decision was his. For Harms, who had seen several doctors for headaches and other symptoms during the previous 18 months, the news was beyond shocking. “It felt like the floor dropped out beneath me,” he recalled. “I was scared witless.” Only later would Harms, a University of Maryland doctoral candidate in geochemistry, learn how lucky he was to have survived both a series of misdiagnoses and a test, performed hours before his emergency surgery, that could have killed him. © 1996-2013 The Washington Post

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17727 - Posted: 01.29.2013

By KENNETH CHANG Mosquito bite? Poison ivy? Dry skin? Fuzzy sweater? Everyone has an itch to scratch. Why we and other animals itch remains something of a mystery. But now researchers at Johns Hopkins and Yale in the United States and several universities in China have found a key piece of the puzzle, identifying sensory neurons in mice that are dedicated to relaying itchy sensations from the top layers of skin to the spinal cord. “Our study, for the first time, shows the existence of itch-specific nerves,” said Xinzhong Dong, a professor of neuroscience at the Johns Hopkins University School of Medicine and the senior author of a paper about the findings in the journal Nature Neuroscience. Scientists have debated for decades whether separate circuitry existed for itchiness or whether its signals passed through the same nerves used to transmit pain. Earlier data — suppressing pain with morphine can cause chronic itching, for example — indicated some overlap between the two sensations. But the fact that evolution also produced dedicated itch nerves in mice — and almost certainly in people as well — suggests that itching serves an important role in survival and is not just a byproduct of the pain nerves. © 2013 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: 17660 - Posted: 01.08.2013

Cannabis makes pain more bearable rather than actually reducing it, a study from the University of Oxford suggests. Using brain imaging, researchers found that the psychoactive ingredient in cannabis reduced activity in a part of the brain linked to emotional aspects of pain. But the effect on the pain experienced varied greatly, they said. The researchers' findings are published in the journal Pain. The Oxford researchers recruited 12 healthy men to take part in their small study. Participants were given either a 15mg tablet of THC (delta-9-tetrahydrocannabinol) - the ingredient that is responsible for the high - or a placebo. The volunteers then had a cream rubbed into the skin of one leg to induce pain, which was either a dummy cream or a cream that contained chilli - which caused a burning and painful sensation. Each participant had four MRI scans which revealed how their brain activity changed when their perception of the pain reduced. Dr Michael Lee, lead study author from Oxford University's Centre for Functional Magnetic Resonance Imaging of the Brain, said: "We found that with THC, on average people didn't report any change in the burn, but the pain bothered them less." BBC © 2012

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: 17633 - Posted: 12.22.2012

By Liz Kowalczyk Health officials investigating the national fungal meningitis outbreak caused by tainted steroid injections had thought that the worst was over. The number of new cases was dwindling. Then came patients like Anna Adair. An avid gardener and dog-breeder, Adair was rolled into a Michigan emergency room in a wheelchair Nov. 15. She had been bedridden for days, and that morning a bolt of pain in her lower back had caused her to tumble to the bathroom floor. Doctors quickly reached a disturbing realization: An infection caused by black mold had infiltrated her spine, near where she had received an injection made by a Massachusetts pharmacy, and spread into the bone. It was not the ­meningitis that sickened hundreds of others in late summer and early fall, but part of a frightening second wave of ­fungal infections caused by contaminated drugs. Dozens more people have now been diagnosed with excruciating abscesses or inflamed nerves in their backs that are proving formidable to cure. In a health alert issued Thursday, the federal Centers for Disease Control and Prevention said it is worried that some patients with spinal infections may not even be aware of their condition because the symptoms mimic the very back pain they originally sought to treat with steroids. The agency is now recommending that doctors consider performing MRI scans to screen all patients who have persistent back pain and received steroids from one of three contaminated batches. Previously, it advised scanning just those with new or worsening pain. © 2012 NY Times Co.

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: 17631 - Posted: 12.22.2012

By Scicurious I would like to start this post with a challenge. Can you get through this entire post WITHOUT feeling itchy? I know I couldn’t even write the first line. And I’m not alone. Itch is contagious. Watching someone else scratch can make you itch, and you should try to get through a lecture on a skin condition. I wonder how dermatologists can take it. What IS an itch? The clinical definition is that it’s an “unpleasant sensation associated with the urge to scratch”. Ok, then. Itching is a very important part of clinical diagnosis, from things like poison ivy to allergies to severe use of methamphetamine. In addition, there is a psychological disorder of severe itch which can be both disfiguring and incredibly distressing. But where does it come from and why do we itch? There’s an obvious evolutionary reason (OMG a spider on my arm getitoffgetitoffgetitioff!!!!), but what about social itch? We know about the neurobiological “itch matrix”, which involves areas of the brain associated with touch and somatosensory processing, the premotor areas (for scratching), the anterior insula, prefrontal cortex, thalamus, and cerebellum. From a combination of all of these areas (accompanied, of course, by other things like the visual areas to process seeing the spider on your hand), you get an itch and a scartching response, and other involved areas (like the insula and cingulate) may help make it unpleasant enough for you to want to deal with it. All of these areas are also associated with the processing of other stimuli, like touch and pain, which may contribute to the sensation of itch. © 2012 Scientific American,

Related chapters from BP7e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 14: Attention and Consciousness
Link ID: 17590 - Posted: 12.11.2012

By LISA SANDERS, M.D. On Thursday, we challenged Well readers to puzzle their way through the case of a 25-year-old elephant trainer who developed “the worst headache of his life.” The case was made more confusing by the fact that he had been head-butted by a zebra several years earlier. Turns out the zebra was a bit of a red herring – for the doctors at the time, and for many of you. The correct diagnosis is… Herpes zoster, commonly known as shingles The internist assigned to the case, Dr. Bilal Ahmed, was able to make the diagnosis because when he examined the patient the next day, he saw the characteristic zoster rash above the patient’s right eye that had developed overnight. Nearly 200 people wrote in with their thoughts on what Dr. Ahmed might have seen to reveal the diagnosis when he looked at the patient. The first person to guess the correct diagnosis was Lotty Fulkerson of Massachusetts, a licensed practical nurse who has seen a lot of zoster. It was the combination of the patient’s terrible pain and the fact that the doctor saw something that told him the diagnosis that made her think it was probably shingles. Only three other readers guessed correctly. Herpes zoster, also known as shingles, is caused by the re-emergence of the herpes virus that is the source of the childhood illness chickenpox. The term “shingles” comes from the Latin word “cingulum,” which means belt or girdle; the rash of herpes zoster often appears in a band or belt-like pattern. When the original chickenpox infection resolves, the virus doesn’t die but instead takes refuge in branches of the nerves just outside the spinal cord, where it will reside for decades. In up to a third of patients who have had chickenpox, it re-emerges, causing pain and a rash and sometimes more. Why these survivor viruses re-emerge is unclear, but it may be linked to a weakened immune system. Copyright 2012 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: 17556 - Posted: 12.01.2012

By JUSTIN HECKERT The girl who feels no pain was in the kitchen, stirring ramen noodles, when the spoon slipped from her hand and dropped into the pot of boiling water. It was a school night; the TV was on in the living room, and her mother was folding clothes on the couch. Without thinking, Ashlyn Blocker reached her right hand in to retrieve the spoon, then took her hand out of the water and stood looking at it under the oven light. She walked a few steps to the sink and ran cold water over all her faded white scars, then called to her mother, “I just put my fingers in!” Her mother, Tara Blocker, dropped the clothes and rushed to her daughter’s side. “Oh, my lord!” she said — after 13 years, that same old fear — and then she got some ice and gently pressed it against her daughter’s hand, relieved that the burn wasn’t worse. “I showed her how to get another utensil and fish the spoon out,” Tara said with a weary laugh when she recounted the story to me two months later. “Another thing,” she said, “she’s starting to use flat irons for her hair, and those things get superhot.” Tara was sitting on the couch in a T-shirt printed with the words “Camp Painless But Hopeful.” Ashlyn was curled on the living-room carpet crocheting a purse from one of the skeins of yarn she keeps piled in her room. Her 10-year-old sister, Tristen, was in the leather recliner, asleep on top of their father, John Blocker, who stretched out there after work and was slowly falling asleep, too. The house smelled of the homemade macaroni and cheese they were going to have for dinner. A South Georgia rainstorm drummed the gutters, and lightning illuminated the batting cage and the pool in the backyard. Without lifting her eyes from the crochet hooks in her hands, Ashlyn spoke up to add one detail to her mother’s story. “I was just thinking, What did I just do?” she said. © 2012 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: 17507 - Posted: 11.19.2012

Women with migraines did not appear to experience a decline in cognitive ability over time compared to those who didn’t have them, according to a nine-year follow up study funded by the National Institutes of Health. The study also showed that women with migraine had a higher likelihood of having brain changes that appeared as bright spots on magnetic resonance imaging (MRI), a type of imaging commonly used to evaluate tissues of the body. "The fact that there is no evidence of cognitive loss among these women is good news," said Linda Porter, Ph.D., pain health science policy advisor in the Office of the Director at the National Institute of Neurological Disorders and Stroke (NINDS), which provided funding for the study. "We’ve known for a while that women with migraine tend to have these brain changes as seen on MRI. This nine-year study is the first of its kind to provide long-term follow-up looking for associated risk." "An important message from the study is that there seems no need for more aggressive treatment or prevention of attacks," said Mark C. Kruit, M.D., Ph.D., one of the principal investigators, and a neuroradiologist from Leiden University Medical Center, the Netherlands, which led the study. Dr. Kruit and associates evaluated MRIs for changes in the white matter, brainstem, and cerebellum that appeared on the scans as bright spots known as hyperintensities. Previous studies have shown an association between such hyperintensities and risk factors for atherosclerotic disease, increased risk of stroke and cognitive decline.

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 14: Attention and Consciousness
Link ID: 17488 - Posted: 11.14.2012

by Greg Miller Seeing someone yawn or hearing someone laugh makes you likely to follow suit. The same goes for scratching an itch. Now, for the first time, researchers have investigated the neural basis of contagious itch, identifying several brain regions whose activity predicts how susceptible people are to feeling itchy when they see someone else scratch. Researchers in the United Kingdom showed volunteers video clips of people scratching an arm or a spot on their chest. Sure enough, subjects reported feeling more itchy, and most scratched themselves at least once during the experiment. When a subset of the volunteers watched the videos inside an functional magnetic resonance imaging scanner, the scans revealed activity in several of the same brain regions known to fire up in response to an itch-inducing histamine injection. Activity in three of these areas correlated with subjects' self-reported itchiness, the team reports online today in the Proceedings of the National Academy of Sciences. Personality tests suggest that the trait that best predicts susceptibility to contagious itch is neuroticism, not empathy, as some researchers have suggested. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 17484 - Posted: 11.13.2012

Why some people respond to treatments that have no active ingredients in them may be down to their genes, a study in the journal PLoS ONE suggests. The so-called "placebo effect" was examined in 104 patients with irritable bowel syndrome (IBS) in the US. Those with a particular version of the COMT gene saw an improvement in their health after placebo acupuncture. The scientists warn that while they hope their findings will be seen in other conditions, more work is needed. Edzard Ernst, a professor of complementary medicine at the University of Exeter, said: "This is a fascinating but very preliminary result. "It could solve the age-old question of why some individuals respond to placebo, while others do not. "And if so, it could impact importantly on clinical practice. "But we should be cautious - the study was small, we need independent replications, and we need to know whether the phenomenon applies just to IBS or to all diseases." Gene variants The placebo effect is when a patient experiences an improvement in their condition while undergoing an inert treatment such as taking a sugar pill or, in this case, placebo acupuncture, where the patient believes they are receiving acupuncture but a sham device prevents the needles going into their body. BBC © 2012

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: 17416 - Posted: 10.24.2012

by Robert F. Service According to George Bernard Shaw: "The most intolerable pain is produced by prolonging the keenest pleasure." Not to be picky George, but actually both sensations result from the activity of a diverse family of proteins on the surface of cells. This year's Nobel Prize in chemistry was awarded to two Americans—Robert Lefkowitz of Duke University in Durham, North Carolina, and Brian Kobilka of Stanford University School of Medicine in Palo Alto, California—who revealed the inner workings of these proteins, which also orchestrate a variety of things such as the way we see, smell, taste, feel, and fight infections. The notion that a single family of proteins was responsible for so many different physiological processes was far from evident early on. One hint came at the end of the 19th century, when scientists studying the effects of the hormone adrenaline discovered that it had different effects in various parts of the body. It made heart rate and blood pressure increase, but it decreased digestive activity and caused pupils to relax. One idea was that proteins called receptors on different cells somehow captured adrenaline molecules and either ferried the hormone into cells or transferred a message inside to trigger a response. In the 1940s, an American biologist named Raymond Ahlquist made enough progress to conclude that there must be two types of adrenaline receptors, one that caused smooth muscle cells to contract, and the other that stimulated the heart. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 10: Vision: From Eye to Brain; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 5: The Sensorimotor System
Link ID: 17354 - Posted: 10.11.2012

By Katherine Harmon A bite from the black mamba snake (Dendroaspis polylepis) can kill an adult human within 20 minutes. But mixed in with that toxic venom is a new natural class of compound that could be used to help develop new painkillers. Named “mambalgins,” these peptides block acute and inflammatory pain in mice as well as morphine does, according to a new study. Researchers, led by Sylvie Diochot, of the Institute of Molecular and Cellular Pharmacology at Nice University, Sophia Antipolis in France, purified the peptides from the venom and profiled the compounds’ structure. They then were able to test the mambalgins in strains of mice with various genetic tweaks to their pain pathways. Diochot and her colleagues determined that the mambalgins work by blocking an as-yet untargeted set of neurological ion channels associated with pain signals. The findings were published online October 3 in Nature (Scientific American is part of Nature Publishing Group). As a bonus, mambalgins did not have the risky side effect of respiratory depression that morphine does. And the mice developed less tolerance to them over time than is typical with morphine. Experimenting with the newfound compounds should also help researchers learn more about the mechanisms that drive pain. As the researchers noted in their paper, “It is essential to understand pain better to develop new analgesics. The black mamba peptides discovered here have the potential to address both of these aims.” © 2012 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: 17333 - Posted: 10.04.2012