Chapter 5. The Sensorimotor System

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Merrit Kennedy As doctors in London performed surgery on Dagmar Turner's brain, the sound of a violin filled the operating room. The music came from the patient on the operating table. In a video from the surgery, the violinist moves her bow up and down as surgeons behind a plastic sheet work to remove her brain tumor. The King's College Hospital surgeons woke her up in the middle of the operation in order to ensure they did not compromise parts of the brain necessary for playing the violin, such as parts that control precise hand movements and coordination. "We knew how important the violin is to Dagmar, so it was vital that we preserved function in the delicate areas of her brain that allowed her to play," Keyoumars Ashkan, a neurosurgeon at King's College Hospital, said in a press release. Turner, 53, learned that she had a slow-growing tumor in 2013. Late last year, doctors found that it had become more aggressive and the violinist decided to have surgery to remove it. In an interview with ITV News, Turner recalled doctors telling her, "Your tumor is on the right-hand side, so it will not affect your right-hand side, it will affect your left-hand side." "And I'm just like, 'Oh, hang on, this is my most important part. My job these days is playing the violin,' " she said, making a motion of pushing down violin strings with her left hand. Ashkan, an accomplished pianist, and his colleagues came up with a plan to keep the hand's functions intact. © 2020 npr

Keyword: Epilepsy; Movement Disorders
Link ID: 27054 - Posted: 02.20.2020

Elena Renken The sting of a paper cut or the throb of a dog bite is perceived through the skin, where cells react to mechanical forces and send an electrical message to the brain. These signals were believed to originate in the naked endings of neurons that extend into the skin. But a few months ago, scientists came to the surprising realization that some of the cells essential for sensing this type of pain aren’t neurons at all. It’s a previously overlooked type of specialized glial cell that intertwines with nerve endings to form a mesh in the outer layers of the skin. The information the glial cells send to neurons is what initiates the “ouch”: When researchers stimulated only the glial cells, mice pulled back their paws or guarded them while licking or shaking — responses specific to pain. This discovery is only one of many recent findings showing that glia, the motley collection of cells in the nervous system that aren’t neurons, are far more important than researchers expected. Glia were long presumed to be housekeepers that only nourished, protected and swept up after the neurons, whose more obvious role of channeling electric signals through the brain and body kept them in the spotlight for centuries. But over the last couple of decades, research into glia has increased dramatically. “In the human brain, glial cells are as abundant as neurons are. Yet we know orders of magnitude less about what they do than we know about the neurons,” said Shai Shaham, a professor of cell biology at the Rockefeller University who focuses on glia. As more scientists turn their attention to glia, findings have been piling up to reveal a family of diverse cells that are unexpectedly crucial to vital processes. All Rights Reserved © 2020

Keyword: Glia; Pain & Touch
Link ID: 27002 - Posted: 01.28.2020

Scott Grafton When people ask me about the “mind-body connection,” I typically suggest walking on an icy sidewalk. Skip the yoga, mindfulness, or meditation, and head to the corner on a cold, windy, snowy day. Every winter, much of North America becomes exceedingly slippery with ice. Emergency rooms across the continent see a sharp uptick in fractured limbs and hips as people confidently trudge outside in such conditions, unveiling a profound disconnection between what people believe and what they can actually do with their bodies. One might think that a person could call on experience from years past to adjust their movement or provide a little insight or caution. But the truth is that the body forgets what it takes to stay upright in these perilous conditions. Why is there so much forgetting and relearning on an annual basis? We remember how to ride a bike. Why can’t we remember how to walk on ice? I attempt to answer this and other questions concerning the connection (or lack thereof) between motion in the mind and motion by the body in my new book, Physical Intelligence: The Science of How the Body and the Mind Guide Each Other Through Life. Pantheon, January 2020 Falling on ice reveals a delicate tradeoff that the brain must reconcile as it pilots the body. On the one hand, it needs to build refined motor programs to execute skills such as walking, running, and throwing. On the other hand, those programs can’t be too specific. There is a constant need to tweak motor plans to account for dynamic conditions. When I throw a backpack on, my legs don’t walk in the same way as they do without the pack: my stance widens, my stride shortens. Often, the tweaking needs to happen in moments. As I pick the pack up, I need to lean in or I could tip myself over. Just as importantly, as soon as I put it down, I need to forget I ever held it in the first place. © 1986–2020 The Scientist

Keyword: Learning & Memory
Link ID: 27001 - Posted: 01.28.2020

By Megan Schmidt Scientists say they’ve figured out what causes essential tremor, a common neurological disorder characterized by involuntary, rhythmic trembling that typically occurs in the hands. In a paper published in Science Translational Medicine this week, researchers at National Taiwan University and Columbia University Irving Medical Center discovered that people with essential tremor have abnormal connections among the neurons in their cerebellum, a region in the back of the brain that’s involved in the coordination of voluntary movement. Researchers say people with these abnormalities tend to generate overactive brain waves, or too much electrical activity, in this region of the brain, which is what fuels the tremors. In addition to pinpointing the roots of the disorder, the researchers say their work uncovered some new approaches that could potentially treat and diagnose essential tremor more effectively. Essential tremor is often mistaken for Parkinson’s disease, but there are some key distinctions that set these movement disorders apart. Parkinson’s, which is less common than essential tremor, is caused by the progressive loss of dopamine neurons in the midbrain, a small region of the brain that plays an important role in motor function. Essential tremor, as this new research reveals, is linked to abnormalities in the hindbrain — specifically, the cerebellum. © 2020 Kalmbach Media Co.

Keyword: Movement Disorders
Link ID: 26994 - Posted: 01.25.2020

Abby Olena Understanding the array of neural signals that occur as an organism makes a decision is a challenge. To tackle it, the authors of a study published last week (January 16) in Cell imaged large swaths of the larval zebrafish brain as the animals decided which way to move their tails to avoid an undesirable situation. Finding patterns in the data, they were then able to use imaging to predict—10 seconds in advance—the timing and direction of the fish’s movement. “In a lot of other model systems it’s really difficult to actually . . . record something that’s happening throughout the whole brain with a high level of precision,” says Kristen Severi, a biologist at the New Jersey Institute of Technology who was not involved in the study. “When you have something like a larval zebrafish where you have access to the entire brain with single-cell resolution in a transparent vertebrate, it’s a great place to start to try to look for activity patterns that might be distributed and might be hard to connect.” Even if an animal has learned to do something, it doesn’t execute the exact same motor responses every time, says biophysicist Alipasha Vaziri of the Rockefeller University. He adds that common approaches to studying the neural basis of decision-making may not tell the whole story. For instance, monitoring a handful of neurons and then extrapolating from their activity what’s happening brain-wide means that researchers might miss the big picture. Likewise, recording across the whole brain and then averaging results across trials risks losing details essential to understanding how the brain encodes this behavior. © 1986–2020 The Scientist

Keyword: Brain imaging
Link ID: 26990 - Posted: 01.24.2020

By Karen Weintraub A small injury to a nerve outside the brain and spinal cord is relatively easy to repair just by stretching it, but a major gap in such a peripheral nerve poses problems. Usually, another nerve is taken from elsewhere in the body, and it causes an extra injury and returns only limited movement. Now researchers at the University of Pittsburgh have found an effective way to bridge such a gap—at least in mice and monkeys—by inserting a biodegradable tube that releases a protein called a growth factor for several months. In a study published Wednesday in Science Translational Medicine, the team showed that the tube works as a guide for the nerve to grow along the proper path, and the naturally occurring protein induces the nerve to grow faster. Kacey Marra, a professor at the university’s departments of plastic surgery and bioengineering, says she’s been working for a dozen years on the device, which she particularly hopes will help soldiers injured in combat. More than half of injured soldiers suffer nerve injuries, she says. And as the daughter and granddaughter of military men, she considers it her mission to help their successors. Combat gear does a good job of protecting a soldier’s chest and head, but arms and legs are often exposed, which is why peripheral nerve injuries are so common, Marra says. Car crashes and accidents involving machinery such as snowblowers can also damage nerves involved in hand, arm, leg and foot control. In the U.S., there are about 600,000 nerve injuries every year, she says, though she is unsure how many are severe enough to require the relocation of a second nerve because that information is not tracked yet. When the injuries are severe, the only current treatment is to take a nerve from somewhere else on the body, Marra says. But patients recover just about 50 to 60 percent of function in the damaged nerve. © 2020 Scientific American,

Keyword: Regeneration
Link ID: 26985 - Posted: 01.23.2020

By Benedict Carey Soldiers with deep wounds sometimes feel no pain at all for hours, while people without any detectable injury live in chronic physical anguish. How to explain that? Over drinks in a Boston-area bar, Ronald Melzack, a psychologist, and Dr. Patrick Wall, a physiologist, sketched out a diagram on a cocktail napkin that might help explain this and other puzzles of pain perception. The result, once their idea was fully formed, was an electrifying theory that would become the founding document for the field of modern pain studies and establish the career of Dr. Melzack, whose subsequent work deepened medicine’s understanding of pain and how it is best measured and treated. Dr. Melzack died on Dec. 22 in a hospital near his home in Montreal, where he lived, his daughter, Lauren Melzack, said. He was 90, and had spent most of his professional life as a professor of psychology at McGill University. When Dr. Melzack and Dr. Wall, then at the Massachusetts Institute of Technology, met that day in 1959 or 1960 (accounts of their encounter vary), pain perception was thought to work something like a voltmeter, in which nerves send signals up to the brain that reflect the severity of the injury. But that model failed to explain not only battlefield experience but also a host of clinical findings and everyday salves. Most notably, rubbing a wound lessens its sting — and accounting for just that common sensation proved central to the new theory. Doctors knew that massaging the skin activated so-called large nerve fibers, which are specialized to detect subtle variations of touch; and that deeper, small fibers sounded the alarm of tissue damage. The two researchers reasoned that all these sensations must pass through a “gate” in the spinal cord, which adds up their combined signals before sending a message to the brain. In effect, activating the large fibers blocks signals from the smaller ones, by closing the gate. © 2020 The New York Times Company

Keyword: Pain & Touch
Link ID: 26950 - Posted: 01.13.2020

Amber Dance The girl tried hard to hold her arms and hands steady, but her fingers wriggled and writhed. If she closed her eyes, the squirming got worse. It wasn’t that she lacked the strength to keep her limbs still — she just didn’t seem to have control over them. Carsten Bönnemann remembers examining the teenager at a hospital in Calgary, Canada, in 2013. As a paediatric neurologist with the US National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, he often travelled to weigh in on puzzling cases. But he had never seen anything like this. If she wasn’t looking at her limbs, the girl didn’t seem to have any clue where they were. She lacked the sense of her body’s position in space, a crucial ability known as proprioception. “This is something that just doesn’t occur,” says Bönnemann. His team sequenced the girl’s genes, and those of another girl with similar symptoms1, and found mutations in a gene called PIEZO2. Their timing was fortunate: just a few years earlier, researchers looking for the mechanisms that cells use to sense touch had found that the gene encoded a pressure-sensitive protein2. The discovery of Piezo2 and a related protein, Piezo1, was a high point in a decades-long search for the mechanisms that control the sense of touch. The Piezos are ion channels — gates in the cell membrane that allow ions to pass through — that are sensitive to tension. “We’ve learned a lot about how cells communicate, and it’s almost always been about chemical signalling,” says Ardem Patapoutian, a molecular neurobiologist at Scripps Research in La Jolla, California, whose group identified the Piezos. “What we’re realizing now is that mechanical sensation, this physical force, is also a signalling mechanism, and very little is known about it.” © 2020 Springer Nature Limited

Keyword: Pain & Touch
Link ID: 26944 - Posted: 01.09.2020

By Jane E. Brody If you live with or work with someone who suffers from migraine, there’s something very important you should know: A migraine is not “just a headache,” as many seem to think. Nor is it something most sufferers can simply ignore and get on with their lives. And if you are a migraine sufferer, there’s something potentially life-changing that you should know: There are now a number of medications available that can either prevent or alleviate many attacks, as well as a newly marketed wearable nerve-stimulating device that can be activated by a smartphone to relieve the pain of migraine. Migraine is a neurological disorder characterized by recurrent attacks of severe, often incapacitating headache and dysfunction of the autonomic nervous system, which controls the body’s myriad automatic activities like digestion and breathing. The throbbing or pulsating pain of migraine is often accompanied by nausea and vomiting. Translation: Migraine is a headache, all right, but with body-wide effects because the brain converses with the rest of the body. It is often severe enough to exact a devastating toll on someone’s ability to work, interact with others, perform the tasks of daily life, or even be in a normal living environment. When in the throes of a migraine attack, sufferers may be unable to tolerate light, noise, smells or even touch. Dr. Stephen Silberstein, a neurologist at Thomas Jefferson University and director of the Jefferson Headache Center, told me “There are 47 million people in this country with migraine, and for six million, the condition is chronic, which means they have more than 15 headache days a month,” he said. “It’s time to destigmatize migraine and provide sufferers with effective treatment,” said Dr. David W. Dodick, neurologist at the Mayo Clinic in Scottsdale. “They’re not fakers, weak individuals who are trying to get out of work.” © 2020 The New York Times Company

Keyword: Pain & Touch
Link ID: 26936 - Posted: 01.07.2020

By Sharon Jayson AUSTIN, Texas — Retired state employees Vickey Benford, 63, and Joan Caldwell, 61, are Golden Rollers, a group of the over-50 set that gets out on assorted bikes — including trikes for adults they call “three wheels of awesome” — for an hour of trail riding and camaraderie. “I love to exercise, and I like to stay fit,” said Caldwell, who tried out a recumbent bike, a low-impact option that can be easier on the back. “It keeps me young.” Benford encouraged Caldwell to join the organized rides, which have attracted more than 225 riders at city rec centers and senior activity centers. The cyclists can choose from a small, donated fleet of recumbent bikes, tandem recumbents and tricycles. “With seniors, it’s less about transportation and more about access to the outdoors, social engagement and quality of life,” said Christopher Stanton, whose idea for Golden Rollers grew out of the Ghisallo Cycling Initiative, a youth biking nonprofit he founded in 2011. But that’s not all, according to brain scientists. They point to another important benefit: Exercising both body and brain can help people stay healthier longer. The new thinking about aging considers not just how long one lives, but how vibrant one stays later in life. “If you’re living, you want to be living well,” said Tim Peterson, an assistant professor of internal medicine at the Washington University School of Medicine in St. Louis. “Most people who were interested in life span and were studying genes — which control life span — switched to ‘healthspan.’” “Healthspan,” a coinage now gaining traction, refers to the years that a person can expect to live in generally good health — free of chronic illnesses and cognitive decline that can emerge near life’s end. Although there’s only so much a person can do to delay the onset of disease, there’s plenty that scientists are learning to improve your chances of a better healthspan. © 2020 Kaiser Family Foundation

Keyword: Development of the Brain
Link ID: 26932 - Posted: 01.04.2020

By Gretchen Reynolds What’s good for your muscles can also be good for your mind. A Single Workout Can Alter the Brain A single, moderate workout may immediately change how our brains function and how well we recognize common names and similar information, according to a promising new study of exercise, memory and aging. The study adds to growing evidence that exercise can have rapid effects on brain function and also that these effects could accumulate and lead to long-term improvements in how our brains operate and we remember. Until recently, scientists thought that by adulthood, human brains were relatively fixed in their structure and function, especially compared to malleable tissues, like muscle, that continually grow and shrivel in direct response to how we live our lives. But multiple, newer experiments have shown that adult brains, in fact, can be quite plastic, rewiring and reshaping themselves in various ways, depending on our lifestyles. A hormone that is released during exercise may improve brain health and lessen the damage and memory loss that occur during dementia, a new study finds. The study, which was published this month in Nature Medicine, involved mice, but its findings could help to explain how, at a molecular level, exercise protects our brains and possibly preserves memory and thinking skills, even in people whose pasts are fading. Considerable scientific evidence already demonstrates that exercise remodels brains and affects thinking. Researchers have shown in rats and mice that running ramps up the creation of new brain cells in the hippocampus, a portion of the brain devoted to memory formation and storage. Exercise also can improve the health and function of the synapses between neurons there, allowing brain cells to better communicate. © 2019 The New York Times Company

Keyword: Alzheimers
Link ID: 26925 - Posted: 12.30.2019

By Debbie Jackson BBC Scotland "Fluffing your son's hair, really hugging him, holding his hand." For someone who has been through what she has in the space of a year, Corinne Hutton doesn't need much to make her happy. Last January she got the double hand transplant she had been waiting more than five years for, and feared would never happen. This January, she will celebrate her "handiversary", a year since a surgeon handed her back her independence. Being able to do the simplest things for 11-year-old son Rory means the world to Finding Your Feet charity founder Cor. "From an emotional point of view to be able to do things for him - make the packed lunches or the washing, or do the ironing is great," she said. "But on top of that, being able to hold his hand, fluff his hair, little things that might not be hugely exciting to him - but they matter a lot to me. "People don't appreciate what it means to have lost them," she said. Cor became the first Scot to undergo a double hand transplant when, in a 12-hour procedure, Prof Simon Kay attached two donor hands to her arms at Leeds general Infirmary. The 48-year-old lost her hands and feet in 2013 after suffering acute pneumonia and sepsis, which almost killed her. After more than a dozen false alarms over the years, a match for her own blood group, skin tone and hand size had been found. Much celebration and wonder was made of the news that the transplant had finally happened, but the aftermath was far from easy. © 2019 BBC.

Keyword: Pain & Touch
Link ID: 26922 - Posted: 12.30.2019

By Eva Frederick One day in 2014, primatologist Yuko Hattori was trying to teach a mother chimpanzee in her lab to keep a beat. Hattori would play a repetitive piano note, and the chimp would attempt to tap out the rhythm on a small electronic keyboard in hopes of receiving a tasty piece of apple. Everything went as expected in the experiment room, but in the next room over, something strange was happening. Another chimpanzee, the mother’s son, heard the beat and began to sway his body back and forth, almost as if he were dancing. “I was shocked,” Hattori says. “I was not aware that without any training or reward, a chimpanzee would spontaneously engage with the sound.” Hattori has now published her research showing that chimps respond to sounds, both rhythmic and random, by “dancing.” “This study is very thought-provoking,” says Andrea Ravignani, a cognitive biologist at the Seal Rehabilitation and Research Centre who researches the evolution of rhythm, speech, and music. The work, she says, could shed light on the evolution of dancing in humans. For their the study, Hattori and her colleague Masaki Tomonaga at Kyoto University played 2-minute clips of evenly spaced, repetitive piano tones (heard in the video above) to seven chimpanzees (three males and four females). On hearing the sound, the chimps started to groove, swaying back and forth and sometimes tapping their fingers or their feet to the beat or making howling “singing” sounds, the researchers report today in the Proceedings of the National Academy of Sciences. All of the chimps showed at least a little bit of rhythmic movement, though the males spent much more time moving to the music than females. © 2019 American Association for the Advancement of Science.

Keyword: Evolution; Hearing
Link ID: 26916 - Posted: 12.26.2019

By Richard Sima Luke Miller, a cognitive neuroscientist, was toying with a curtain rod in his apartment when he was struck by a strange realization. When he hit an object with the rod, even without looking, he could tell where it was making contact like it was a sensory extension of his body. “That’s kind of weird,” Miller recalls thinking to himself. “So I went [to the lab], and we played around with it in the lab.” Sensing touch through tools is not a new concept, though it has not been extensively investigated. In the 17th century, philosopher René Descartes discussed the ability of blind people to sense their surroundings through their walking cane. While scientists have researched tool use extensively, they typically focused on how people move the tools. “They, for the most part, neglected the sensory aspect of tool use,” Miller says. In a 2018 Nature study, Miller and his colleagues at Claude Bernard Lyon 1 University in France reported that humans are actually quite good at pinpointing where an object comes into contact with a handheld tool using touch alone, as if the object were touching their own skin. A tool is not innervated like our skin, so how does our brain know when and where it is touched? Results in a follow-up study, published in December in Current Biology, reveal that the brain regions involved with sensing touch on the body similarly processes it on the tool. “The tool is being treated like a sensory extension of your body,” Miller says. In the initial experiment, the researchers asked 16 right-handed subjects to determine where they felt touches on a one-meter-long wooden rod. In a total of 400 trials, each subject compared the locations of two touches made on the rod: If they were felt in different locations, participants did not respond. If they were in the same location, the people in the study tapped a foot pedal to indicate whether the touches were close or far from their hand. Even without any experience with the rod or feedback on their performance, the participants were, on average, 96 percent accurate. © 2019 Scientific American,

Keyword: Pain & Touch
Link ID: 26914 - Posted: 12.26.2019

Scientists say they have discovered a possible underlying cause of the neurological disorder, motor neurone disease (MND). The University of Exeter team says it has found evidence that MND is linked to an imbalance of cholesterol and other fats in cells. It says the research could lead to more accurate diagnosis and new treatments. MND affects around 5,000 people in the UK and causes more than 2,000 deaths a year. What is MND? Motor neurone disease is a group of diseases that affect the nerve cells in the brain and spinal cord that tell your muscles what to do. Also known as ALS, it causes muscle weakness and stiffness. Eventually people with the disease are unable to move, talk, swallow and finally, breathe. There is no cure and the exact causes are unclear - it's been variously linked to genes, exposure to heavy metals and agricultural pollution. What did the researchers find? Scientists at the University of Exeter say they had a "eureka moment" when they realised that 13 genes - which, if altered, can cause the condition - were directly involved in processing cholesterol. They say their theory could help predict the course and severity of the disease in patients and monitor the effect of potential new drugs. The theory is outlined in a paper, published in Brain: A Journal of Neurology. Lead author Prof Andrew Crosby said: "For years, we have known that a large number of genes are involved in motor neurone disease, but so far it hasn't been clear if there's a common underlying pathway that connects them." The finding particularly relates to what is known as the "spastic paraplegias", where the malfunction is in the upper part of the spinal cord. Dr Emma Baple, also from the University of Exeter Medical School, said: "Currently, there are no treatments available that can reverse or prevent progression of this group of disorders. Patients who are at high risk of motor neurone disease really want to know how their disease may progress and the age at which symptoms may develop, but that's very difficult to predict." © 2019 BBC

Keyword: ALS-Lou Gehrig's Disease
Link ID: 26902 - Posted: 12.18.2019

By Gretchen Reynolds Top athletes’ brains are not as noisy as yours and mine, according to a fascinating new study of elite competitors and how they process sound. The study finds that the brains of fit, young athletes dial down extraneous noise and attend to important sounds better than those of other young people, suggesting that playing sports may change brains in ways that alter how well people sense and respond to the world around them. For most of us with normal hearing, of course, listening to and processing sounds are such automatic mental activities that we take them for granted. But “making sense of sound is actually one of the most complex jobs we ask of our brains,” says Nina Kraus, a professor and director of the Auditory Neuroscience Laboratory at Northwestern University in Evanston, Ill., who oversaw the new study. Sound processing also can be a reflection of broader brain health, she says, since it involves so many interconnected areas of the brain that must coordinate to decide whether any given sound is familiar, what it means, if the body should respond and how a particular sound fits into the broader orchestration of other noises that constantly bombard us. For some time, Dr. Kraus and her collaborators have been studying whether some people’s brains perform this intricate task more effectively than others. By attaching electrodes to people’s scalps and then playing a simple sound, usually the spoken syllable “da,” at irregular intervals, they have measured and graphed electrical brain wave activity in people’s sound-processing centers. © 2019 The New York Times Company

Keyword: Attention
Link ID: 26901 - Posted: 12.18.2019

By Tina Hesman Saey WASHINGTON — Clumps of misfolded proteins cause traffic jams in brain cells. Those jams may have deadly consequences in neurodegenerative diseases. Clusters of prions block passage of crucial cargo along intracellular roadways in brain cells, cell biologist Tai Chaiamarit of the Scripps Research Institute in La Jolla, Calif., reported December 10 at the joint annual meeting of the American Society for Cell Biology and the European Molecular Biology Organization. Prions, misshaped versions of a normal brain protein, clump together in large aggregates that are hallmarks of degenerative brain diseases, such as mad cow disease in cattle, chronic wasting disease in deer and Creutzfeldt-Jakob disease in people. It’s unclear why those clumpy proteins are so deadly to nerve cells called neurons, but the new study may provide clues about what goes wrong in these diseases. Axons, the long stringlike projections of nerve cells that carry electrical signals to other nerves, are the sites of prion traffic jams, Chaiamarit and colleagues found. As more prions clump together, they cause swollen bulges that make the axon look like a snake that has just swallowed a big meal. Through a microscope, Chaiamarit and colleagues saw mitochondria being transported toward the cell’s furthest reaches derailed at the bulges. Mitochondria, cells’ energy-generating organelles, are carried outbound from the main body of the cell by a motor protein called kinesin-1. The protein motors along molecular rails called microtubules. A different motor protein, dynein, transports mitochondria back toward the cell body along those same rails. © Society for Science & the Public 2000–2019

Keyword: Prions
Link ID: 26895 - Posted: 12.13.2019

By Sharon Begley, STAT Even allowing for the fact that these were lilliputian brains, they were not behaving at all according to plan. From the first days of the tiny lab-grown organs’ development, primitive “progenitor cells” romped out of their birthplaces in the deep interior and quickly turned into neurons and glia, specialized cells that do the brain’s heavy lifting, from thinking and feeling and moving to boring old neurological housekeeping. But the cells were jumping the gun. In healthy developing human brains, progenitor cells spend a good chunk of prenatal existence simply reproducing, vastly increasing their numbers and postponing becoming other brain cells. The impatient progenitor cells, however, were in cerebral organoids—minuscule 3-D versions of the brain—created from the cells of people with Huntington’s disease in hopes of mimicking the patients’ actual brain development decades earlier. It was new evidence that, in their understanding of this devastating genetic illness, scientists know only half the story: In addition to being a neurodegenerative disease, it is also neurodevelopmental, starting in the womb. These recent findings and other research are spurring a radical rethinking of Huntington’s, with implications for the age when any potential cure is likely to be most effective. “It’s not conclusive, but there is suggestive evidence that neurodevelopment is altered in Huntington’s disease,” said neurobiologist Mahmoud Pouladi of the National University of Singapore, who led the organoid work. If so, then if scientists discover a way to repair the mutant gene or remove the aberrant molecules it makes, “the earlier you intervene the better it should be.” In contrast, today’s most-watched clinical trials in Huntington’s include only adults, often middle-aged ones, reflecting the belief that most mutation carriers can reach their 30s or beyond cerebrally unscathed. In fact, doctors and advocacy groups strongly discourage genetic testing for Huntington’s in anyone under 18, presuming there’s nothing to be gained. According to the genetic-testing guidelines from the Huntington’s Disease Society of America, “Predictive testing of minors currently has no medical benefits and the possibility for psychosocial harm and lowered self-esteem is high.” © 2019 Scientific American

Keyword: Huntingtons
Link ID: 26889 - Posted: 12.11.2019

By Jonah Engel Bromwich Pete Frates, a former college baseball player whose participation in the social media phenomenon known as the Ice Bucket Challenge helped raise more than $100 million toward fighting amyotrophic lateral sclerosis, commonly known as A.L.S. or Lou Gehrig’s disease, died on Monday at his home in Beverly, Mass. He was 34. His death was announced in a statement by Boston College, his alma mater. Quoting his family, it said he died “after a heroic battle with A.L.S.” Mr. Frates learned he had the disease in 2012. A.L.S. attacks the body’s nerve cells and leads to full paralysis. Patients are typically expected to live for two to five years from the time of diagnosis. Mr. Frates did not create the Ice Bucket Challenge, in which participants dumped buckets of ice water over their heads while pledging to donate money to fight A.L.S. But a Facebook video in July 2014 showing him doing his version of the challenge — in which he bobbed his head to Vanilla Ice’s song “Ice Ice Baby” — prompted a surge in participation that summer, to where it became a viral sensation. LeBron James, Bill Gates, Oprah Winfrey and other celebrities stepped forward to be drenched, and millions of others followed suit. Mr. Frates became one of the most visible supporters of the effort, and in August 2014 he completed the challenge again (this time with ice water) at Fenway Park, along with members of the Boston Red Sox organization. The videos were inescapable for anyone on Facebook, and the A.L.S. Association, a Washington-based nonprofit that works to fight the disease, received more than $115 million. In 2015 the organization released an infographic showing how those funds were being spent. About $77 million, or 67 percent, of the money was used for research that ultimately identified the NEK1 gene, which contributes to the disease. The finding gave scientists guidance in developing treatment drugs. © 2019 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 26885 - Posted: 12.10.2019

By Austin Frakt Some days I’m grumpy; other times, my head hurts or my feet or my arms do. Yet when I play the trumpet, my mood improves and the pain disappears. Why? Alternative medicine — including music therapy — is full of pain-relief claims. Although some are simply too good to be true, the oddities of pain can explain why others hold up, as well as why my trumpet playing helps. One thing we tend to believe about pain, but is wrong, is that it always stems from a single, fixable source. Another is that pain is communicated from that source to our brains by “pain nerves.” That’s so wrong it’s called “the naïve view” by neuroscientists. In truth, pain is in our brain. Or as the author and University of California, San Diego, neuroscientist V. S. Ramachandran put it, “Pain is an opinion.” We feel it because of how our brain interprets input transmitted to it from all our senses, not necessarily because of the inherent properties of the input itself. There are no nerves dedicated to sensing and transmitting pain. Anyone who has willed themselves to not feel a tickle as ticklish can appreciate the difference between stimulation and our perception of it. Pain can be experienced and relieved in phantom limbs. Discomfort and swelling increase when people believe a painful hand or knee is larger. They decrease when it seems smaller, for example in a distorted image or based on virtual reality technology. Injections are less painful when we don’t watch them. Using our brains, we can exert some control over it. © 2019 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 26865 - Posted: 12.02.2019