Chapter 5. The Sensorimotor System

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Jules Montague Steve Thomas and I are talking about brain implants. Bonnie Tyler’s Holding Out For a Hero is playing in the background and for a moment I almost forget that a disease has robbed Steve of his speech. The conversation breaks briefly; now I see his wheelchair, his ventilator, his hospital bed. Steve, a software engineer, was diagnosed with ALS (amyotrophic lateral sclerosis, a type of motor neurone disease) aged 50. He knew it was progressive and incurable; that he would soon become unable to move and, in his case, speak. He is using eye-gaze technology to tell me this (and later to turn off the sound of Bonnie Tyler); cameras pick up light reflection from his eye as he scans a screen. Movements of his pupils are translated into movements of a cursor through infrared technology and the cursor chooses letters or symbols. A speech-generating device transforms these written words into spoken ones – and, in turn, sentences and stories form. Eye-gaze devices allow some people with limited speech or hand movements to communicate, use environmental controls, compose music, and paint. That includes patients with ALS – up to 80% have communication difficulties, cerebral palsy, strokes, multiple sclerosis and spinal cord injuries. It’s a far cry from Elle editor-in-chief Jean-Dominique Bauby, locked-in by a stroke in 1995, painstakingly blinking through letters on an alphabet board. His memoir, written at one word every two minutes, later became a film, The Diving Bell and the Butterfly. Although some still use low-tech options (not everyone can meet the physical or cognitive requirements for eye-gaze systems; occasionally, locked-in patients can blink but cannot move their eyes), speech-to-text and text-to-speech functionality on smartphones and tablets has revolutionised communication. © 2017 Guardian News and Media Limited

Keyword: Robotics
Link ID: 24200 - Posted: 10.16.2017

Victoria Lorrimar Michael Burdett The idea of dangerous, inhumane artificial intelligence taking over the world is familiar to many of us, thanks to cautionary tales such as the Matrix and Terminator franchises. But what about the more sympathetic portrayals of robots? The benevolence of Arnold Schwarzenegger’s Terminator character in the later movies of the franchise may have been the exception in older portrayals of AI, but human-like machines are often represented more positively in contemporary films. Think of Ex Machina, Chappie or A.I. Artificial Intelligence. This shift is very likely representative of a wider shift in how we think about these technologies in reality. Blade Runner 2049, long-anticipated sequel to the original 1982 Blade Runner film, is a part of this shift. The ability of science fiction to inspire technological innovation is well-known. A lot of science fiction writers are scientists and technologists (Arthur C Clarke and Geoffrey Landis are two examples), and ideas from science fiction have sparked more serious scientific research (touch screens and tablet computers are common examples). But science fiction serves other purposes too. It can be a tool for exploring the social and ethical implications of technologies being developed now – a fictional laboratory for testing possible futures. It can also prepare us to deal with certain technologies as they arise in the real world. © 2010–2017, The Conversation US, Inc.

Keyword: Consciousness; Robotics
Link ID: 24160 - Posted: 10.07.2017

By Michael Price Expensive medications tend to make us feel better, even when they’re no different than cheap generics. But they can also make us feel worse, according to a new study. Researchers have found that we’re more likely to experience negative side effects when we take a drug we think is pricier—a flip side of the placebo effect known as the “nocebo” effect. The work could help doctors decide whether to recommend brand-name or generic drugs depending on each patient’s expectations. In the study, researchers asked 49 people to test out a purported anti-itch cream that, in reality, contained no active ingredient. Some got “Solestan® Creme,” a fake brand name in a sleek blue box designed to look like other expensive brands on the market. Others received “Imotadil-LeniPharma Creme”—another fake, this time housed in a chintzier orange box resembling those typically used for generic drugs. “I put a lot of effort into making the designs convincing,” says study leader Alexandra Tinnermann, a neuroscientist at University Medical Center Hamburg-Eppendorf in Germany. The researchers rubbed one of the two creams on the volunteers’ forearms and waited a few minutes for it soak in. They told the participants that the cream could cause increased sensitivity to pain—a known side effect of real medications called hyperalgesia. Then the scientists affixed a small device to the volunteers’ arms that delivered a brief flash of heat up to about 45°C (or 113°F). © 2017 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 24154 - Posted: 10.06.2017

By GRETCHEN REYNOLDS Because we can never have enough reasons to keep exercising, a new study with mice finds that physical activity not only increases the number of new neurons in the brain, it also subtly changes the shape and workings of these cells in ways that might have implications for memory and even delaying the onset of dementia. As most of us have heard, our brains are not composed of static, unchanging tissue. Instead, in most animals, including people, the brain is a dynamic, active organ in which new neurons and neural connections are created throughout life, especially in areas of the brain related to memory and thinking. This process of creating new neurons, called neurogenesis, can be altered by lifestyle, including physical activity. Many past studies have shown that in laboratory rodents, exercise doubles or even triples the number of new cells produced in adult animals’ brains compared to the brains of animals that are sedentary. But it has not been clear whether the new brain cells in active animals are somehow different from comparable new neurons in inactive animals or if they are just more numerous. That question has long interested scientists at the Laboratory of Neurosciences at the National Institute on Aging, who have been examining how running alters the brains and behavior of lab animals. Last year, in an important study published in NeuroImage, the researchers found for the first time that young brain cells in adult mice that spent a month with running wheels in their cages did seem to be different from those in animals that did not run. For the experiment, the scientists injected a modified rabies vaccine into the animals, where it entered the nervous system and brain. They then tracked and labeled connections between brain cells and learned that compared to the sedentary animals’ brain cells, the runners’ newborn neurons had more and longer dendrites, the snaky tendrils that help to connect the cells into the neural communications network. They also found that more of these connections led to portions of the brain that are important for spatial memory, which is our internal map of where we have been and how we got there. © 2017 The New York Times Company

Keyword: Neurogenesis; Development of the Brain
Link ID: 24145 - Posted: 10.04.2017

By Dan Stark I used to tell people considering deep brain stimulation — which involves the surgical implantation of electrodes into the brain — that it gave the typical Parkinson’s sufferer perhaps 10 years of relief, during which the symptoms would be relatively minor. The bet — this is, after all, brain surgery that carries some risk of serious adverse results — would be that sometime during that decade, researchers would come up with a real solution. In other words, DBS was a way to buy time. Still, 10 years is no small period, particularly for those who have no other hope. My experience is typical. I had DBS just under 12 years ago. Things went so well that I became a huge fan of the procedure. But DBS works on only some Parkinson’s symptoms. (Drooling, for example, is not affected.) For slightly more than a decade, DBS performed wonders on me, eliminating the shakes that had accompanied my attempts to beat back Parkinson’s symptoms with medicine alone. But because DBS masks the symptoms while not affecting the underlying disease, in the end it will fail the Parkinson’s patient. For me, the failure was in the form of a one-two punch. The first blow was self-inflicted. In April, one of the batteries powering my neural implants died. That was my fault; one should monitor the batteries and replace them in advance. Because I hadn’t, I got a taste of what life would be like without the stimulators. © 1996-2017 The Washington Post

Keyword: Parkinsons
Link ID: 24132 - Posted: 10.02.2017

By GRETCHEN REYNOLDS For most of us, temptations are everywhere, from the dessert buffet to the online shoe boutique. But a new study suggests that exercise might be a simple if unexpected way to increase our willpower and perhaps help us to avoid making impulsive choices that we will later regret. Self-control is one of those concepts that we all recognize and applaud but do not necessarily practice. It requires forgoing things that entice us, which, let’s face it, is not fun. On the other hand, lack of self-control can be consequential for health and well-being, often contributing to problems like weight gain, depression or money woes. Given these impacts, scientists and therapists have been interested in finding ways to increase people’s self-restraint. Various types of behavioral therapies and counseling have shown promise. But such techniques typically require professional assistance and have for the most part been used to treat people with abnormally high levels of impulsiveness. There have been few scientifically validated options available to help those of us who might want to be just a little better at resisting our more devilish urges. So for the new study, which was published recently in Behavior Modification, a group of researchers at the University of Kansas in Lawrence began wondering about exercise. Exercise is known to have considerable psychological effects. It can raise moods, for example, and expand people’s sense of what they are capable of doing. So perhaps, the researchers speculated, exercise might alter how well people can control their impulses. To find out, the scientists decided first to mount a tiny pilot study, involving only four men and women. © 2017 The New York Times Company

Keyword: Obesity; Attention
Link ID: 24119 - Posted: 09.28.2017

By LISA SANDERS, M.D. “Mom?” the middle-aged man asked. He recognized the voice, but the words were muffled and strange. I’ll be right over, he said into the phone. The 15-minute drive from his small Connecticut town to his mother’s seemed to last forever. Had she had a stroke? She was 94, and though she’d always been healthy, at her age, anything could happen. He burst into her tidy brick home to find her sitting in the living room, waiting. Her eyes were bright but scared, and her voice was just a whisper. He helped her to his car, then raced to the community hospital a couple of towns over. The doctors in the emergency room were also worried about a stroke. Her left eyelid hung lower across her eye than her right. She was seeing double, she told them. And the left side of her mouth and tongue felt strangely heavy, making it hard to speak. Initial blood tests came back normal; so did the CT scan of her brain. It wasn’t clear what was wrong with the patient, so she was transferred to nearby Yale New Haven Hospital. Dr. Paul Sanmartin, a resident in the second year of his neurology training, met the patient early the next morning. He’d already heard about her from the overnight resident: a 94-year-old woman with the sudden onset of a droopy eyelid, double vision and difficulty speaking, probably due to a stroke. As he entered the room, he realized he wasn’t sure what 94 was supposed to look like, but this woman looked much younger. She did have a droopy left lid, but her eyes moved in what looked to him to be perfect alignment, and her speech, though quiet, was clear. The patient’s story was also different from what he expected. She had macular degeneration and had been getting shots in her left eye for more than a decade. Her last injection was nearly two weeks earlier, and she’d had double vision and the droopy eyelid on and off ever since. © 2017 The New York Times Company

Keyword: Movement Disorders
Link ID: 24111 - Posted: 09.26.2017

By JANE E. BRODY If you’ve never had a migraine, I have two things to say to you: 1) You’re damn lucky. 2) You can’t begin to imagine how awful they are. I had migraines – three times a month, each lasting three days — starting from age 11 and finally ending at menopause. Although my migraines were not nearly as bad as those that afflict many other people, they took a toll on my work, family life and recreation. Atypically, they were not accompanied by nausea or neck pain, nor did I always have to retreat to a dark, soundless room and lie motionless until they abated. But they were not just “bad headaches” — the pain was life-disrupting, forcing me to remain as still as possible. Despite being the seventh leading cause of time spent disabled worldwide, migraine “has received relatively little attention as a major public health issue,” Dr. Andrew Charles, a California neurologist, wrote recently in The New England Journal of Medicine. It can begin in childhood, becoming more common in adolescence and peaking in prevalence at ages 35 to 39. It afflicts two to three times more women than men, and one woman in 25 has chronic migraines on more than 15 days a month. But while the focus has long been on head pain, migraines are not just pains in the head. They are a body-wide disorder that recent research has shown results from “an abnormal state of the nervous system involving multiple parts of the brain,” said Dr. Charles, of the U.C.L.A. Goldberg Migraine Program at the David Geffen School of Medicine in Los Angeles. He told me he hoped the journal article would educate practicing physicians, who learn little about migraines in medical school. Before it was possible to study brain function through a functional M.R.I. or PET scan, migraines were thought to be caused by swollen, throbbing blood vessels in the scalp, usually – though not always — affecting one side of the head. This classic migraine symptom prompted the use of medications that narrow blood vessels, drugs that help only some patients and are not safe for people with underlying heart disease. © 2017 The New York Times Company

Keyword: Pain & Touch
Link ID: 24072 - Posted: 09.18.2017

Mariah Quintanilla Kenneth Catania knows just how much it hurts to be zapped by an electric eel. For the first time, the biologist at Vanderbilt University in Nashville has measured the strength of a defensive electrical attack on a real-life potential predator — himself. Catania placed his arm in a tank with a 40-centimeter-long electric eel (relatively small as eels go) and determined, in amperes, the electrical current that flowed into him when the eel struck. At its peak, the current reached 40 to 50 milliamperes in his arm, he reports online September 14 in Current Biology. This zap was painful enough to cause him to jerk his hand from the tank during each trial. “If you’ve ever been on a farm and touched an electric fence, it’s pretty similar to that,” he says. This is Catania’s latest study in a body of research analyzing the intricacies of an electric eel’s behavior. The way electric eels have been described by biologists in the past has been fairly primitive, says Jason Gallant, a biologist who heads the Michigan State University Electric Fish Lab in East Lansing who was not involved in the study. Catania’s work reveals that “what the electric eel is doing is taking the electric ability that it has and using that to its absolute advantage in a very sophisticated, deliberate way,” he says. Electric eels use electric current to navigate, communicate and hunt for small prey. But when faced with a large land-based predator, eels will launch themselves from the water and electrify the animal with a touch of the head. |© Society for Science & the Public 2000 - 2017.

Keyword: Aggression
Link ID: 24068 - Posted: 09.15.2017

By Nathaniel P. Morris A growing trend in medicine has doctors prescribing visits to parks for their patients. A pediatrician named Robert Zarr at Unity Health Care in Washington, D.C., has worked with the National Park Service and other institutions to create DC Park Rx, an initiative that helps health care providers prescribe activity in outdoor spaces to patients. And National Geographic recently highlighted the rise of this practice in Vermont, where doctors are now prescribing thousands of visits to state parks. In the last several years park prescription programs have spread nationwide, from Maine to California, South Dakota to New Mexico. Proponents of these programs promote outdoor activity as a means of tackling chronic medical conditions like obesity, high blood pressure and type 2 diabetes. But park prescriptions also hold considerable promise for patients suffering from mental health issues. A large body of evidence suggests that exposure to nature may promote mental well-being. A 2010 meta-analysis of 10 studies including over 1,200 participants found people who exercised in green environments demonstrated significant improvements in mood and self-esteem. A 2011 systematic review looked at 11 trials that compared indoor and outdoor activity, finding that exercise in natural settings was “associated with greater feelings of revitalization and positive engagement, decreases in tension, confusion, anger and depression, and increased energy.” Another recent review of studies found activity in natural environments correlated with reductions in negative emotions like sadness, anger and fatigue. © 2017 Scientific American,

Keyword: Depression
Link ID: 24065 - Posted: 09.15.2017

By Helen Thomson DON’T mind the gap. A woman has reached the age of 24 without anyone realising she was missing a large part of her brain. The case highlights just how adaptable the organ is. The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea. She told doctors she’d had problems walking steadily for most of her life, and her mother reported that she hadn’t walked until she was 7 and that her speech only became intelligible at the age of 6. Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing (see scan, above). The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease. The cerebellum – sometimes known as the “little brain” – is located underneath the two hemispheres. It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain’s total volume but contains 50 per cent of its neurons. Although it is not unheard of to have part of your brain missing, either congenitally or from surgery, the woman joins an elite club of just nine people who are known to have lived without their entire cerebellum. A detailed description of how the disorder affects a living adult is almost non-existent, say doctors from the Chinese hospital, because most people with the condition die at a young age and the problem is only discovered on autopsy (Brain, doi.org/vh7). © Copyright New Scientist Ltd.

Keyword: Development of the Brain
Link ID: 24056 - Posted: 09.12.2017

By JANE E. BRODY Many years ago I was plagued with debilitating headaches associated with a number of seemingly unrelated activities that included cooking for company and sewing drapes for the house. I thought I might be allergic to natural gas or certain fabrics until one day I realized that I tensed my facial muscles when I concentrated intently on a project. The cure was surprisingly simple: I became aware of how my body was reacting and changed it through self-induced behavior modification. I consciously relaxed my muscles whenever I focused on a task that could precipitate a tension-induced headache. Fast-forward about five decades: Now it was my back that ached when I hurriedly cooked even a simple meal. And once again, after months of pain, I realized that I was transferring stress to the muscles of my back and had to learn to relax them, and to allow more time to complete a project to mitigate the stress. Happy to report, I recently prepared dinner for eight with nary a pain. I don’t mean to suggest that every ache and pain can be cured by self-awareness and changing one’s behavior. But recent research has demonstrated that the mind – along with other nonpharmacological remedies — can be powerful medicine to relieve many kinds of chronic or recurrent pains, especially low back pain. As Dr. James Campbell, a neurosurgeon and pain specialist, put it, “The best treatment for pain is right under our noses.” He suggests not “catastrophizing” – not assuming that the pain represents something disastrous that keeps you from leading the life you’ve chosen. Acute pain is nature’s warning signal that something is wrong that should be attended to. Chronic pain, however, is no longer a useful warning signal, yet it can lead to perpetual suffering if people remain afraid of it, the doctor said. © 2017 The New York Times Company

Keyword: Pain & Touch
Link ID: 24053 - Posted: 09.11.2017

Laura Sanders The brain chemical missing in Parkinson’s disease may have a hand in its own death. Dopamine, the neurotransmitter that helps keep body movements fluid, can kick off a toxic chain reaction that ultimately kills the nerve cells that make it, a new study suggests. By studying lab dishes of human nerve cells, or neurons, derived from Parkinson’s patients, researchers found that a harmful form of dopamine can inflict damage on cells in multiple ways. The result, published online September 7 in Science, “brings multiple pieces of the puzzle together,” says neuroscientist Teresa Hastings of the University of Pittsburgh School of Medicine. The finding also hints at a potential treatment for the estimated 10 million people worldwide with Parkinson’s: Less cellular damage occurred when some of the neurons were treated early on with antioxidants, molecules that can scoop up harmful chemicals inside cells. Study coauthor Dimitri Krainc, a neurologist and neuroscientist at Northwestern University Feinberg School of Medicine in Chicago, and colleagues took skin biopsies from healthy people and people with one of two types of Parkinson’s disease, inherited or spontaneously arising. The researchers then coaxed these skin cells into becoming dopamine-producing neurons. These cells were similar to those found in the substantia nigra, the movement-related region of the brain that degenerates in Parkinson’s. |© Society for Science & the Public 2000 - 2017.

Keyword: Parkinsons
Link ID: 24049 - Posted: 09.08.2017

A test that involves drawing a spiral on a sheet of paper could be used to diagnose early Parkinson's disease. Australian researchers have trialled software that measures writing speed and pen pressure on the page. Both are useful for detecting the disease, which causes shaking and muscle rigidity. The Melbourne team said the test could be used by GPs to screen their patients after middle age and to monitor the effect of treatments. The study, published in Frontiers of Neurology, involved 55 people - 27 had Parkinson's and 28 did not. Speed of writing and pen pressure while sketching are lower among Parkinson's patients, particularly those with a severe form of the disease. Image copyright RMIT University Image caption Treatment options are effective only when the disease is diagnosed early In the trial, a tablet computer with special software took measurements during the drawing test and was able to distinguish those with the disease, and how severe it was. Poonam Zham, study researcher from RMIT University, said: "Our aim was to develop an affordable and automated electronic system for early-stage diagnosis of Parkinson's disease, which could be easily used by a community doctor or nursing staff." The system combines pen speed and pressure into one measurement, which can be used to tell how severe the disease is. David Dexter, deputy research director at Parkinson's UK, said current tests for the disease were not able to accurately measure how advanced someone's condition was. "This can impact on the ability to select the right people for clinical research, which is essential to develop new and better treatments for Parkinson's. "This new test could provide a more accurate assessment by measuring a wider range of features that may be affected by Parkinson's, such as co-ordination, pressure, speed and cognitive function." He added that the test could be a "stepping stone" to better clinical trials for Parkinson's. © 2017 BBC.

Keyword: Parkinsons
Link ID: 24042 - Posted: 09.07.2017

By Matt Reynolds Putting on a brave face won’t fool this algorithm. A new system that rates how much pain someone is in just by looking at their face could help doctors decide how to treat patients. By examining tiny facial expressions and calibrating the system to each person, it provides a level of objectivity in an area where that’s normally hard to come by. “These metrics might be useful in determining real pain from faked pain,” says Jeffrey Cohn at the University of Pittsburgh in the US. The system could make the difference between prescribing potentially addictive painkillers and catching out a faker. Objectively measuring pain levels is a tricky task, says Dianbo Liu, who created the system with his colleagues at the Massachusetts Institute of Technology. People experience and express pain differently, so a doctor’s estimate of a patient’s pain can often differ from a self-reported pain score. In an attempt to introduce some objectivity, Liu and his team trained an algorithm on videos of people wincing and grimacing in pain. Each video consisted of a person with shoulder pain, who had been asked to perform a different movement and then rate their pain levels. The result was an algorithm that can use subtle differences in facial expressions to inform a guess about how a given person is feeling. Certain parts of the face are particularly revealing, says Liu. Large amounts of movement around the nose and mouth tended to suggest higher self-reported pain scores. © Copyright New Scientist Ltd.

Keyword: Pain & Touch; Emotions
Link ID: 24026 - Posted: 09.02.2017

By Mitch Leslie When people with asthma have trouble breathing, they may reach for an inhaler containing salbutamol, a drug that expands the airways. Salbutamol may have another beneficial effect—protecting against Parkinson’s disease. Individuals who inhaled the highest doses of salbutamol were about half as likely to develop the devastating neurological condition as those who didn’t take the drug, a study reveals. “I’m sure it’s going to be a landmark paper,” says neurologist Joseph Jankovic of Baylor College of Medicine in Houston, Texas, who wasn’t involved in the research. In Parkinson’s disease, gobs of the protein α-synuclein accumulate in certain brain cells and may kill them. Scientists have tried to craft drugs that speed the elimination of the protein or prevent it from clumping. Neurologist and genomicist Clemens Scherzer of Harvard Medical School in Boston and colleagues decided to try a different strategy. “We wanted to find a drug that could turn down the production of α-synuclein,” he says. To identify promising compounds, the team grew human nerve cells in the lab and tested whether more than 1100 medications, vitamins, dietary supplements, and other molecules altered their output of α-synuclein. Three of the drugs that cut the protein’s production, including salbutamol, work by stimulating the b2-adrenoreceptor—a molecule on some body cells that triggers a variety of effects, including relaxing the airways. The researchers found that these drugs appear to alter how tightly the DNA containing the α-synuclein gene coils, and thus whether the gene is active. © 2017 American Association for the Advancement of Science

Keyword: Parkinsons
Link ID: 24023 - Posted: 09.01.2017

Ewen Callaway Japanese researchers report promising results from an experimental therapy for Parkinson’s disease that involves implanting neurons made from ‘reprogrammed’ stem cells into the brain. A trial conducted in monkeys with a version of the disease showed that the treatment improved their symptoms and seemed to be safe, according to a report published on 30 August in Nature1. The study’s key finding — that the implanted cells survived in the brain for at least two years without causing any dangerous effects in the body — provides a major boost to researchers’ hopes of testing stem-cell treatments for Parkinson’s in humans, say scientists. Jun Takahashi, a stem-cell scientist at Kyoto University in Japan who led the study, says that his team plans to begin transplanting neurons made from induced pluripotent stem (iPS) cells into people with Parkinson’s in clinical trials soon. The research is also likely to inform several other groups worldwide that are testing different approaches to treating Parkinson’s using stem cells, with trials also slated to begin soon. Parkinson’s is a neurodegenerative condition caused by the death of cells called dopaminergic neurons, which make a neurotransmitter called dopamine in certain areas of the brain. Because dopamine-producing brain cells are involved in movement, people with the condition experience characteristic tremors and stiff muscles. Current treatments address symptoms of the disease but not the underlying cause. © 2017 Macmillan Publishers Limited,

Keyword: Parkinsons; Stem Cells
Link ID: 24019 - Posted: 08.31.2017

By Mo Costandi Voluntary movements are one of the brain’s main “outputs,” yet science still knows very little about how networks of neurons plan, initiate and execute them. Now, researchers from Columbia University and the Champalimaud Center for the Unknown in Lisbon, Portugal, say they have discovered an “activity map” that the brain uses to guide animals’ movements. The findings, published Wednesday in Neuron, could advance our understanding of how the brain learns new movements—and of what goes wrong in related disorders such as Parkinson's disease. Movements are controlled and coordinated by multiple brain structures including the primary motor cortex. Located at the back of the frontal lobe, it contains cells whose long fibers extend down through the spinal cord, where they contact “secondary” motor neurons that signal the body muscles. A set of deep brain structures called the basal ganglia are also critical for movement, as evidenced by their degeneration in conditions such as Parkinson’s. One component of the basal ganglia, called the striatum, receives information about possible actions from the motor cortex and is thought to be involved in selecting, preparing and executing the appropriate commands before they are sent to the body. Earlier research had shown that signals leave the striatum along one of two distinct pathways: one that facilitates movement, and another that suppresses it. A number of more recent studies show that both pathways are active during motion, however, suggesting that they do not act by simply sending “stop” and “go” signals. And although it has long been suspected that different groups of neurons in the striatum represent distinct actions, exactly how they might do so has remained unclear. © 2017 Scientific American

Keyword: Parkinsons; Brain imaging
Link ID: 24016 - Posted: 08.31.2017

Andrea Hsu Dan Fabbio was 25 and working on a master's degree in music education when he stopped being able to hear music in stereo. Music no longer felt the same to him. When he was diagnosed with a brain tumor, he immediately worried about cancer. Fortunately, his tumor was benign. Unfortunately, it was located in a part of the brain known to be active when people listen to and make music. Fabbio told his surgeon that music was the most important thing is his life. It was his passion as well as his profession. His surgeon understood. He's someone whose passion has been mapping the brain so he can help patients retain as much function as possible. Dr. Web Pilcher, chair of the Department of Neurosurgery at the University of Rochester Medical Center, and his colleague Brad Mahon, a cognitive neuroscientist, had developed a brain mapping program. Since 2011, they've used the program to treat all kinds of patients with brain tumors: mathematicians, lawyers, a bus driver, a furniture maker. Fabbio was their first musician. The idea behind the program is to learn as much as possible about the patient's life and the patient's brain before surgery to minimize damage to it during the procedure. "Removing a tumor from the brain can have significant consequences depending upon its location," Pilcher says. "Both the tumor itself and the operation to remove it can damage tissue and disrupt communication between different parts of the brain." © 2017 npr

Keyword: Hearing; Pain & Touch
Link ID: 24002 - Posted: 08.26.2017

Laurel Hamers Scientists have traced the sensation of itch to a place you can’t scratch. The discomfort of a mosquito bite or an allergic reaction activates itch-sensitive nerve cells in the spinal cord. Those neurons talk to a structure near the base of the brain called the parabrachial nucleus, researchers report in the Aug. 18 Science. It’s a region that’s known to receive information about other sensations, such as pain and taste. The discovery gets researchers one step closer to finding out where itch signals ultimately end up. “The parabrachial nucleus is just the first relay center for [itch signals] going into the brain,” says study coauthor Yan-Gang Sun, a neuroscientist at the Chinese Academy of Sciences in Shanghai. Understanding the way these signals are processed by the brain could someday provide relief for people with chronic itch, Sun says. While the temporary itchiness of a bug bite is annoying, longer term, “uncontrollable scratching behavior can cause serious skin damage.” Previous studies have looked at the way an itch registers on the skin or how neurons convey those sensations to the spinal cord. But how those signals travel to the brain has been a trickier question, and this research is a “major step” toward answering it, says Zhou-Feng Chen, director of the Center for the Study of Itch at Washington University School of Medicine in St. Louis. |© Society for Science & the Public 2000 - 2017.

Keyword: Pain & Touch
Link ID: 23972 - Posted: 08.18.2017