Chapter 11. Motor Control and Plasticity

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 1 - 20 of 1315

By Jocelyn Kaiser A virus that shuttles a therapeutic gene into cells has strengthened the muscles, improved the motor skills, and lengthened the lifespan of mice afflicted with two neuromuscular diseases. The approach could one day help people with a range of similar disorders, from muscular dystrophy to amyotrophic lateral sclerosis, or ALS. Many of these diseases involve defective neuromuscular junctions—the interface between neurons and muscle cells where brain signals tell muscles to contract. In one such disease, a form of familial limb-girdle myasthenia, people carry two defective copies of the gene called DOK7, which codes for a protein that’s needed to form such junctions. Their hip and shoulder muscles atrophy over many years, and some eventually have trouble breathing or end up in a wheelchair. Mice similarly missing a properly working Dok7 gene are severely underweight and die within a few weeks. In the new study, researchers led by molecular biologist Yuji Yamanashi of the University of Tokyo first injected young mice engineered to have defective Dok7 with a harmless virus carrying a good copy of the Dok7 gene, which is expressed only in muscle. Within about 7 weeks, the rodents recovered. Their muscle cells cranked out the DOK7 protein, and under a microscope their muscles had larger neuromuscular junctions than those of untreated mice with defective Dok7. What’s more, the mice grew to a healthy body weight and had essentially normal scores on tests of motor skills and muscle strength. © 2014 American Association for the Advancement of Science.

Keyword: Movement Disorders; Aggression
Link ID: 20096 - Posted: 09.19.2014

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, below left). 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 Reed Business Information Ltd.

Keyword: Brain imaging; Aggression
Link ID: 20068 - Posted: 09.12.2014

By Tanya Lewis, In an experiment that sounds more like science fiction than reality, two humans were able to send greetings to each other using only a digital connection linking their brains. Using noninvasive means, researchers made brain recordings of a person in India thinking the words "hola" and "ciao," and then decoded and emailed the messages to France, where a machine converted the words into brain stimulation in another person, who perceived the signals as flashes of light. From the sequence of flashes, the French recipient was able to successfully interpret the greetings, according to a new study published today (Sept. 5) in the journal PLOS ONE. The researchers wanted to know if it is possible for two people to communicate by reading out the brain activity of one person and injecting that activity into a second person. "Could we develop an experiment that would bypass the talking or typing part of [the] Internet and establish direct brain-to-brain communication between subjects located far away from each other, in India and France?" co-author Dr. Alvaro Pascual-Leone said in a statement. Pascual-Leone is a neurologist at Beth Israel Deaconess Medical Center in Boston, and a professor at Harvard Medical School, in Cambridge, Massachusetts. To answer that question, Pascual-Leone and his colleagues at Starlab Barcelona, in Spain, and Axilum Robotics, in Strasbourg, France, turned to several widely used brain technologies. Electroencephalogram, or EEG, recordings are taken by placing a cap of electrodes on a person's scalp, and recording the electrical activity of large regions of the brain's cortex. Previous studies have recorded EEG from a person thinking about an action, such as moving his or her arm, while a computer translates the signal into an output used to move a robotic exoskeleton or drive a wheelchair.

Keyword: Brain imaging; Aggression
Link ID: 20038 - Posted: 09.06.2014

By GRETCHEN REYNOLDS Amyotrophic lateral sclerosis has been all over the news lately because of the ubiquitous A.L.S. ice bucket challenge. That attention has also reinvigorated a long-simmering scientific debate about whether participating in contact sports or even vigorous exercise might somehow contribute to the development of the fatal neurodegenerative disease, an issue that two important new studies attempt to answer. Ever since the great Yankees first baseman Lou Gehrig died of A.L.S. in 1941 at age 37, many Americans have vaguely connected A.L.S. with athletes and sports. In Europe, the possible linkage has been more overtly discussed. In the past decade, several widely publicized studies indicated that professional Italian soccer players were disproportionately prone to A.L.S., with about a sixfold higher incidence than would have been expected numerically. Players were often diagnosed while in their 30s; the normal onset is after 60. These findings prompted some small, follow-up epidemiological studies of A.L.S. patients in Europe. To the surprise and likely consternation of the researchers, they found weak but measurable associations between playing contact sports and a heightened risk for A.L.S. The data even showed links between being physically active — meaning exercising regularly — and contracting the disease, raising concerns among scientists that exercise might somehow be inducing A.L.S. in susceptible people, perhaps by affecting brain neurons or increasing bodily stress. But these studies were extremely small and had methodological problems. So to better determine what role sports and exercise might play in the risk for A.L.S., researchers from across Europe recently combined their efforts into two major new studies. The results should reassure those of us who exercise. The numbers showed that physical activity — whether at work, in sports or during exercise — did not increase people’s risk of developing A.L.S. © 2014 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 20031 - Posted: 09.03.2014

By JOHN MARKOFF STANFORD, Calif. — In factories and warehouses, robots routinely outdo humans in strength and precision. Artificial intelligence software can drive cars, beat grandmasters at chess and leave “Jeopardy!” champions in the dust. But machines still lack a critical element that will keep them from eclipsing most human capabilities anytime soon: a well-developed sense of touch. Consider Dr. Nikolas Blevins, a head and neck surgeon at Stanford Health Care who routinely performs ear operations requiring that he shave away bone deftly enough to leave an inner surface as thin as the membrane in an eggshell. Dr. Blevins is collaborating with the roboticists J. Kenneth Salisbury and Sonny Chan on designing software that will make it possible to rehearse these operations before performing them. The program blends X-ray and magnetic resonance imaging data to create a vivid three-dimensional model of the inner ear, allowing the surgeon to practice drilling away bone, to take a visual tour of the patient’s skull and to virtually “feel” subtle differences in cartilage, bone and soft tissue. Yet no matter how thorough or refined, the software provides only the roughest approximation of Dr. Blevins’s sensitive touch. “Being able to do virtual surgery, you really need to have haptics,” he said, referring to the technology that makes it possible to mimic the sensations of touch in a computer simulation. The software’s limitations typify those of robotics, in which researchers lag in designing machines to perform tasks that humans routinely do instinctively. Since the first robotic arm was designed at the Stanford Artificial Intelligence Laboratory in the 1960s, robots have learned to perform repetitive factory work, but they can barely open a door, pick themselves up if they fall, pull a coin out of a pocket or twirl a pencil. © 2014 The New York Times Company

Keyword: Robotics; Aggression
Link ID: 20023 - Posted: 09.02.2014

Learning is easier when it only requires nerve cells to rearrange existing patterns of activity than when the nerve cells have to generate new patterns, a study of monkeys has found. The scientists explored the brain’s capacity to learn through recordings of electrical activity of brain cell networks. The study was partly funded by the National Institutes of Health. “We looked into the brain and may have seen why it’s so hard to think outside the box,” said Aaron Batista, Ph.D., an assistant professor at the University of Pittsburgh and a senior author of the study published in Nature, with Byron Yu, Ph.D., assistant professor at Carnegie Mellon University, Pittsburgh. The human brain contains nearly 86 billion neurons, which communicate through intricate networks of connections. Understanding how they work together during learning can be challenging. Dr. Batista and his colleagues combined two innovative technologies, brain-computer interfaces and machine learning, to study patterns of activity among neurons in monkey brains as the animals learned to use their thoughts to move a computer cursor. “This is a fundamental advance in understanding the neurobiological patterns that underlie the learning process,” said Theresa Cruz, Ph.D., a program official at the National Center for Medical Rehabilitations Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “The findings may eventually lead to new treatments for stroke as well as other neurological disorders.”

Keyword: Learning & Memory; Aggression
Link ID: 20008 - Posted: 08.28.2014

by Tom Siegfried René Descartes was a very clever thinker. He proved his own existence, declaring that because he thought, he must exist: “I think, therefore I am.” But the 17th century philosopher-mathematician-scientist committed a serious mental blunder when he decided that the mind doing the thinking was somehow separate from the brain it lived in. Descartes believed that thought was insubstantial, transmitted from the ether to the pineal gland, which played the role of something like a Wi-Fi receiver embedded deep in the brain. Thereafter mind-brain dualism became the prevailing prejudice. Nowadays, though, everybody with a properly working brain realizes that the mind and brain are coexistent. Thought processes and associated cognitive mental activity all reflect the physics and chemistry of cells and molecules inhabiting the brain’s biological tissue. Many people today do not realize, though, that there’s a modern version of Descartes’ mistaken dichotomy. Just as he erroneously believed the mind was distinct from the brain, some scientists have mistakenly conceived of the brain as distinct from the body. Much of the early research in artificial intelligence, for instance, modeled the brain as a computer, seeking to replicate mental life as information processing, converting inputs to outputs by logical rules. But even if such a machine could duplicate the circuitry of the brain, it would be missing essential peripheral input from an attached body. Actual intelligence requires both body and brain, as the neurologist Antonio Damasio pointed out in his 1994 book, Descartes’ Error. “Mental activity, from its simplest aspects to its most sublime, requires both brain and body proper,” Damasio wrote. © Society for Science & the Public 2000 - 2013.

Keyword: Consciousness
Link ID: 20002 - Posted: 08.27.2014

Ian Sample, science editor Scientists have prevented muscle wastage in mice with a form of muscular dystrophy by editing the faulty gene that causes the disease. The radical procedure could not be performed in humans, but researchers believe the work raises hopes for future gene-editing therapies to stop the disease from progressing in people. Duchenne muscular dystrophy is caused by mutations in a gene on the X chromosome and affects around one in 3,500 boys. Because girls have two X chromosomes they tend not to be affected, but can be carriers of the disease. The pivotal gene is used to make a protein called dystrophin which is crucial for muscle fibre strength. Without the protein, muscles in the body, including the heart and skeletal muscles, weaken and waste away. Most patients die by the age of 25 from breathing or heart problems. Researchers in the US used a powerful new gene-editing procedure called CRISPR to correct mutations in the dystrophin gene in mice that were destined to develop the disease. They extracted mouse embryos from their mothers and injected them with the CRISPR biological machinery, which found and corrected the faulty gene. After the injections, the mouse embryos were reimplanted in females and carried to term. Tests on the mice found that the therapy helped to restore levels of dystrophin, and that their skeletal muscle performed normally, even when only 17% of their cells contained corrected genes. The procedure could not be done in humans, but the proof-of-principle experiment demonstrates that correcting only a small proportion of cells could lead to a dramatic improvement for patients. © 2014 Guardian News and Media Limited

Keyword: Movement Disorders; Aggression
Link ID: 19966 - Posted: 08.16.2014

By Lenny Bernstein Comedian Robin Williams was grappling with severe depression when he committed suicide Monday, and on Thursday we learned that he also was in the early stages of Parkinson's disease. Sadly, the two conditions are often found together. In a 2012 study conducted by the National Parkinson Foundation, 61 percent of 5,557 Parkinson's patients surveyed reported that they also suffered from depression, with symptoms that ranged from mild to severe. Both conditions are associated with a shortage of dopamine, a neurotransmitter that helps regulate movement and control the brain's pleasure center. "Dopamine is a feel-good chemical. If you are low in dopamine, you are not going to feel so good," said Joyce Oberdorf, president and CEO of the National Parkinson Foundation. "There are [also] other neurotransmitters that can be low." A separate study published Friday found that newly-diagnosed Parkinson's patients have higher rates of depression, anxiety, fatigue, and apathy than a control group of people without Parkinson's. Researchers from the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania found that 13.9 percent of patients had symptoms of depression when they were diagnosed with Parkinson's, a proportion that rose to 18.7 percent after 24 months. Just 6.6 percent of people without the disease had depression, and that dropped to just 2.4 percent after 24 months. Despite their depressive symptoms, most of the Parkinson's patients who also had that condition were not treated with anti-depressants at any point in the two-year study. The findings were published in the journal Neurology.

Keyword: Parkinsons; Aggression
Link ID: 19961 - Posted: 08.16.2014

by Catherine Brahic Think crayfish and you probably think supper, perhaps with mayo on the side. You probably don't think of their brains. Admittedly, crayfish aren't known for their grey matter, but that might be about to change: they can grow new brain cells from blood. Humans can make new neurons, but only from specialised stem cells. Crayfish, meanwhile, can convert blood to neurons that resupply their eyestalks and smell circuits. Although it's a long way from crayfish to humans, the discovery may one day help us to regenerate our own brain cells. Olfactory nerves are continuously exposed to damage and so naturally regenerate in many animals, from flies to humans, and crustaceans too. It makes sense that crayfish have a way to replenish these nerves. To do so, they utilise what amounts to a "nursery" for baby neurons, a little clump at the base of the brain called the niche. In crayfish, blood cells are attracted to the niche. On any given day, there are a hundred or so cells in this area. Each cell will split into two daughter cells, precursors to full neurons, both of which migrate out of the niche. Those that are destined to be part of the olfactory system head to two clumps of nerves in the brain called clusters 9 and 10. It's there that the final stage of producing new smell neurons is completed. © Copyright Reed Business Information Ltd.

Keyword: Neurogenesis; Aggression
Link ID: 19954 - Posted: 08.13.2014

By ZACH SCHONBRUN EAST RUTHERFORD, N.J. — Victor Cruz dumped a bucket of ice water on his head at home on Sunday and then stepped out on thin ice himself — challenging the Giants’ co-owners to do the same. Taking part in the Ice Bucket Challenge — a social media craze that raises awareness for Lou Gehrig’s disease (amyotrophic lateral sclerosis) — Cruz, a wide receiver, posted the video on his Twitter feed. “That water was cold, man,” Cruz said Monday. The Ice Bucket Challenge was started by friends and family members of Pete Frates, a 29-year-old from Beverly, Mass., who played baseball at Boston College and was found to have A.L.S., a neurodegenerative condition, in 2012. As a reward for withstanding the icy punishment, the participant gets to nominate another person, who has 24 hours to complete the task. Cruz aimed high, calling out the co-owners John Mara and Steve Tisch to step under the bucket themselves. Just before practice on Monday, the 59-year-old Mara, wearing a white Giants T-shirt and black shorts, allowed Cruz to dump a Gatorade tub filled with ice water over his head. Before doing so, Mara nominated the Jets’ owner, Woody Johnson; the Patriots’ owner, Robert K. Kraft; and Patriots Coach Bill Belichick to do the same. “Feels good,” a smiling Mara said in a video posted on the Giants’ team website. It is unclear if Tisch will follow suit. Those who fail to complete the task within 24 hours are asked to donate to A.L.S. research. © 2014 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 19937 - Posted: 08.12.2014

By Fredrick Kunkle The way older people walk may provide a reliable clue about how well their brain is aging and could eventually allow doctors to determine whether they are at risk of Alzheimer’s, researchers have found. The study, involving thousands of older people in several countries, suggests that those whose walking pace begins to slow and who also have cognitive complaints are more than twice as likely to develop dementia within 12 years. The findings are among the latest attempts to find and develop affordable, inexpensive diagnostic tools to determine whether a person is at risk for dementia. Last month, researchers attending the Alzheimer’s Association International Conference in Copenhagen presented several studies focused on locating biomarkers of dementia in its earliest stages. Among other things, scientists reported a connection between dementia and sense of smell that suggested a common scratch-and-sniff test could be used to help identify onset of dementia, while other researchers suggested that eye scans could also be useful someday be able to detect Alzheimer’s. Different studies found a new abnormal protein linked to Alzheimer’s and a possible link between sleep disorders and the onset of dementia. Now, researchers at the Albert Einstein College of Medicine of Yeshiva University and Montefiore Medical Center say that a simple test to measure a patient’s cognitive abilities and walking speed could provide a new diagnostic tool to identify people at risk for dementia. It could be especially important tool in low- and middle-income countries with less access to sophisticated and costly technology, the scientists said.

Keyword: Alzheimers
Link ID: 19910 - Posted: 08.02.2014

Using data from over 18,000 patients, scientists have identified more than two dozen genetic risk factors involved in Parkinson’s disease, including six that had not been previously reported. The study, published in Nature Genetics, was partially funded by the National Institutes of Health (NIH) and led by scientists working in NIH laboratories. A gene chip. Scientists used gene chips to help discover new genes that may be involved with Parkinson's disease “Unraveling the genetic underpinnings of Parkinson’s is vital to understanding the multiple mechanisms involved in this complex disease, and hopefully, may one day lead to effective therapies,” said Andrew Singleton, Ph.D., a scientist at the NIH’s National Institute on Aging (NIA) and senior author of the study. Dr. Singleton and his colleagues collected and combined data from existing genome-wide association studies (GWAS), which allow scientists to find common variants, or subtle differences, in the genetic codes of large groups of individuals. The combined data included approximately 13,708 Parkinson’s disease cases and 95,282 controls, all of European ancestry. The investigators identified potential genetic risk variants, which increase the chances that a person may develop Parkinson’s disease. Their results suggested that the more variants a person has, the greater the risk, up to three times higher, for developing the disorder in some cases.

Keyword: Parkinsons; Aggression
Link ID: 19889 - Posted: 07.29.2014

Maggie Fox NBC News Walking is an almost magic elixir, doctors like to say. It can reverse diabetes, lower blood pressure, and help people keep the fat off. Now a study shows it can also help people with Parkinson’s disease. Parkinson’s patients who walked just three times a week felt less tired, less depressed and they found their Parkinson’s symptoms improved, also. “The results of our study suggest that walking may provide a safe and easily accessible way of improving the symptoms of Parkinson’s disease and improve quality of life,” Dr. Ergun Uc of the University of Iowa and the Veterans Affairs Medical Center of Iowa City, who led the study. The findings would only apply to Parkinson’s patients who can still walk easily. Parkinson’s is caused by the loss of brain cells that produce a message carrying-chemical, or neurotransmitter, that is important for movement. Symptoms can start with a barely noticeable trembling but worsen to difficulty walking and talking, depression and other disability. There’s no cure and the drugs used to treat the condition usually stop helping over time. Some people have trouble walking. But for those who don’t, the study found, walking can help their symptoms. And other research suggests that regular exercise can help slow down the progression of Parkinson’s. Various programs show that dancing,cycling, Pilates and even boxing can help. But walking has a big advantage – people can do it anywhere, without special equipment, and on their own schedules.

Keyword: Parkinsons
Link ID: 19786 - Posted: 07.03.2014

Simon Makin Running helps mice to recover from a type of blindness caused by sensory deprivation early in life, researchers report. The study, published on 26 June in eLife1, also illuminates processes underlying the brain’s ability to rewire itself in response to experience — a phenomenon known as plasticity, which neuroscientists believe is the basis of learning. More than 50 years ago, neurophysiologists David Hubel and Torsten Wiesel cracked the 'code' used to send information from the eyes to the brain. They also showed that the visual cortex develops properly only if it receives input from both eyes early in life. If one eye is deprived of sight during this ‘critical period’, the result is amblyopia, or ‘lazy eye’, a state of near blindness. This can happen to someone born with a droopy eyelid, cataract or other defect not corrected in time. If the eye is opened in adulthood, recovery can be slow and incomplete. In 2010, neuroscientists Christopher Niell and Michael Stryker, both at the University of California, San Francisco (UCSF), showed that running more than doubled the response of mice's visual cortex neurons to visual stimulation2 (see 'Neuroscience: Through the eyes of a mouse'). Stryker says that it is probably more important, and taxing, to keep track of the environment when navigating it at speed, and that lower responsiveness at rest may have evolved to conserve energy in less-demanding situations. “It makes sense to put the visual system in a high-gain state when you’re moving through the environment, because vision tells you about far away things, whereas touch only tells you about things that are close,” he says. © 2014 Nature Publishing Group

Keyword: Vision; Aggression
Link ID: 19779 - Posted: 07.01.2014

By Jim Tankersley COLUMBUS, Ohio — First they screwed the end of the gray cord into the metal silo rising out of Ian Burkhart’s skull. Later they laid his right forearm across two foam cylinders, and they wrapped it with thin strips that looked like film from an old home movie camera. They ran him through some practice drills, and then it was time for him to try. If he succeeded at this next task, it would be science fiction come true: His thoughts would bypass his broken spinal cord. With the help of an algorithm and some electrodes, he would move his once-dead limb again — a scientific first. “Ready?” the young engineer, Nick Annetta, asked from the computer to his left. “Three. Two. One.” Burkhart, 23, marshaled every neuron he could muster, and he thought about his hand. 1 of 14 The last time the hand obeyed him, it was 2010 and Burkhart was running into the Atlantic Ocean. The hand had gripped the steering wheel as he drove the van from Ohio University to North Carolina’s Outer Banks, where he and friends were celebrating the end of freshman year. The hand unclenched to drop his towel on the sand. Burkhart splashed into the waves, the hand flying above his head, the ocean warm around his feet, the sun roasting his arms, and he dived. In an instant, he felt nothing. Not his hand. Not his legs. Only the breeze drying the saltwater on his face.

Keyword: Robotics
Link ID: 19770 - Posted: 06.25.2014

THE star of the World Cup may not be able to bend it like Beckham, but they might be able to kick a ball using the power of their mind. If all goes to plan, a paralysed young adult will use an exoskeleton controlled by their thoughtsMovie Camera to take the first kick of the football tournament in Thursday's opening ceremony in São Paulo, Brazil. The exoskeleton belongs to the Walk Again Project, an international collaboration using technology to overcome paralysis. Since December, the project has been training eight paralysed people to use the suit, which supports the lower body and is controlled by brain activity detected by a cap of electrodes placed over the head. The brain signals are sent to a computer, which converts them into movement. Lead robotic engineer Gordon Cheng, at the Technical University of Munich, Germany, says that there is a phenomenal amount of technology within the exoskeleton, including sensors that feed information about pressure and temperature back to the arms of the user, which still have sensation. The team hopes this will replicate to some extent the feeling of kicking a ball. The exoskeleton isn't the only technology on show in Brazil. FIFA has announced that fans will decide who is man of the match by voting for their favourite player on Twitter during the second half of each game using #ManOfTheMatch. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 19720 - Posted: 06.12.2014

by Laura Sanders Transplanted cells can flourish for over a decade in the brain of a person with Parkinson’s disease, scientists write in the June 26 Cell Reports. Finding that these cells have staying power may encourage clinicians to pursue stem cell transplants, a still-experimental way to counter the brain deterioration that comes with Parkinson’s. Penelope Hallett of Harvard University and McLean Hospital in Belmont, Mass., and colleagues studied postmortem brain tissue from five people with advanced Parkinson’s. The five had received stem cell transplants between four and 14 years earlier. In all five people’s samples, neurons that originated from the transplanted cells showed signs of good health and appeared capable of sending messages with the brain chemical dopamine, a neurotransmitter that Parkinson’s depletes. Results are mixed about whether these transplanted cells are a good way to ease Parkinson’s symptoms. Some patients have shown improvements after the new cells stitched themselves into the brain, while others didn’t benefit from them. The cells can also cause unwanted side effects such as involuntary movements. P. J. Hallett et al. Long-term health of dopaminergic neuron transplants in Parkinson’s disease patients. Cell Reports. Vol. 7, June 26, 2014. doi: 10.1016/j.celrep.2014.05.027. © Society for Science & the Public 2000 - 2013

Keyword: Parkinsons; Aggression
Link ID: 19707 - Posted: 06.07.2014

By Kelly Servick During the World Cup next week, there may be 1 minute during the opening ceremony when the boisterous stadium crowd in São Paulo falls silent: when a paraplegic young person wearing a brain-controlled, robotic exoskeleton attempts to rise from a wheelchair, walk several steps, and kick a soccer ball. The neuroscientist behind the planned event, Miguel Nicolelis, is familiar with the spotlight. His lab at Duke University in Durham, North Carolina, pioneered brain-computer interfaces, using surgically implanted electrodes to read neural signals that can control robotic arms. Symbolically, the project is a homecoming for Nicolelis. He has portrayed it as a testament to the scientific progress and potential of his native Brazil, where he founded and directs the International Institute of Neuroscience of Natal. The press has showered him with attention, and the Brazilian government chipped in nearly $15 million in support. But scientifically, the project is a departure. Nicolelis first intended the exoskeleton to read signals from implanted electrodes, but decided instead to use a noninvasive, EEG sensor cap. That drew skepticism from Nicolelis’s critics—and he has a few—that the system wouldn’t really be a scientific advance. Others have developed crude EEG-based exoskeletons, they note, and it will be impossible to tell from the demo how this system compares. A bigger concern is that the event could generate false hope for paralyzed patients and give the public a skewed impression of the field’s progress. © 2014 American Association for the Advancement of Science

Keyword: Robotics
Link ID: 19698 - Posted: 06.06.2014

By MICHAEL BEHAR One morning in May 1998, Kevin Tracey converted a room in his lab at the Feinstein Institute for Medical Research in Manhasset, N.Y., into a makeshift operating theater and then prepped his patient — a rat — for surgery. A neurosurgeon, and also Feinstein Institute’s president, Tracey had spent more than a decade searching for a link between nerves and the immune system. His work led him to hypothesize that stimulating the vagus nerve with electricity would alleviate harmful inflammation. “The vagus nerve is behind the artery where you feel your pulse,” he told me recently, pressing his right index finger to his neck. The vagus nerve and its branches conduct nerve impulses — called action potentials — to every major organ. But communication between nerves and the immune system was considered impossible, according to the scientific consensus in 1998. Textbooks from the era taught, he said, “that the immune system was just cells floating around. Nerves don’t float anywhere. Nerves are fixed in tissues.” It would have been “inconceivable,” he added, to propose that nerves were directly interacting with immune cells. Nonetheless, Tracey was certain that an interface existed, and that his rat would prove it. After anesthetizing the animal, Tracey cut an incision in its neck, using a surgical microscope to find his way around his patient’s anatomy. With a hand-held nerve stimulator, he delivered several one-second electrical pulses to the rat’s exposed vagus nerve. He stitched the cut closed and gave the rat a bacterial toxin known to promote the production of tumor necrosis factor, or T.N.F., a protein that triggers inflammation in animals, including humans. “We let it sleep for an hour, then took blood tests,” he said. The bacterial toxin should have triggered rampant inflammation, but instead the production of tumor necrosis factor was blocked by 75 percent. “For me, it was a life-changing moment,” Tracey said. What he had demonstrated was that the nervous system was like a computer terminal through which you could deliver commands to stop a problem, like acute inflammation, before it starts, or repair a body after it gets sick. “All the information is coming and going as electrical signals,” Tracey said. For months, he’d been arguing with his staff, whose members considered this rat project of his harebrained. “Half of them were in the hallway betting against me,” Tracey said. © 2014 The New York Times Company

Keyword: Robotics
Link ID: 19649 - Posted: 05.23.2014