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When the spinal cord is injured, the damaged nerve fibers — called axons — are normally incapable of regrowth, leading to permanent loss of function. Considerable research has been done to find ways to promote the regeneration of axons following injury. Results of a study performed in mice and published in Cell Metabolism suggests that increasing energy supply within these injured spinal cord nerves could help promote axon regrowth and restore some motor functions. The study was a collaboration between the National Institutes of Health and the Indiana University School of Medicine in Indianapolis. “We are the first to show that spinal cord injury results in an energy crisis that is intrinsically linked to the limited ability of damaged axons to regenerate,” said Zu-Hang Sheng, Ph.D., senior principal investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a co-senior author of the study. Like gasoline for a car engine, the cells of the body use a chemical compound called adenosine triphosphate (ATP) for fuel. Much of this ATP is made by cellular power plants called mitochondria. In spinal cord nerves, mitochondria can be found along the axons. When axons are injured, the nearby mitochondria are often damaged as well, impairing ATP production in injured nerves. “Nerve repair requires a significant amount of energy,” said Dr. Sheng. “Our hypothesis is that damage to mitochondria following injury severely limits the available ATP, and this energy crisis is what prevents the regrowth and repair of injured axons.” Adding to the problem is the fact that, in adult nerves, mitochondria are anchored in place within axons. This forces damaged mitochondria to remain in place while making it difficult to replace them, thus accelerating a local energy crisis in injured axons.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27091 - Posted: 03.04.2020

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,

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26985 - Posted: 01.23.2020

Nicole Ireland · Recent video from Thailand showing paralyzed Humboldt Broncos hockey player Ryan Straschnitzki moving his legs after an electrical stimulation device was surgically implanted in his spine has sparked excitement — as well as questions — about therapies available to Canadians with spinal injuries. The procedure Straschnitzki, 20, had is called epidural stimulation, and although promising, it's still highly experimental, experts in both Canada and the U.S. say. It's in early stages of clinical trials in the U.S. and Europe to evaluate the safety and effectiveness of restoring physical abilities — from bowel and bladder function to moving arms and legs — to people who desperately want to get some normalcy back after spinal injury. Barry Munro understands all too well why people's immediate reaction is to ask why they can't try the procedure here in Canada. He's been hoping for — and working toward — finding a cure for spinal cord injury ever since he dove into a lake in his 20s and was left quadriplegic. Now 55, Munro is chief development officer for the Canadian Spinal Research Organization and works with the North American Spinal Injury Consortium. For more than 30 years, he's seen the headlines come and go, inciting hope that a cure is on the horizon. "I've been down this road before," Munro told CBC News. "I really, really believe in finding a cure and believe it will happen and I have that hope. But — there's a big but — we have to be careful." Milos Popovich, director of the KITE Research Institute at the University Health Network's Toronto Rehabilitation Institute, echoes that need to proceed with caution. He said that epidural stimulation must proceed through many more stages of scientifically sound clinical trials to prove it works before it could be made available as a therapy in Canada. ©2019 CBC/Radio-Canada.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26810 - Posted: 11.11.2019

By James Gallagher Health and science correspondent, BBC News Nerves inside paralysed people's bodies have been "rewired" to give movement to their arms and hands, say Australian surgeons. Patients can now feed themselves, put on make-up, turn a key, handle money and type at a computer. Paul Robinson, 36 from Brisbane, said the innovative surgery had given him independence he had never imagined. Completely normal function has not been restored, but doctors say the improvement is life-changing. How does the procedure work? Injuries to the spinal cord stop messages getting from the brain to control the rest of the body. The impact is paralysis. Patients in the trial had quadriplegia affecting movement in all their limbs. But crucially they were still able to move some muscles in their upper arms. The functioning nerves leading from the spinal cord to these muscles were then rewired. The nerves were cut and then attached to nerves that control other muscles - such as for extending the arm or opening or closing the hand. For example, nerves that once turned the palm up to face the ceiling could be used to extend all the fingers in the hand. So now when a patient thinks of rotating their hand, their fingers extend. "We believe that nerve transfer surgery offers an exciting new option, offering individuals with paralysis the possibility of regaining arm and hand functions to perform everyday tasks, and giving them greater independence and the ability to participate more easily in family and work life," said Dr Natasha van Zyl from Austin Health in Melbourne. © 2019 BBC

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 26393 - Posted: 07.05.2019

Catherine Offord The Japanese government’s health ministry has given the go-ahead for a trial of human induced pluripotent stem cells to treat spinal cord injury, Reuters reports today (February 18). Researchers at Keio University plan to recruit four adults who have sustained recent nerve damage in sports or traffic accidents. “It’s been 20 years since I started researching cell treatment. Finally we can start a clinical trial,” Hideyuki Okano of Keio University School of Medicine told a press conference earlier today, The Japan Times reports. “We want to do our best to establish safety and provide the treatment to patients.” The team’s intervention involves removing differentiated cells from patients and reprogramming them via human induced pluripotent stem cells (iPSCs) into neural cells. Clinicians will then inject about 2 million of these cells into each patient’s site of injury. The approach has been successfully tested in a monkey, which recovered the ability to walk after paralysis, according to the Times. It’s not the first time Japan has approved the use of iPSCs in clinical trials. Last year, researchers at Kyoto University launched a trial using the cells to treat Parkinson’s disease. And in 2014, a team at the RIKEN Center for Developmental Biology led the first transplant of retina cells grown from iPSCs to treat a patient’s eye disease. © 1986 - 2019 The Scientist

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 25976 - Posted: 02.21.2019

David Cyranoski Japan has approved a stem-cell treatment for spinal-cord injuries. The event marks the first such therapy for this kind of injury to receive government approval for sale to patients. “This is an unprecedented revolution of science and medicine, which will open a new era of healthcare,” says oncologist Masanori Fukushima, head of the Translational Research Informatics Center, a Japanese government organization in Kobe that has been giving advice and support to the project for more than a decade. But independent researchers warn that the approval is premature. Ten specialists in stem-cell science or spinal-cord injuries, who were approached for comment by Nature and were not involved in the work or its commercialization, say that evidence that the treatment works is insufficient. Many of them say that the approval for the therapy, which is injected intravenously, was based on a small, poorly designed clinical trial. They say that the trial’s flaws — including that it was not double-blinded — make it difficult to assess the treatment’s long-term efficacy, because it is hard to rule out whether patients might have recovered naturally. And, although the cells used — known as mesenchymal stem cells (MSCs) — are thought to be safe, the infusion of stem cells into the blood has been connected with dangerous blood clots in the lungs. And all medical procedures carry risks, which makes them hard to justify unless they are proven to offer a benefit. © 2019 Springer Nature Publishing AG

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 25896 - Posted: 01.24.2019

Ian Sample Science editor Two men who were paralysed in separate accidents more than six years ago can stand and walk short distances on crutches after their spinal cords were treated with electrical stimulation. David Mzee, 28, and Gert-Jan Oskam, 35, had electrical pulses beamed into their spines to stimulate their leg muscles as they practised walking in a supportive harness on a treadmill. Doctors believe the timing of the pulses – to coincide with natural movement signals that were still being sent from the patients’ brains – was crucial. It appeared to encourage nerves that bypassed the injuries to form new connections and improve the men’s muscle control. In many spinal cord injuries a small portion of nerves remain intact but the signals they carry are too feeble to move limbs or support a person’s body weight. “They have both recovered control of their paralysed muscles and I don’t think anyone with a chronic injury, one they’ve had for six or seven years, has been able to do that before,” said Grégoire Courtine, a neuroscientist at the Swiss Federal Institute of Technology in Lausanne. “When you stimulate the nerves like this it triggers plasticity in the cells. The brain is trying to stimulate, and we stimulate at same time, and we think that triggers the growth of new nerve connections.” Mzee was paralysed in a gymnastics accident in 2010. He recovered the use of his upper body and some control of his right leg after intensive rehabilitation at a paraplegic centre in Zurich. Doctors there told him further improvement was unlikely, but after five months of training with electrical stimulation, he regained control of the muscles in his right leg and can now take a few steps without assistance. © 2018 Guardian News and Media Limited

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 25633 - Posted: 11.01.2018

By Emily Willingham In 1995 the late actor Christopher Reeve, who most famously played Superman, became paralyzed from the neck down after a horseback-riding accident. The impact from the fall left him with a complete spinal cord injury at the neck, preventing his brain from communicating with anything below it. Cases like Reeve’s are generally considered intractable injuries, absent any way to bridge the gap to restore disrupted communication lines. When Reeve died in 2004 a means of reconnection had yet to be built. Now, 14 years later, researchers have coaxed nerve cells to span the divide of a complete spinal cord injury. Their findings, described August 29 in Nature, are specific to only one kind of nerve cell and much work remains before a means of reconnection reaches patients, but the results make an impression. “From the scientific perspective, this is pretty significant,” says Yu-Shang Lee, an assistant professor of medicine at Cleveland Clinic’s Lerner Research Institute, who was not involved in the study. “As far as scientific impact, it is a good leap.” That leap across a completely compromised spinal cord relied on studies in rats and mice. The research team knew a certain type of nerve cell sometimes helps restore signaling from the spinal cord in partial spinal cord injury. Even when all direct connections to the brain are ruined, these cells can help sustain limited walking function, says Michael Sofroniew, professor of neurobiology at the University of California, Los Angeles, one of the senior authors on the study. He and his colleagues banked on the idea these cells, propriospinal neurons, might do the same if they could grow into an area of complete injury in their experimental animals. So they tried to get these cells to extend their electrical conduction fibers, the axons, into the spinal breach. © 2018 Scientific American

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 25404 - Posted: 08.31.2018

Ian Sample Science editor Rats with spinal cord injuries have regained the use of their paws after being given a groundbreaking gene therapy that helps to mend damaged nerves in the spine. The new therapy works by dissolving the dense scar tissue that forms a thick barrier between severed nerves when the spinal column is broken. Animals that were given the treatment produced an enzyme called chondroitinase which breaks down scar tissue and allows the broken nerves to reconnect with each other. Tests showed that when the therapy was given for two months, rats relearned the kinds of skilled movements they needed to grab little sugar balls from a platform. “The gene therapy has enabled us to treat large areas of the spinal cord with only one injection,” said Elizabeth Bradbury, who led the research at King’s College London. “This is important because the spinal cord is long and the pathology spreads down its whole length after injury.” While more animal studies are needed before the therapy can go into human trials, researchers hope that ultimately the treatment will help people with spinal injuries who have lost the ability to perform daily tasks, such as using a knife and fork, picking up a mug, and writing. © 2018 Guardian News and Media Limited

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 25095 - Posted: 06.16.2018

By James Gallagher Health and science correspondent, BBC News Scientists say they have taken a significant step towards the goal of giving paralysed people control of their hands again. The team at King's College London used gene therapy to repair damage in the spinal cord of rats. The animals could then pick up and eat sugar cubes with their front paws. It is early stage research, but experts said it was some of the most compelling evidence that people's hand function could one day be restored. The spinal cord is a dense tube of nerves carrying instructions from the brain to the rest of the body. The body repairs a wounded spinal cord with scar tissue. However, the scar acts like a barrier to new connections forming between nerves. How the gene therapy works The researchers were trying to dissolve components of the scar tissue in the rats' spinal cord. They needed to give cells in the cord a new set of genetic instructions - a gene - for breaking down the scar. The instructions they gave were for an enzyme called chondroitinase. And they used a virus to deliver them. Finally, a drug was used to activate the instructions. The animals regained use of their front paws after the gene therapy had been switched on for two months. Dr Emily Burnside, one of the researchers, said: "The rats were able to accurately reach and grasp sugar pellets. "We also found a dramatic increase in activity in the spinal cord of the rats, suggesting that new connections had been made in the networks of nerve cells." The researchers hope their approach will work for people injured in car crashes or falls. © 2018 BBC.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 25092 - Posted: 06.15.2018

By Ruth Williams Four patients with chronic spinal damage and a complete loss of motor and sensory functions below their waists have received transplants of human neural stem cells in a first-of-its-kind clinical trial. A report in Cell Stem Cell today (June 1) documents the procedure and the subsequent clinical follow up of the patients, who exhibit no signs of untoward effects but rather tiny hints of improvement. “It’s an extremely interesting and important piece of work,” says neurologist Eva Feldman of the University of Michigan who was not involved with the work. “The rodent model results were very compelling and . . . laid the groundwork for this very small, proof-of-concept safety trial.” While these results seem tantalizing, “the numbers [of patients] are extremely small,” says Feldman, and “the patients themselves notice no change in function or quality of life.” Severe spinal injuries can have devastating consequences, often leaving patients with complete paralysis below the injury site and with little hope of recovery. While there is currently no therapy that can promote neuronal repair in such patients, evidence from animal studies, including those carried out in primates, has indicated that transplantation of human-derived neural stem cells to the site of injury can promote some functional recovery of downstream musculature. © 1986-2018 The Scientist

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 25059 - Posted: 06.05.2018

By Ashley Yeager | Human neural stem cells transplanted into the injured spines of monkeys matured into nerve cells, spurring neuronal connections and giving the animals an improved ability to grasp an orange, researchers report today (February 26) in Nature Medicine. “This type of cellular therapy, though still in its infancy, may eventually be a reasonable approach to treating central nervous system injury and possibly even neurodegenerative disease in humans,” Jonathan Glass, a neurologist at Emory University School of Medicine, tells The Scientist by email. Glass, who was not involved in the study, notes that the differentiation of stem cells over time is “impressive,” as is their ability to make connections in the monkeys’ central nervous systems, but more work needs to be done to show if the cells can grow extremely long axons to connect motor and sensory neurons after spinal injury in humans. Up to this point, most of the work on transplanting neural stem cells had been done in rats. This is the first study to show the treatment can be successfully scaled up to primates. “We definitely have more confidence to do this type of treatment in humans,” study coauthor Mark Tuszynski, a neuroscientist at the University of California, San Diego, School of Medicine, tells The Scientist. In the study, Tuszynski and his colleagues cut into a section of the spinal cord of rhesus monkeys and then two weeks later inserted a graft of human neural progenitor cells into the injury site. In the first four monkeys, the grafts did not stay in position, a finding that forced the researchers to add to the transplants more fibrinogen–thrombin, a protein-enzyme mixture the makes the graft adhere more quickly to site. The team also had to tilt the operating table to drain cerebral spinal fluid, which would wash the graft away. © 1986-2018 The Scientist

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 24705 - Posted: 02.27.2018

Daqing Li and Ying Li In 1969 Geoffrey Raisman, who has died aged 77, introduced the term “plasticity” to describe the ability of damaged nerve tissue to form new synaptic connections. He discovered that damaged nerves in the central nervous system (CNS) could be repaired and developed the theory that white matter (nerve fibres and supporting cells) is like a pathway – when it is disrupted by injury, such as spinal cord injury, growth of the regenerating fibres is blocked. In 1985 he described how olfactory ensheathing cells (OECs) “open doors” for newly formed nerve fibres in the nose to enter the CNS. Believing that reconstruction of the damaged pathway is essential to repair of the injured CNS and using the unique door-opening capability of OECs, in 1997, together with colleagues, Geoffrey showed that transplantation of OECs into the damaged spinal cord in experimental models repairs the damaged pathway and results in the regeneration of severed nerve fibres and the restoration of lost functions. The study led to a joint clinical trial with Pawel Tabakow and his team at Wroclaw Medical University, Poland. In 2014 the first patient with a complete severance of the thoracic spinal cord received transplantation of his own OECs. The operation enabled the patient, Darek Fidyka, to gain significant neurological recovery of sensation and voluntary movement. He can now get out of his wheelchair and ride a tricycle. The wider application of OECs has also been investigated. In 2012, with his team at University College London, collaborating with the UCL Institute of Ophthalmology and Southwest hospital, at the Third Military Medical University in Chongqing, China, Geoffrey described the protective effect of OECs in an experimental glaucoma model. The discovery has led to a plan to translate this research to clinical application which, it is hoped, will help many sufferers regain sight.

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 23266 - Posted: 02.22.2017

Katherine Bourzac Kristopher Boesen, who broke his neck in a car accident, regained the ability to move his arms and hands after his spinal cord was injected with stem cells. Two years after having a stroke at 31, Sonia Olea Coontz remained partially paralysed on her right side. She could barely move her arm, had slurred speech and needed a wheelchair to get around. In 2013, Coontz enrolled in a small clinical trial. The day after a doctor injected stem cells around the site of her stroke, she was able to lift her arm up over her head and speak clearly. Now she no longer uses a wheelchair and, at 36, is pregnant with her first child. Coontz is one of stem-cell therapy's “miracle patients”, says Gary Steinberg, chair of neurosurgery at Stanford School of Medicine in California, and Coontz's doctor. Conventional wisdom said that her response was impossible: the neural circuits damaged by the stroke were dead. Most neuroscientists believed that the window for functional recovery extends to only six months after the injury. Stem-cell therapies have shown great promise in the repair of brain and spinal injuries in animals. But animal models often behave differently from humans — nervous-system injuries in rats, for example, heal more readily than they do in people. Clinical trial results have been mixed. Interesting signals from small trials have faded away in larger ones. There are plenty of unknowns: which stem cells are the right ones to use, what the cells are doing when they work and how soon after an injury they can be used. © 2016 Macmillan Publishers Limited,

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 23210 - Posted: 02.10.2017

Tim Radford Eight paraplegics – some of them paralysed for more than a decade by severe spinal cord injury – have been able to move their legs and feel sensation, after help from an artificial exoskeleton, sessions using virtual reality (VR) technology and a non-invasive system that links the brain with a computer. In effect, after just 10 months of what their Brazilian medical team call “brain training” they have been able to make a conscious decision to move and then get a response from muscles that have not been used for a decade. Of the octet, one has been able to leave her house and drive a car. Another has conceived and delivered a child, feeling the contractions as she did so. The extent of the improvements was unexpected. The scientists had intended to exploit advanced computing and robotic technology to help paraplegics recover a sense of control in their lives. But their patients recovered some feeling and direct command as well. The implication is that even apparently complete spinal cord injury might leave some connected nerve tissue that could be reawakened after years of inaction. The patients responded unevenly, but all have reported partial restoration of muscle movement or skin sensation. Some have even recovered visceral function and are now able to tell when they need the lavatory. And although none of them can walk unaided, one woman has been able to make walking movements with her legs, while suspended in a harness, and generate enough force to make a robot exoskeleton move. © 2016 Guardian News and Media Limited

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory and Learning
Link ID: 22549 - Posted: 08.12.2016

By D. T. Max When a spinal cord is damaged, location is destiny: the higher the injury, the more severe the effects. The spine has thirty-three vertebrae, which are divided into five regions—the coccygeal, the sacral, the lumbar, the thoracic, and the cervical. The nerve-rich cord traverses nearly the entire length of the spine. The nerves at the bottom of the cord are well buried, and sometimes you can walk away from damage to these areas. In between are insults to the long middle region of the spine, which begins at the shoulders and ends at the midriff. These are the thoracic injuries. Although they don’t affect the upper body, they can still take away the ability to walk or feel below the waist, including autonomic function (bowel, bladder, and sexual control). Injuries to the cord in the cervical area—what is called “breaking your neck”—can be lethal or leave you paralyzed and unable to breathe without a ventilator. Doctors who treat spinal-cord-injury patients use a letter-and-number combination to identify the site of the damage. They talk of C3s (the cord as it passes through the third cervical vertebra) or T8s (the eighth thoracic vertebra). These morbid bingo-like codes help doctors instantly gauge the severity of a patient’s injury. Darek Fidyka, who is forty-one years old, is a T9. He was born and raised in Pradzew, a small farming town in central Poland, not far from Lodz. ... Several of the wounds punctured his lungs, and one nearly cut his spinal cord in half. As Fidyka lay on the ground, he felt his body change. “I can remember very vividly losing feeling in my legs, bit by bit,” he says. “It started in the upper part of the spine and was moving down slowly while I lay waiting for the ambulance to arrive.”

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 22230 - Posted: 05.19.2016

For decades, it was thought that scar-forming cells called astrocytes were responsible for blocking neuronal regrowth across the level of spinal cord injury, but recent findings challenge this idea. According to a new mouse study, astrocyte scars may actually be required for repair and regrowth following spinal cord injury. The research was funded by the National Institutes of Health, and published in Nature. “At first, we were completely surprised when our early studies revealed that blocking scar formation after injury resulted in worse outcomes. Once we began looking specifically at regrowth, though, we became convinced that scars may actually be beneficial,” said Michael V. Sofroniew, M.D., Ph.D., professor of neurobiology at the University of California, Los Angeles, and senior author of the study. “Our results suggest that scars may be a bridge and not a barrier towards developing better treatments for paralyzing spinal cord injuries.” Neurons communicate with one another by sending messages down long extensions called axons. When axons in the brain or spinal cord are severed, they do not grow back automatically. For example, damaged axons in the spinal cord can result in paralysis. When an injury occurs, astrocytes become activated and go to the injury site, along with cells from the immune system and form a scar. Scars have immediate benefits by decreasing inflammation at the injury site and preventing spread of tissue damage. However, long-term effects of the scars were thought to interfere with axon regrowth.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 22086 - Posted: 04.09.2016

By Esther Hsieh Spinal implants have suffered similar problems as those in the brain—they tend to abrade tissue, causing inflammation and ultimately rejection by the body. Now an interdisciplinary research collaboration based in Switzerland has made a stretchable implant that appears to solve this problem. Like Lieber's new brain implant, it matches the physical qualities of the tissue where it is embedded. The “e-dura” implant is made from a silicone rubber that has the same elasticity as dura mater, the protective skin that surrounds the spinal cord and brain, explains Stéphanie Lacour, a professor at the school of engineering at the Swiss Federal Institute of Technology in Lausanne. This feature allows the implant to mimic the movement of the surrounding tissues. Embedded in the e-dura are electrodes for stimulation and microchannels for drug therapy. Ultrathin gold wires are made with microscopic cracks that allow them to stretch. Also, the electrodes are coated with a special platinum-silicone mixture that is stretchable. In an experiment that lasted two months, the scientists found that healthy rats with an e-dura spinal implant could walk across a ladder as well as a control group with no implant. Yet rats with a traditional plastic implant (which is flexible but not stretchable) started stumbling and missing rungs a few weeks after surgery. The researchers removed the implants and found that rats with a traditional implant had flattened, damaged spinal cords—but the e-dura implants had left spinal cords intact. Cellular testing also showed a strong immune response to the traditional implant, which was minimal in rats with the e-dura implant. © 2016 Scientific American

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 22039 - Posted: 03.28.2016

By SINDYA N. BHANOO Moderate levels of exercise may increase the brain’s flexibility and improve learning, a new study suggests. The visual cortex, the part of the brain that processes visual information, loses the ability to “rewire” itself with age, making it more difficult for adults to recover from injuries and illness, said Claudia Lunghi, a neuroscientist at the University of Pisa and one of the study’s authors. In a study in the journal Current Biology, she and her colleagues asked 20 adults to watch a movie with one eye patched while relaxing in a chair. Later, the participants exercised on a stationary bike for 10-minute intervals while watching a movie. When one eye is patched, the visual cortex compensates for the limited input by increasing its activity level. Dr. Lunghi and her colleagues tested the imbalance in strength between the participants’ eyes after the movie — a measure of changeability in the visual cortex. © 2015 The New York Times Company

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 15: Language and Lateralization; Chapter 5: The Sensorimotor System
Link ID: 21681 - Posted: 12.08.2015

By James Gallagher Health editor, BBC News website An elastic implant that moves with the spinal cord can restore the ability to walk in paralysed rats, say scientists. Implants are an exciting field of research in spinal cord injury, but rigid designs damage surrounding tissue and ultimately fail. A team at Ecole Polytechnique Federale de Lausanne (EPFL) has developed flexible implants that work for months. It was described by experts as a "groundbreaking achievement of technology". The spinal cord is like a motorway with electrical signals rushing up and down it instead of cars. Injury to the spinal cord leads to paralysis when the electrical signals are stuck in a jam and can no longer get from the brain to the legs. The same group of researchers showed that chemically and electrically stimulating the spinal cord after injury meant rats could "sprint over ground, climb stairs and even pass obstacles". Rat walks up stairs Previous work by the same researchers But that required wired electrodes going directly to the spinal cord and was not a long-term option. Implants are the next step, but if they are inflexible they will rub, causing inflammation, and will not work properly. The latest innovation, described in the journal Science, is an implant that moves with the body and provides both chemical and electrical stimulation. When it was tested on paralysed rats, they moved again. One of the scientists, Prof Stephanie Lacour, told the BBC: "The implant is soft but also fully elastic to accommodate the movement of the nervous system. "The brain pulsates with blood so it moves a lot, the spinal cord expands and retracts many times a day, think about bending over to tie your shoelaces. "In terms of using the implant in people, it's not going to be tomorrow, we've developed dedicated materials which need approval, which will take time. © 2015 BBC.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20465 - Posted: 01.10.2015