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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 BP7e: 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 BP7e: 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 13: Memory, Learning, and Development
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 BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 15: Brain Asymmetry, Spatial Cognition, and Language; 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 BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20465 - Posted: 01.10.2015

Injections of a new drug may partially relieve paralyzing spinal cord injuries, based on indications from a study in rats, which was partly funded by the National Institutes of Health. The results demonstrate how fundamental laboratory research may lead to new therapies. “We’re very excited at the possibility that millions of people could, one day, regain movements lost during spinal cord injuries,” said Jerry Silver, Ph.D., professor of neurosciences, Case Western Reserve University School of Medicine, Cleveland, and a senior investigator of the study published in Nature. Every year, tens of thousands of people are paralyzed by spinal cord injuries. The injuries crush and sever the long axons of spinal cord nerve cells, blocking communication between the brain and the body and resulting in paralysis below the injury. On a hunch, Bradley Lang, Ph.D., the lead author of the study and a graduate student in Dr. Silver’s lab, came up with the idea of designing a drug that would help axons regenerate without having to touch the healing spinal cord, as current treatments may require. “Originally this was just a side project we brainstormed in the lab,” said Dr. Lang. After spinal cord injury, axons try to cross the injury site and reconnect with other cells but are stymied by scarring that forms after the injury. Previous studies suggested their movements are blocked when the protein tyrosine phosphatase sigma (PTP sigma), an enzyme found in axons, interacts with chondroitin sulfate proteoglycans, a class of sugary proteins that fill the scars.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20394 - Posted: 12.04.2014

By BENEDICT CAREY A Polish man who was paralyzed from the chest down after a knife attack several years ago is now able to get around using a walker and has recovered some sensation in his legs after receiving a novel nerve-regeneration treatment, according to a new report that has generated both hope and controversy. The case, first reported widely by the BBC and other British news outlets, has stirred as much excitement on the Internet as it has extreme caution among many experts. “It is premature at best, and at worst inappropriate, to draw any conclusions from a single patient,” said Dr. Mark H. Tuszynski, director of the translational neuroscience unit at the medical school of the University of California, San Diego. That patient — identified as Darek Fidyka, 40 — is the first to recover feeling and mobility after getting the novel therapy, which involves injections of cultured cells at the site of the injury and tissue grafts, the report said. The techniques have shown some promise in animal studies. But the medical team, led by Polish and English doctors, also emphasized that the results would “have to be confirmed in a larger group of patients sustaining similar types of spinal injury” before the treatment could be considered truly effective. The case report was published in the journal Cell Transplantation. The history of spinal injury treatment is studded with false hope and miracle recoveries that could never be replicated, experts said. In previous studies, scientists experimented with some of the same methods used on Mr. Fidyka, with disappointing results. © 2014 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 20230 - Posted: 10.22.2014

By Fergus Walsh Medical correspondent A paralysed man has been able to walk again after a pioneering therapy that involved transplanting cells from his nasal cavity into his spinal cord. Darek Fidyka, who was paralysed from the chest down in a knife attack in 2010, can now walk using a frame. The treatment, a world first, was carried out by surgeons in Poland in collaboration with scientists in London. Prof Wagih El Masri Consultant spinal injuries surgeon Details of the research are published in the journal Cell Transplantation. BBC One's Panorama programme had unique access to the project and spent a year charting the patient's rehabilitation. Darek Fidyka, 40, from Poland, was paralysed after being stabbed repeatedly in the back in the 2010 attack. He said walking again - with the support of a frame - was "an incredible feeling", adding: "When you can't feel almost half your body, you are helpless, but when it starts coming back it's like you were born again." He said what had been achieved was "more impressive than man walking on the moon". UK research team leader Prof Geoff Raisman: Paralysis treatment "has vast potential" The treatment used olfactory ensheathing cells (OECs) - specialist cells that form part of the sense of smell. OECs act as pathway cells that enable nerve fibres in the olfactory system to be continually renewed. In the first of two operations, surgeons removed one of the patient's olfactory bulbs and grew the cells in culture. Two weeks later they transplanted the OECs into the spinal cord, which had been cut through in the knife attack apart from a thin strip of scar tissue on the right. They had just a drop of material to work with - about 500,000 cells. About 100 micro-injections of OECs were made above and below the injury. BBC © 2014

Related chapters from BP7e: 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 13: Memory, Learning, and Development
Link ID: 20229 - Posted: 10.22.2014

By Rachel Feltman With the help of electrical stimulation, a paralyzed rat is "walking" again. It's actually being controlled by a computer that monitors its gait and adjusts it to keep the rat balanced. When a spinal cord is severed, the electrical pulses sent out by the brain to control limb movement are interrupted. With this method of treatment, the rat's leg movements are driven by electrical pulses shot directly into the spinal cord (which has unfortunately been severed in the name of science). Scientists have been working on this method in humans for awhile, but have only had moderate success — some subjects have regained sensation and movement in their legs, but haven't walked on their own. In the experiment described in the video above, published Wednesday in Science Translational Medicine, researchers tweaked this use of electrical stimulation: They primed the rats with a drug to boost their ability to respond to the electrical signal. Then, while the rats were placed in treadmill harnesses to support their weight, the researchers trained a camera on their subjects. The camera tracked the rats as they took electrically stimulated steps, and corrected their movement in real time. This instant feedback made the system precise enough to get the rats up tiny sets of stairs. MIT Technology Review reports that the team hopes to use a human volunteer within the next year. If the system works on humans, doctors can prescribe its use in rehabilitation therapy. You can watch the actual experiment in the video below:

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20122 - Posted: 09.27.2014

by Lisa Grossman Hasta la vista, nerve damage. Experiments with bullfrog nerves show that a Terminator-style liquid metal alloy could one day be placed in the body to help severed nerves reconnect. The alloy would stay in place until the nerve has healed, before being slurped back out with a syringe. The peripheral nervous system consists of nerves that carry electrical signals from the brain to the rest of the body. Because they aren't protected by the spine or the skull, peripheral nerves are more vulnerable to injuries than those in the central nervous system. Severed nerves can reconnect if treated quickly enough, but at a rate of just 1 millimetre per day. Also, existing methodsMovie Camera for grafting nerve ends back together have serious shortcomings. For instance, most existing scaffolds for grafts must ultimately be removed, requiring risky follow-up surgery. Even more worrisome, if the nerves don't pass signals to muscles during the healing process, the muscles can atrophy to the point where they never fully recover. Liu and his colleagues wondered if liquid metal could act as a backup system for damaged nerves, helping signals pass through a graft while the nerve healed. They used an alloy of gallium, indium and selenium, which is a very good electrical conductor. The alloy is liquid at room temperature, allowing it to be removed with a syringe when it's no longer needed. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19560 - Posted: 05.03.2014

By Meghan Rosen Paralyzed rats can now decide for themselves when it’s time to take a leak. Animals in a new study regained bladder control thanks to a new treatment that coaxes severed nerves to grow. Instead of dribbling out urine, the rodents squeezed out shots of pee almost as well as healthy rats do, researchers report June 25 in the Journal of Neuroscience. The study is the first to regenerate nerves that restore bladder function in animals with severely injured spinal cords. “This is a very big deal,” says neurologist John McDonald of the Kennedy Krieger Institute in Baltimore, Md. If the treatment works in people with spinal cord injuries, he says, “it would change their lives.” Unlike paralyzed rats, severely paralyzed humans can’t leak urine to relieve a full bladder. Unless injured people are fitted with a catheter, urine backs up into the kidneys. “These people get kidney failure all the time,” says study leader Jerry Silver, a neuroscientist at Case Western Reserve University in Cleveland. “It’s a terrible problem. If they didn’t have the catheter, they would die.” Some of the worst spinal cord injuries sever the bundle of nerve cells that reach from a mammal’s brain down through the vertebrae. The neurons can’t just grow back. Instead, the cells’ stumps get stuck in a gummy thicket of scar tissue that forms around the wound. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 15: Brain Asymmetry, Spatial Cognition, and Language; Chapter 5: The Sensorimotor System
Link ID: 18316 - Posted: 06.26.2013

By Christine Gorman In the January 2013 issue of Scientific American, D. Kacy Cullen and Douglas H. Smith of the University of Pennsylvania reported on their work using stretch-grown axons (the long thin "arm" of a nerve cell) to some day connect prosthetic devices to the peripheral nervous systems of people who had to have part of their arm amputated. There wasn't enough room to talk about it in the article, but there is another way that these "living bridges" could be used to help people with devastating injuries. The stretch-grown axons could also be used to treat people with major nerve damage that does not necessarily require amputation. The biohybrid bridge provides a conduit for the undamaged part of the peripheral nervous system to bypass the injured nerve and regrow its own axons all the way to the end of the affected limb. If such bridges could be implanted within a few days to weeks of the injury, they would benefit from the fact that neural support cells are still active throughout the length of the limb (these cells usually take a few months to disappear after nerve death) and could guide the regrowing nerve fiber to its final destination. Cullen and Smith hope to begin testing their stretch-grown axons soon in a few U.S. soldiers who were injured while fighting overseas. Cullen described their efforts in a recent email: Peripheral nerve injury (PNI) is a major source of warfighter morbidity. Indeed, only 50% of patients achieve good to normal restoration of function following surgical repair, regardless of the strategy. Moreover, failure of nerve regeneration may necessitate amputation of an otherwise salvaged limb. This stems from the inadequacy of current PNI repair strategies, where even the “gold-standard“ treatment – the nerve autograft – is largely ineffective for major nerve trauma. © 2013 Scientific American

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17682 - Posted: 01.15.2013

by Jessica Hamzelou A single session of nerve stimulation has improved the movement of people with spinal cord injuries. Mimicking the passage of nerve signals by stimulating a muscle as well as the brain has boosted recovery and helped people to regain better control of their movements. Voluntary movement requires a signal from the brain, which is passed down the spinal cord and then to neurons in muscles. Damage to the spinal cord can interrupt this pathway, resulting in paralysis. To improve the control of movement in people with these injuries, Monica Perez and Karen Bunday at the University of Pittsburgh in Pennsylvania used electrical and magnetic stimulation to strengthen the connection between two nerves involved in voluntary movement of the index finger. The pair used transcranial magnetic stimulation (TMS), a non-invasive technique in which a magnetic field alters brain activity, to target the corticospinal tract. This bundle of nerves connects movement-associated parts of the brain with the spinal cord. "The corticospinal tract plays a major role in the recovery of motor function in spinal cord injury," says Perez. Just 1 to 2 milliseconds after stimulating the brain, they used an electrode to stimulate a nerve that innervates an index-finger muscle – mimicking normal brain-to-muscle nerve signalling. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17554 - Posted: 12.01.2012

Scientists have reversed paralysis in dogs after injecting them with cells grown from the lining of their nose. The pets had all suffered spinal injuries which prevented them from using their back legs. The Cambridge University team is cautiously optimistic the technique could eventually have a role in the treatment of human patients. The study is the first to test the transplant in "real-life" injuries rather than laboratory animals. The only part of the body where nerve fibres continue to grow in adults is the olfactory system. Found in the at the back of the nasal cavity, olfactory ensheathing cells (OEC) surround the receptor neurons that both enable us to smell and convey these signals to the brain. The nerve cells need constant replacement which is promoted by the OECs. For decades scientists have thought OECs might be useful in spinal cord repair. Initial trials using OECs in humans have suggested the procedure is safe. In the study, funded by the Medical Research Council and published in the neurology journal Brain, the dogs had olfactory ensheathing cells from the lining of their nose removed. These were grown and expanded for several weeks in the laboratory. BBC © 2012

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 17509 - Posted: 11.19.2012

by Helen Thomson Paralysis may no longer mean life in a wheelchair. A man who is paralysed from the trunk down has recovered the ability to stand and move his legs unaided thanks to training with an electrical implant. Andrew Meas of Louisville, Kentucky, says it has changed his life (see "I suddenly noticed I can move my pinkie", below). The stimulus provided by the implant is thought to have either strengthened persistent "silent" connections across his damaged spinal cord or even created new ones, allowing him to move even when the implant is switched off. The results are potentially revolutionary, as they indicate that the spinal cord is able to recover its function years after becoming damaged. Previous studies in animals with lower limb paralysis have shown that continuous electrical stimulation of the spinal cord below the area of damage allows an animal to stand and perform locomotion-like movements. That's because the stimulation allows information about proprioception – the perception of body position and muscle effort – to be received from the lower limbs by the spinal cord. The spinal cord, in turn, allows lower limb muscles to react and support the body without any information being received from the brain (Journal of Neuroscience, doi.org/czq67d). Last year, Susan Harkema and Claudia Angeli at the Frazier Rehab Institute and University of Louisville in Kentucky and colleagues tested what had been learned on animals in a man who was paralysed after being hit by a car in 2006. He was diagnosed with a "motor complete" spinal lesion in his neck, which means that no motor activity can be recorded below the lesion. © Copyright Reed Business Information Ltd

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17420 - Posted: 10.25.2012

John von Radowitz A protein needed to re-grow injured nerves in limbs has been identified, raising the prospect of new treatments. The findings, in mice, have implications for helping patients recover from peripheral nerve injuries. They also open up new pathways for investigating how to regenerate neurons in the spinal cord and brain. Peripheral nerves provide the sense of touch and drive the muscles that move the arms, legs and feet. Unlike central nervous system nerves of the spinal cord, they can regrow after being cut or crushed. But how this happens is still not well understood. Scientists conducting the new research, reported in the journal Neuron, identified a signalling protein that helps switch on the regeneration process. The molecule, called leucine zipper kinase (DLK), regulates signals that tell a nerve cell it has been injured, often communicating over distances of several feet. Mice lacking DLK were unable to regrow severed nerves. Lead researcher Professor Aaron DiAntonio, from Washington University in St Louis, US, said: "DLK is a key molecule linking an injury to the nerve's response to that injury, allowing the nerve to regenerate. © independent.co.uk

Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 15: Brain Asymmetry, Spatial Cognition, and Language; Chapter 13: Memory, Learning, and Development
Link ID: 16944 - Posted: 06.21.2012

By Ferris Jabr The rat stood on its hind limbs at one end of a narrow runway. It wore a tiny black vest attached to a robotic arm that hovered above its head. Without such mechanical support, the rat would have fallen over—its spinal cord had two deep cuts, rendering its back legs useless. Rubia van den Brand, then a doctoral candidate at the University of Zurich, stood at the other end of the runway, urging the animal to walk. Although the robotic arm kept the rat upright, it could not help the creature move; if the rodent were ever to walk again, it would have to will its feet forward. For the first time since van den Brand began her experiments, the rat moved one of its back legs on its own—a small, effortful step. She ran to her boss's office with the news and a crowd immediately gathered in the lab to watch what many had deemed impossible. Van den Brand and Grégoire Courtine, now at the École Polytechnique Fédérale de Lausanne (E.P.F.L.), along with their colleagues, have trained rats with nearly severed spinal cords to walk again. One week after being injured, the rats could not move their hind limbs at all. Six weeks later they could walk, run, climb stairs and even sprint—but only with the support of the robotic arm accompanied by electrical and chemical stimulation of the spinal cord. Rats that trained on a moving treadmill instead of on a stationary runway moved their feet reflexively but never learned to walk voluntarily. Only conscious participation in walking encouraged new connections between the rodents' brains, spinal cords and limbs, which they needed to take those first deliberate steps. "It's kind of like how a toddler learns to walk," Courtine says. "Their spinal cord is full of activity and the brain needs to learn to take control of the spinal cord. As long as the brain has something to control it can learn progressively to communicate again with these cells." © 2012 Scientific American,

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16864 - Posted: 06.02.2012

A "miniature honeycomb" - or scaffold - could one day be used to encourage damaged nerves to grow and recover, according to an international group of researchers. The scaffold can channel clusters of nerves through its honeycomb of holes, eventually healing a severed nerve. The findings of their study on mouse nerves are published in the journal Biofabrication. Academics hope to one day treat spinal cord injuries with the scaffold. When nerves are severed, such as in car accidents, it can result in a loss of feeling and movement. Repairing this damage can be a challenge - but nerves outside of the brain and spinal cord can repair themselves, if only over short distances. One technique to improve this repair is to use tubes. Either end of the severed nerve is placed in a tube and the two ends of the nerve should grow and join in the middle. Researchers at the University of Sheffield and Laser Zentrum Hannover, Germany, investigated using a honeycomb structure. Dr Frederik Claeyssens, from the department of materials science and engineering at Sheffield, told the BBC: "That is much more like the structure of the nerve itself. BBC © 2012

Related chapters from BP7e: Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 16693 - Posted: 04.23.2012

Leila Haghighat At the turn of the twentieth century, the promise of regenerating damaged tissue was so far-fetched that Thomas Hunt Morgan, despairing that his work on earthworms could ever be applied to humans, abandoned the field to study heredity instead. Though he won the Nobel Prize in 1933 for his work on the role of chromosomes in inheritance, if he lived today, the advances in regenerative medicine may have tempted him to reconsider. Three studies published this week show that introducing new cells into mice can replace diseased cells — whether hair, eye or heart — and help to restore the normal function of those cells. These proof-of-principle studies now have researchers setting their sights on clinical trials to see if the procedures could work in humans. “You can grow cells in a Petri dish, but that’s not regenerative medicine,” says Robin Ali, a geneticist at University College London, who led the eye study. “You have to think about the biology of repair in a living system.” Sprouting hair In work published in Nature Communications, Japanese researchers grew different types of hair on nude mice, using stem cells from normal mice and balding humans to recreate the follicles from which hair normally emerges1. Takashi Tsuji, a regenerative-medicine specialist at Tokyo University of Science who led the study, says that the technique holds promise for treating male pattern baldness. © 2012 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 7: Vision: From Eye to Brain
Link ID: 16674 - Posted: 04.19.2012

By Tina Hesman Saey The farmer’s wife in the nursery rhyme Three Blind Mice may need a different mouse hunting strategy. Thanks to new cell transplants, some formerly night-blind mice can see in the dark again, perhaps even well enough to evade the carving knife of the farmer’s wife. Injections of light-gathering nerve cells called rods into the retinas of night-blind mice integrated into the brain’s visual system and restored sight, Robin Ali of the University College London Institute of Ophthalmology and colleagues report online April 18 in Nature. The finding gives new hope that cell transplants may reverse damage to the brain and eyes caused by degenerative diseases and help heal spinal cord injuries. Other researchers have tried, and failed, to repair damaged retinas with stem cell transplants, says Christian Schmeer, a neurologist at the University Hospital Jena in Germany. The new study is the first to demonstrate that transplanted nerve cells can restore function. "They show it is possible and they do it convincingly," Schmeer says. At the same time, Schmeer cautions, “there’s still a lot to be done until it’s ready for clinical use.” In the study, Ali’s group transplanted immature rod cells from newborn mice into the retinas of adult mice. Rods, found in the back of the eye, work in dim light conditions. Other retina cells called cones sense bright light. In previous studies, the researchers had been able to transplant about 1,000 rods into mice’s retinas, but that wasn’t enough to restore vision. By optimizing techniques, the researchers coaxed about 26,000 rod cells to incorporate into the retina of each injected eye. © Society for Science & the Public 2000 - 2012

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 7: Vision: From Eye to Brain
Link ID: 16673 - Posted: 04.19.2012

By Erica Westly Nerve cells in our limbs can regenerate after injury, but neurons in the central nervous system, which includes the brain and spinal cord, cannot. Figuring out why this is the case is critical to helping brain and spinal cord injuries heal. A study published in the January 26 issue of Neuron may offer a promising solution. Not only did the researchers, Rachid El Bejjani and Marc Hammarlund of Yale University, identify what appears to be a key chemical regulator of neuron repair, but drugs that target this regulator already exist, making the path to clinical treatments easier. The molecule they identified, called Notch, is a receptor that influences many biochemical pathways inside cells. Scientists used to think that Notch was active only during fetal and childhood development, but increasing evidence suggests that Notch is also involved in neurodegenerative conditions such as Alzheimer’s disease and stroke. Using C. elegans, a microscopic worm, El Bejjani and Hammarlund showed that Notch impeded neurons from healing themselves. When they blocked Notch’s activity with a drug, the neurons’ growth improved. The drug used in the study is already being tested in rodents and humans for potential use in Alz­hei­mer’s and other disorders, although whether it can help damaged neurons regenerate in mammals is unclear. “We know that the Notch pathway is con­served in vertebrates, but we don’t know if the re­generation mechanism is conserved,” Hammarlund says. If Notch stops neurons from growing back in humans as it does in C. elegans, it could be a major breakthrough in spinal cord medicine. © 2012 Scientific American

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 16650 - Posted: 04.14.2012