||Last Updated: Nov 17th, 2006 - 22:35:04
Severed nerve fibers in spinal cord can regenerate for long distances
The body's spinal cord is like a super highway of nerves. When an injury occurs, the body's policing defenses put up a roadblock in the form of a scar to prevent further injury, but it stops all neural traffic from moving forward.
Aug 19, 2006, 21:45
Common brain cells may have stem-cell-like potential
University of Florida researchers have shown ordinary human brain cells may share the prized qualities of self-renewal and adaptability normally associated with stem cells. Writing online in Development, scientists from UF's McKnight Brain Institute describe how they used mature human brain cells taken from epilepsy patients to generate new brain tissue in mice. Furthermore, they can coax these pedestrian human cells to produce large amounts of new brain cells in culture, with one cell theoretically able to begin a cycle of cell division that does not stop until the cells number about 10 to the 16th power.
Aug 17, 2006, 16:02
Using Embryonic Stem Cells to Awaken Latent Motor Nerve Repair
In a dramatic display of stem cells’ potential for healing, a team of Johns Hopkins scientists reports that they’ve engineered new, completed, fully-working motor neuron circuits -- neurons stretching from spinal cord to target muscles -- in paralyzed adult animals. The research, in which mouse embryonic stem (ES) cells were injected into rats whose virus-damaged spinal cords model nerve disease, shows that such cells can be made to re-trace complex pathways of nerve development long shut off in adult mammals, the researchers say.
Jul 1, 2006, 17:23
Understanding how axons find their destinations
During embryonic development, nerve cells hesitantly extend tentacle-like protrusions called axons that sniff their way through a labyrinth of attractive and repulsive chemical cues that guide them to their target. While several recent studies discovered molecules that repel motor neuron axons from incorrect targets in the limb, scientists at the Salk Institute for Biological Studies have identified a molecule, known as FGF, that actively lures growing axons closer to the right destination.
Jun 16, 2006, 23:45
Novel stem cell technology leads to better spinal cord repair
Researchers believe they have identified a new way, using an advance in stem-cell technology, to promote recovery after spinal cord injury of rats, according to a study published in today's Journal of Biology. Scientists from the New York State Center of Research Excellence in Spinal Cord Injury showed that rats receiving a transplant of a certain type of immature support cell from the central nervous system (generated from stem cells) had more than 60 percent of their sensory nerve fibers regenerate. Just as importantly, the study showed that more than two-thirds of the nerve fibers grew all the way through the injury sites eight days later, a result that is much more promising than previous research. The rats that received the cell transplants also walked normally in two weeks.
Apr 30, 2006, 19:18
Myosin-II: A new focus for the mechanism of nerve growth
Researchers at Yale shed new light on the mechanism of nerve cell growth by identifying novel functions for a molecular "motor" protein, myosin-II, according to an article in the March issue of Nature Cell Biology.
Mar 19, 2006, 20:23
Structural remodeling of neurons demonstrated in mature brains
Despite the prevailing belief that adult brain cells don't grow, a researcher at MIT's Picower Institute for Learning and Memory reports in the Dec. 27 issue of Public Library of Science (PLoS) Biology that structural remodeling of neurons does in fact occur in mature brains. This finding means that it may one day be possible to grow new cells to replace ones damaged by disease or spinal cord injury, such as the one that paralyzed the late actor Christopher Reeve.
Dec 29, 2005, 15:58
How "baby" neurons are integrated into brain
In experiments with mice, scientists from Johns Hopkins' Institute for Cell Engineering have discovered the steps required to integrate new neurons into the brain's existing operations. For more than a century, scientists thought the adult brain could only lose nerve cells, not gain them, but in fact, new neurons do form during adulthood in all mammals, including humans, and become a working part of the adult brain in mice at the very least. In the first study to show how these "baby" neurons are integrated into the brain's existing networks, the Johns Hopkins researchers show that a brain chemical called GABA readies baby neurons to make connections to old ones. The discovery is described in the Dec. 11 advance online section of Nature.
Dec 25, 2005, 00:53
Nerve regeneration is possible in spinal cord injuries
A team of scientists at UCSF has made a critical discovery that may help in the development of techniques to promote functional recovery after a spinal cord injury. By stimulating nerve cells in laboratory rats at the time of the injury and then again one week later, the scientists were able to increase the growth capacity of nerve cells and to sustain that capacity. Both factors are critical for nerve regeneration.
Dec 4, 2005, 10:41
Silenced smedwi-2 gene shows role in regeneration
Researchers at the University of Utah have discovered that when a gene called smedwi-2 is silenced in the adult stem cells of planarians, the quarter-inch long worm is unable to carry out a biological process that has mystified scientists for centuries: regeneration. The study published in the Nov. 25 issue of Science was led by Alejandro Sánchez Alvarado, Ph.D., Howard Hughes Medical Institute investigator and professor of neurobiology and anatomy at the U of U School of Medicine, and carried out by members of his laboratory, in particular Helen Hay Whitney Foundation post-doctoral fellow Peter W. Reddien who is now an Associate Member at the Whitehead Institute for Biomedical Research.
Nov 25, 2005, 06:27
Novel role for ubiquitin/proteosome in regulation of actin dynamics
In a recent study, Dr. Ingolf Bach and colleagues from the University of Massachusetts Medical School, Worcester and the University of Hamburg (Germany) describe a novel role for the ubiquitin/proteosome protein degradation pathway in the regulation of local actin dynamics in neurons.
Oct 2, 2005, 17:53
Myosin II involved in guidance of the nerve branches
A protein that helps the ends of growing nerve cells push forward is also involved in guidance of the nerve branches, according to a study by researchers at Washington University School of Medicine in St. Louis.
Sep 16, 2005, 21:24
Gradient guides nerve growth down spinal cord
The same family of chemical signals that attracts developing sensory nerves up the spinal cord toward the brain serves to repel motor nerves, sending them in the opposite direction, down the cord and away from the brain, report researchers at the University of Chicago in the September 2005 issue of Nature Neuroscience (available online August 14). The finding may help physicians restore function to people with paralyzing spinal cord injuries.
Sep 6, 2005, 00:30
Ephrin-B3 inhibits regrowth of spinal nerve cells
A molecule that helps the body's motor nerve cells grow along proper paths during embryonic development also plays a major role in inhibiting spinal-cord neurons from regenerating after injury, researchers at UT Southwestern Medical Center have found. In cultured cells, the researchers found that a component of myelin – a substance that normally insulates and stabilizes long nerve fibers in adult vertebrates – chemically blocks the ability of nerve cells to grow through myelin that is released when the spinal cord is damaged. While other myelin components also block nerve growth, a component called ephrin-B3 inhibits such activity as well or better than that of other known blocking agents combined, UT Southwestern researchers report in an upcoming issue of the Proceedings of the National Academy of Sciences.
Jul 12, 2005, 13:04
New findings might advance search for new therapies for injured nerve fibers
Long distance messengers star in many heroic tales, perhaps the most famous being the one about the runner who carried the news about the victory of the Greeks over the Persians in the fateful battle of Marathon. A team of researchers at the Weizmann Institute of Science has now discovered how molecular messengers perform a crucial role in the ability of injured nerve cells to heal themselves.
Mar 3, 2005, 17:27
For the first time scientists have regenerated a damaged optic nerve
Scientists have regenerated a damaged optic nerve for the first time from the eye to the brain in laboratory mice. This feat holds great promise for victims of diseases that destroy the optic nerve, and for sufferers of central nervous system injuries.
Feb 24, 2005, 19:17
A STAT3 Call for Regeneration
Regeneration in the CNS after spinal cord injury is limited because of obstacles such as glial scars and myelin-based inhibitory factors. On the other hand, axons in the PNS are much more resilient. This week, Qiu et al. provide evidence for Janus kinase (JAK)–signal transducer and activator of transcription (STAT) signaling downstream of the cytokines. The JAK2–STAT3 pathway appears to be growth-promoting after a peripheral nerve injury.
Feb 16, 2005, 15:20