Scientists restore walking after spinal cord injury

Spinal cord damage blocks the routes that the brain uses to send messages to the nerve cells that control walking. Until now, doctors believed that the only way for injured patients to walk again was to re-grow the long nerve highways that link the brain and base of the spinal cord. For the first time, a UCLA study shows that the central nervous system can reorganize itself and follow new pathways to restore the cellular communication required for movement.

Researchers take first steps towards spinal cord reconstruction following injury

A new study has identified what may be a pivotal first step towards the regeneration of nerve cells following spinal cord injury, using the body’s own stem cells.

This seminal study, published in this week’s Proceedings of the National Academy of Science, identifies key elements in the body’s reaction to spinal injury, critical information that could lead to novel therapies for repairing previously irreversible nerve damage in the injured spinal cord.

Blood clotting protein may inhibit spinal cord regeneration

Fibrinogen, a blood-clotting protein found in circulating blood, has been found to inhibit the growth of central nervous system neuronal cells, a process that is necessary for the regeneration of the spinal cord after traumatic injury. The findings by researchers at the University of California, San Diego (UCSD) School of Medicine, may explain why the human body is unable to repair itself after most spinal cord injuries.

Nanomedicine opens the way for nerve cell regeneration

The ability to regenerate nerve cells in the body could reduce the effects of trauma and disease in a dramatic way. In two presentations at the NSTI Nanotech 2007 Conference, researchers describe the use of nanotechnology to enhance the regeneration of nerve cells. In the first method, developed at the University of Miami, researchers show how magnetic nanoparticles (MNPs) may be used to create mechanical tension that stimulates the growth and elongation of axons of the central nervous system neurons. The second method from the University of California, Berkeley uses aligned nanofibers containing one or more growth factors to provide a bioactive matrix where nerve cells can regrow.

When smell cells fail they call in stem cell reserves

Hopkins researchers have identified a backup supply of stem cells that can repair the most severe damage to the nerves responsible for our sense of smell. These reservists normally lie around and do nothing, but when neighboring cells die, the scientists say, the stem cells jump into action. A report on the discovery will appear online next week in Nature Neuroscience.

Conceptualizing a cyborg

Investigators at the University of Pennsylvania School of Medicine describe the basis for developing a biological interface that could link a patient’s nervous system to a thought-driven artificial limb. Their conceptual framework – which brings together years of spinal-cord injury research – is published in the January issue of Neurosurgery.

Stem cells as cancer therapy

It is widely hoped that neural stem cells will eventually be useful for replacing nerves damaged by degenerative diseases like Alzheimer disease and multiple sclerosis. But there may also be another use for such stem cells–delivering anti-cancer drugs to cancer cells.

A Perspective article in PLoS Medicine, by Professor Riccardo Fodder, discusses a new study in mice, published in the launch issue of PLoS ONE (www.plosone.org), that showed that neural stem cells could be used to help deliver anti-cancer drugs to metastatic cancer cells.

Major breakthrough in the mechanism of myelin formation

The discovery reported in this study sheds light on the mechanisms that control how myelin is formed during development of the nerves. The article, which will be published in the November 3rd issue of Science, constitutes an important step forward in our understanding of the process of myelination, and opens the way to new research in this field. The results of their study that could have a major impact on the treatment of diseases such as multiple sclerosis, and peripheral neuropathies.

Elevated testosterone kills nerve cells

-A Yale School of Medicine study shows for the first time that a high level of testosterone, such as that caused by the use of steroids to increase muscle mass or for replacement therapy, can lead to a catastrophic loss of brain cells.

Taking large doses of androgens, or steroids, is known to cause hyperexcitability, a highly aggressive nature, and suicidal tendencies. These behavioral changes could be evidence of alterations in neuronal function caused by the steroids, said the senior author, Barbara Ehrlich, professor of pharmacology and physiology.

Neurons grown from embryonic stem cells restore function in paralyzed rats

For the first time, researchers have enticed transplants of embryonic stem cell-derived motor neurons in the spinal cord to connect with muscles and partially restore function in paralyzed animals. The study suggests that similar techniques may be useful for treating such disorders as spinal cord injury, transverse myelitis, amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy. The study was funded in part by the NIH's National Institute of Neurological Disorders and Stroke (NINDS).

New roles for growth factors: Enticing nerve cells to muscles

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. Their findings appear in the June 15 issue of Neuron.

MIT researchers use nanofibers to restore vision in blinded rodents

Rodents blinded by a severed tract in their brains’ visual system had their sight partially restored within weeks, thanks to a tiny biodegradable scaffold invented by MIT bioengineers and neuroscientists.

This technique, which involves giving brain cells an internal matrix on which to regrow, just as ivy grows on a trellis, may one day help patients with traumatic brain injuries, spinal cord injuries and stroke.

Researchers discover botulism toxin’s insidious route into nerve cells

Botulinum neurotoxin A can be either the greatest wrinkle remover or one of the world’s most potent biological weapons. To perform either job, however, the toxin must first find a way to enter cells.

But understanding how the toxin — one of seven neurotoxins produced by the bacterium Clostridium botulinum — enters nerve cells has proved elusive for scientists. Despite a decade-long search for the receptor by labs around the world, researchers had come up empty handed.

Now, a research team led by Howard Hughes Medical Institute (HHMI) researcher Edwin R. Chapman reports that it has identified the cellular receptor for botulinum neurotoxin A. The group’s work was published in the March 16, 2006, edition of ScienceXpress, which provides electronic publication of selected Science papers in advance of print. The finding offers important new insights that suggest how the toxin shuts down nerve cells with deadly efficiency.

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.