Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSF study finds nerve regeneration is possible in spinal cord injuries

05.12.2005


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.

The study, reported in the November 15 issue of the Proceedings of the National Academy of Sciences, builds on earlier findings in which the researchers were able to induce cell growth by manipulating the nervous system before a spinal cord injury, but not after.


Key to the research is an important difference in the properties of the nerve fibers of the central nervous system (CNS), which consists of the brain and spinal cord, and those of the peripheral nervous system (PNS), which is the network of nerve fibers that extends throughout the body.

Nerve cells normally grow when they are young and stop when they are mature. When an injury occurs in CNS cells, the cells are unable to regenerate on their own. In PNS cells, however, an injury can stimulate the cells to regrow. PNS nerve regeneration makes it possible for severed limbs to be surgically reattached to the body and continue to grow and regain function.

Regeneration occurs because PNS cell bodies are sensitive to damage to their nerve processes, and they react by sending out a signal that triggers the nerve fibers to regrow, explains Allan Basbaum, PhD, senior study author and chair of the UCSF Department of Anatomy. "Apparently this communication doesn’t take place within the CNS."

Scientists do not yet know the biochemical cause for the difference, he adds.

The traditional scientific approach in efforts to enhance CNS regeneration is to manipulate the biochemical environment of the cells at the site of the spinal cord injury, according to Basbaum. Instead of this type of investigation, Basbaum’s team used nervous system manipulation techniques to apply the principles of PNS cell growth capability to CNS cells.

The researchers took advantage of an unusual class of nerve fibers that has both a PNS and a CNS branch. Previously, the researchers had shown in animal studies that an injury made to the peripheral branch prior to a spinal cord injury provided the essential communication signal that enabled the CNS branch to grow. But this only worked if the PNS injury--which served as priming for CNS cell growth--was made at least a week before the CNS injury. "Clearly this would have no utility in clinical situations, where treatments cannot be made in anticipation of spinal cord injury," says Basbaum. Another challenge the researchers faced was stimulating CNS cells to grow beyond the injury site and into healthy tissue, which is essential to help regain function.

"A PNS injury at the time of spinal cord damage will only promote growth of nerve fibers into the spinal cord lesion, but not into the tissue beyond it. This is because growth capacity is enhanced, but it is not sustained," he explains. In the new study, researchers evaluated the effect of two peripheral nerve lesions (injuries) in animals with spinal cord injury. One lesion was made at the time of the cord injury and a second was made a week later. Both lesions were located in the animals’ sciatic nerve, which is part of the PNS.

The researchers found that the two "priming lesions" not only promoted significant spinal cord regeneration within the area of the spinal cord injury, but more important, the regenerating axons grew back into normal areas of the spinal cord, where the hope is that functional connections can be reestablished. Axons are the long, fragile, fibers that conduct impulses between nerve cells in the brain, spinal cord and limbs.

"Getting the growth beyond the lesion is key. If we can get those axons to grow even a few centimeters past the lesion, they can start sending signals and developing new circuits throughout the body," says Basbaum. Basbaum adds that timing is critical for successful nerve regeneration. "There is a window of opportunity just after the injury when the potential for growth through and beyond the lesion is greatest. If we wait too long after an injury, the cells revert back to their normal, no-growth state. Plus, scar tissue begins to form, making growth difficult." "These findings give us hope. The nervous system is capable of being modified to a level where we can achieve nerve fiber growth. Ultimately, the goal is to promote growth and sustain it long enough for recovery of movement to occur in spinal cord injury patients," he concludes. Study co-authors include first-author Simona Neumann, PhD, and Kate Skinner, MD, both of UCSF. The research was funded by the Roman Reed Spinal Cord Injury Research Fund of California and the National Institutes of Health.

Linda Gebroe | EurekAlert!

More articles from Studies and Analyses:

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>