Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Releasing the brakes on spinal cord growth

08.02.2012
The new working group led by Professor Frank Bradke at the DZNE is studying how nerve cells can be stimulated to regenerate themselves in the case of paraplegia

While broken bones, muscle tears or wounds in the skin usually heal by themselves, the situation is different in the spinal cord. If the spinal cord is severed, it never grows together again. The result is paraplegia.

Yet why doesn’t the spinal cord regenerate? And how can people suffering from paraplegia nevertheless be helped? These questions stand at the centre of research being conducted by Professor Frank Bradke and his new working group at the German Centre for Neurodegenerative Diseases (DZNE) in Bonn.

Nerve cells in the central nervous system are surrounded by a myelin sheath. This layer protects the nerve cells but also prevents their regeneration following injuries. It contains a whole series of molecules that may prevent the regrowth of nerve fibres. According to Bradke, these molecules are “comparable to stop signs for road traffic.” If a nerve fibre encounters such a stop sign, it does not grow any further. Scientists around the world are working to identify these growth-inhibiting molecules. Bradke has chosen a different approach, however: he and his working group are focusing on the nerve cells themselves. Why do they stop at the stop signs? Can nerve cells be made to ignore the stop signs and simply continue growing?
“We are trying to turn nerve cells into somewhat more reckless drivers,” says Bradke. Bradke’s previous work has already demonstrated that this approach is highly promising: he has shown using animal models that small quantities of Taxol, a substance that is also used in cancer therapy, can stabilise the cytoskeleton of the nerve cells in such a way that severed nerve cells are stimulated to grow again.

Bradke’s discovery that Taxol could help regrow severed nerves was the result of many years of research on nerve cell development. In the early stages of development a nerve cell starts to produce a range of cellular projections. One of these projections becomes the axon and grows rapidly. Axons can be up to one metre long in the spinal cord of humans and they transmit electrical nerve signals to downstream cells. All other projections become dendrites – they are shorter and receive the signals from upstream nerve cells. During his doctoral studies Bradke was already investigating how the development of the axon differs from that of dendrites and why it is that axons continue to grow while dendrites stop growing.
Bradke demonstrated that the cytoskeleton plays a fundamental role in this respect. The growth cone at the end of the axon contains actin bundles. These must be flexible enough so that the axon can grow. The axon itself contains microtubules which give the long projections of the nerve cells their structure. In the growth cone these must be stable enough to push the actin filaments forwards. A nerve projection can only grow when the microtubules are stable enough and the actin filaments are unstable enough. This is the case in axons but not in dendrites. Following an injury to the spinal cord, microtubules in the axons are destroyed and become unstable – the axon can therefore no longer grow. Would it be possible, asked Bradke, to restore the ability of axons to grow simply by stabilising the microtubules? Taxol is a substance that stabilises microtubules. Bradke and his colleagues showed that administering small quantities of Taxol induced nerve growth. “Taxol also has another property: it prevents the formation of scars. This makes the regeneration of the nerve fibres considerably easier,” says Bradke.

These research results are still a long way from practical implementation in clinical settings, but they do give important suggestions for new directions in research. Treatments that directly affect the cytoskeleton can boost the growth of nerve cells. “In the long term our research can also contribute to a better understanding of neurodegenerative diseases of the brain such as stroke, Parkinson and Alzheimer’s Disease, because nerve cells are also damaged in these diseases and axons lose their contacts with downstream cells,” Bradke says.

Frank Bradke studied at Freie Universität Berlin and at University College London. In 1994 he received a Bachelor of Science in Anatomy and Developmental Biology and in 1995 he received his Diploma in Biochemistry. During his doctoral work he conducted research at the European Molecular Biology Laboratory (EMBL) in Heidelberg. He took up postdoctoral positions at the University of California, San Francisco, and Stanford in 2000 and then became the head of the Neurobiology Working Group at the Max Plank Institute in Martinsried. In 2009 Frank Bradke received his venia legendi from LMU Munich. Since 2011 he has been a full professor and Senior Research Group Leader of the "Axonal Growth and Regeneration Working Group" at DZNE in Bonn.
Contact information:
Dr. Katrin Weigmann
Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)
Media and Public Relations
E-mail: katrin.weigmann@dzne.de
Tel: +49 (0) 228 / 43302 263
Mobile: +49 (0) 173 – 5471350

Katrin Weigmann | idw
Further information:
http://www.dzne.de
http://www.dzne.de/en/centers/bonn-cologne-juelich/research-groups/bradke.html

More articles from Life Sciences:

nachricht Chip-based optical sensor detects cancer biomarker in urine
05.12.2019 | The Optical Society

nachricht Scientist identify new marker for insecticide resistance in malaria mosquitoes
05.12.2019 | Liverpool School of Tropical Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Detailed insight into stressed cells

05.12.2019 | Life Sciences

State of 'hibernation' keeps haematopoietic stem cells young - Niches in the bone marrow protect from ageing

05.12.2019 | Life Sciences

First field measurements of laughing gas isotopes

05.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>