A complex combination of treatments, including stem cells and growth factors, can heal damaged neural circuits, allowing partially paralyzed rats to walk. These findings represent a significant step forward in regenerative medicine, providing new treatment possibilities for Amyotrophic Lateral Sclerosis (ALS) and other neurodegenerative diseases, as well as some types of spinal-cord injury.

“This work is a major stepping-stone to human application of stem-cell transplant approaches,” says Hans S. Keirstead, co-director of the Stem Cell Research Center at the University of California, Irvine. He says that the ability to grow new neural fibers out of the spinal cord “renders transplantation approaches to repair realistic.”

Previous research has shown that cell transplants and other treatments can help paralyzed rodents walk. But those experiments have focused mainly on repairing local damage within the spinal cord. They could help patients whose motor neurons — cells carrying messages from brain to spinal cord — remain intact after injury or disease.

In contrast, the current study, conducted by a team of scientists at Johns Hopkins University, focused on a longer-distance repair problem. It is the first study to show that newly grown nerve fibers can emerge from the spinal cord, extend all the way to the muscle, then form functional connections with muscle. This feat is particularly important for ALS and other disorders characterized by the loss of motor neurons. “Some may have thought this was a bridge you can’t cross,” says David Owens, research director at the National Institutes of Neurological Disorders and Stroke, which sponsored the study.
Read the full article in Technology Review (includes links to before/after video clips)

The before/after video is also viewable via Youtube:

Links to other articles on this breakthrough: