Injections of human stem cells seem to directly repair some of the damage caused by spinal cord injury, according to research that helped partially paralyzed mice walk again.
The experiment, reported Monday, isn't the first to show that stem cells offer tantalizing hope for spinal cord injury — other scientists have helped mice recover, too.
But the new work went an extra step, suggesting the connections that the stem cells form to help bridge the damaged spinal cord are key to recovery.
Surprisingly, they didn't just form new nerve cells. They also formed cells that create the biological insulation that nerve fibers need to communicate. A number of neurological diseases, such as multiple sclerosis, involve loss of that insulation, called myelin.
"The actual cells that we transplanted, the human cells, are the ones that are making myelin," explained lead researcher Aileen Anderson of the University of California, Irvine. "We're extremely excited about these cells."
The research is reported in Monday's issue of Proceedings of the National Academy of Sciences, reports SF Gate.
"We were excited to find that the cells responded to the damage by making appropriate new cells that could assist in repair. This study supports the possibility that formation of new myelin and new neurons may contribute to recovery," Cummings said. The findings appear in this week's Proceedings of the National Academy of Science.
After the researchers injected the stem cells into the mice, these cells which can develop into a range of neural cell types ifferentiated into new cells called oligodendrocytes that restored the myelin lining damaged axons in the mice.
Myelin is a nerve fiber covering that plays a critical role in maintaining the nervous system's electrical conduction. When injury or disease affects myelin, it can result in sensory and motor deficiencies and paralysis.
The transplanted stem cells also differentiated into new neurons that formed synaptic connections with the mouse neurons, the study authors said, informs Forbes.