The findings point to the promise of using this type of cells for possible therapies to help humans who have spinal cord injuries. Study results appear online in the Proceedings of the National Academy of Sciences Early Edition.

In their study, Brian Cummings, Aileen Anderson and colleagues injected adult human neural stem cells into mice with limited mobility due to spinal cord injuries. These transplanted stem cells differentiated into new oligodendrocyte cells that restored myelin around damaged mouse axons. Additionally, transplanted cells differentiated into new neurons that formed synaptic connections with mouse neurons.

Myelin is the biological insulation for nerve fibers that is critical for maintenance of electrical conduction in the central nervous system. When myelin is stripped away through disease or injury, sensory and motor deficiencies result and, in some cases, paralysis can occur. Previous Reeve-Irvine research has shown that transplantation of oligodendrocyte precursors derived from human embryonic stem cells restores mobility in rats.

"We set out to find whether these cells would be able to respond to the injury in an appropriate and beneficial way on their own," Cummings said. "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."

Mice that received human neural stem cells nine days after spinal cord injury showed improvements in walking ability compared to mice that received either no cells or a control transplant of human fibroblast cells (which cannot differentiate into nervous system cells). Further experiments showed behavi
'"/>

Contact: Tom Vasich
tmvasich@uci.edu
949-824-6455
University of California - Irvine
19-Sep-2005