LABORATORY tests have shown that mice with spinal injuries showed improvements after getting injections of adult human neural stem cells.

The mice also showed evidence of spinal-cord-lesion repair and better mobility. A study published in the Proceedings of the National Academy of Sciences was described as a promising step, and supports the need to study multiple stem cell types for the possibility of treating human neurological injury and disease.

Experts at the University of California at Irvine’s departments of physical medicine and rehabilitation, anatomy and neurobiology, and the Reeve-Irvine Research Center, only studied mice, not people. It is not clear if the results would be the same for people.

Nine days after spinal cord injury, each mouse got four shots. Some mice got shots of adult human neural stem cells. Those cells can develop into cells of the nervous system, which includes the brain and spinal cord.

For comparison, some spine-injured mice got shots that didn’t include any cells. Other mice got shots of a type of human liver cell, which can’t become part of the nervous system.

Adult stem cells are different from embryonic stem cells. Both types of stem cells can develop into different kinds of cells. Embryonic stem cells may have a wider range of possibilities than adult stem cells.

The mice that got the stem cells improved in two ways: Some repair of spinal damage and there was better movement 16 weeks after the shots were given.

The mice used their hind paws to help coordinate movement, stated the news release. The mice in the comparison groups didn’t show either benefit.

Next, the mice got a shot of diphtheria toxin. That killed the human cells. Afterward, improvements faded for the stem cell group.
That suggests that the human stem cells played a role in the mice’s progress, but the process isn’t clear yet, the researchers write.

The human adult neural stem cells did three things in the study, according to the team. They either survived the injection, migrated to the right spot on the spine or formed a type of cell that restored a protective coating called myelin that had been stripped away by spinal damage.