Human adult stem cells may offer hope for spinal cord repair

By Tom Nordlie • Published: December 29th, 2014
Category: Health in a Heartbeat

Imagine the human spinal cord as the body’s big electrical cable, and you’ll understand how paralysis can happen after a spinal cord injury.

Like a cable, the spinal cord transmits electrical signals — in this case, nerve impulses from the brain — and they travel to small nerves downstream, to control voluntary muscle movements.

If a spinal injury damages the cable, it disrupts the flow of electricity.

The result can be paralysis if nerves below the break don’t receive the electrical impulses they need.

Perhaps the worst aspect of this situation is that the healing process can generate scar tissue at the damage site, which in turn prevents nerve cells from reconnecting across the damaged part of the spinal cord.

That’s why a study published recently in the journal Neuron is intriguing. It suggests a possible way to fix the broken cable.

The study involved rats with recent spinal cord injuries. They received transplants of human adult stem cells. These are immature cells that our bodies produce continuously throughout adulthood to replace old, dying cells.

Once inside the rats’ spinal cords, the transplanted cells flourished. Some of them extended long, thin structures called axons through the scar tissue. Some of the rat nerve cells did the same.

Even better, the old and new nerve cells began connecting with each other.

However, despite this progress, the rats didn’t regain voluntary muscle movement. Researchers aren’t sure why. It could be that the new cells weren’t given enough time to mature before the experiment ended.

Whatever the reason, it seems that much work remains to be done before adult stem cells can be used to re-establish spinal cord functioning in people.

But physically reconnecting the nerve cells could be a great beginning.