This work is a promising step, and supports the need to study multiple stem cell types for the possibility of treating human neurological injury and disease.

The actual cells that we transplanted, the human cells, are the ones that are making myelin. We're extremely excited about these cells.

Mechanism is always important, because without understanding it, it's difficult to predict how animal data would translate to people.

We show that these [stem] cells make connections with the nervous system of the mouse in a way that is appropriate and could mediate recovery. That's a big thing.

Immediately after the injury, nerve cells inside die and others lose their ability to pass on signals.

This is a first step in what has to be a long series of steps to get to anything clinical.