University study upends old beliefs about spinal cord injuries

Researchers at UCLA say that scar tissue formed by a certain type of cell after a spinal cord injury does not impede recovery, as had been assumed for at least 20 years. The cells, called gilal cells, surround neurons in the central nervous system.

After a spinal cord injury, axons that connect the brain to the body can re-form in peripheral nerves, but not in the area where the injury occurred. This causes paralysis below the point of injury. For decades, doctors believed this inability of axons to form was due to scar tissue formed by a type of gilal cells known as astrocytes. It appeared that axons would not regrow past the scar tissue, as if they were “stalled” there.

However, after testing on lab mice, the UCLA researchers said the scar tissue has no effect. Axons in paralyzed mice did not regrow, even in mice whose genes had been manipulated to prevent their astrocytes from forming scar tissue. However, a “carrot and stick” approach of encouraging nerve regrowth appeared promising in the mice with scar tissue.

We are probably a long way off from a reliable “cure” for paralysis, but progress is being made. In the meantime, people with a spinal injury, often due to someone else’s negligence, generally must adjust to a new life.