Breakthrough: Nerve Connections Regrown After Spinal Cord Injury

For the first time, researchers have been able to induce significant regeneration of nerve connections that control voluntary movement after spinal cord injury.  This has the potential to develop into curing paralysis and other motor function impairments.

The breakthrough came during a study on mice when scientists manipulated an enzyme involved in cell growth. The researchers were working on a way to switch on the signalling pathway that encourages new growth.  They did it by knocking out a gene called PTEN.  PTEN activity is low early during development which allows cell proliferation, and then it turns on when growth is completed.

The technique worked, and significant regrowth was present in the mice.  Until now, this had been impossible in the spinal cord.

Currently the ability to grow new nerve cells is present at birth but diminishes with age.  This means that the nerve cell fibers, known as axons, do not regenerate.

Zhigang He, a senior neurology researcher, first showed in a 2008 study that blocking PTEN in mice enabled the regeneration of connections from the eye to the brain after optic nerve damage at the Harvard Medical Center.

He then partnered with Oswald Steward and Binhai Zheng to see if the same approach could promote nerve regeneration in injured spinal cord sites.

“Paralysis and loss of function from spinal cord injury has been considered untreatable, but our discovery points the way toward a potential therapy to induce regeneration of nerve connections following spinal cord injury in people,” said Dr. Steward.

The UC San Diego, US Irvine, and Harvard University team achieved this breakthrough.

Although not quite ready for human research, the scientists are now working on tests to see if the technique can actually restore spinal cord function.