http://www.sciencedaily.com/releases/2009/12/091209121152.htm
<p>ScienceDaily (Dec. 10, 2009) — Brain and spinal-cord injuries typically leave people with permanent impairment because the injured nerve fibers (axons) cannot regrow. A study from Children’s Hospital Boston, published in the December 10 issue of the journal Neuron, shows that axons can regenerate vigorously in a mouse model when a gene that suppresses natural growth factors is deleted…</p>