A recent study showed that regeneration of damaged nerves due to brain or spinal cord is possible by silencing natural growth inhibitors.

Researchers at the Children's Hospital Boston removed the two key inhibitory regulators of the mTOR pathway known as PTEN and TSC1. Found in the brain cells of mice, these regulators are known to be active in cells during growth and development, but eventually slow down in control once neurons have matured. 

Within two weeks the mice were mechanically damaged for the optic nerve. The study showed that after two weeks of staying injured, nearly 50% of the damaged neurons in the mice who had the gene deletions of PTEN or TSC1 survived whereas survival rate for mice minus the deletions was just about 20%. Moreover 10% among the surviving mice exhibited noteworthy re-growth of axons which appeared to increase over time. 

Zhigang He, PhD, Associate Professor of Neurology at Children's said: "This is the first time it has been possible to see such significant regeneration by manipulating single molecules."