A study on mice performed by scientists at Emory University School of Medicine showed damaged peripheral nerves had improved regeneration when the mice were treated with enzymes. Peripheral nerves are the nerves that go from the spine to the muscle and skin. A nerve cell has a nucleus and a long process, called the axon. The nerve signal (which is responsible for feeling and muscle movement) travels along the axon. When the nerve is damaged, the axon is damaged and function is lost.
The axon can regenerate after injury, but such repair generally does not proceed well. There is no treatment to enhance nerve repair. Peripheral nerves do not regenerate well because of the presence of growth inhibitory substances, called proteoglycans, near of the damaged nerve.
In the study, the scientists treated the peripheral portion of severed nerves with enzymes that degrade specific types of proteoglycans. For two weeks after the injury, axons regenerated through enzyme-treated tissues much more effectively than through untreated tissues. Not only did the axons regenerate, those that did extended more than twice as far.