ABSTRACT
My friends who study the problem of axon regeneration in the central nervous system regard my fascination with peripheral nervous system regeneration as similar to the attitude of the late-night reveller who was asked why he was looking for his lost keys on the side of the street opposite to where he dropped them: his explanation was that “Its lighter over here.” There is some truth to this. It is undeniably more satisfying to study regeneration when it does occur, and it has provided insights into fundamental changes in the nervous system necessary to support regeneration, as well as the components of a sustaining environment for axon growth. Yet, studied on its own, it is unlikely to yield the keys to central nervous system regeneration. There is no need to make excuses for studying peripheral nerve regeneration: it remains an important health issue. In humans, peripheral nerve regeneration is slow and apparently much less successful than in small laboratory animals, and so there is much to be learned about fostering peripheral regeneration, not only after traumatic nerve injury, but also following resolution of toxic and metabolic neuropathies. In addition, insights gained from regeneration studies are also illuminating the understanding of neuropathic pain.
