In addition, knowing how these neurons regenerate could provide insights into fixing neurons in the central nervous system where damage is irreversible.
Nerve cells are uniquely shaped, consisting of a cell body from which a long "arm," called an axon, extends. Axons can reach up to one meter in length and are the main conduit for nerve communication throughout our bodies, by conveying electric signals to muscles or other cells. Due to their great length, axons, like electrical or telecommunications lines, are vulnerable to damage. When a power line goes down in a storm, monitoring systems raise the alarm and repair crews are dispatched to the site. How does an axon 'raise the alarm' after damage in our own bodies?
In a study published in Neuron, Dr. Michael Fainzilber and Ph.D. students Shlomit Hanz and Eran Pearlson of the Biological Chemistry Department have now shown that a special protein is produced at the site of damage in the axon. Called importin beta, it normally resides far away from the axon, near the nucleus of nerve cells. There, it facilitates the entry of molecules into the nucleus along with its "sister" molecule, importin alpha.
The scientists found that importin beta is produced in the axons upon injury. It then binds to importing alpha, which is normally present in axons, and to proteins that contain the "healing message" (which still have to be identified). The whole group fastens itself to an "engine" called dynein that chugs along "tracks" leading from the axon to the nucl
Contact: Alex Smith
American Committee for the Weizmann Institute of Science