9728517 GIORDANO Injury to a nerve in the adult mammalian central nervous system results in a permanent loss of function. In contrast, the axons of the optic nerve in zebrafish and other cold-blooded vertebrates display a remarkable capacity for functional regeneration. These differences in regenerative capacity are due, in part, to differences in the environment encountered by regenerating axons. Astrocytes, a type of glia cell, make up a large part of this non-neuronal environment and can influence axonal growth in the embryonic and the injured adult CNS. Axonal regeneration in fish may be a consequence of the unique morphological and physiological properties of astrocytes, which may be linked to the expression of specific cytoskeletal proteins,the intermediate filaments (IFP). This study will employ molecular and biochemical methods to examine the expression of IFPs in order to characterize the astrocyte cell types in the zebrafish optic nerve. The long term objective of the project is to determine the mechanisms by which non-neuronal cells of the zebrafish visual system support neuronal growth both during development and following injury.
