The proposed studies will further characterize proteoglycans that are rapidly transported in axons of the intact and regenerating goldfish optic nerve. Proteoglycans are of interest in this regard because of their increasing implication in neuronal functions of mature, developing and regenerating nervous tissue. The studies will address the specific aims of (1) further characterizing the composition, membranous localization and subsynaptic distribution of proteoglycans undergoing axonal transport, (2) assessing the effects of synaptic activity on proteoglycan turnover and redistribution and (3) further characterizing changes in proteoglycan transport that have been shown to accompany optic nerve regeneration. The latter aim will include study of the role of transported proteoglycans in the growth of neurites from regenerating retina in explant culture. These studies will utilize methods commonly utilized in proteoglycan research including labeling with radioactive markers, ion exchange chromatography, gel filtration chromatography, affinity chromatography, SDS gel electrophoresis, and enzymatic chemical treatment of proteoglycans and constituent oligosaccharide chains. The results of these studies should help lead to an understanding of the roles for proteoglycans in normal nerve function and in the remarkably successful regeneration of fish CNS neurons.
