Retrograde transport of goldfish optic nerve proteins labeled by N-succinimidyl [3H]propionate.

Following injection of the acylating reagent N-succinimidyl [3H]propionate into the optic nerve of goldfish, labeled protein appeared in the ipsilateral retina and contralateral tectum in a time-dependent manner. Autoradiography indicated the presence of the labeled material in the neuroplasm of the retinal ganglion cells and their projections. While most of the recoverable injected radioactivity was confined to the injection site even after 1 week, labeled proteins arriving in the retina by retrograde flow or in the tectum by anterograde flow had distinctly different patterns, a result suggesting specific transport processes rather than diffusion. In contrast to reported studies with the labeling agent in other species, a prominent 68,000 molecular weight component was not seen. The results are discussed in relation to the role of retrograde transport in regeneration.