Independence of the rapid axonal transport of protein from the flow of free amino acids.

Abstract

The level of TCA-precipitable and TCA-soluble radioactivity was measured in the optic nerve and optic tectum of goldfish after injecting tritiated leucine into one eye. It was demonstrated that protein synthesized in the retina is transported down the nerve to the contralateral optic tectum, at a rate of 50–70 mm/day. This rapid transport of protein cannot be accounted for by a transport of free amino acid. It was demonstrated that free amino acid is able to reach the optic nerve but unable to reach the contralateral optic tectum.