Taurine in the developing rabbit visual system: Changes in concentration and axonal transport including a comparison with axonally transported proteins

[³⁵S]Taurine injected intravitreally into rabbits was transported axonally to the optic nerve terminals. Considerably more [³⁵S]taurine was transported in young rabbits than in mature rabbits. The time course of taurine transport did not parallel that of proteins labeled with [³H]proline in the same system. The concentration of taurine in all components of the visual system, except retina, was greater in young animals than in mature animals, and was especially high in optic nerve. The possible functions of the high concentrations of taurine and the greater amount of axonally transported taurine in developing mammalian CNS are discussed.