Effect of colchicine on axonal transport and morphology of retinal ganglion cells

Summary Intraocular injection of colchicine in doses which do not affect the protein synthesis in the retina has profound effects on the axonal transport of protein in the retinal ganglion cells of the rabbit. Rapid axonal transport in these cells is completely inhibited after treatment with relatively low amounts of colchicine. In contrast to this, a certain fraction of the slow axonal transport is resistant to colchicine treatment. Colchicine in doses which completely inhibits fast axonal transport caused discrete morphological changes in the perikaryon and in the axon of the retinal ganglion cell. No disappearance of microtubules and no general proliferation of neurofilaments was observed in the perikaryon of the retinal ganglion cells. There was a slight or moderate increase in the number of filaments in the intra-retinal part of the axons of the retinal ganglion cells.This work has been supported by grants from the Swedish Medical Research Council (B71-12X-2543-03, B71-13X-2226-05A) and the Swedish National Cancer Society (265-B70-02X).