Behavioral investigation of neurotoxicity: the effects of colchicine, lumicolchicine and vincristine sulfate on goldfish optic nerve regeneration.

Experiments were carried out to investigate a behavioral method of assessing neurotoxicity. The proposition is that developing or regenerating neurons. The regenerating optic nerve in goldfish was examined as a preparation for investigating the effects of chemicals on neuronal development. Restoration of optic nerve connections following crushing of the optic nerve, as detected by a noninvasive behavioral technique permitting sequential testing of individual fish, occurred within 17 days. The effect on regeneration of biweekly, intraperitoneal administration of alkaloid neurotoxins was investigated. Regeneration was inhibited by colchicine and vincristine sulfate but not by lumicolchicine. The potency of vincristine was approximately twice that of colchicine. Neither drug had a detectable effect on the maintenance of optic nerve function in sham-operated fish. The results suggest that the behavioral protocol can be used to identify chemical agents which impair neuronal development in vivo, and to estimate their relative neurotoxicity.