Factor(s) from goldfish brain induce neuritic outgrowth from explanted regenerating retinas

The extensive outgrowth from explanted goldfish retina in vitro stimulated by the axotomy of the optic nerve several days prior to the explantation, enables a more direct examination of the events which accompany optic nerve regeneration. Thus far neuritic outgrowth has been obtained in serum-containing medium. In the present report we demonstrate for the first time that factor(s) from adult goldfish brain can support neuritic outgrowth from retinal explant and replace the serum. This finding suggests that goldfish neuronotrophic factor(s) are active on retinal ganglia cells. Under the same experimental conditions nerve growth factor from submaxillary gland did not exhibit outgrowth stimulatory activity.