Explant culture of adult goldfish retina: a model for the study of CNS regeneration.

Conditions are described for culture of retinal explants of adult goldfish which favour outgrowth of neuritic processes onto a substratum. A growth index to quantitate the outgrowth was developed. If the optic nerve is crushed several days prior to explantation, a marked enhancement of neuritic outgrowth is seen relative to control retinas. Histological examination of the explants revealed that retinal ganglion cells in explants from unoperated eyes became hypertrophied in vitro with a time course similar to that observed in vivo following optic nerve crush. Experiments with hemiaxotomized retinas indicate that the perikaryal regenerative response is mediated intracellularly.