抄録
Retina, an isolated sensory organ, is a kind of central nervous tissues. We demonstrate changes of neural regeneration capability of mammalian retina from an early postnatal stage to a mature one in vitro. Retinal explants from mice at postnatal days 2-15 were three-dimensionally cultured in collagen gel. The regeneration of neurites from the explants was investigated at each stage after birth. The explant from the central region in the retina could not regenerate neurites after postnatal day 9, but those from peripheral regions expressed such ability until postnatal day 12. This regional difference in the disappearance stages of retinal regenerative capability coincides with that of retinal maturation. After postnatal day 15 no regenerating neurites from the explants was observed. The optic nerve (ON) transection resolved this difficulty in adult rodents. The retina was dissected from the animals 1,3,5,7,11, and 15 days after the ON transection. A drastic outgrowth of neurites was observed when the axotomy had been performed 7 days prior to explantation. The period was also critical period for degradation of adult rat retinal ganglion cells (RGCs). With this culture method we revealed that interleukins, IL-ig and IL-6, and hepatocyte conditioned media enhanced neural regeneration from retina explant of adult rats.
