Rapid initiation of neurite outgrowth onto laminin from explants of adult mouse retina induced by optic nerve crush.

One optic nerve of an adult mouse was crushed in the orbit. After 8 days, both retinas were explanted onto laminin-coated coverslips. Within 24 h, neurites grew out onto this substrate from explants with prior crush and by 48 h two-thirds of explants had neurites. On polylysine or plain glass, outgrowth was generally not seen until 48 h and this was significantly reduced compared to laminin. Explants without optic nerve crush did not extend neurites until about 5 days later. We suggest that axotomy induces a time-dependent regenerative response in adult mammalian retinal ganglion cells which includes the expression of laminin responsiveness.