Transient outgrowth from retinae implanted in the neonatal rat cerebral cortex.

Retinae placed in the cortex of neonatal rodents show substantial outgrowth, both along the subpial margin and within the cortical white matter, which is not sustained beyond 6 days post-transplantation. These results, in combination with previous studies, suggest that optic axon outgrowth is sustained for a finite period, after which it requires target-derived influences for its long-term maintenance.