Responses to light of retinal neurons regenerating axons into peripheral nerve grafts in the rat.

We have recorded unitary activity from axons regenerated into peripheral nerve grafts inserted into the retina of adult rats. Some retinal ganglion cells regenerating axons into these grafts had responses to light similar to those of intact retinal ganglion cells. The number of units that responded to light in these blind-ended grafts declined between 9 and 48 weeks after graft insertion. Axotomized retinal ganglion cells regenerating axons into peripheral nerve grafts thus appear, at least temporarily, to maintain or resume normal function.