NGF enhances neurite regeneration from nerve-transected terminals of young adult and aged mouse dorsal root ganglia in vitro.

Dorsal root ganglia with nerve fibers, dissected from 3-month-old young adult mice and 26-month-old aged mice, were embedded in collagen gel. In the young adult mice regenerating neurites appeared from nerve-transected terminals after 12-24 h in culture, regardless of the length of fibers, but in the aged mice, regenerating neurites were first seen after 12-48 h. Administration of nerve growth factor to the explants markedly enhanced the growth of regenerating neurites from both the young adult and aged mice.