Fig. 5. Classification of four types of new nerve sprouts. (A-D) Nerves in whole-mounted, wounded corneas are green (FITC anti-GAP-43) against a red propidium iodide-stained background. Four types of new nerve sprouts were seen: (A) New growing sprouts from intact nerves; (B) New growth from basal layers; (C) New growth from a cut stump (arrowhead shows the cut end of the nerve); (D) complex nerves with no clear orientation. New sprouts from intact existing nerves formed the majority of the total new nerve population and were the only type of nerve changing dramatically with time and different drug treatment (A). Arrows in (A,C), cut edge at 0 hours. Bars, 50 µm.