Application of CNTF or FGF-2 increases the number of M2-like macrophages after optic nerve injury in adult Rana pipiens.

We have previously shown that a single application of the growth factors ciliary neurotrophic factor (CNTF) or fibroblast growth factor 2 (FGF-2) to the crushed optic nerve of the frog, Rana pipiens, increases the numbers and elongation rate of regenerating retinal ganglion cell axons. Here we investigate the effects of these factors on the numbers and types of macrophages that invade the regeneration zone. In control PBS-treated nerves, many macrophages are present 100 μm distal to the crush site at 1 week after injury; their numbers halve by 2 weeks.