Goldshmit, Y., Sztal, T.E., Jusuf, P.R., Hall, T.E., Nguyen-Chi, M., and Currie, P.D. (2012) Fgf-dependent glial cell bridges facilitate spinal cord regeneration in zebrafish. The Journal of neuroscience : the official journal of the Society for Neuroscience. 32(22):7477-7492.
Adult zebrafish show a remarkable capacity to regenerate their spinal column after injury, an ability that stands in stark
contrast to the limited repair that occurs within the mammalian CNS post-injury. The reasons for this interspecies difference
in regenerative capacity remain unclear. Here we demonstrate a novel role for Fgf signaling during glial cell morphogenesis
in promoting axonal regeneration after spinal cord injury. Zebrafish glia are induced by Fgf signaling, to form an elongated
bipolar morphology that forms a bridge between the two sides of the resected spinal cord, over which regenerating axons actively
migrate. Loss of Fgf function inhibits formation of this “glial bridge” and prevents axon regeneration. Despite the poor potential
for mammalian axonal regeneration, primate astrocytes activated by Fgf signaling adopt a similar morphology to that induced
in zebrafish glia. This suggests that differential Fgf regulation, rather than intrinsic cell differences, underlie the distinct
responses of mammalian and zebrafish glia to injury.