Reelin/Disabled-1 Signalling Contributes to Functional Recovery on Zebrafish After Spinal Cord Injury.

Reelin, an extracellular matrix glycoprotein, plays important roles in neural development. Mutation-induced loss of its functions in mammals leads to severe disorders associated with impaired motor coordination, tremors and ataxia. Little is known about Reelin's role in functional recovery after central nervous system injury. We determined the effect of knock-down of Reelin and its downstream signal-transducing molecule Disabled-1 (Dab-1) on functional recovery after spinal cord injury in larval zebrafish. Larvae deficient in Reelin and Dab-1 were generated by application of two non-overlapping antisense morpholinos for each molecule. Individual knock-down of Reelin and Dab-1 expression impaired locomotor recovery after injury, inhibited remyelination of regrown axons and reduced numbers of motor neurons caudal to the lesion site. These results indicate that the Reelin/Dab-1 signalling pathway is involved in axon regeneration after injury of a paradigmatic vertebrate in the central nervous system.