Motor Neuron Regeneration in Adult Zebrafish

M. M. Reimer, I. Sorensen, V. Kuscha, R. E. Frank, C. Liu, C. G. Becker, T. Becker
2008 Journal of Neuroscience  
The mammalian spinal cord does not regenerate motor neurons that are lost as a result of injury or disease. Here we demonstrate that adult zebrafish, which show functional spinal cord regeneration, are capable of motor neuron regeneration. After a spinal lesion, the ventricular zone shows a widespread increase in proliferation, including slowly proliferating olig2-positive (olig2+) ependymo-radial glial progenitor cells. Lineage tracing in olig2:green fluorescent protein transgenic fish
more » ... s that these cells switch from a gliogenic phenotype to motor neuron production. Numbers of undifferentiated small HB9+ and islet-1+ motor neurons, which are double labeled with the proliferation marker 5-bromo-2-deoxyuridine (BrdU), are transiently strongly increased in the lesioned spinal cord. Large differentiated motor neurons, which are lost after a lesion, reappear at 6-8 weeks after lesion, and we detected ChAT+/BrdU+ motor neurons that were covered by contacts immunopositive for the synaptic marker SV2. These observations suggest that, after a lesion, plasticity of olig2+ progenitor cells may allow them to generate motor neurons, some of which exhibit markers for terminal differentiation and integration into the existing adult spinal circuitry.
doi:10.1523/jneurosci.1189-08.2008 pmid:18716209 pmcid:PMC6671064 fatcat:z753dr7f6zdirg5by3ovkzrc7q