title: Axon-Schwann cell interactions during peripheral nerve regeneration in zebrafish larvae.
abstract: BACKGROUND
  Peripheral nerve injuries can severely affect the way that animals perceive signals from the surrounding environment. While damage to peripheral axons generally has a better outcome than injuries to central nervous system axons, it is currently unknown how neurons re-establish their target innervations to recover function after injury, and how accessory cells contribute to this task. Here we use a simple technique to create reproducible and localized injury in the posterior lateral line (pLL) nerve of zebrafish and follow the fate of both neurons and Schwann cells.
  
  
  RESULTS
  Using pLL single axon labeling by transient transgene expression, as well as transplantation of glial precursor cells in zebrafish larvae, we individualize different components in this system and characterize their cellular behaviors during the regenerative process. Neurectomy is followed by loss of Schwann cell differentiation markers that is reverted after nerve regrowth. We show that reinnervation of lateral line hair cells in neuromasts during pLL nerve regeneration is a highly dynamic process with promiscuous yet non-random target recognition. Furthermore, Schwann cells are required for directional extension and fasciculation of the regenerating nerve. We provide evidence that these cells and regrowing axons are mutually dependant during early stages of nerve regeneration in the pLL. The role of ErbB signaling in this context is also explored.
  
  
  CONCLUSIONS
  The accessibility of the pLL nerve and the availability of transgenic lines that label this structure and their synaptic targets provides an outstanding in vivo model to study the different events associated with axonal extension, target reinnervation, and the complex cellular interactions between glial cells and injured axons during nerve regeneration.
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Ceci
authors.forename: Camila
authors.initials: C
authors.lastname: Mardones-Krsulovic
authors.forename: Mario
authors.initials: M
authors.lastname: Sánchez
authors.forename: Leonardo E
authors.initials: LE
authors.lastname: Valdivia
authors.affiliation: FONDAP Center for Genome Regulation, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile. allende@uchile.cl.
authors.forename: Miguel L
authors.initials: ML
authors.lastname: Allende
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000502:physiology*; D001973:Bromodeoxyuridine; D017690:Cell Transplantation; D004268:DNA-Binding Proteins / Q000235:genetics; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva; D009416:Nerve Regeneration / Q000235:genetics / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D018739:Oncogene Proteins v-erbB / Q000378:metabolism; D059348:Peripheral Nerve Injuries / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D012583:Schwann Cells / Q000473:pathology / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D018739:Oncogene Proteins v-erbB; D029961:Zebrafish Proteins; D049452:Green Fluorescent Proteins; D001973:Bromodeoxyuridine