Neuronal activity biases axon selection for myelination in vivo

Details

• Alternative Title:
  Nat Neurosci
• Personal Author:
  Hines, Jacob H. ; Ravanelli, Andrew M. ; Schwindt, Rani ; Scott, Ethan K. ; Appel, Bruce
• Description:
  An essential feature of vertebrate neural development is ensheathment of axons with myelin, an insulating membrane formed by oligodendrocytes. Not all axons are myelinated, but mechanisms directing myelination of specific axons are unknown. Using zebrafish, we found that activity-dependent secretion stabilized myelin sheath formation on select axons. When VAMP2-dependent exocytosis was silenced in single axons, oligodendrocytes preferentially ensheathed neighboring axons. Nascent sheaths formed on silenced axons were shorter in length, but when activity of neighboring axons was also suppressed, inhibition of sheath growth was relieved. Using in vivo time-lapse microscopy, we found that only 25% of oligodendrocyte processes that initiated axon wrapping were stabilized during normal development and that initiation did not require activity. Instead, oligodendrocyte processes wrapping silenced axons retracted more frequently. We propose that axon selection for myelination results from excessive and indiscriminate initiation of wrapping followed by refinement that is biased by activity-dependent secretion from axons.
• Keywords:
  Action Potentials Animals Animals, Genetically Modified Axons Exocytosis Genes, Reporter Green Fluorescent Proteins Homeodomain Proteins Microscopy, Confocal Myelin Sheath Neurogenesis Oligodendroglia Potassium Channels, Inwardly Rectifying Recombinant Fusion Proteins Spinal Cord Synaptic Vesicles Tetrodotoxin Time-Lapse Imaging Transcription Factors Veratridine Zebrafish

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• Source:
  Nat Neurosci. 18(5):683-689
• Pubmed ID:
  25849987
• Pubmed Central ID:
  PMC4414883
• Document Type:
  Journal Article
• Funding:
  T32 MH015442/MH/NIMH NIH HHSUnited States/ ; T32 MN015442/MN/OMHHE CDC HHSUnited States/ ; R01 NS046668/NS/NINDS NIH HHSUnited States/ ; T32 5T32CA08208613/CA/NCI NIH HHSUnited States/ ; P30 NS048154/NS/NINDS NIH HHSUnited States/ ; T32 CA082086/CA/NCI NIH HHSUnited States/
• Volume:
  18
• Issue:
  5
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:aef266e5c6b72801a26e9b78626f714455f227b5c40836f65de070c47166585e
• Download URL:
  https://stacks.cdc.gov/view/cdc/31724/cdc_31724_DS1.pdf
• File Type:
  [PDF - 2.50 MB ]