ZFIN ID: ZDB-PUB-170518-9
TNFa/TNFR2 signaling is required for glial ensheathment at the dorsal root entry zone
Smith, C.J., Wheeler, M.A., Marjoram, L., Bagnat, M., Deppmann, C.D., Kucenas, S.
Date: 2017
Source: PLoS Genetics   13: e1006712 (Journal)
Registered Authors: Bagnat, Michel, Kucenas, Sarah, Smith, Cody
Keywords: Pioneer axons, Spinal cord, Embryos, Neurons, Axons, Larvae, Zebrafish, Nerves
MeSH Terms:
  • Animals
  • Astrocytes/metabolism
  • Axons/metabolism
  • Central Nervous System/growth & development
  • Central Nervous System/metabolism
  • Ganglia, Spinal
  • Gene Expression Regulation, Developmental
  • Mice
  • Neuroglia/cytology
  • Neuroglia/metabolism*
  • Neurons, Afferent/metabolism
  • Peripheral Nervous System/growth & development
  • Peripheral Nervous System/metabolism
  • Receptors, Tumor Necrosis Factor, Type II/biosynthesis
  • Receptors, Tumor Necrosis Factor, Type II/genetics*
  • Signal Transduction
  • Spinal Cord/growth & development
  • Spinal Cord/metabolism
  • Spinal Nerve Roots/growth & development
  • Spinal Nerve Roots/metabolism*
  • Tumor Necrosis Factor-alpha/biosynthesis
  • Tumor Necrosis Factor-alpha/genetics*
  • Zebrafish/genetics
  • Zebrafish/growth & development
PubMed: 28379965 Full text @ PLoS Genet.
Somatosensory information from the periphery is routed to the spinal cord through centrally-projecting sensory axons that cross into the central nervous system (CNS) via the dorsal root entry zone (DREZ). The glial cells that ensheath these axons ensure rapid propagation of this information. Despite the importance of this glial-axon arrangement, how this afferent nerve is assembled during development is unknown. Using in vivo, time-lapse imaging we show that as centrally-projecting pioneer axons from dorsal root ganglia (DRG) enter the spinal cord, they initiate expression of the cytokine TNFalpha. This induction coincides with ensheathment of these axons by associated glia via a TNF receptor 2 (TNFR2)-mediated process. This work identifies a signaling cascade that mediates peripheral glial-axon interactions and it functions to ensure that DRG afferent projections are ensheathed after pioneer axons complete their navigation, which promotes efficient somatosensory neural function.