The outgrowth response of the axons of developing and regenerating rat retinal ganglion cells in vitro to neurotrophin treatment

J Neurocytol. 2003 Nov;32(9):1055-75. doi: 10.1023/B:NEUR.0000021902.65233.8d.

Abstract

BDNF and NT-4 (but not NT-3 or CNTF) significantly enhanced the outgrowth of early embryonic and adult regenerating RGC axons when provided with a supportive substrate in vitro. BDNF and NT-4 treatment transiently increased RGC axon outgrowth from E15 rat retinas but not from retinas at older embryonic ages. The transient effect of BDNF and NT-4 and the inability of the neurotrophins to promote outgrowth from older embryonic retinal explants suggests a time frame of neurotrophin action and that other chemical factors (target-derived or otherwise) may be necessary for the continued maintenance of developing RGC axons. BDNF and NT-4 also enhanced the outgrowth of regenerating axons from adult retinal explants, but appeared to have a more subtle effect on axon outgrowth, in that the growth-promoting effects of BDNF and NT-4 appeared continuous throughout the incubation period. The suppression of RGC axon outgrowth from embryonic and adult retinae cultured in trkB-IgG-containing medium suggests that the response of developing and regenerating axons, to BDNF and NT-4 are likely to occur through trkB signalling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / drug effects*
  • Axons / metabolism
  • Axons / ultrastructure*
  • Brain-Derived Neurotrophic Factor / metabolism
  • Brain-Derived Neurotrophic Factor / pharmacology
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology
  • Ciliary Neurotrophic Factor / metabolism
  • Ciliary Neurotrophic Factor / pharmacology
  • Fetus
  • Growth Cones / drug effects
  • Growth Cones / metabolism
  • Growth Cones / ultrastructure
  • Immunoglobulin G / metabolism
  • Immunoglobulin G / pharmacology
  • Microscopy, Electron
  • Nerve Growth Factors / metabolism
  • Nerve Growth Factors / pharmacology*
  • Nerve Regeneration / drug effects*
  • Nerve Regeneration / physiology
  • Neurotrophin 3 / metabolism
  • Neurotrophin 3 / pharmacology
  • Organ Culture Techniques
  • Rats
  • Receptor, trkB / drug effects
  • Receptor, trkB / metabolism
  • Retina / embryology
  • Retina / growth & development
  • Retina / ultrastructure
  • Retinal Ganglion Cells / drug effects*
  • Retinal Ganglion Cells / metabolism
  • Retinal Ganglion Cells / ultrastructure*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology

Substances

  • Brain-Derived Neurotrophic Factor
  • Ciliary Neurotrophic Factor
  • Immunoglobulin G
  • Nerve Growth Factors
  • Neurotrophin 3
  • Receptor, trkB
  • neurotrophin 4