Formation of functional synapses by regenerating adult rat retinal ganglion cell axons in midbrain target regions in vitro

J Neurobiol. 1993 Apr;24(4):456-73. doi: 10.1002/neu.480240405.


The ability of adult rat retinal ganglion cell (RGC) axons to reinnervate normal target regions was examined in vitro. In co-culture experiments, adult rat retinal explants were placed adjacent to fetal rat midbrain sections that contained the superior colliculus (SC) which is the main target for RGC axons. Adult rat RGCs regrew axons over more than 500 microns on a polylysine-laminin substrate to reach the co-cultured explants. By using neurofilament immunohistochemistry and the fluorescent dye DiI for anterograde and retrograde tracing, it was shown that (1) adult rat RGCs with a stereotyped morphology survived in explant cultures for more than 4 weeks in the presence of fetal midbrain explants, (2) regenerating RGC axons preferentially terminated within midbrain target regions, and (3) RGCs formed functional synapses. In addition, the maturation of the SC region in midbrain explants was examined histologically and ultrastructurally to demonstrate appropriate target development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / analysis
  • Animals
  • Axons / physiology
  • Cells, Cultured
  • Evoked Potentials / physiology
  • Female
  • In Vitro Techniques
  • Mesencephalon / embryology
  • Mesencephalon / physiology*
  • Nerve Regeneration / physiology*
  • Neural Pathways / physiology
  • Neurons / ultrastructure
  • Rats
  • Rats, Inbred Lew
  • Retinal Ganglion Cells / physiology*
  • Retinal Ganglion Cells / ultrastructure
  • Superior Colliculi / embryology
  • Superior Colliculi / enzymology
  • Superior Colliculi / physiology
  • Synapses / physiology*
  • Tectum Mesencephali / cytology
  • Tectum Mesencephali / physiology


  • Acetylcholinesterase