Thursday, January 23, 2014 CC-BY-NC
Axon Guidance part 1

Maintainer: admin


  • growth cone moves in an ordered and directed manner - Ramon Cajal
  • Roger Sperry: Novel prize, experiments in neural pathways in amphibians
    • retinotectal pathway regenerate after being transect: chemoaffinity theory
      • eye rotation results in 180 change in visual field
      • visual map not determined by experience

2Retinotectal pathway

  • retinotectal pathway: ganglian cells from retina exit via optic nerve, cross at optic chiams, go to super collicus nuclei (tectum)
  • chemical cues exist at many points along the way to guide axon
  • use dye to retina and time lapse video microscopy to see the pathway
  • neuroepithelium rotation : results in the axon grows toward the part of graft
  • nasal/anterior cross and go to caudal of tectum
  • temperal go to rostral of ipsolateral tectum

3Growth cone

  • enlargement at the end of growing axon
  • has filopodia (finger-like projection) and lamellipodia (sheet-like projections)
  • contain microtubules, mitochondira, vesicels, and sites of actin polymerization
  • site of new membrane addition
  • actin polymer is linked to adhesion molecules on the plasma membrane
  • actin retrograde flow allow microtubule to grow and the growth cone advances

  • stuff in this lecture is quite basic, just make sure you know how growth cone works