Adult Neurogenesis

Adult Neurogenesis occurs after birth.  Cell division or proliferation is initiated in the ventricular zone and then neuronal precusors migrate through the white matter to specific cortical layers.  Cells then extend dendrites and axons to integrate within neural circuits.

Differences between embryonic neurogenesis (ENG) and adult neurogenesis (ANG)

  • ENG establishes cortical layers. ANG is adding to prexisting cortical layers
  • ENG occurs at high levels.  ANG at much lower levels
  • ENG occurs in all regions of the developing brain.  ANG occurs in two brain areas, the hippocampus and olfactory bulb
  • In EMG, new neurons migrate to outer layer using radial glia.  In ANG new neurons migrate to specific positions within the existing layers, migrating in streams through existing white matter.
  • IN EMG new neurons are derived from a stem cell population, which produces neurons and glia in set patterns.  In ANG new neurons are derived from specialized glia populations and the environment influences whether neurons or glia are produced
  • EMG produces all types of neurons.  ANG produces very specific types of neurons

Kriegstein and Alvarez-Buylla (2009) The Glial Nature of Embryonic and Adult Neural Stem Cells
Annu. Rev. Neurosci. 32:149–84

Thanks to Stephen Conway for figures

Page by Elaine Reynolds

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