A diagram illustrates the process of Neurogenesis in the mammalian neocortex which consists of the following stages: Pre-neurogenesis, Neurogenesis, and Late neurogenesis and gliogenesis. The progressive layers of the central nervous system are also indicated. Progenitor cell types include the Neuroepithelial cell N E C, the Ventricular radial glial cell v R G, the Intermediate progenitor I P, the Outer radial glial cell o R G, or any R G lacking apical attachment. Differentiated cell types include the Deep layer neuron, the Upper layer neuron, and the Macroglia that comprise the oligodendrocyte and the astrocyte.
A diagram illustrates progressive zones and layers of the central nervous system as follows from lowest to highest: Ventricular zone, Outer subventricular zone, Intermediate zone, deeper layers, the cortical plate neocortex, and the upper layers. The layers are given by order of birthdate.
The stages over time are as follows. Pre-neurogenesis is when Neuroepithelial cells build the Ventricular Zone and the subventricular Zone. Neurogenesis introduces Ventricular Zone radial glia. The next stage involves Intermediate progenitors followed by Outer radial glia and finally, Late neurogenesis and gliogenesis involve transitions.
During Pre-neurogenesis, symmetrical proliferative N E C duplicate to 2 N E C, forming the Ventricular and subventricular zones.
Neuroepithelial cells create Ventricular radial glial cells. This allows the next stage, neurogenesis, to occur, including Ventricular radial glial cells and a deep layer neuron.
Intermediate progenitors are introduced in the next stage and these in turn lead to 2 deep layer neurons.
The following stage includes Outer radial glia and more Intermediate progenitors.
During Late neurogenesis and gliogenesis, glial cells are formed in the Outer subventricular zone. Upper layer neurons are formed in all layers of the central nervous system.