Skip to main content
. Author manuscript; available in PMC: 2015 Jun 1.
Published in final edited form as: Curr Opin Neurobiol. 2014 Feb 16;26:132–141. doi: 10.1016/j.conb.2014.01.015

Fig. 3. Models for the generation of subtypes of excitatory projection neurons.

Fig. 3

Two models are depicted that can explain how distinct progenitors generate Satb2+ callosal projection neurons and Satb2− subcerebral projection neurons. These are two extreme models and other models can be envisioned. Model 1: Segregated Lineages. An early progenitor generates two progenitor subtypes. These progenitors self-renew to amplify the progenitor pool and establish two independent progenitor lineages. One of the progenitor lineages is specified to produce Satb2− neurons that mostly populate deep layers, while the second progenitor lineage is specified to produce Satb2+ neurons that largely populate layers II–III but also reside in deeper layers. Model 2: Nested Lineages. A multipotent progenitor persists for an extended period of time and generates two progenitor subtypes. These progenitor subtypes proliferate to expand the two independent progenitor lineages. One of these progenitor subtypes generates Satb2+ neurons and the second one produces Satb2− neurons.