Figure 2: Timing of neurodevelopmental events in the cerebral cortex.
A) Key patterning centers set up morphogen and transcription factor gradients across the developing neuroepithelium to influence area-specific cell fates. B) Schematic comparison of the mouse and human cerebral cortical development at peak stages of neurogenesis. While the processes are broadly conserved, several important differences can be highlighted: prominent expansion of the outer subventricular zone (OSVZ) and of the outer radial glia population which resides therein (Fietz et al., 2010; Hansen et al., 2010; Reillo et al., 2011); expansion of the subplate (SP), which is associated with the expansion of the axonal plexus, but not necessarily cell numbers (Duque et al., 2016); expansion of the upper layer excitatory neuron types (Hodge et al., 2018); discontinuation of the radial glia scaffold (Nowakowski et al., 2016); emergence of persisting Cajal-Retzius cells (Meyer and Gonzalez-Gomez, 2018); expansion of axonal plexus in the OSVZ and the emergence of multilaminar axonal-cellular compartment (Zunic Isasegi et al., 2018); early arrival of thalamocortical plexus in the cortical anlage (Marin-Padilla, 1983). C) Broad comparison of key neurogenesis periods across species, including data from (Clancy et al., 2001; Rakic, 1974). Embryonic days (E) next to species names indicate approximate length of gestation.