By Neuroscience News –
A new study challenges the classical “inside-out” model of cortical development. Using Mosaic Analysis with Double Markers (MADM) single-cell lineage tracing, the team demonstrated that radial glial progenitor cells split early in brain development into distinct, parallel developmental branches.
Rather than a single progenitor pool sequentially producing deeper-layer extra-telencephalic projection neurons (ET-PNs) followed by superficial-layer intra-telencephalic projection neurons (IT-PNs), cortical neurogenesis involves early lineage branching. One progenitor branch exclusively generates IT-PNs across all layers, while a parallel branch yields both ET-PNs and IT-PNs.
