Neocortical expansion driven by basal progenitors.

The emergence of indirect neurogenesis, driven by highly proliferative basal progenitors, contributed to the significant enlargement of the mammalian neocortex during brain evolution.

In recent years, several human-specific genes and enhancers have been described that differentially affect the biology of progenitor cells and potentially contribute to the increased neocortical complexity and disease-susceptibility of the human brain.

Emerging research is uncovering multiple pathways that disrupt basal progenitor biology, emphasizing these pathways’ involvement not only in classical neurogenesis-related disorders such as microcephaly but also in neurodevelopmental conditions traditionally linked to impairments in neuronal connectivity. sciencenewshighlights ScienceMission https://sciencemission.com/Basal-progenitors

The diversification and expansion of distinct progenitor cell subtypes during embryogenesis are essential to form the sophisticated brain structures present in vertebrates. In particular, the emergence of highly proliferative basal progenitors contributed to the evolutionary enlargement of the mammalian neocortex. Basal progenitors are at the center of indirect neurogenesis and can be divided into two main subtypes: the classical TBR2-positive intermediate progenitor cells and the outer radial glial cells, which are especially abundant in gyrencephalic species. While the function of some transcriptomic regulators is conserved across the mammalian clade, recent studies have identified human-specific genes and enhancers that uniquely affect progenitor biology, possibly driving the increased neocortical complexity and disease-susceptibility of the human brain.