Molecular Pathways Underlying Projection Neuron Production and Migration during Cerebral Cortical Development

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Mammalian cerebral cortex development relies on glutamatergic neurons originating from radial glia (RG) progenitors.
• Neuroblast migration during corticogenesis involves distinct modes: multipolar (MP) migration and RG-guided locomotion.
• The transition from MP to bipolar cell morphology is a critical, yet not fully understood, step in radial neuronal migration.

Purpose of the Study:

• To review recent advances in understanding the molecular mechanisms regulating radial neuronal migration during corticogenesis.
• To explore the significance of RG-guided locomotion in the evolution of the mammalian neocortical 6-layer structure.
• To highlight the critical MP to bipolar transition step in radial migration.

Main Methods:

• Literature review of studies on radial neuronal migration.
• Analysis of gene mutations and knockdown effects impacting migration steps.
• Discussion of evolutionary aspects of neuronal migration.

Main Results:

• Radial neuronal migration involves four key steps: progenitor maintenance/departure, MP migration/transition, RG-guided locomotion, and terminal translocation/maturation.
• The MP to bipolar transition, occurring at the subplate layer, is particularly sensitive to genetic perturbations.
• RG-guided locomotion may be essential for the evolution of the mammalian neocortical structure.

Conclusions:

• The molecular mechanisms underlying each step of radial neuronal migration are increasingly understood.
• The unique migration modes in mammals, especially RG-guided locomotion, likely contributed to neocortical evolution.
• Further research into the critical MP to bipolar transition is warranted.