Cortex folding by combined progenitor expansion and adhesion-controlled neuronal migration.

Area of Science:

• Developmental neuroscience
• Genetics
• Computational biology

Background:

• Cerebral cortex folding (gyrification) is crucial for mammalian brain function but its developmental mechanisms remain incompletely understood.
• Previous research demonstrated that genetic deletion of Flrt1/3 adhesion molecules induces cortical folding in mice by affecting neuron migration.
• The role of progenitor expansion in modulating Flrt1/3-mediated cortical folding was not previously investigated.

Purpose of the Study:

• To investigate how progenitor expansion interacts with Flrt1/3 gene deletion to influence cerebral cortex folding.
• To identify the specific roles of intermediate and apical progenitor expansion in modulating gyrification patterns.

Main Methods:

• Utilized a mouse model with combined genetic deletions of Flrt1/3 and either Cep83 (intermediate progenitors) or Fgf10 (apical progenitors).
• Analyzed the resulting cortical folding patterns, neuron migration, and progenitor populations.
• Employed computational modeling to simulate and understand the biophysical mechanisms underlying observed folding.

Main Results:

• Combining Flrt1/3 deletion with Cep83 deletion (intermediate progenitor expansion) led to enhanced sulci formation.
• Combining Flrt1/3 deletion with Fgf10 deletion (apical progenitor expansion) resulted in enhanced gyri formation.
• Computational modeling supported the roles of cell adhesion, density, and migration in promoting gyrification.

Conclusions:

• Progenitor expansion significantly modulates Flrt1/3-dependent cortical folding.
• The type of progenitor expanded (intermediate vs. apical) influences the specific folding patterns (sulci vs. gyri).
• Adhesive properties, cell densities, and neuronal migration are critical, interacting factors in cortical gyrification.