Untangling Cortical Complexity During Development.

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• The cerebral cortex contains billions of diverse neurons crucial for cognitive and motor functions.
• Neuronal identity, connectivity, and molecular processes established during development underpin these functions.
• Elucidating the cellular and molecular mechanisms of neocortical development remains a significant challenge.

Purpose of the Study:

• To review the regimental organization of the cerebral cortex.
• To dissect the cellular subtypes contributing to cortical complexity.
• To outline molecular hallmarks for understanding cellular diversity, with a focus on excitatory neurons.

Main Methods:

• Classification of cerebral cortical neuronal subtypes based on morphology, function, synaptic properties, location, connectivity, and gene expression.
• Review of historical and modern techniques including fate mapping, genome-wide analysis, and transcriptome profiling.
• Analysis of developmental processes: neuronal determination, migration, positioning, layer-specific transcription, and network formation.

Main Results:

• The cerebral cortex exhibits a highly organized structure with distinct neuronal subtypes.
• Neuronal diversity arises from orchestrated developmental processes.
• Molecular hallmarks and gene expression patterns define specific neuronal subtypes.

Conclusions:

• Precise neuronal organization and molecular identity are essential for complex brain functions.
• Understanding neuronal subtypes and their molecular characteristics is vital for advancing neuroscience.
• This review provides insights into the cellular diversity of the cerebral cortex, particularly excitatory neurons.