The multiple facets of Cajal-Retzius neurons

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Cajal-Retzius cells (CRs) are the earliest born neurons in the developing cortex of vertebrates.
• They play critical roles in cortical development, including guiding neuronal migration and forming cortical layers via reelin secretion.
• CRs are transient, undergoing significant cell death by the end of cortical development.

Purpose of the Study:

• To review the identification criteria for CRs.
• To summarize the ontogeny, migration, functions, and death dynamics of CRs.
• To explore the molecular heterogeneity of CRs using transcriptomic data.

Main Methods:

• Review of existing literature.
• Analysis of morphological, electrophysiological, molecular, and genetic data.
• Examination of public transcriptomic datasets using single-cell technologies.

Main Results:

• CRs have diverse origins and migratory paths.
• They influence multiple developmental processes beyond reelin secretion, including patterning and synaptogenesis.
• Single-cell technologies reveal significant molecular heterogeneity within CR populations across species.

Conclusions:

• CRs are essential transient cells with multifaceted roles in cortical development.
• Understanding CR heterogeneity is key to comprehending their precise functions.
• Transcriptomic analysis provides a powerful tool for characterizing CRs throughout their lifespan.