Developmental diversification of cortical inhibitory interneurons.

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Cortical interneurons are crucial for higher-order brain functions.
• Understanding the generation of interneuron diversity is key to understanding brain development and function.
• Dysregulation of interneuron development is implicated in neuropsychiatric and neurodevelopmental disorders.

Purpose of the Study:

• To investigate the molecular mechanisms driving the diversity of cortical interneurons during development.
• To identify key transcription factors and gene modules involved in interneuron precursor specification and differentiation.
• To uncover the embryonic origins of distinct interneuron subtypes.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) was employed to profile cell transcriptomes.
• Developmental time course analysis was performed on mouse cells from ganglionic eminences.
• Integration of scRNA-seq datasets across developmental stages was used to identify conserved and divergent transcriptomic signatures.

Main Results:

• Transcriptomic heterogeneity in mitotic progenitors is shaped by maturation trajectories and transcription factor expression.
• Postmitotic progenitors diverge into distinct states, including an interneuron precursor state.
• The transcription factor Mef2c was identified as essential for the development of early precursors of parvalbumin-expressing neurons.

Conclusions:

• Early inhibitory precursor diversification is driven by conserved maturation pathways and specific transcription factors.
• Mef2c plays a critical role in delineating and developing specific interneuron subtypes, particularly parvalbumin-expressing neurons.
• Identified gene modules provide insights into the specification of human interneuron subtypes and potential therapeutic targets for related disorders.