Adult mouse cortical cell taxonomy revealed by single cell transcriptomics

Area of Science:

• Neuroscience
• Genomics
• Cell Biology

Background:

• Understanding the diversity of cell types in the nervous system is crucial but remains incomplete.
• The primary visual cortex is a key area for visual processing, yet its cellular composition is not fully elucidated.

Purpose of the Study:

• To construct a comprehensive cellular taxonomy of the adult mouse primary visual cortex.
• To identify and classify distinct neuronal and non-neuronal cell types based on their transcriptomic profiles.
• To investigate the relationship between transcriptomic signatures and cellular properties.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) was employed to analyze gene expression at the individual cell level.
• Bioinformatic analyses were used to cluster cells into transcriptomic types.
• Electrophysiological recordings and axon tracing were performed to validate cell type classifications.

Main Results:

• A total of 49 distinct transcriptomic cell types were identified, including 23 GABAergic, 19 glutamatergic, and 7 non-neuronal types.
• Analysis revealed cell type-specific mRNA processing patterns.
• Genetic access to these identified cell types using transgenic Cre lines was characterized.
• Specific electrophysiological and axon projection properties were associated with several transcriptomic cell types.

Conclusions:

• The study establishes a detailed cellular taxonomy for the mouse visual cortex, significantly advancing our understanding of neural diversity.
• Transcriptomic signatures serve as reliable indicators of specific cellular properties, including electrophysiology and connectivity.
• This work provides a foundation for future research into the functional roles of distinct cell types in the visual cortex.