Spatially patterned excitatory neuron subtypes and projections of the claustrum

Area of Science:

• Neuroscience
• Molecular Biology
• Brain Anatomy

Background:

• The claustrum's precise anatomical boundaries and functional organization are debated.
• Histochemical and circuit-based studies offer conflicting views on its extent and projections.

Purpose of the Study:

• To resolve debates on claustrum extent and function using a cell-type-specific approach.
• To characterize the molecular and projectional diversity within the claustrum.

Main Methods:

• Single-cell RNA-sequencing to identify neuron subtypes.
• Multicolor retrograde tracing and multiplexed in situ hybridization to map spatial arrangement and targets.

Main Results:

• Identified two distinct excitatory neuron subtypes within the mouse claustrum.
• Revealed a core-shell spatial organization of these subtypes.
• Demonstrated differential downstream projections for each subtype.

Conclusions:

• The claustrum exhibits subtype-specific molecular and projectional heterogeneity.
• This heterogeneity reconciles differing views on claustrum extent and complexity.
• Subtype diversity is key to understanding the claustrum's functional intricacies.