Connectome-seq: high-throughput mapping of neuronal connectivity at single-synapse resolution via barcode sequencing

Area of Science:

• Neuroscience
• Molecular Biology
• Genomics

Background:

• Mapping neuronal connectivity at single-cell resolution is crucial for understanding brain function.
• Existing methods face limitations in tracing long-distance circuits and preserving cell type information.

Purpose of the Study:

• To introduce Connectome-seq, a novel high-throughput method for mapping neuronal connectivity at single-synapse resolution.
• To simultaneously capture synaptic connections and molecular identities of connected neurons.

Main Methods:

• Utilized engineered synaptic proteins, RNA barcoding, and parallel single-nucleus and single-synaptosome sequencing.
• Employed an adeno-associated virus-based approach for efficient circuit tracing.
• Validated the method in the mouse pontocerebellar circuit.

Main Results:

• Successfully mapped established and potentially novel synaptic connections within the mouse pontocerebellar circuit.
• Identified molecular markers enriched in connected neurons through integrated connectivity and gene expression analysis.
• Demonstrated the capability to link specific molecular profiles to circuit-specific connectivity.

Conclusions:

• Connectome-seq offers a scalable platform for comprehensive neuronal circuit analysis with single-cell precision.
• The method provides valuable gene expression information alongside connectivity data.
• Enables systematic circuit mapping across brain regions, conditions, and biological states.