A Guide to Single-Cell Transcriptomics in Adult Rodent Brain: The Medium Spiny Neuron Transcriptome Revisited

Area of Science:

• Neuroscience
• Genomics
• Cell Biology

Background:

• Single-cell technologies offer insights into brain complexity.
• Standardized cell isolation is essential for comparable transcriptomic data.
• Current methods require refinement for isolating intact neuronal cells.

Purpose of the Study:

• To analyze and simplify critical single-cell isolation steps from adult brain tissue.
• To develop standardized methods for improved cell isolation and fluorescence-activated cell sorting.
• To generate high-resolution single-cell RNA sequencing (scRNA-Seq) data for specific neuronal subtypes.

Main Methods:

• Enzymatic digestion and tissue trituration optimization.
• Improved fluorescence-activated cell sorting for debris-rich samples.
• Region-specific cellular labeling compatible with stereotaxic coordinates.
• Single-cell RNA sequencing (scRNA-Seq) of D1 and D2 dopamine receptor expressing medium spiny neurons (MSNs).

Main Results:

• Simplified and standardized protocols for single-cell isolation from brain tissue.
• Successful scRNA-Seq data generation from distinct MSN subtypes.
• Comparison highlighting the need for single-cell resolution over population-based data.
• Identification of novel subtype-specific marker genes for MSNs.

Conclusions:

• The developed methods enhance the comparability of single-cell isolation data from adult brain.
• The study provides a refined transcriptome of MSNs at unprecedented resolution.
• Established and novel marker genes for MSN subtypes are confirmed and identified, aiding future research.