Single-Cell RTPCR, a Technique to Decipher the Electrical, Anatomical, and Genetic Determinants of Neuronal Diversity

The patch-clamp technique has allowed detailed studies on the electrical properties of neurons. Dye loading through patch pipettes has allowed characterizing the morphological properties of the neurons. In addition, the patch-clamp technique also allows harvesting mRNA from single cells to study gene expression at the single-cell level (known as single-cell reverse transcription–polymerase chain reaction [RT–PCR] [1-3] ). The combination of these three approaches allows determination of the Gene expression, Electrophysiology and Morphology (GEM) profile of neurons (gene expression, electrophysiology, and morphology) using a single patch pipette and patch-clamp recording. This combination provides a powerful technique to study and correlate the neuron’s gene expression with its phenotype (electrical behavior and morphology) ( 4 – 7 ) . The harvesting and amplification of single-cell mRNA for gene expression studies is a challenging task, especially for researchers with sparse or no training in molecular biology (see Notes 1 and 2 ). Here, we describe in detail the GEM profiling approach with special attention to the gene expression profiling.