G protein-coupled inwardly rectifying potassium channels in dorsal root ganglion neurons

Aim: G protein-coupled inwardly rectifying potassium channels (GIRK) are important for neuronal signaling and membrane excitability. In the present study, we intend to find whether GIRK channels express functionally in adult rat dorsal root ganglion (DRG) neurons. Methods: We used RT-PCR to detect mRNA for 4 subunits of GIRK in the adult DRG. The whole-cell patch clamp recording was used to confirm GIRK channels functionally expressed. Results: The mRNA for the 4 subunits of GIRK were detected in the adult DRG. GTP γ S enhanced inwardly rectifying potassium (K + ) currents of the DRG neurons, while Ba 2+ inhibited such currents. Furthermore, the GIRK channels were shown to be coupled to the GABA B receptor, a member of the G protein-coupled receptor family, as baclofen increased the inwardly rectifying K + currents. Conclusion: GIRK channels are expressed and functionally coupled with GABA B receptors in adult rat DRG neurons.