Expression of BKCa channels and the modulatory β-subunits in the rat and porcine trigeminal ganglion

Large conductance calcium-activated potassium (BKCa) channels contribute to electrical impulses, proper signal transmission of information and regulation of neurotransmitter release. Migraine has been proposed to be a trigeminovascular disease involving the sensory trigeminal pathways and the cerebral arteries. We hypothesize that BKCa channel α- and β-subunits are present in the rat and porcine trigeminal ganglion (TG) thus enabling a role in migraine. BKCa channel mRNA was detected using reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization. BKCa channel protein was visualized by western blotting and histochemistry. The presence of the modulatory β1–β4 subunit mRNAs was investigated using RT-PCR. β1-, β2- and β4-subunit mRNAs were expressed in rat TG whereas β2- and β4-subunits were detected in porcine TG. Western blotting revealed β2- and β4-subunit proteins in rat and porcine TG. The present study showed BKCa channel expression in rat and porcine TG. The main modulatory β-subunits detected in TG of both species were β2- and β4-subunits.