We also probed for differences in the interaction between the GIRK2 isoforms and endogenous GIRK1 in cultured Girk2 −/− hippocampal neurons. Whole-cell currents were evoked by a selective activator of GIRK1-containing channels (ML297)42, 43. ML297-induced currents of comparable size were observed in Girk2 −/− pyramidal neurons expressing GIRK2a or GIRK2c, and in wild-type control neurons (Fig. 5J), indicating that viral expression of either GIRK2 isoform restores a normal level of GIRK1-containing heteromeric channel activity.
