Consistent with a previous report35, the pan-GIRK2 antibody yielded a punctate labeling pattern in wild-type cultures, with extensive labeling seen in dendritic processes (Fig. 2C). No such labeling was seen in hippocampal cultures from Girk2 −/− mice (Fig. 2D), confirming antibody specificity. The labeling patterns for recombinant GIRK2a and GIRK2c expressed in Girk2 −/− pyramidal neurons were overlapping but distinct (Fig. 3). While both subunits were detected in the soma and dendrites of infected neurons, GIRK2a labeling was more restricted to the cell body and proximal dendrites (Fig. 3A). In contrast, GIRK2c labeling was uniformly distributed throughout the neuron, including distal dendrites (Fig. 3B). Quantification of GIRK2 isoform labeling confirmed that GIRK2c exhibited a higher density of labeling than GIRK2a in secondary and tertiary dendrites of infected hippocampal pyramidal neurons (Fig. 3C).
