In the CA1 region, immunolabelling for GIRK1 was strong in the stratum lacunosum–moleculare, whereas the stratum radiatum showed an uneven labelling with moderate intensity in the proximal half and high intensity in the distal half, and the stratum oriens showed moderate intensity (Fig. 4A5 and A6). In the CA3 region, GIRK1 immunoreactivity was strongest in the strata oriens, radiatum and lacunosum–moleculare, whereas the stratum lucidum displayed more moderate expression (Fig. 4A5 and A6). In the dentate gyrus, GIRK1 immunoreactivity was strong in the molecular layer and weak in the hilus (Fig. 4A5 and A6). In the pyramidal and granule cell layers, no labelling was observed.
