Fig. 6

Co-clustering of GABA_B receptors and GIRK2 in the hippocampus of wild type and APP/PS1. Electron micrographs of the stratum radiatum of the hippocampal CA1 field at 12 months of age showing double immunogold labelling for GABA_B1 (10 nm) and GIRK2 (5 nm) in pyramidal cells, as detected using the SDS-FRL technique in wild type and APP/PS1 mice. A–D In wild type, immunoparticles for GABA_B1 (10 nm) co-clustered with those for GIRK2 (5 nm) (green ellipses/circles) in dendritic spines (s). In oblique dendrites (oDen), double labelling revealed that many clusters (red ellipses/circles) and immunoparticles (red arrows) for GABA_B1 (10 nm) were segregated, and also clusters (blue ellipses/circles) and immunoparticles (blue arrows) for GIRK2 (5 nm) could be found, although in some cases clusters of the two proteins (green ellipses/circles) were also detected. Presynaptically, immunoparticles for GABA_B1 (10 nm) co-clustered (green ellipses/circles) with those for GIRK2 (5 nm) in axon terminals (at) and edge of active zone (az, pink overlay). E–G In APP/PS1, immunoparticles for GABA_B1 (10 nm, red arrows) were segregated from immunoparticles for GIRK2 (5 nm, blue arrows) in spines (s), oblique dendrites (oDen), or axon terminals (at). Scale bars: A–G, 0.2 μm