Figure 5.

Hippocampal G‐protein‐gated inwardly rectifying potassium channels (GirK) protein pattern is altered by amyloid‐β (Aβ)_1–42 in vivo. (a) Bar plots showing GIRK1 immunostaining intensity (measured as optical density), as percentage of control (vehicle) values (dashed line, 100%) in the stratum lacunosum‐moleculare of the dorsal hippocampus in intracerebroventricular (i.c.v.)‐injected mice with vehicle (n = 7 animals), Aβ_1–42 (n = 6), Aβ_1–42 + ML297 (n = 6), ML297 (n = 4) or tertiapin‐Q (TQ) (n = 4). Number of hippocampal sections for each condition (n = 15–26 slices) is indicated in the corresponding bar. Differences versus. control (vehicle) are indicated by asterisks (*p < .05; ***p < .001). (b) Confocal fluorescence photomicrograph showing the distribution of GIRK1 subunit (green labeling), with intense immunolabeling in the stratum lacunosum‐moleculare, and DAPI stained cells (blue labeling) in the dorsal hippocampus of a representative vehicle‐injected mouse. The image illustrates how random 15 × 15 µm squares were distributed through the stratum lacunosum‐moleculare to measure GIRK1 optical density. Calibration bar: 500 µm (c–f) Representative confocal microscopy images showing GIRK1 immunostaining in i.c.v.‐injected mice with Aβ_1–42 (c), Aβ_1–42 + ML297 (d), ML297 (e), and TQ (f). Calibration bar in (b) also applies for (c–f)