Figure 3.

Regional and cellular distribution of GABA_B1 in wild‐type and APP/PS1 mice. A‐H. Immunoreactivity for GABA_B1 in the hippocampus of wild‐type and APP/PS1 mice at 12 months of age using a pre‐embedding immunoperoxidase method at the light microscopic level. In the CA1 and CA3 regions and dentate gyrus (DG), GABA_B1 immunoreactivity was very similar both in the wild‐type and the APP/PS1 mice, regardless of accumulation of amyloid plaques (asterisks). Labeling for GABA_B1 showed the highest intensity in the stratum lacunosum‐moleculare (slm) and molecular layer (ml) and weaker in the strata oriens (so) and radiatum (sr). Immunoreactivity for GABA_B1 was also detected in interneurons throughout all layers (white arrows), with similar distribution pattern and labeling intensity in wild‐type and APP/PS1 mice. I,J. Immunoreactivity for β‐amyloid in wild‐type and APP/PS1 mice at 12 months of age, showing high accumulation of Aβ throughout all layers of the hippocampus. Abbreviations: CA1 region of the hippocampus; CA3, CA3 region of the hippocampus; DG, dentate gyrus; so, stratum oriens; sp, stratum pyramidale; sr, stratum radiatum; slm, stratum lacunosum‐moleculare; ml, molecular layer; gc, granule cell layer; h, hilus. Scale bars: A,B,I,J 200 µm; C‐H, 100 µm.