Confocal microscopic images of NMDAR1 receptors within the hippocampus. In rats infused with aCSF (A, B, C), fluorescence labeling showed large NMDAR1-positive neurons (red) in dentate gyrus (A), hilar region (B) and CA3 area (C). All nuclei are stained green (Sytox). Scale bars: (A) 100 μm; (B, C) 25 μm. Immunohistochemistry of NMDAR1-positive neurons revealed dark staining in the cytoplasm that extended along the dendrites in cells within the dentate gyrus (G), hilar region (H), and CA3 (I). Scale bars: (G) 100 μm; (H, I) 25 μm. Confocal microscopic images showed reduced NMDAR1 staining within the hippocampus of LPS infused rats: dentate gyrus (D), hilar region (E) and CA3 area (F). Scale bars: (D, E, F) 25 μm. Immunohistochemistry of NMDAR1-positive neurons revealed fewer cells expressing NMDAR1 receptors with a lower degree of immunoreactivity throughout the dentate gyrus (J), hilar region (K) and CA3 (L). Scale bars: (J) 100 μm, (K, L) 25 μm.