Cellular localization of COX-2 in the NTS, BNST, PVN, and CeA after LPS injection. A, Fluorescent microscopy for COX-2 (red; arrowheads) and DAPI (blue) in the NTS, BNST, PVN, and CeA, 2 h after 5 μg LPS or saline injection in CRTH2+/+ mice. B, C, Fluorescent microscopy for COX-2 (red), the endothelial marker CD31 (green; B), the neuronal marker NeuN (green; C), and DAPI (blue) in the NTS, BNST, and CeA, 2 h after 5 μg LPS injection. Arrowheads indicate colocalization of COX-2 with CD31 or NeuN. Scale bars: 50 μm.