Confocal laser scanning microscopy (CLSM) images of 5-HT-LIR (5-HT) in taste buds of rat and mouse circumvallate papillae. Longitudinal sections show a small subset of taste cells displaying 5-HT-LIR in rat (A) and mouse taste buds (B). Both cytoplasm and nuclei of taste cells display 5-HT-LIR. Transverse sections show 5-HT-LIR in rat (C-E) and mouse taste buds (F-H). The red cells are immunoreactive taste cells (C and F). Sytox-stained nuclei are shown in green (D and G), which stain all cells. Merges of red and green images are shown in E and H. Scale bars = 20 μm.