Fig. 1

Neither delayed EOI removal nor persistent EOI upregulated the 5-HT3A receptor subtype in the Sp5. A Upper panel shows low magnification photograph of 5-HT3A receptor subtype immunostaining in the Sp5 brainstem section of the sham rat. Scale bar, 500 μm. Lower panel shows representative high-magnification photograph of 5-HT3A receptor subtype immunostaining in the area encircled by a white rectangle (ventrolateral region) in the upper panel. Scale bar, 200 μm. B Representative high-magnification photographs showing co-expression of 5-HT3A receptor subtype with NeuN in the Sp5 in sham, REOI, and PEOI rats. Scale bar, 50 μm. C-E Semi-quantitative analysis on the ratio of 5-HT3A receptor subtype/NeuN double-positive cells to NeuN-positive cells, the area of 5-HT3A receptor subtype staining, and mean fluorescence intensity of 5-HT3A receptor subtype showed no significant change in REOI and PEOI rats compared with sham rats (n = 3 rats per group, each symbol represents one rat with five sections measured per rat). F Western blotting illustrated no change in 5-HT3A receptor subtype expression in either REOI or PEOI rats in the Sp5 (n = 5 rats per group). Results represent mean ± SD; one-way ANOVA followed by Tukey’s multiple-comparison test. 5-HT3A R, 5-HT3A receptor subtype