Fig. 2

Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) improves the colitis-related histological score. taVNS (with stimulation parameters of 10 volts, a 500 µs pulse width, 30 s on/off duration, 10 min stimulation duration, and a frequency of 20 Hz) and no stimulation (anesthesia without any stimulation) were performed for the taVNS and CTRL (no stimulation) groups, respectively, beginning one day before the induction of acute colitis and continued daily until the mice were sacrificed. After 24 h, acute colitis was induced in the colitis (dextran sulfate sodium (DSS)) groups by adding 5% DSS to their drinking water for five days, while control groups continued to receive regular water. Histological appearance of hematoxylin and eosin-stained colonic tissue (40 × magnification) (A) and histological score (B). One-way ANOVA and multiple parametric comparison tests (Bonferroni and Šídák) were used to calculate P values. The significance level was set at p < 0.05. n = 8 mice/group. Each value is presented as the mean ± SD. This experiment was repeated at least four times