Fig. 7.
Effects of electrical stimulation of vagal afferent nerves on VMR induced by CRD in rats. Twelve rats were used in this study. Each rat had preelectrical stimulation trial and immediately after electrical stimulation trial. Different parameters of EVS were applied on different days for the same rat. Graded CRD evoked reproducible VMR (0 μA). Low-intensity EVS (40 μA) reduced VMR in response to all intensities of CRD. In contrast, higher intensity EVS (400 μA) had no effect on VMR induced by CRD. Data are presented as means ± SE. *P < 0.05. ANOVA showed a significant effect for distension level and group interaction. Post hoc comparisons of means revealed a significant difference between the group receiving electrical stimulation at 40 μA, 20 Hz (*P < 0.05) and 400 μA, 20 Hz at 40, 60, and 80 mmHg CRD. Data are shown as means ± SE. *P < 0.05 compared with 0 Hz and 10 Hz electrical stimulation (1-way repeated-measures ANOVA followed by the Bonferroni test).