Results collected from 11 and 17 CRD-excited neurones from sham-treated controls and viscerally hypersensitive (EA) rats, respectively. CRD pressure ≤ 50 mmHg had no effect on ACC neuronal firing in control rats. In EA rats, the basal firing rate (CRD pressure, 0 mmHg) was higher and neural firings in response to both low- and high-pressure distension were markedly increased. Another set of results was collected from 36 neurones in six EA rats after acute splanchnicectomy combined with pelvic nerve section. All 36 neurones failed to respond to CRD. Nerve section had no effect on the enhanced spontaneous basal firings. In 11 sham-operated, EA rats, 10 of 20 neurones increased spike firings in response to 50 mmHg CRD, eight neurones increased spike firings in response to 30 and 50 mmHg CRD, and two neurones responded to all CRD pressures (10, 30 and 50 mmHg). P≤ 0.05 versus sham-treated control (Dunnett's T3 test following one-way ANOVA). P≤ 0.05 versus sham-treated control rats. **P≤ 0.05 versus EA sham operation. (One-way repeated measures ANOVA followed by Bonferroni's test).