C57BL/6NTac, but not C57BL/6J, mice develop ZYM-induced VH. Visceromotor (EMG) responses were measured during colorectal balloon distension pre- and post intracolonic ZYM instillation for each strain. The graph shows the following groups: BL/6J-naïve (before ZYM, open teal square), BL/6J-ZYM (21 days after ZYM, real square), BL/6NTac-naïve (before ZYM, open orange circle), and BL/6NTac (21 days after ZYM, orange circle) mice (n = 7–10). Each mouse was normalized to its own naïve/baseline response to the maximum distension pressure of 60 mmHg. ANOVA on the cumulative AUC across all distension pressures revealed a significant main effect of strain (F [1, 11], P = .015) and a significant Strain × Time interaction (F [1, 11] = 6.863, P = .024). Follow-up 1-way ANOVA considering only VMR to 60-mmHg distention pressure confirmed a significant main effect of group (F [3, 38]) = 3.493, P < .05). Post hoc group comparisons using Fisher’s LSD also confirmed that the VMR to 60-mmHg distention pressure differed between B/6NTac-ZYM and all other conditions (all P < .05). * Indicates significant difference between C57BL/6NTac-ZYM and all other conditions. Abbreviations: LSD, Least significant difference.