Figure 1. Loss of visceromotor responses to rectal distension in ls/ls mice.

A, electromyographic recording of visceromotor responses to incremental rectal distension in a control C57BL/6 mouse (up to 120 mmHg). B, rectal distension up to 120 mmHg did not evoke a measurable visceromotor response in ls/ls mouse, although somatic stimuli (tail pinch, hindlimb pinch, paw pinch and whisker pinch) were effective. C, quantification of visceromotor responses to rectal distension in control and ls/ls mice. D, distension pressures over 200 mmHg evoked small visceromotor responses in some, but not all ls/ls mice.