FIG. 5.

Sensitization of muscular pelvic nerve afferent fiber responses to stretch. A: responses to stretch of a low-threshold muscular afferent are shown before, during (1 min), and 5 min after application of inflammatory soup (IS, pH 6.0) to its receptive field. In this example, the afferent responded vigorously to the IS (note that activity returned to control before stretch was tested). B: responses of a high-threshold muscular afferent are shown before and 5 min after application of IS (pH 6.0) to its receptive field. In this example, the afferent did not respond to the IS. The horizontal lines beneath recordings indicate the application of IS (1 min) or stretch (20 s) and the loads applied.