Proposed Model of TC-Evoked Afferent Bursts As the bladder fills, rapid TCs occur. The rate of rise of these TCs is a function of the length-tension relationship of detrusor smooth muscle. TCs stimulate bursts of afferent nerve activity that increase with the rate of rise of the TCs and saturate at ∼3 mmHg/s. The peak afferent activity and maximal TC rate of rise both occur when intravesical pressure is near threshold (∼12 mmHg), which may be indicative of the optimal length-tension relationship for voiding contractions. For simulated and naturally occurring TCs, the SK blocker apamin increased the gain of the relationship between TC leading slope and afferent activity. The molecular identity of the bladder pressure transducer is unknown.