Examples of the effect of UTP on ATP-evoked currents in lumbosacral (A, B) and thoracolumbar (C) bladder neurons. UTP significantly facilitated sustained (A) and fast (C) currents but not slow currents (B). D, Summary of the effect of UTP on ATP-evoked sustained (n = 16), slow (n = 24), and fast (n = 5) currents. Error bars indicate SEM. *p < 0.05, **p < 0.01.