Fig. 2.

Bladder (top traces) and EUS EMG activity (bottom traces) recorded during a continuous-transvesical infusion CMG in an anesthetized rat. A: intravesical pressure and EUS EMG activity were relatively stable during the filling phase. A reflex bladder contraction, indicated by an abrupt, large increase in bladder pressure, was accompanied by large-amplitude EUS EMG activity. B: same recording indicated by asterisk in A shown at faster time scale. The bracket in B indicates the recording period in C, and the bracket in C indicates the recording period in D at a faster time scale. Note the decline in intravesical pressure during EUS EMG bursting in B and C, which indicates the period of voiding. C: tonic EUS EMG activity precedes the large rise in intravesical pressure and shifts to a bursting pattern at the peak of bladder contraction before the onset of voiding. Small oscillations in intravesical pressure coincide with each burst of EMG activity. D: recordings in C shown at very fast time scale showing individual EUS EMG bursts composed of active (AP) and silent periods (SP; brackets) and the small fluctuations in intravesical pressure accompanying each burst. Vertical calibration, intravesical pressure (in cmH₂O); horizontal calibration, time (in minutes or seconds); Inf, start of saline infusion.