Fig. 1.

Representative recordings of simultaneous measurement of intravesical pressure (IVP) and EUS-EMG activity or urethral perfusion pressure (UPP) in a rat (A and B) or a mouse (C). The EUS-EMG exhibits tonic activity before the onset of voiding and bursting activity during voiding (A). The bursting produces rhythmic contractions and relaxation of the EUS and is thought to generate a urethral pumping action during voiding, which is seen as high-frequency oscillations (HFOs) on UPP (B). In contrast, most mice exhibited reduced EUS activity without bursting and no obvious pressure oscillation on the cystometrogram during voiding.

([A, C] Adapted from Kadekawa K, Yoshimura N, Majima T, et al. Characterization of bladder and external urethral activity in mice with or without SCI–a comparison study with rats. Am J Physiol Regul Integr Comp Physiol 2016;310:R752–8; and [B] From Miyazato M, Sasatomi K, Hiragata S, et al. Suppression of detrusor-sphincter dysynergia by GABA-receptor activation in the lumbosacral spinal cord in spinal cord-injured rats. Am J Physiol Regul Integr Comp Physiol 2008;295:R336–42.)