A computational model of action potential in the mouse detrusorsmooth muscle cell

Urinary incontinence is associated with enhanced spontaneous phasic contractions of the detrusor smooth muscle (DSM). It is suggested that the spontaneously evoked action potentials (sAPs) in DSM cells initiate and modulate the contractions. In order to further our understanding of the underlying ionic mechanisms in sAP generation, we present here a biophysically detailed computational model of a single DSM cell. We constructed mathematical models for nine ion channels found in DSM cells based on published experimental data. After incorporating all ion channels, our DSM model is capable of reproducing experimentally recorded spike-type sAPs of varying configurations. Our model, constrained heavily by physiological data, provides a powerful tool to investigate the ionic mechanisms underlying the genesis of DSM electrical activity, which can further shed light on urinary bladder function and dysfunction.