A, raw recordings of spontaneous action potentials. B, original recordings from panel A at expanded time scale. Ba and b, IJP evoked by 1 pulse of oral NS at either valley or peak, respectively, of slow wave. Bc, an IJP induced by 4 pulses. Arrows indicated nerve stimulation. Smooth muscle of taenia caeci was characterized by slow waves on which 1–3 spontaneous action potentials were superimposed.