Figure 3. Electrical coupling between the three cell layers of the gastric antrum and the lack of rectification between ICC_my and the circular muscle layer of the gastric antrum.

Aa, electrotonic potentials recorded from the longitudinal, ICC_my and circular layer, each produced by injecting current (Ab) into the circular layer in the interval between slow waves. In this experiment the membrane potentials of the circular smooth muscle layer, ICC_my and longitudinal layer were −64, −63 and −62 mV, respectively. B, a family of electrotonic potentials (Ba) recorded from an ICC_my generated by injection of hyperpolarizing and depolarizing currents (Bb) into a circular muscle cell. Bc, the relationship between injected current and membrane potential response was close to linear (see text). The membrane potentials of the circular smooth muscle layer and ICC_my were −67 and −66 mV, respectively. The time bars apply to all traces.