High resolution

Module 7: Figure K+ slows ICC pacing



Depolarization alters the ICC pacemaker waveform.

The pacemaker of ICC in the mouse small intestine is altered as the resting membrane potential is depolarized by increasing the concentration of K+ in the bathing medium. Note the progressive decline in frequency, amplitude and rate of rise of the transients. The rate of rise indicates the rate at which the wave spreads along the long thin ICC cells. As the membrane depolarizes, the contribution of the voltage-operated channels (VOCs) to synchronize the internal release declines thus slowing down the Ca2+ waves and hence the rate of rise. Reproduced from Kito and Suzuki (2003).