High resolution

Module 7: ICC pacemaker

Cytosolic Ca2+ oscillator responsible for pacemaker activity in interstitial cells of Cajal.

Interstitial cells of Cajal (ICC) release periodic pulses of Ca2+ that begin as puffs and progress into global Ca2+ waves. Each puff activates a Cl channel to give a spontaneous transient inward current (STIC) that sum to form the spontaneous transient depolarizations (STD). The STD spreads into neighbouring smooth muscle cells through current flow through gap junctions to activate contraction. See text for a description of the oscillator that drives this activation process.