The basal or basic electrical rhythm (BER) or electrical control activity (ECA) is the spontaneous depolarization and repolarization of pacemaker cells known as interstitial cells of Cajal (ICCs) in the smooth muscle of the stomach, small intestine, and large intestine.
Smooth muscle within the GI tract causes the involuntary peristaltic motion that moves consumed food down the esophagus and towards the rectum.
The physical contractions of the smooth muscle cells can be caused by action potentials in efferent motor neurons of the enteric nervous system, or by receptor mediated calcium influx.
In order for a contraction to occur, a hormone or neurocrine signal must induce the smooth muscle cell to have an action potential.
The basal electrical rhythm allows the smooth muscle cell to depolarize and contract rhythmically when exposed to hormonal signals.
This action potential is transmitted to other smooth muscle cells via gap junctions, creating a peristaltic wave.
[4] These chloride channels trigger spontaneous transient inward current which couples the calcium oscillations to electrical activity.