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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. This electrical rhythm is spread through gap junctions in the smooth muscle of the GI tract. These pacemaker cells, also called the ICCs, control the frequency of contractions in the gastrointestinal tract. The cells can be located in either the circular or longitudinal layer of the smooth muscle in the GI tract; circular for the small and large intestine, longitudinal for the stomach. The frequency of contraction differs at each location in the GI tract beginning with 3 per minute in the stomach, then 12 per minute in the duodenum, 9 per minute in the ileum, and a normally low one contraction per 30 minutes in the large intestines that increases 3 to 4 times a day due to a phenomenon called mass movement. The basal electrical rhythm controls the frequency of contraction but additional neuronal and hormonal controls regulate the strength of each contraction.
Gap junction modulation describes the functional manipulation of gap junctions, specialized channels that allow direct electrical and chemical communication between cells without exporting material from the cytoplasm. Gap junctions play an important regulatory role in various physiological processes including signal propagation in cardiac muscles and tissue homeostasis of the liver. Modulation is required, since gap junctions must respond to their environment, whether through an increased expression or permeability. Impaired or altered modulation can have significant health implications and are associated with the pathogenesis of the liver, heart and intestines.
References
- ↑ Haddock RE, Hill CE. Rhythmicity in arterial smooth muscle. J Physiol (Lond ). 2005; 566: 645-656, Aalkaer C, Nilsson H. Vasomotion: cellular background for the oscillator and for the synchronization of smooth muscle cells. Br J Pharmacol. 2005; 144: 605-616.
- ↑ Aalkaer C, Nilsson H. Vasomotion: cellular background for the oscillator and for the synchronization of smooth muscle cells. Br J Pharmacol. 2005; 144: 605-616.
- ↑ Jaggar JH, Porter VA, Lederer WJ, Nelson MT. Calcium sparks in smooth muscle. Am J Physiol Cell Physiol. 2000; 278: C235-256.
- 1 2 Nilsson H, Aalkjaer C. Vasomotion: mechanisms and physiological importance. Molecular Interventions. 2003; 3: 79-89.
- ↑ Haddock RE, Hirst GDS, Hill CE. Voltage independence of vasomotion in isolated irideal arterioles of the rat. J. Physiol. 2002; 540: 219-229.
- ↑ Parthimos D, Haddock RE, Hill CE, Griffith TM. Dynamics of A Three-Variable Nonlinear Model of Vasomotion: Comparison of Theory and Experiment. Biophys J. 2007; 93: 1534-1556.
- ↑ Meyer C, de Vries G, Davidge ST, Mayes DC. Reassessing the Mathematical Modeling of the Contribution of Vasomotion to Vascular Resistance. J Appl Physiol. 2002; 92: 888-889.
- ↑ Gratton RJ, Gandley RE, McCarthy JF, Michaluk WK, Slinker BK, McLaughlin MK. Contribution of vasomotion to vascular resistance: a comparison of arteries from virgin and pregnant rats. J Appl Physiol. 1998; 85: 2255-2260.