Quantitative cellular description of gastric slow wave activity

2008 ◽  
Vol 294 (4) ◽  
pp. G989-G995 ◽  
Author(s):  
Alberto Corrias ◽  
Martin L. Buist
Keyword(s):  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Quantitative Description ◽  
Wave Activity ◽  
Slow Waves ◽  
Slow Wave Activity ◽  
Good Correspondence ◽  
Gastric Slow Wave ◽  
Intracellular Ca ◽  
Cells Of Cajal

Interstitial cells of Cajal (ICC) are responsible for the spontaneous and omnipresent electrical activity in the stomach. A quantitative description of the intracellular processes whose coordinated activity is believed to generate electrical slow waves has been developed and is presented here. In line with recent experimental evidence, the model describes how the interplay between the mitochondria and the endoplasmic reticulum in cycling intracellular Ca2+ provides the primary regulatory signal for the initiation of the slow wave. The major ion channels that have been identified as influencing slow wave activity have been modeled according to data obtained from isolated ICC. The model has been validated by comparing the simulated profile of the slow waves with experimental recordings and shows good correspondence in terms of frequency, amplitude, and shape in both control and pharmacologically altered conditions.

Selective lesioning of interstitial cells of Cajal by methylene blue and light leads to loss of slow waves

1994 ◽  
Vol 266 (3) ◽  
pp. G485-G496 ◽  
Author(s):  
L. W. Liu ◽  
L. Thuneberg ◽  
J. D. Huizinga
Keyword(s):  
Methylene Blue ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Electrical Activity ◽  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Wave Activity ◽  
Slow Waves ◽  
Slow Wave Activity ◽  
Cells Of Cajal

Incubation with 50 microM methylene blue (MB) and subsequent intense illumination resulted in abolition of the slow-wave activity in the submuscular interstitial cells of Cajal-circular muscle (ICC-CM) preparations of canine colon. This was often accompanied by a decrease in resting membrane potential. Repolarization of cells back to -70 mV did not restore the slow-wave activity, indicating that MB plus light directly interrupted the generation mechanism of slow waves. After MB incubation, a 2-min illumination consistently changed the mitochondrial conformation in ICCs from very condensed to orthodox, without inducing any obvious changes in smooth muscle cells. After 4- to 10-min illumination, ICCs became progressively more damaged with swollen and ruptured mitochondria, loss of cytoplasmic contrast and detail, loss of caveolae, and rupture of the plasma membrane. No damage was seen in smooth muscle cells or nerves. Gap junctional ultrastructure was preserved. Intense illumination without preincubation with MB left the slow waves and the ultrastructure of ICC-CM preparations unaffected. In CM preparations, without the submuscular ICC-smooth-muscle network, MB plus light induced no changes in electrical activity. We conclude that the correlation between selective damage to the submuscular ICCs (relative to smooth muscle) and selective loss of the slow-wave activity (relative to other electrical activity of the CM) strongly indicates that the ICCs play an essential role in the generation of slow waves.

Slow-wave activity in colon: role of network of submucosal interstitial cells of Cajal

1991 ◽  
Vol 260 (4) ◽  
pp. G636-G645 ◽  
Author(s):  
R. Serio ◽  
C. Barajas-Lopez ◽  
E. E. Daniel ◽  
I. Berezin ◽  
J. D. Huizinga
Keyword(s):  
Smooth Muscle ◽  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Wave Activity ◽  
Slow Waves ◽  
Slow Wave Activity ◽  
Plateau Potentials ◽  
Cells Of Cajal

The present study compares the electrophysiological properties of two preparations dissected from the canine colon circular muscle layer: first, containing the submucosal network of interstitial cells of Cajal (ICC) with two to four associated smooth muscle cell layers, and second, a circular muscle preparation devoid of the submucosal ICC network. In the ICC-rich preparations, consistent slow-wave activity was observed with prolonged plateau potentials of approximately 10-s duration. The plateau potentials were sensitive to D 600. In approximately 45% of circular muscle preparations devoid of the submucosal ICC network (confirmed using electron microscopy) slow waves, of different waveshape, were recorded at frequencies identical to those in whole circular muscle preparations. These slow waves did not show a plateau potential. Compared with ICC-rich preparations with a resting membrane potential of about -80 mV, circular muscle preparations had lower membrane potentials, about -70 mV when active, and about -60 mV when quiescent. Heptanol (1 mM) electrically uncoupled cells, since it abolished electrotonic current spread and allowed measurement of the input resistance by intracellular current injection. Heptanol also affected ionic conductances. Heptanol abolished slow waves; the underlying mechanism needs further investigation. In the presence of heptanol, cells in the isolated ICC network and in circular smooth muscle preparations showed spontaneous hyperpolarizing potential fluctuations at a frequency of four to six per second. These oscillations were abolished by current-induced hyperpolarization and TEA (30 mM) and are therefore likely due to spontaneously active K+ conductance.

scholarly journals Expression of anoctamin 1/TMEM16A by interstitial cells of Cajal is fundamental for slow wave activity in gastrointestinal muscles

2009 ◽  
Vol 587 (20) ◽  
pp. 4887-4904 ◽  
Author(s):  
Sung Jin Hwang ◽  
Peter J. A. Blair ◽  
Fiona C. Britton ◽  
Kate E. O’Driscoll ◽  
Grant Hennig ◽  
...  
Keyword(s):  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Anoctamin 1 ◽  
Cells Of Cajal

Pacemaker activity recorded in interstitial cells of Cajal of the gastrointestinal tract

1989 ◽  
Vol 257 (4) ◽  
pp. C830-C835 ◽  
Author(s):  
C. Barajas-Lopez ◽  
I. Berezin ◽  
E. E. Daniel ◽  
J. D. Huizinga
Keyword(s):  
Methylene Blue ◽  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Resting Membrane Potential ◽  
Pacemaker Activity ◽  
Cells Of Cajal

The hypothesis was tested that interstitial cells of Cajal can generate slow wave activity. Intracellular recordings were performed only in the most superficial cells at the submucosal surface of the canine colonic circular muscle layer. An omnipresent and characteristic slow wave activity was present in all cells with a mean amplitude of 37 +/- 3 mV, a frequency of 4.6 +/- 0.1 counts/min (cpm), and a duration of 5.6 +/- 0.5 s; the average resting membrane potential was -70 +/- 1 mV. To determine the type of cell from which these recordings were obtained, methylene blue was injected by microiontophoresis. The strips were immediately fixed while the microelectrode was kept in the cell. A small segment of the tissue containing this cell was then processed for electron microscopy and serially sectioned. Electron-microscopic evidence showed that the microelectrode tip was positioned in an interstitial cell of Cajal (ICC): 1) several sections were observed with round cytoplasmic lesions of decreasing diameter followed by sections from the same cell without the lesion and 2) electron-dense material was observed in these sections due to the injected methylene blue. These cells were identified as part of the ICC network present at the muscle-submucosa interface of the circular muscle and were positively identified as ICC by the presence of cell processes. This is the first report giving direct evidence for the occurrence of electrical slow waves in ICC. It is essential support for the hypothesis that ICC are the actual pacemaker cells of the gut musculature.

scholarly journals Interstitial cells of Cajal integrate excitatory and inhibitory neurotransmission with intestinal slow-wave activity

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Sabine Klein ◽  
Barbara Seidler ◽  
Anna Kettenberger ◽  
Andrei Sibaev ◽  
Michael Rohn ◽  
...  
Keyword(s):  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Inhibitory Neurotransmission ◽  
Cells Of Cajal
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