Are relaxation oscillators an appropriate model of gastrointestinal electrical activity?
Are relaxation oscillators an appropriate model of gastrointestinal electrical activity?
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张弛振荡器是胃肠电活动的合适模型吗？
DOI：
10.1152/ajpgi.1989.256.2.g265
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Sanders,KM
中科院分区：
文献类型：
--
作者：
Publicover,NG;Sanders,KM
近二十年来，基于松弛振荡器的数学模型严重影响了胃肠运动研究的术语和实验设计。松弛振荡器方程已被用于刺激食道、胃、小肠、结肠和直肠乙状结肠区的电活动。有人认为，胃肠电活动的许多特性不能用经典的“芯-导体”或“电缆”激励和传导模型充分解释。本文批判性地回顾了弛豫振荡器模型，并对每个假定的芯导体理论的不足之处提供了解释。此外，我们质疑松弛振荡器方程是否能够模拟胃肠道慢波的波形、药物或电刺激时波形的变化、在生理频率下刺激时慢波活动的模式、胃慢波和电紧张扩散到非活动区域之间的恒定静息膜电位的延长时间。我们得出结论，弛豫振荡器方程不能完全描述胃肠电活动；激发和传播可以通过一种理论来模拟，该理论提供了电缆方程中包含的形态特征、离子电导和其他元素。
Mathematical models based on relaxation oscillators have heavily influenced the terminology and experimental designs of investigations in gastrointestinal motility for nearly two decades. Relaxation oscillator equations have been used to stimulate the electrical activities of the esophagus, stomach, small intestine, colon, and rectosigmoid region. It has been suggested that many attributes of gastrointestinal electrical activity cannot be adequately explained by classic "core-conductor" or "cable" models of excitation and conduction. This article critically reviews the relaxation oscillator model and provides an explanation for each of the putative inadequacies of core-conductor theory. Furthermore, we question whether relaxation oscillator equations are able to simulate the waveforms of gastrointestinal slow waves, alterations in waveform in response to drugs or electrical stimulation, patterns of slow-wave activity when stimulated at physiological frequencies, prolonged periods of constant resting membrane potential between gastric slow waves and electrotonic spread into inactive regions. We conclude that the relaxation oscillator equations do not fully describe gastrointestinal electrical activity; excitation and propagation can be modeled by a theory that provides for morphological features, ionic conductances, and other elements included in the cable equations.