Evidence from experimental studies shows that oscillations due to electro-mechanical coupling can be generated spontaneously in smooth muscle cells. Such cellular dynamics are known as pacemaker dynamics. In this article, we address pacemaker dynamics associated with the interaction of [Formula: see text] and [Formula: see text] fluxes in the cell membrane of a smooth muscle cell. First we reduce a pacemaker model to a two-dimensional system equivalent to the reduced Morris-Lecar model and then perform a detailed numerical bifurcation analysis of the reduced model. Existing bifurcation analyses of the Morris-Lecar model concentrate on external applied current, whereas we focus on parameters that model the response of the cell to changes in transmural pressure. We reveal a transition between Type I and Type II excitabilities with no external current required. We also compute a two-parameter bifurcation diagram and show how the transition is explained by the bifurcation structure.

中文翻译：

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平滑肌细胞模型中起搏器动力学的数值分岔分析

实验研究的证据表明，平滑肌细胞中可以自发地产生由机电耦合引起的振荡。这种细胞动力学称为起搏器动力学。在本文中，我们讨论了与平滑肌细胞细胞膜中 [公式：见正文] 和 [公式：见正文] 通量相互作用相关的起搏器动力学。首先，我们将起搏器模型简化为与简化的 Morris-Lecar 模型等效的二维系统，然后对简化的模型进行详细的数值分岔分析。Morris-Lecar 模型的现有分岔分析集中在外部施加的电流上，而我们专注于模拟细胞对跨壁压力变化的响应的参数。我们揭示了 I 型和 II 型兴奋性之间的过渡，无需外部电流。我们还计算了一个双参数分叉图，并展示了分叉结构如何解释转换。