Three roads to islet bursting: emergent oscillations in coupled phantom bursters.
Three roads to islet bursting: emergent oscillations in coupled phantom bursters.
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DOI：
10.1529/biophysj.103.038471
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发表时间：
2004-07
影响因子：
3.4
通讯作者：
C. Zimliki;D. Mears;A. Sherman
中科院分区：
文献类型：
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作者：
C. Zimliki;D. Mears;A. Sherman
在分离的胰腺β细胞中，葡萄糖诱导的膜电位和Ca（2+）振荡发生在很宽的频率范围内，从bb0.6 /min（快）到<1/min（慢）。然而，完整胰岛内的细胞通常振荡周期为10-60秒（中等）。幻相爆发的概念解释了β细胞是如何产生如此宽的频率范围的。在这里，我们探索了一个更新的幻膜破裂模型，以确定单一参数的异质性如何解释在单个细胞中观察到的宽频率范围和介质振荡的稀有性。然后，我们将单细胞模型纳入具有参数异质性的胰岛模型。我们表明，强耦合的胰岛必须主要由中等振荡的单个细胞或快速和慢速细胞的混合物组成，才能产生中等振荡。令人惊讶的是，我们发现这种限制并不适用于中等耦合，并且稳健的中等振荡胰岛可以从基本上全部缓慢或全部快速的单细胞群体中产生。因此，有了耦合的幻相爆发器，中等振荡的胰岛可以由全快、全慢或两者兼而有之的细胞构建而成。
Glucose-induced membrane potential and Ca(2+) oscillations in isolated pancreatic beta-cells occur over a wide range of frequencies, from >6/min (fast) to <1/min (slow). However, cells within intact islets generally oscillate with periods of 10-60 s (medium). The phantom bursting concept addresses how beta-cells can generate such a wide range of frequencies. Here, we explore an updated phantom bursting model to determine how heterogeneity in a single parameter can explain both the broad frequency range observed in single cells and the rarity of medium oscillations. We then incorporate the single-cell model into an islet model with parameter heterogeneity. We show that strongly coupled islets must be composed of predominantly medium oscillating single cells or a mixture of fast and slow cells to robustly produce medium oscillations. Surprisingly, we find that this constraint does not hold for moderate coupling, and that robustly medium oscillating islets can arise from populations of single cells that are essentially all slow or all fast. Thus, with coupled phantom bursters, medium oscillating islets can be constructed out of cells that are either all fast, all slow, or a combination of the two.