The phantom burster model for pancreatic β-cells
The phantom burster model for pancreatic β-cells
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DOI：
10.1016/s0006-3495(00)76525-8
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发表时间：
2000-12-01
影响因子：
3.4
通讯作者：
Satin, LS
中科院分区：
文献类型：
--
作者：
Bertram, R;Previte, J;Satin, LS
胰腺β细胞表现出具有宽范围周期的爆发振荡。然而，在分离的细胞中的周期通常是几秒钟或几分钟，在完整的胰岛中，它们是中间的（10-60秒）。我们开发了一个数学模型，β细胞的电活动能够产生这种广泛的爆发振荡。与以前的模型不同，爆发是由两个缓慢过程的相互作用驱动的，一个具有相对较小的时间常数（16 s），另一个具有大得多的时间常数（1-2 min）。在中间时间尺度上产生猝发，而不需要具有中间时间常数的缓慢过程，因此不需要幻象猝发。该模型表明，表现出快速模式的孤立细胞可能仍然具有较慢的过程，可以通过注入合适的外源电流来实现。在此指导下，我们设计了一个实验协议，使用动态钳技术，可靠eleclampus胰岛样，中期振荡从孤立的细胞。最后，我们表明，快速爆发和缓慢爆发之间的强电耦合可以产生同步介质爆发，这表明胰岛可能由本质上快速或缓慢的细胞组成，很少或没有本质上是介质。
Pancreatic beta -cells exhibit bursting oscillations with a wide range of periods. Whereas periods in isolated cells are generally either a few seconds or a few minutes, in intact islets of Langerhans they are intermediate (10-60 s). We develop a mathematical model for beta -cell electrical activity capable of generating this wide range of bursting oscillations. Unlike previous models, bursting is driven by the interaction of two slow processes, one with a relatively small time constant (16 s) and the other with a much larger time constant (1-2 min). Bursting on the intermediate time scale is generated without need for a slow process having an intermediate time constant, hence phantom bursting. The model suggests that isolated cells exhibiting a fast pattern may nonetheless possess slower processes that can be brought out by injecting suitable exogenous currents. Guided by this, we devise an experimental protocol using the dynamic clamp technique that reliably elicits islet-like, medium period oscillations from isolated cells. Finally, we show that strong electrical coupling between a fast burster and a slow burster can produce synchronized medium bursting, suggesting that islets may be composed of cells that are intrinsically either fast or slow, with few or none that are intrinsically medium.