Control of firing patterns by two transient potassium currents: leading spike, latency, bistability
Control of firing patterns by two transient potassium currents: leading spike, latency, bistability
复制标题
通过两个瞬态钾电流控制放电模式：前导尖峰、潜伏期、双稳态
DOI：
10.1007/s10827-010-0297-5
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发表时间：
2011-08-01
影响因子：
1.2
通讯作者：
Rinzel, John
中科院分区：
文献类型：
--
作者：
Meng, Xiangying;Lu, Qishao;Rinzel, John
瞬时钾电流显著影响放电特性，特别是在调节重复放电前的潜伏期。耳蜗背核（DCN）锥体细胞有两种瞬时钾电流IKifi和IKis，分别为快失活和慢失活，其放电模式具有显著的可变性。它们表现出立即的重复放电，或者只有在长时间的潜伏期后才有或没有领先的尖峰，即所谓的暂停和积累模式。我们考虑了DCN锥体细胞的基于电导的10变量单室模型（Kanold和Manis 2001）。我们开发和分析了一个简化的三变量积分和火灾模型（KM-LIF），捕捉定性的射击功能。我们应用动力学系统方法来解释放电行为的生物物理和数学机制，包括特征放电模式，潜伏期阶段，重复放电的开始，以及潜伏期持续时间的定时（即）中的一些不连续性。第一尖峰延迟和第一尖峰间间隔）。此外，我们得到了新的见解与领先尖峰相平面分析。我们进一步证明了可能的异质性ofIKis的影响。通过调节IKifandIKis的相对量，可以控制重复放电前的潜伏期，使其覆盖很大的范围。最后，我们发现，对于整个系统的鲁棒双稳态时，enoughIKisis存在。
Transient potassium currents distinctively affect firing properties, particularly in regulating the latency before repetitive firing. Pyramidal cells of the dorsal cochlear nucleus (DCN) have two transient potassium currents,IKifandIKis, fast and slowly inactivating, respectively, and they exhibit firing patterns with dramatically variable latencies. They show immediate repetitive firing, or only after a long latency with or without a leading spike, the so-called pauser and buildup patterns. We consider a conductance-based, ten-variable, single-compartment model for the DCN pyramidal cells (Kanold and Manis 2001). We develop and analyze a reduced three-variable integrate-and-fire model (KM-LIF) which captures the qualitative firing features. We apply dynamical systems methods to explain the underlying biophysical and mathematical mechanisms for the firing behaviors, including the characteristic firing patterns, the latency phase, the onset of repetitive firing, and some discontinuities in the timing of latency duration (e.i. first spike latency and first inter spike interval). Moreover, we obtain new insights associated with the leading spike by phase plane analysis. We further demonstrate the effects of possible heterogeneity ofIKis. The latency before repetitive firing can be controlled to cover a large range by tuning of the relative amounts ofIKifandIKis. Finally, we find for the full system robust bistability when enoughIKisis present.