Theta-frequency bursting and resonance in cerebellar granule cells:: Experimental evidence and modeling of a slow K+-dependent mechanism
Theta-frequency bursting and resonance in cerebellar granule cells:: Experimental evidence and modeling of a slow K+-dependent mechanism
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DOI：
10.1523/jneurosci.21-03-00759.2001
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发表时间：
2001-02-01
影响因子：
5.3
通讯作者：
Naldi, G
中科院分区：
文献类型：
--
作者：
D'Angelo, E;Nieus, T;Naldi, G
神经元以高度非线性的方式处理信息，产生振荡、爆发和共振，在优先频率下增强反应能力。有人提出，缓慢的复极化电流可能是振荡/猝发终止和引起共振的高通滤波的原因(Hutcheon和Yarom，2000)。然而，不同的机制，包括电张力效应(Mainen和Sejinowski，1996)、复苏电流的表达(Raman和Bean，1997)和网络反馈，也可能是重要的。在这项研究中，我们报道了大鼠小脑颗粒细胞的theta频率(3-12 Hz)爆发和共振，并表明这些神经元表达一种先前未知的缓慢复极化K+电流(IK-low)。我们的实验和建模结果表明，对于突发和共振，IK-Slow都是必要的。持续的(可能是复活的)Na+电流对突起和共振产生复杂的放大作用，而颗粒细胞的紧凑结构排除了电张力效应。颗粒细胞的Theta频率爆发和共振可能在决定小脑的同步性、节律性和学习能力方面发挥重要作用。
Neurons process information in a highly nonlinear manner, generating oscillations, bursting, and resonance, enhancing responsiveness at preferential frequencies. It has been proposed that slow repolarizing currents could be responsible for both oscillation/burst termination and for high-pass filtering that causes resonance (Hutcheon and Yarom, 2000). However, different mechanisms, including electrotonic effects (Mainen and Sejinowski, 1996), the expression of resurgent currents (Raman and Bean, 1997), and network feedback, may also be important. In this study we report theta-frequency (3-12 Hz) bursting and resonance in rat cerebellar granule cells and show that these neurons express a previously unidentified slow repolarizing K+ current (IK-slow). Our experimental and modeling results indicate that IK-slow was necessary for both bursting and resonance. A persistent (and potentially a resurgent) Na+ current exerted complex amplifying actions on bursting and resonance, whereas electrotonic effects were excluded by the compact structure of the granule cell. Theta-frequency bursting and resonance in granule cells may play an important role in determining synchronization, rhythmicity, and learning in the cerebellum.