Interaction of Kv3 potassium channels and resurgent sodium current influences the rate of spontaneous firing of Purkinje neurons
Interaction of Kv3 potassium channels and resurgent sodium current influences the rate of spontaneous firing of Purkinje neurons
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DOI：
10.1523/jneurosci.5204-05.2006
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发表时间：
2006-04-26
影响因子：
5.3
通讯作者：
Knopfel, T
中科院分区：
文献类型：
--
作者：
Akemann, W;Knopfel, T
浦肯野神经元在没有突触驱动的情况下自发地产生动作电位，从而向小脑深核中的靶细胞施加紧张性但可塑性的输入。浦肯野神经元表达两种具有生物物理特性的离子电流，这些离子电流专门用于高频放电：由Kv3.3介导的复苏钠电流和钾电流。这些离子电流如何决定浦肯野神经元的内在活动，目前还只是部分了解。来自缺乏Kv3.3的突变小鼠的浦肯野神经元具有降低的自发放电速率。动态钳记录表明，正常的放电率救援插入人工Kv3电流Kv3.3敲除浦肯野神经元。数值模拟表明，Kv3.3通过与复苏的钠电流的合作增加自发放电率。我们的结论是自发动作电位放电的浦肯野神经元的速率是由Kv3.3钾电流和复苏的钠电流的相互作用控制。
Purkinje neurons spontaneously generate action potentials in the absence of synaptic drive and thereby exert a tonic, yet plastic, input to their target cells in the deep cerebellar nuclei. Purkinje neurons express two ionic currents with biophysical properties that are specialized for high-frequency firing: resurgent sodium currents and potassium currents mediated by Kv3.3. How these ionic currents determine the intrinsic activity of Purkinje neurons has only partially been understood. Purkinje neurons from mutant mice lacking Kv3.3 have a reduced rate of spontaneous firing. Dynamic-clamp recordings demonstrated that normal firing rates are rescued by inserting artificial Kv3 currents into Kv3.3 knock-out Purkinje neurons. Numerical simulations indicated that Kv3.3 increases the spontaneous firing rate via cooperation with resurgent sodium currents. We conclude that the rate of spontaneous action potential firing of Purkinje neurons is controlled by the interaction of Kv3.3 potassium currents and resurgent sodium currents.