Ion channels generating complex spikes in cartwheel cells of the dorsal cochlear nucleus
Ion channels generating complex spikes in cartwheel cells of the dorsal cochlear nucleus
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DOI：
10.1152/jn.00536.2006
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发表时间：
2007-02-01
影响因子：
2.5
通讯作者：
Trussell, Laurence O.
中科院分区：
文献类型：
--
作者：
Kim, Yuil;Trussell, Laurence O.
它们的特征在于简单和复杂动作电位的混合物的发射。要了解什么离子通道决定这两种类型的尖峰波形的产生，我们记录从侧手翻细胞使用短杆菌肽穿孔补丁技术在小鼠耳蜗背核的脑切片和应用通道选择性阻断剂。复杂的尖峰，区分它们是否直接从负膜电位或以后在一个长的去极化。Ca ~（2+）通道和Ca ~（2+）依赖性K ~+通道是复合峰电位的主要决定因素。发作复杂的尖峰需要T型和可能的R型钙通道，并由BK和SK K+通道的形状。随后在去极化中出现的复合尖峰依赖于P/Q-和L-型Ca 2+通道以及BK和SK通道。BK通道也有助于简单锋电位的快速复极化。简单尖峰的特点是后去极化，这可能是触发复杂的尖峰，是由T/R型Ca 2+和SK通道。快速尖峰依赖于N+通道，一个大的持续性Na+电流可能提供了一个去极化驱动器的自发活动在车轮细胞。因此，侧手翻细胞的各种电行为是由各种离子通道的相互作用决定的，其中Ca 2+起着重要作用。
They are characterized by firing of mixtures of both simple and complex action potentials. To understand what ion channels determine the generation of these two types of spike waveforms, we recorded from cartwheel cells using the gramicidin perforated-patch technique in brain slices of mouse dorsal cochlear nucleus and applied channel-selective blockers. Complex spikes were distinguished by whether they arose directly from a negative membrane potential or later during a long depolarization. Ca2+ channels and Ca2+- dependent K+ channels were major determinants of complex spikes. Onset complex spikes required T-type and possibly R-type Ca2+ channels and were shaped by BK and SK K+ channels. Complex spikes arising later in a depolarization were dependent on P/Q- and L-type Ca2+ channels as well as BK and SK channels. BK channels also contributed to fast repolarization of simple spikes. Simple spikes featured an afterdepolarization that is probably the trigger for complex spiking and is shaped by T/R-type Ca2+ and SK channels. Fast spikes were dependent on N+ channels; a large persistent Na+ current may provide a depolarizing drive for spontaneous activity in cartwheel cells. Thus the diverse electrical behavior of cartwheel cells is determined by the interaction of a wide variety of ion channels with a prominent role played by Ca2+.