Dendritic D-type potassium currents inhibit the spike afterdepolarization in rat hippocampal CA1 pyramidal neurons
Dendritic D-type potassium currents inhibit the spike afterdepolarization in rat hippocampal CA1 pyramidal neurons
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DOI：
10.1113/jphysiol.2006.127068
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发表时间：
2007-05-15
影响因子：
5.5
通讯作者：
Martina, Marco
中科院分区：
文献类型：
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作者：
Metz, Alexia E.;Spruston, Nelson;Martina, Marco
在CA 1锥体神经元中，爆发性放电与神经依赖性行为和突触强度的调制相关。在这些细胞中爆发性放电的机制之一是跟随每个动作电位的后去极化（ADP）。以前的工作表明ADP是由位于索马和树突中的几个去极化和超极化电导相互作用的结果。用膜片钳技术记录大鼠急性海马脑片，我们发现D型钾电流调节ADP的大小和CA 1区锥体神经元的爆发。对α-树毒素的敏感性表明含Kv 1的钾通道介导了该电流。双体细胞树突记录，外树突记录，和局部应用dendrotoxin一起表明，该通道介导的电流位于顶端树突。因此，我们的数据为CA 1锥体神经元中Kv 1样通道的树突状分离提供了证据，并确定了这些通道的新作用，表明它们通过限制ADR的大小来抑制动作电位爆发
In CA1 pyramidal neurons, burst firing is correlated with hippocampally dependent behaviours and modulation of synaptic strength. One of the mechanisms underlying burst firing in these cells is the afterdepolarization (ADP) that follows each action potential. Previous work has shown that the ADP results from the interaction of several depolarizing and hyperpolarizing conductances located in the soma and the dendrites. By using patch-clamp recordings from acute rat hippocampal slices we show that D-type potassium current modulates the size of the ADP and the bursting of CA1 pyramidal neurons. Sensitivity to a-dendrotoxin suggests that Kv1-containing potassium channels mediate this current. Dual somato-dendritic recording, outside-out dendritic recordings, and focal application of dendrotoxin together indicate that the channels mediating this current are located in the apical dendrites. Thus, our data present evidence for a dendritic segregation of Kv1-like channels in CA1 pyramidal neurons and identify a novel action for these channels, showing that they inhibit action potential bursting by restricting the size of the ADR