Kv4.3-mediated A-type K+ currents underlie rhythmic activity in hippocampal interneurons
Kv4.3-mediated A-type K+ currents underlie rhythmic activity in hippocampal interneurons
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DOI：
10.1523/jneurosci.3208-06.2007
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发表时间：
2007-02-21
影响因子：
5.3
通讯作者：
Lacaille, Jean-Claude
中科院分区：
文献类型：
--
作者：
Bourdeau, Mathieu L.;Morin, France;Lacaille, Jean-Claude
海马依赖性学习和记忆过程与θ频率节律活动相关。中间神经元和锥体细胞网络的相互作用是这种活动的基础，但中间神经元电压门控膜电导的贡献仍不清楚。我们发现，在CA 1腔隙分子（LM）和辐射（RAD）交界处（LM/RAD）的中间神经元显示电压依赖性阈下膜电位振荡（MPO）产生的电压门控河豚毒素敏感的Na+和4-氨基吡啶（4-AP）敏感的K+电流。它们还表现出突出的4-AP敏感的A型K+电流，门控特性显示在阈下膜电位激活。我们发现LM/RAD细胞是表达K+通道亚基Kv4.3的特定中间神经元亚群的一部分，用Kv4.3小干扰RNA转染它们选择性地损害A型K+电流和MPO。因此，我们的研究结果揭示了一种新的功能Kv4.3介导的A型K+电流在生成内在MPO的特定亚群的interneurons，可能参与海马θ相关的节律活动。
Hippocampal-dependent learning and memory processes are associated with theta frequency rhythmic activity. Interneuron and pyramidal cell network interactions underlie this activity, but contributions of interneuron voltage-gated membrane conductances remain unclear. We show that interneurons at the CA1 lacunosum-moleculare (LM) and radiatum (RAD) junction (LM/RAD) display voltage-dependent subthreshold membrane potential oscillations (MPOs) generated by voltage-gated tetrodotoxin-sensitive Na+ and 4-aminopyridine (4-AP)-sensitive K+ currents. They also exhibit prominent 4-AP-sensitive A-type K+ currents, with gating properties showing activation at subthreshold membrane potentials. We found that LM/RAD cells are part of specific interneuron subpopulations expressing the K+ channel subunit Kv4.3 and their transfection with Kv4.3 small interfering RNA selectively impaired A-type K+ currents and MPOs. Thus, our findings reveal a novel function of Kv4.3-mediated A-type K+ currents in the generation of intrinsic MPOs in specific subpopulations of interneurons that may participate in hippocampal theta-related rhythmic activity.