Coherent Phasic Excitation during Hippocampal Ripples
Coherent Phasic Excitation during Hippocampal Ripples
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DOI：
10.1016/j.neuron.2011.08.016
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发表时间：
2011-10-06
期刊：
影响因子：
16.2
通讯作者：
Schmitz, Dietmar
中科院分区：
文献类型：
--
作者：
Maier, Nikolaus;Tejero-Cantero, Alvaro;Schmitz, Dietmar
高频海马网络振荡，或“涟漪”，被认为与情景记忆有关。根据目前的理论，记忆痕迹是由在波纹相关网络状态期间被激活的主要神经元的集合表示的。在这里，我们进行了在体内和体外实验，以探讨在波纹的突触机制。我们发现突触后电流是锁相的涟漪，甚至在遥远的CA 1锥体神经元之间也是一致的。这些快电流是一致的兴奋性突触后电流（EPSC），因为它们被观察到在Cl-的平衡电位，它们显示EPSC的动力学特征。此外，它们在细胞内阻断GABA能传递后存活，并有效调节动作电位的时间。此外，我们的数据显示了一个渐进的同步阶段的兴奋和抑制过程中的波纹。总之，我们的研究结果表明，在涟漪反映一个精致的时间协调的活动锥体细胞的组件的阶段性兴奋的存在。
High-frequency hippocampal network oscillations, or "ripples," are thought to be involved in episodic memory. According to current theories, memory traces are represented by assemblies of principal neurons that are activated during ripple-associated network states. Here we performed in vivo and in vitro experiments to investigate the synaptic mechanisms during ripples. We discovered postsynaptic currents that are phase-locked to ripples and coherent among even distant CA1 pyramidal neurons. These fast currents are consistent with excitatory postsynaptic currents (EPSCs) as they are observed at the equilibrium potential of Cl-, and they display kinetics characteristic of EPSCs. Furthermore, they survived after intracellular blockade of GABAergic transmission and are effective to regulate the timing of action potentials. In addition, our data show a progressive synchronization of phasic excitation and inhibition during the course of ripples. Together, our results demonstrate the presence of phasic excitation during ripples reflecting an exquisite temporal coordination of assemblies of active pyramidal cells.