Mechanisms of fast ripples in the hippocampus
Mechanisms of fast ripples in the hippocampus
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DOI：
10.1523/jneurosci.3112-04.2004
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发表时间：
2004-10-06
影响因子：
5.3
通讯作者：
Staley, KJ
中科院分区：
文献类型：
--
作者：
Dzhala, VI;Staley, KJ
海马快波（FR）与人类和实验性癫痫的发作有关。为了表征FR振荡（200-600 Hz）的机制，我们研究了体外大鼠海马脑片单个神经元和神经元网络的活动。爆发性锥体细胞的动作电位和局部场电位振荡之间的相关性表明，动作电位爆发的同步启动和局部神经元之间相似的内在放电模式都是FR振荡的必要条件。通过阻断调节来增加个体锥体细胞锋电位序列定时的保真度，显著增加FR振幅，而阻断钾离子传导降低个体锥体细胞动作电位爆发中动作电位定时的保真度，并降低FR振幅。阻断离子型谷氨酸受体可抑制单个锥体细胞动作电位爆发的发生，并消除快波。因此，同步突发发作介导的经常性兴奋性突触传递和类似的内在尖峰定时机制在相邻的锥体细胞的海马网络内的FR振荡的必要条件。
Hippocampal fast ripples (FRs) have been associated with seizure onset in both human and experimental epilepsy. To characterize the mechanisms underlying FR oscillations (200-600 Hz), we studied activity of single neurons and neuronal networks in rat hippocampal slices in vitro. The correlation between the action potentials of bursting pyramidal cells and local field potential oscillations suggests that synchronous onset of action potential bursts and similar intrinsic firing patterns among local neurons are both necessary conditions for FR oscillations. Increasing the fidelity of individual pyramidal cell spike train timing by blocking accommodation dramatically increased FR amplitude, whereas blockade of potassium conductances decreased the fidelity of action potential timing in individual pyramidal cell action potential bursts and decreased FR amplitude. Blockade of ionotropic glutamate receptors desynchronized onset of action potential bursts in individual pyramidal cells and abolished fast ripples. Thus, synchronous burst onset mediated by recurrent excitatory synaptic transmission and similar intrinsic spike timing mechanisms in neighboring pyramidal cells are necessary conditions for FR oscillations within the hippocampal network.