Transient depression of excitatory synapses on interneurons contributes to epileptiform bursts during gamma oscillations in the mouse hippocampal slice.
Transient depression of excitatory synapses on interneurons contributes to epileptiform bursts during gamma oscillations in the mouse hippocampal slice.
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DOI：
10.1152/jn.00069.2005
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发表时间：
2005-08
影响因子：
2.5
通讯作者：
R. Traub;I. Pais;A. Bibbig;F. LeBeau;E. Buhl;Helen Garner;H. Monyer;M. Whittington
中科院分区：
文献类型：
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作者：
R. Traub;I. Pais;A. Bibbig;F. LeBeau;E. Buhl;Helen Garner;H. Monyer;M. Whittington
在代谢型谷氨酸受体 (mGluR) 激活的条件下，海马切片中会出现持续的伽马频率 (30-70 Hz) 网络振荡。过度的 mGluR 激活产生了网络活动的双稳态模式，在此期间，伽玛振荡的振幅增加被同步爆发和非常快的振荡（> 70 Hz）终止。我们提供的实验证据表明，在这种行为过程中，锥体细胞到中间神经元的突触抑制发生，在伽马节律期间自发发生，并与癫痫样爆发的发生相关。我们进一步提供证据表明锥体细胞中的兴奋性突触后电位（EPSP）在爆发间伽马振荡期间被增强。当这两种类型的突触可塑性在现象学上被纳入先前证明可以解释持续伽玛振荡的许多特征的网络模型中时，我们发现伽玛时期确实与非常快的振荡和癫痫样爆发的时期交替。因此，相同的神经元网络可以产生伽马振荡或癫痫样爆发，其方式取决于网络驱动的程度和网络引起的突触功效波动。
Persistent gamma frequency (30-70 Hz) network oscillations occur in hippocampal slices under conditions of metabotropic glutamate receptor (mGluR) activation. Excessive mGluR activation generated a bistable pattern of network activity during which epochs of gamma oscillations of increasing amplitude were terminated by synchronized bursts and very fast oscillations (>70 Hz). We provide experimental evidence that, during this behavior, pyramidal cell-to-interneuron synaptic depression takes place, occurring spontaneously during the gamma rhythm and associated with the onset of epileptiform bursts. We further provide evidence that excitatory postsynaptic potentials (EPSPs) in pyramidal cells are potentiated during the interburst gamma oscillation. When these two types of synaptic plasticity are incorporated, phenomenologically, into a network model previously shown to account for many features of persistent gamma oscillations, we find that epochs of gamma do indeed alternate with epochs of very fast oscillations and epileptiform bursts. Thus the same neuronal network can generate either gamma oscillations or epileptiform bursts, in a manner depending on the degree of network drive and network-induced fluctuations in synaptic efficacies.