Bi-directional astrocytic regulation of neuronal activity within a network.
Bi-directional astrocytic regulation of neuronal activity within a network.
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DOI：
10.3389/fncom.2012.00092
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发表时间：
2012
影响因子：
3.2
通讯作者：
Kazantsev VB
中科院分区：
文献类型：
--
作者：
Gordleeva SY;Stasenko SV;Semyanov AV;Dityatev AE;Kazantsev VB
三方突触的概念认为，星形胶质细胞可以通过 Ca2+ 依赖性神经胶质递质的释放来影响突触前和突触后区室。由于星形胶质细胞的 Ca2+ 瞬变通常持续几秒钟，因此我们假设星形胶质细胞对突触传递的调节也可能以秒为单位发生。在这里，我们考虑了三方突触的基本生理功能，并研究了神经网络活动水平的星形胶质细胞调节。自发放电网络中单个神经元的放电动力学由霍奇金-赫胥黎模型描述。神经元接收由可变频率的泊松尖峰序列驱动的兴奋性突触输入。释放的神经递质的平均场浓度用于描述突触前动力学。兴奋性突触后电流（PSC）的振幅服从伽马分布定律。在我们的模型中，星形胶质细胞抑制突触前释放并增强 PSC。结果，低频突触输入被抑制，而高频输入被放大。对作为网络活动指标的神经元尖峰频率的分析表明，与二分突触相比，三分突触传递极大地改变了局部网络的操作。具体来说，星形胶质细胞通过增加或减少神经元的放电来支持网络活动的稳态调节。因此，星形胶质细胞的激活可以调节神经网络向双稳态活动状态的转变，具有两个稳定的放电水平和它们之间的自发转变。
The concept of a tripartite synapse holds that astrocytes can affect both the pre- and post-synaptic compartments through the Ca2+-dependent release of gliotransmitters. Because astrocytic Ca2+ transients usually last for a few seconds, we assumed that astrocytic regulation of synaptic transmission may also occur on the scale of seconds. Here, we considered the basic physiological functions of tripartite synapses and investigated astrocytic regulation at the level of neural network activity. The firing dynamics of individual neurons in a spontaneous firing network was described by the Hodgkin–Huxley model. The neurons received excitatory synaptic input driven by the Poisson spike train with variable frequency. The mean field concentration of the released neurotransmitter was used to describe the presynaptic dynamics. The amplitudes of the excitatory postsynaptic currents (PSCs) obeyed the gamma distribution law. In our model, astrocytes depressed the presynaptic release and enhanced the PSCs. As a result, low frequency synaptic input was suppressed while high frequency input was amplified. The analysis of the neuron spiking frequency as an indicator of network activity revealed that tripartite synaptic transmission dramatically changed the local network operation compared to bipartite synapses. Specifically, the astrocytes supported homeostatic regulation of the network activity by increasing or decreasing firing of the neurons. Thus, the astrocyte activation may modulate a transition of neural network into bistable regime of activity with two stable firing levels and spontaneous transitions between them.
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影响因子：
16.2
作者：
McGuinness, Lindsay;Taylor, Chanel;Emptage, Nigel J.
通讯作者：
Emptage, Nigel J.
影响因子：
3.4
作者：
Araque, A;Parpura, V;Haydon, PG
通讯作者：
Haydon, PG
影响因子：
2.4
作者：
Kazantsev, V. B.
通讯作者：
Kazantsev, V. B.
影响因子：
--
作者：
Liu, Qing-Song;Xu, Qiwu;Nedergaard, Maiken
通讯作者：
Nedergaard, Maiken
DOI：
10.1073/pnas.0306731101
发表时间：
2004-03-02
影响因子：
11.1
作者：
Liu, QS;Xu, QW;Nedergaard, M
通讯作者：
Nedergaard, M