Fluctuating synaptic conductances recreate in vivo-like activity in neocortical neurons
Fluctuating synaptic conductances recreate in vivo-like activity in neocortical neurons
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DOI：
10.1016/s0306-4522(01)00344-x
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发表时间：
2001-01-01
期刊：
影响因子：
3.3
通讯作者：
Sejnowski, TJ
中科院分区：
文献类型：
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作者：
Destexhe, A;Rudolph, M;Sejnowski, TJ
为了研究体内新皮层神经元中存在的波动活动的基础，我们使用动态钳技术将计算模型与全细胞记录相结合。一个简化的“点电导”模型被用来代表成千上万的随机释放突触产生的电流。突触活动由两个独立的快速谷氨酸能和GABA能电导表示，并由随机游走过程描述。这种方法的优点是所有模型参数都可以通过电压钳实验确定。我们发现，点电导模型捕获的幅度和频谱特性的突触电导在背景活动。为了确定它是否可以在体内重建类似的活动，我们将这个点电导模型注入单室模型。或在大鼠前额叶皮层神经元中的体外动态钳夹。这个过程成功地再现了几个属性的神经元胞内记录在体内，如去极化膜电位，存在高振幅的膜电位波动，低输入电阻和不规则的自发放电活动。此外，点电导模型可以模拟由于背景activity.We的结论，在体内皮层神经元的许多特性可以解释由快速的谷氨酸能和GABA能电导随机变化的响应增强。(C)2001年IBRO。由爱思唯尔科技有限公司出版。保留所有权利。
To investigate the basis of the fluctuating activity present in neocortical neurons in vivo, we have combined computational models with whole-cell recordings using the dynamic-clamp technique. A simplified 'point-conductance' model was used to represent the currents generated by thousands of stochastically releasing synapses. Synaptic activity was represented by two independent fast glutamatergic and GABAergic conductances described by stochastic random-walk processes. An advantage of this approach is that all the model parameters can be determined from voltage-clamp experiments. We show that the point-conductance model captures the amplitude and spectral characteristics of the synaptic conductances during background activity. To determine if it can recreate in vivo-like activity, we injected this point-conductance model into a single-compartment model. or in rat prefrontal cortical neurons in vitro using dynamic clamp. This procedure successfully recreated several properties of neurons intracellularly recorded in vivo, such as a depolarized membrane potential, the presence of high-amplitude membrane potential fluctuations, a low-input resistance and irregular spontaneous firing activity. In addition, the point-conductance model could simulate the enhancement of responsiveness due to background activity.We conclude that many of the characteristics of cortical neurons in vivo can be explained by fast glutamatergic and GABAergic conductances varying stochastically. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.