Compensation for variable intrinsic neuronal excitability by circuit-synaptic interactions.
Compensation for variable intrinsic neuronal excitability by circuit-synaptic interactions.
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DOI：
10.1523/jneurosci.0980-10.2010
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发表时间：
2010-07-07
期刊：
影响因子：
--
通讯作者：
Marder E
中科院分区：
文献类型：
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作者：
Grashow R;Brookings T;Marder E
最近的理论和实验工作表明，神经元通过调节离子通道表达和突触强度来自我调节以维持目标兴奋水平。因此，功能相同的电路可以产生类似的活动，尽管底层网络和蜂窝属性不同。为了在实验上测试突触和内在电导在神经元内在特性存在变异性的情况下产生靶向活动的程度，我们使用动态钳位技术创建了混合两细胞电路，该电路由四种类型的口胃(STG)神经元通过相互抑制耦合到同一模型的Morris-LeCar神经元上。我们测量了雄性北极蟹胃背侧(DG)、胃磨区(GM)、幽门外侧区(LP)和幽门扩张器(PD)神经元的6种固有特性(输入电阻、最小膜电位、对+1nA注入电流的放电频率、FI曲线斜率、峰高和峰电压阈值)。每种细胞类型的固有特性变化2到7倍。我们用7个不同值的抑制性突触电导将每个生物神经元耦合到Morris-LeCar模型，并使用动态钳位添加7个不同值的人造h-电导，从而为每个生物神经元创建49个不同的电路。尽管内在兴奋性存在差异，但在突触和h-电导的某些值上，每个神经元形成的网络产生了相似的电路性能。这项工作从实验上证实了先前建模研究的结果；调节突触和内在电导可以从具有可变内在兴奋性的神经元产生类似的电路输出。
Recent theoretical and experimental work indicates that neurons tune themselves to maintain target levels of excitation by modulating ion channel expression and synaptic strengths. As a result, functionally equivalent circuits can produce similar activity despite disparate underlying network and cellular properties. To experimentally test the extent to which synaptic and intrinsic conductances can produce target activity in the presence of variability in neuronal intrinsic properties, we used the dynamic clamp to create hybrid two-cell circuits built from four types of stomatogastric (STG) neurons coupled to the same model Morris-Lecar neuron by reciprocal inhibition. We measured six intrinsic properties (input resistance, minimum membrane potential, firing rate in response to +1nA of injected current, slope of the FI curve, spike height and spike voltage threshold) of Dorsal Gastric (DG), Gastric Mill (GM), Lateral Pyloric (LP) and Pyloric Dilator (PD) neurons from male crabs, Cancer borealis. The intrinsic properties varied two to seven-fold in each cell type. We coupled each biological neuron to the Morris-Lecar model with seven different values of inhibitory synaptic conductance, and also used the dynamic clamp to add seven different values of an artificial h-conductance, thus creating 49 different circuits for each biological neuron. Despite the variability in intrinsic excitability, networks formed from each neuron produced similar circuit performance at some values of synaptic and h-conductances. This work experimentally confirms results from previous modeling studies; tuning synaptic and intrinsic conductances can yield similar circuit output from neurons with variable intrinsic excitability.