Action potential generation in neurons depends on a membrane potential threshold and therefore on how subthreshold inputs influence this voltage. In oscillatory networks, for example, many neuron types have been shown to produce membrane potential ([Formula: see text]) resonance: a maximum subthreshold response to oscillatory inputs at a nonzero frequency. Resonance is usually measured by recording [Formula: see text] in response to a sinusoidal current ([Formula: see text]), applied at different frequencies (f), an experimental setting known as current clamp (I-clamp). Several recent studies, however, use the voltage clamp (V-clamp) method to control [Formula: see text] with a sinusoidal input at different frequencies [[Formula: see text]] and measure the total membrane current ([Formula: see text]). The two methods obey systems of differential equations of different dimensionality, and while I-clamp provides a measure of electrical impedance [[Formula: see text]], V-clamp measures admittance [[Formula: see text]]. We analyze the relationship between these two measurement techniques. We show that, despite different dimensionality, in linear systems the two measures are equivalent: [Formula: see text]. However, nonlinear model neurons produce different values for Z and [Formula: see text]. In particular, nonlinearities in the voltage equation produce a much larger difference between these two quantities than those in equations of recovery variables that describe activation and inactivation kinetics. Neurons are inherently nonlinear, and notably, with ionic currents that amplify resonance, the voltage clamp technique severely underestimates the current clamp response. We demonstrate this difference experimentally using the PD neurons in the crab stomatogastric ganglion. These findings are instructive for researchers who explore cellular mechanisms of neuronal oscillations.

中文翻译：

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神经元模型对电流钳位电压输入中的振荡输入的频率依赖性响应。

神经元中动作电位的产生取决于膜电位阈值，因此取决于阈值以下输入如何影响该电压。例如，在振荡网络中，许多神经元类型已显示出产生膜电位（[公式：参见文本]）的共振：在非零频率下对振荡输入的最大亚阈值响应。通常通过记录响应于不同频率（f）的正弦电流（公式）的测量值来测量谐振，该实验设置被称为电流钳（I-clamp）。但是，最近的一些研究使用电压钳（V-clamp）方法以不同频率的正弦输入控制[公式]并测量总膜电流（[公式：参见]。文本]）。这两种方法服从不同维数的微分方程组，而I型夹钳可测量电阻抗[[公式：参见文字]]，而V型夹钳可测量导纳[[公式：参见文字]]。我们分析了这两种测量技术之间的关系。我们显示，尽管维数不同，但在线性系统中，这两个量度是等效的：[公式：请参见文本]。但是，非线性模型神经元会产生不同的Z和[公式：参见文本]。特别是，电压方程中的非线性在这两个量之间产生的差异要比描述激活和失活动力学的恢复变量方程中的非线性大得多。神经元本质上是非线性的，尤其是离子电流会放大共振，电压钳位技术严重低估了电流钳位响应。我们在螃蟹的胃胃神经节中使用PD神经元实验证明了这种差异。这些发现对研究神经元振荡的细胞机制的研究者具有指导意义。