Carnevale N T, Lebeda F J
J Neurosci Methods. 1987 Jan;19(1):69-87. doi: 10.1016/0165-0270(87)90022-7.
Advances in anatomical and biophysical techniques have produced a wealth of data from certain classes of mammalian central neurons. In order to evaluate quantitatively these data and the hypotheses of neuronal function to which they lead, we have developed LADDER, a computer program for simulating neuronal electrotonus under current- or voltage-clamp conditions. This program models a neuron as an unbranched series of isopotential compartments composed of resistive and capacitive elements, i.e., a ladder network. Synaptic inputs are represented by realistic time-varying conductance changes. LADDER solves the set of simultaneous linear differential equations that describe this model by numerical integration in the time domain. Several tests confirmed the accuracy of LADDER's calculations. Simulated responses to current pulses were quantitatively similar to the charging transients that have been reported in hippocampal CA3 pyramidal neurons. These digital simulations also agreed closely with previously reported results from an analog neuronal model. In addition, transfer of synaptic charge in the model neuron, under both current- and voltage-clamp conditions, equalled theoretical predictions from two-port analyses of linear electrotonus. To illustrate the application of LADDER, we present the results of simulations involving the spread of voltage and current arising from various synaptic inputs.
解剖学和生物物理学技术的进步已从某些种类的哺乳动物中枢神经元中产生了大量数据。为了定量评估这些数据以及它们所引出的神经元功能假说，我们开发了LADDER，这是一个用于在电流钳或电压钳条件下模拟神经元电紧张的计算机程序。该程序将神经元建模为由电阻性和电容性元件组成的无分支等电位隔室系列，即梯形网络。突触输入由实际的随时间变化的电导变化表示。LADDER通过在时域中进行数值积分来求解描述该模型的联立线性微分方程组。多项测试证实了LADDER计算的准确性。对电流脉冲的模拟响应在数量上与海马CA3锥体神经元中报道的充电瞬变相似。这些数字模拟也与先前报道的模拟神经元模型的结果非常吻合。此外，在电流钳和电压钳条件下，模型神经元中突触电荷的转移等于线性电紧张双端口分析的理论预测。为了说明LADDER的应用，我们展示了涉及各种突触输入引起的电压和电流传播的模拟结果。
