Fohlmeister J F, Adelman W J, Poppele R E
Biophys J. 1980 Apr;30(1):79-97. doi: 10.1016/S0006-3495(80)85078-8.
The space-clamped squid axon membrane and two versions of the Hodgkin-Huxley model (the original, and a strongly adapting version) are subjected to a first order dynamic analysis. Stable, repetitive firing is induced by phase-locking nerve impulses to sinusoidal currents. The entrained impulses are then pulse position modulated by additional, small amplitude perturbation sinusoidal currents with respect to which the frequencies response of impulse density functions are measured. (Impulse density is defined as the number of impulses per unit time of an ensemble of membranes with each membrane subject to the same stimulus). Two categories of dynamic response are observed: one shows clear indications of a corner frequency, the other has the corner frequency obscured by dynamics associated with first order conductance perturbations in the interspike interval. The axon membrane responds with first order perturbations whereas the unmodified Hodgkin-Huxley model does not. Quantitative dynamic signatures suggest that the relaxation times of axonal recovery excitation variables are twice as long as those of the corresponding model variables. A number of other quantitative differences between axon and models, including the values of threshold stimuli are also observed.
对空间钳制的乌贼轴突膜和两种版本的霍奇金 - 赫胥黎模型（原始版本和强适应版本）进行一阶动态分析。通过将神经冲动与正弦电流锁相来诱导稳定、重复的放电。然后，夹带的冲动由额外的小幅度扰动正弦电流进行脉冲位置调制，并测量相对于这些电流的冲动密度函数的频率响应。（冲动密度定义为一组膜在单位时间内的冲动数量，每个膜受到相同的刺激）。观察到两类动态响应：一类显示出明显的转折频率迹象，另一类的转折频率被峰间间隔中与一阶电导扰动相关的动态所掩盖。轴突膜以一阶扰动做出响应，而未修改的霍奇金 - 赫胥黎模型则不然。定量动态特征表明，轴突恢复激发变量的弛豫时间是相应模型变量弛豫时间的两倍。还观察到轴突与模型之间的许多其他定量差异，包括阈值刺激的值。
