Cartee L A
Center for Auditory Prosthesis Research, Research Triangle Institute, P.O. Box 12194, Research Triangle Park, NC 27709-2194, USA.
Hear Res. 2000 Aug;146(1-2):153-66. doi: 10.1016/s0378-5955(00)00110-6.
This study examines existing equation sets describing neural membrane ionic currents, such as the Hodgkin-Huxley (1952) equations, used to define the membrane currents in a numerical model of the auditory neuron and determines their adequacy for modeling the summation and refraction properties of auditory neurons in response to electrical stimulation. Specifically, the summation and refraction time constants of each equation set are compared to physiological measures of these time constants. Since previous studies have shown the cell body and peripheral process of the auditory neuron may influence the measurement of neural time constants, the physiological time constants used for comparison are those which were recorded using intrameatal electrical stimulation. The intrameatal electrode should stimulate the neuron in an area where the axon has a uniform geometry. Accordingly, the neural model used to duplicate this experiment was also of uniform geometry. Of the membrane equation sets evaluated, none was clearly superior for modeling both the refraction and summation properties of the auditory neuron, though some equation sets were capable of accurately modeling either the refraction or the summation properties, provided operating temperatures were adjusted to provide appropriate kinetics.
本研究考察了现有的描述神经膜离子电流的方程组,如用于在听觉神经元数值模型中定义膜电流的霍奇金-赫胥黎(1952年)方程组,并确定它们对模拟听觉神经元对电刺激的总和与折射特性的适用性。具体而言,将每个方程组的总和与折射时间常数与这些时间常数的生理测量值进行比较。由于先前的研究表明听觉神经元的细胞体和外周突可能会影响神经时间常数的测量,因此用于比较的生理时间常数是通过鼓室内电刺激记录得到的。鼓室内电极应在轴突几何形状均匀的区域刺激神经元。因此,用于重复该实验的神经模型也具有均匀的几何形状。在所评估的膜方程组中,没有一个在模拟听觉神经元的折射和总和特性方面明显优于其他方程组,不过有些方程组能够准确模拟折射或总和特性,前提是调整工作温度以提供适当的动力学。