FIRING BEHAVIOR OF DORSAL SPINOCEREBELLAR TRACT NEURONS
FIRING BEHAVIOR OF DORSAL SPINOCEREBELLAR TRACT NEURONS
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DOI：
10.1113/jphysiol.1978.sp012192
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发表时间：
1978-01-01
影响因子：
5.5
通讯作者：
ZANGGER, P
中科院分区：
文献类型：
--
作者：
GUSTAFSSON, B;LINDSTROM, S;ZANGGER, P
本文研究了猫脊髓小脑束背侧细胞内恒流注射诱发的重复放电。放电频率随时间的延长而降低，且在大电流强度下下降更为明显。大部分频率变化发生在前10个间隔内，但下降缓慢地持续了几秒钟。在一些细胞中，频率最初升高，第一个尖峰间期大于紧随其后的间期。第一波间期的频率-电流(f/i)曲线呈S形，与脊髓运动神经元相同。随着连续的间隔，f/i曲线的下端延伸到更高的频率，给出了f/i曲线的渐进线性化。在几乎所有的细胞中，这种线性化是在电流开始后200ms完成的。根据棘波后超极化特性，将实验f/i曲线与用简单神经元模型得到的f/i曲线进行了比较。对于第一个脉冲间期，单个神经元的f/i曲线与计算的f/i曲线有很好的一致性，最高可达每秒几百次脉冲。在高频范围内，需要补偿由注入电流引起的初始后尖峰电压轨迹的变化。神经元模型还再现了真实神经元放电的其他方面，如f/i曲线的逐步线性化、负适应以及峰间电压轨迹随电流的增加而变化。显然，棘波后超极化背后的传导过程是调节脊髓小脑束背侧神经元重复放电的主要因素。
The repetitive discharge evoked by constant current injection from an intracellular micropipette was studied in dorsal spinocerebellar tract cells of the cat. The discharge frequency decreased with time, the decrease being more pronounced at high current intensities. Most of the frequency change occurred during the first 10 intervals but the decrease continued slowly for several seconds. In some cells the frequency rose initially, the 1st interspike interval being larger than immediately succeeding ones. The frequency-current (f/I) curves for the 1st interspike intervals were S-shaped, as found in spinal motoneurons. With successive intervals the lower leg of the f/I curve extended to higher frequencies, giving a progressive linearization of the f/I curves. In almost all cells this linearization was completed at 200 ms after current onset. The experimental f/I curves were compared with the f/I curves obtained with a simple neuron model based on the properties of the postspike afterhyperpolarization. For the 1st interspike interval there was a good agreement between the experimental and calculated f/I curves of individual neurons up to frequencies of several hundred impulses per second. In the high frequency range, it was necessary to compensate for changes in initial postspike voltage trajectories caused by the injected current. Other aspects of the firing of real neurons, such as the progressive linearization of the f/I curves, the negative adaptation and the changes in the interspike voltage trajectories with increasing current were also reproduced by the neuron model. Apparently the conductance process underlying the postspike afterhyperpolarization is a major factor in the regulation of repetitive firing in dorsal spinocerebellar tract neurons.