Pongrácz F
Neuroscience. 1985 Aug;15(4):933-46. doi: 10.1016/0306-4522(85)90244-1.
A modeling procedure is proposed which introduces the cable equivalent of dendritic spines into the Rall model of spiny interneurons in the spinal cord. At this point combined morphological and physiological works have given some insight into the possible role of a single spine and the function of a single spine has been studied by theoretical computations [Jack, Noble and Tsien (1975) Electric Current Flow in Excitable Cells, pp. 218-223. Oxford University Press, Oxford; Koch and Poggio (1983) Trends Neurosci. 6, 80-83; Perkel (1983) J. Physiol., Paris 78, 695-699]. The goal of the present paper is two-fold: (a) to stress the gross function of the spine system in the excitability of dendrites; and (b) to emphasize the role of spines in the dynamic input/output function of neurons. The simulation procedure is based on the well-known compartmental method. (1) The kinetics of active somatic and dendritic compartments are taken from a currently available spinal interneuron model to match the physiological data of large dorsal horn neurons carrying spines. (2) Beside the prolongation of the somatic excitatory postsynaptic potential, the model suggests that the spiny neuron increases the differences in the latency and height of excitatory postsynaptic potential as a function of the electrotonic position of input. The characteristics of the excitatory postsynaptic potential can be modified by the changes in spine geometry and the ratio of cytoplasmic resistances of spine stalk to that of main dendritic shaft. (3) Dendritic electroresponsiveness, which was already postulated for dorsal horn neurons, is analysed by the model including calcium and slow potassium systems. It is concluded that the participation of the spine stalk in active processes can highly modify the input dependence of response pattern. Depolarization-dependent Ca2+ accumulation in spines may reflect the interaction of spine stalks. (4) Passive antidromic spread of action potential can be suppressed in spiny cells. Analysis of active antidromic spread shows the probable importance of spines located near the soma. Centripetal vs centrifugal conduction of dendritic action potential may depend on the spine distribution along the tree and change in electrical parameters of spines.
本文提出了一种建模方法，即将树突棘的电缆等效物引入脊髓中有棘中间神经元的拉尔模型。目前，形态学和生理学方面的综合研究对单个棘突的可能作用有了一定的了解，并且通过理论计算对单个棘突的功能进行了研究[杰克、诺布尔和钱（1975年）《可兴奋细胞中的电流流动》，第218 - 223页。牛津大学出版社，牛津；科赫和波吉奥（1983年）《神经科学趋势》6，80 - 83；珀克尔（1983年）《生理学杂志》，巴黎78，695 - 699]。本文的目标有两个：（a）强调棘突系统在树突兴奋性方面的总体功能；（b）强调棘突在神经元动态输入/输出功能中的作用。模拟过程基于著名的房室法。（1）活跃的胞体和树突房室的动力学取自当前可用的脊髓中间神经元模型，以匹配携带棘突的大背角神经元的生理数据。（2）除了延长胞体兴奋性突触后电位外，该模型还表明有棘神经元会根据输入的电紧张位置增加兴奋性突触后电位潜伏期和高度的差异。兴奋性突触后电位的特征可通过棘突几何形状的变化以及棘突柄与主要树突轴的细胞质电阻之比来改变。（3）该模型包括钙和慢钾系统，对背角神经元已经假定的树突电反应性进行了分析。得出的结论是，棘突柄参与活跃过程可高度改变反应模式的输入依赖性。棘突中去极化依赖性的Ca2 +积累可能反映了棘突柄的相互作用。（4）有棘细胞中动作电位的被动逆向传播可被抑制。对活跃逆向传播的分析表明，位于胞体附近的棘突可能具有重要意义。树突动作电位的向心传导与离心传导可能取决于沿树突的棘突分布以及棘突电参数的变化。
