Roitbak A I, Fanardjian V V, Melkonyan D S, Melkonyan A A
Neuroscience. 1987 Mar;20(3):1057-67. doi: 10.1016/0306-4522(87)90263-6.
In 20 cats anaesthetized with pentobarbital the suprasylvian gyrus was stimulated by single stimuli or by trains of 50 s stimuli and the potentials from the cortical surface and the intracellular potentials from glial and nerve cells were recorded. Glial cells were identified according to conventional electrophysiological criteria: the absence of action potentials and postsynaptic potentials; slow depolarization in response to electrical stimulation. The slow negativity of direct response to a single stimulus is similar in shape and time course to the depolarization of the cortical glial cells and is unlike the hyperpolarization of the cortical neurons. Quantitative analysis showed that the basic part of the slow negativity is the glial component, whereas the neuronal component--inhibitory postsynaptic potential--plays a much lesser role. The negative shift of the potential on the cortical surface evoked by its high-frequency stimulation is similar in shape and time course to the depolarization shift of the membrane potential of the cortical glial cells (the mean value and standard error of time to peak for glial depolarization were 567.6 +/- 26.8 ms and 427 +/- 24 ms for negative shift of potential). (The results are based on recordings from 37 cells.) The negative shift decays much quicker; it is not similar in shape and time course to the hyperpolarization shift of the neuronal membrane potentials (the mean value and standard error of time to peak for inhibitory postsynaptic potential was 44.9 +/- 4.5 ms). According to the quantitative analysis, the negative shift of the potential reflects mainly the depolarization of the cortical glial cells. The contribution of the hyperpolarization of neurons to the surface-negative shift can be distinctly observed during the first 0.2-0.3 s of stimulation. It is supposed that accumulation of K+ ions in intercellular clefts results in depolarization of glial syncytium, which is reflected on the cortical surface as a slow negativity and a negative shift of the potential.
在20只戊巴比妥麻醉的猫中，用电刺激孤立回，单次刺激或50秒的串刺激，记录皮层表面电位以及胶质细胞和神经细胞的细胞内电位。胶质细胞根据传统电生理标准来识别：无动作电位和突触后电位；电刺激时出现缓慢去极化。单次刺激直接反应的缓慢负电位在形状和时程上与皮层胶质细胞的去极化相似，与皮层神经元的超极化不同。定量分析表明，缓慢负电位的基本部分是胶质成分，而神经元成分——抑制性突触后电位——起的作用小得多。高频刺激诱发的皮层表面电位负向偏移在形状和时程上与皮层胶质细胞膜电位的去极化偏移相似（胶质细胞去极化达到峰值的时间平均值和标准误分别为567.6±26.8毫秒，电位负向偏移达到峰值的时间平均值和标准误分别为427±24毫秒）。（结果基于37个细胞的记录）。负向偏移衰减更快；其形状和时程与神经元膜电位的超极化偏移不同（抑制性突触后电位达到峰值的时间平均值和标准误为44.9±4.5毫秒）。根据定量分析，电位负向偏移主要反映皮层胶质细胞的去极化。在刺激的最初0.2 - 0.3秒内，可以清楚地观察到神经元超极化对表面负向偏移的贡献。据推测，细胞间缝隙中K +离子的积累导致胶质细胞合体的去极化，这在皮层表面表现为缓慢负电位和电位负向偏移。
