Slow depolarizing potentials recorded from glial cells in the rat superficial dorsal horn.
Slow depolarizing potentials recorded from glial cells in the rat superficial dorsal horn.
复制标题
从大鼠浅表背角神经胶质细胞记录的缓慢去极化电位。
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
H. Tsuruhara
中科院分区：
文献类型：
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作者：
T. Takahashi;H. Tsuruhara
1.在离体大鼠腰髓背角浅层不兴奋细胞上记录细胞内电位。2.这些细胞具有较大的静息膜电位（高达-90 mV），但去极化时无法产生动作电位。静息电位高度依赖于细胞外K+浓度（[K+]o），[K+]o变化10倍时的斜率约为45 mV。3.电刺激背根诱发了一个缓慢的去极化电位持续数秒的不兴奋细胞。慢电位并不伴随着任何明显的变化，在输入电导，也不是他们的幅度依赖于膜电位。4.通过细胞内注射荧光染料荧光黄标记的不兴奋细胞的形态与其为神经胶质细胞一致。5.通过K+敏感电极同时测量[K+]o值和细胞内胶质细胞电位。刺激背根后，K+电极电位的变化与缓慢去极化电位平行发生。当刺激强度改变时，K+-电极反应幅度的变化与慢电位的变化相关。6.用Mg 2+替代细胞外Ca 2+可消除传入刺激诱发的慢电位和K+-电极反应，表明初级传入纤维中的冲动并不直接影响胶质细胞慢电位。7.它的结论是，在胶质细胞的慢电位的结果从[K+]O在浅背角，这是由相邻的internuncial神经元的激活引起的瞬时增加。
1. Intracellular potentials were recorded from inexcitable cells in the superficial dorsal horn of the rat lumbar spinal cord in vitro. 2. These cells had a large resting membrane potential (up to ‐90 mV) but when depolarized were unable to produce action potentials. The resting potential was highly dependent upon extracellular K+ concentrations ([K+]o), with a slope of about 45 mV for a 10‐fold change in [K+]o. 3. Electrical stimulation of dorsal roots evoked a slow depolarizing potential lasting for many seconds in the inexcitable cells. The slow potentials were not accompanied by any appreciable change in input conductance, nor were their amplitudes dependent upon the membrane potential. 4. The morphology of the inexcitable cells marked by intracellular injection of a fluorescent dye, Lucifer Yellow, was consistent with their being glial cells. 5. [K+]o values were measured by K+‐sensitive electrodes simultaneously with intracellular glial potentials. Changes in the K+‐electrode potential occurred in parallel with slow depolarizing potentials following stimulation of dorsal roots. When the stimulus intensity was altered, changes in the magnitude of the K+‐electrode response were correlated with those of the slow potentials. 6. Replacement of extracellular Ca2+ by Mg2+ abolished both the slow potentials and K+‐electrode responses evoked by afferent stimulation, suggesting that impulses in primary afferent fibres do not directly contribute to the glial slow potentials. 7. It is concluded that the slow potentials in glial cells result from a transient increase in [K+]o at the superficial dorsal horn, which is induced by activation of neighbouring internuncial neurones.