VOLTAGE-GATED CURRENTS IN RABBIT RETINAL ASTROCYTES
VOLTAGE-GATED CURRENTS IN RABBIT RETINAL ASTROCYTES
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DOI：
10.1111/j.1460-9568.1994.tb01002.x
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发表时间：
1994-09-01
影响因子：
3.4
通讯作者：
MOBBS, P
中科院分区：
文献类型：
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作者：
CLARK, BA;MOBBS, P
用全细胞膜片钳技术研究了兔视网膜毛细血管周围星形胶质细胞的电压门控电流。这些细胞的静息电位为-70 +/- 4.8 mV（平均值+/- SEM; n = 54），输入电阻和细胞电容分别为558 +/- 3.6 M Ω和19.5 +/- 1.8 pF。去极化至-50 mV的正电位诱发快速激活的内向和外向电流。内向电流是短暂的，消除由胆碱取代Na+在洗澡的解决方案，并减少了50%，在1 μ M河豚毒素的存在下。Na+电流达到峰值的时间是视网膜神经元中发现的Na+电流的两倍以上。神经胶质细胞Na+电流在-55 mV时半失活。外向K+电流的瞬时成分被外部4-氨基吡啶阻断，而更持续的成分被外部四乙基铵阻断。在-150 mV和-50 mV之间的电位下，膜表现为欧姆性。在视网膜星形胶质细胞原位记录的电压门控电流出现定性相似的描述一些胶质细胞在体外。
The voltage-gated currents of the astrocytes associated with the retinal capillaries of the rabbit retina were studied using whole-cell patch clamp recording. The resting potential of these cells was -70 +/- 4.8 mV (mean +/- SEM; n = 54), and the input resistance and cell capacitance were 558 +/- 3.6 M Omega and 19.5 +/- 1.8 pF respectively. Depolarization to potentials positive to -50 mV evoked rapidly activating inward and outward currents. The inward current was transient, eliminated by substitution of choline for Na+ in the bathing solution, and reduced by 50% in the presence of 1 mu M tetrodotoxin. The time-to-peak of the Na+ current was more than twice that for the Na+ current found in retinal neurons. The glial Na+ current was half-inactivated at -55 mV. A transient component of the outward K+ current was blocked by external 4-aminopyridine while a more sustained component was blocked by external tetraethylammonium. At potentials between -150 and -50 mV the membrane behaved Ohmically. Voltage-gated currents in retinal astrocytes recorded in situ appear qualitatively similar to those described for some glial cells in vitro.