Wu J, Harata N, Akaike N
Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
Brain Res. 1994 May 9;645(1-2):303-8. doi: 10.1016/0006-8993(94)91664-0.
The electrophysiological properties of sevoflurane (Sev)-induced current (ISev) were investigated in CA1 pyramidal neurons freshly dissociated from the rat hippocampus by using the nystatin perforated patch recording configuration under voltage-clamp condition. Within the range of Sev concentrations from 3 x 10(-4) to 2 x 10(-3) M, ISev was an inward current which consisted of an initial transient peak component and a successive steady-state plateau component. The peak current component increased in a concentration-dependent manner with a conductance increase. The application of Sev over 2 x 10(-3) M, however, suppressed the peak and steady-state current components with a concomitant decrease in conductance and elicited a transient inward current ('hump' current) immediately after wash out. The current-voltage relationship for ISev showed some outward rectification suggesting a slight voltage-dependency of the ISev. The reversal potential of ISev (ESev) was close to the ECl and shifted by 52 mV for a 10-fold change in extracellular Cl- concentrations, indicating that ISev is passing through Cl- channels. The single channel conductance obtained from the analysis of the variance of ISev fluctuations was 15.3 +/- 1.3 pS.
在电压钳制条件下，采用制霉菌素穿孔膜片钳记录模式，研究了从大鼠海马新鲜分离的CA1锥体神经元中七氟醚（Sev）诱导电流（ISev）的电生理特性。在3×10⁻⁴至2×10⁻³ M的Sev浓度范围内，ISev为内向电流，由初始瞬态峰值成分和连续的稳态平台成分组成。峰值电流成分随浓度增加呈浓度依赖性增加，同时电导增加。然而，应用超过2×10⁻³ M的Sev会抑制峰值和稳态电流成分，同时电导降低，并在洗脱后立即引发瞬态内向电流（“驼峰”电流）。ISev的电流-电压关系显示出一些外向整流，表明ISev存在轻微的电压依赖性。ISev的反转电位（ESev）接近ECl，细胞外Cl⁻浓度每变化10倍，ESev就会偏移52 mV，表明ISev通过Cl⁻通道。通过分析ISev波动的方差获得的单通道电导为15.3±1.3 pS。
