Inoue M, Akaike N
Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Neurosci Res. 1987 Oct;5(1):74-81. doi: 10.1016/0168-0102(87)90025-3.
Frog dorsal root ganglion (DRG) cells treated with collagenase and trypsin were dissociated mechanically. The characteristics of dose-response curves of GABA-induced Cl- currents (ICl) were mainly studied using the "concentration-clamp" technique, by which the external solution around isolated single neurons was rapidly changed within a few milliseconds. The saturating maximum currents induced by various concentrations of GABA normalized to the peak ICl induced by 10(-5) M GABA on the same neuron varied from 1.5 to 5.5 among the neurons, though the absolute maximum currents varied little. The Hill coefficients (n = 1.92 +/- 0.09, mean +/- S.D.) also varied little on the neurons. The time constants of the desensitization phase of fully activated GABA responses were not so markedly different among the neurons. The present results suggested a possibility that the enzyme treatment produced a selective inactivation of alpha 1 unit, a high affinity subtype of the GABA-receptor.
用胶原酶和胰蛋白酶处理的青蛙背根神经节（DRG）细胞通过机械方法进行解离。主要使用“浓度钳”技术研究γ-氨基丁酸（GABA）诱导的氯离子电流（ICl）的剂量-反应曲线特征，通过该技术可在几毫秒内快速改变分离的单个神经元周围的外部溶液。尽管绝对最大电流变化不大，但不同神经元中，各种浓度的GABA诱导的饱和最大电流相对于同一神经元上10^(-5) M GABA诱导的ICl峰值进行归一化后，在1.5至5.5之间变化。神经元的希尔系数（n = 1.92 +/- 0.09，平均值 +/- 标准差）也变化不大。完全激活的GABA反应脱敏阶段的时间常数在不同神经元之间没有显著差异。目前的结果提示，酶处理可能导致GABA受体的高亲和力亚型α1单位发生选择性失活。
