Eder C, Klee R, Heinemann U
Institut für Physiologie der Charité, Abt Neurophysiologie, Humboldt Universität zu Berlin, Germany.
Neuroreport. 1996 Jul 8;7(10):1565-8. doi: 10.1097/00001756-199607080-00006.
Pyramidal neurones of the entorhinal cortex and of hippocampal areas CA1 and CA3 were acutely isolated from juvenile rats. The effect of lowering the concentration of extracellular potassium ions ([K+]o) on fast transient A-currents (IA) was studied using the whole-cell configuration of the patch-clamp technique. Upon lowering [K+]o from 5.4 to 0 mM amplitudes of IA in all pyramidal neurones were reduced only at test potentials positive to -20 mV, but were increased at potentials below -20 mV. Omission of magnesium ions from the intracellular perfusate resulted in an increase of IA in external K+-free solution at any potential tested. Moreover, when [K+]o was reduced steady-state activation and inactivation curves of IA were shifted in the hyperpolarizing direction.
从幼年大鼠中急性分离出内嗅皮层以及海马CA1和CA3区的锥体神经元。采用膜片钳技术的全细胞模式，研究了降低细胞外钾离子浓度（[K+]o）对快速瞬态A电流（IA）的影响。当[K+]o从5.4 mM降至0 mM时，所有锥体神经元中IA的幅度仅在测试电位高于-20 mV时降低，但在低于-20 mV的电位时增加。细胞内灌流液中省略镁离子会导致在任何测试电位下，外部无钾溶液中IA增加。此外，当[K+]o降低时，IA的稳态激活和失活曲线向超极化方向移动。
