FRACTIONAL CONTRIBUTION OF CALCIUM TO THE CATION CURRENT THROUGH GLUTAMATE-RECEPTOR CHANNELS
FRACTIONAL CONTRIBUTION OF CALCIUM TO THE CATION CURRENT THROUGH GLUTAMATE-RECEPTOR CHANNELS
复制标题
DOI：
10.1016/0896-6273(93)90277-x
复制
发表时间：
1993-07-01
期刊：
影响因子：
16.2
通讯作者：
NEHER, E
中科院分区：
文献类型：
--
作者：
SCHNEGGENBURGER, R;ZHOU, Z;NEHER, E
测定内侧隔区前脑神经元流经谷氨酸能NMDA和AMPA/海人藻酸受体通道的离子电流中的钙离子比例。用钙离子指示剂Fura-2(1 MM)通过记录贴片吸管使神经元超载。这种方法可以根据对钙离子敏感的Fura-2荧光的变化直接确定钙离子内流。我们发现，在负的膜电位和1.6 mM的细胞外游离钙离子浓度下，通过NMDA受体通道的电流中钙离子的比例只有6.8%，比先前通过反转电位估计的大约低2倍。有趣的是，在这些神经元中发现的线性传导的AMPA/海人藻酸受体通道有相当高的钙电流分数1.4%。
The Ca2+ fraction of the ion current flowing through glutamatergic NMDA and AMPA/kainate receptor channels was determined in forebrain neurons of the medial septum. The neurons were overloaded with the Ca2+ indicator dye fura-2 (1 mM) via the recording patch pipettes. This approach allowed the direct determination of the Ca2+ influx from changes in the Ca2+-sensitive fura-2 fluorescence. We found that, at negative membrane potentials and at an extracellular free Ca2+ concentration of 1.6 mM, the Ca2+ fraction of the current through the NMDA receptor channels is only 6.8%, about 2-fold lower than previously estimated from reversal potential measurements. Interestingly, a quite high fractional Ca2+ current of 1.4% was determined for the linearly conducting AMPA/kainate receptor channels found in these neurons.