A Ca-dependent Cl− conductance in cultured mouse spinal neurones
A Ca-dependent Cl− conductance in cultured mouse spinal neurones
复制标题
培养小鼠脊髓神经元中 Ca 依赖性 Cl− 电导
作者：
D. Owen;M. Segal;J. Barker
在各种可兴奋组织中观察到由短暂（毫秒）电刺激和/或钙离子进入触发的持久电导变化1 -4。这些事件的电后果取决于受影响的离子电导和跨膜的离子浓度梯度，而变化的持久性质使细胞维持在亚阈值或超阈值水平以激活再生动作电位。我们在这里报告，许多培养的小鼠脊髓神经元表现出电压激活的氯离子电导，持续数秒，并依赖于细胞外钙，[Ca 2 +]0。这种电导可以将细胞维持和稳定在产生动作电位的亚阈值水平，从而补充Ca依赖性K+电导的功能作用5 -8。
Long-lasting conductance changes triggered either by brief (millisecond) electrical stimuli and/or entry of calcium ions have been observed in a variety of excitable tissues1–4. The electrical consequences of these events depend on the ion conductance affected and on the ion concentration gradient across the membrane, while the long-lasting nature of the change sustains the cell at either sub- or supra-threshold levels for activation of regenerative action potentials. We report here that many cultured mouse spinal neurones exhibit a voltage-activated chloride conductance that lasts for seconds and is dependent on extracellular calcium, [Ca2+]0. This conductance may repolarize and stabilize the cell at a level subthreshold for generating action potentials, thus complementing the functional roles of Ca-dependent K+ conductances5–8.