Traynelis S F, Dingledine R
Department of Pharmacology, University of North Carolina, Chapel Hill 27599-7365.
Neurosci Lett. 1989 Mar 27;98(2):194-9. doi: 10.1016/0304-3940(89)90509-0.
Reduction of external calcium and magnesium from 1.5 to 1.2 mM intensified potassium-induced interictal bursts, increased the likelihood of electrographic seizure occurrence in CA1, and rendered seizure initiation independent of N-methyl-D-aspartate (NMDA) receptor activation. In contrast to slices bathed in 1.5 mM divalent cations, in 1.2 mM divalents spontaneous CA1 seizures still occurred in CA1 minislices that contained at least 1500 neurons after removal of the CA3 burst generator, suggesting that divalent cations critically modulate the dependence of CA1 seizure initiation on interictal input. Since this slight reduction in external divalent cations enhanced tissue excitability, similar changes might promote epileptogenesis in situ.
将细胞外钙和镁的浓度从1.5 mM降至1.2 mM，可增强钾诱导的发作间期爆发，增加CA1区脑电图发作的可能性，并使癫痫发作起始独立于N-甲基-D-天冬氨酸（NMDA）受体激活。与浸泡在1.5 mM二价阳离子中的脑片不同，在1.2 mM二价阳离子条件下，去除CA3爆发发生器后，含有至少1500个神经元的CA1微小脑片中仍会出现自发的CA1癫痫发作，这表明二价阳离子对CA1癫痫发作起始对发作间期输入的依赖性具有关键调节作用。由于细胞外二价阳离子的这种轻微减少增强了组织兴奋性，类似的变化可能会在原位促进癫痫发生。
