Dihydropyridine-sensitive calcium currents in bipolar cells of salamander retina are inhibited by reductions in extracellular chloride.
Dihydropyridine-sensitive calcium currents in bipolar cells of salamander retina are inhibited by reductions in extracellular chloride.
复制标题
蝾螈视网膜双极细胞中二氢吡啶敏感的钙电流受到细胞外氯离子减少的抑制。
DOI：
10.1016/s0304-3940(00)00795-3
复制
发表时间：
2000
影响因子：
2.5
通讯作者：
Thoreson,WB
中科院分区：
文献类型：
--
作者：
Thoreson,WB
光感受器中的二氢吡啶敏感性钙电流（伊卡）是不寻常的，因为它们可以被细胞外氯离子的减少所抑制。本研究探讨是否ICain视网膜双极细胞，这在光感受器介导持续的神经传递，也被抑制减少氯化物。在虎蝾螈幼仔视网膜切片制备中，从双极细胞获得了制霉菌素穿孔斑片的全细胞记录。在Ba 2+存在的情况下，电压阶跃高于-40 mV诱发持续的内向电流，该电流被二氢吡啶（-）BayK 8644增强，并被尼索地平抑制。与光感受器类似，用葡萄糖酸盐或CH 3SO 4替代Cl−抑制双极细胞ICa，并使电流/电压关系负移。因此，对Cl−的敏感性可能是介导持续神经传递的L型Ca 2+通道亚型的更普遍的性质。
Dihydropyridine-sensitive calcium currents (ICa) in photoreceptors are unusual in that they can be inhibited by reductions in extracellular chloride. The present study examined whether ICain retinal bipolar cells, which as in photoreceptors mediates sustained neurotransmission, is also inhibited by reductions in chloride. Nystatin-perforated patch, whole cell recordings were obtained from bipolar cells in a retinal slice preparation of larval tiger salamander. In the presence of Ba2+, voltage steps above −40 mV evoked sustained inward currents, which were enhanced by the dihydropyridine, (−)BayK8644, and inhibited by nisoldipine. Similar to photoreceptors, replacing Cl−with gluconate or CH3SO4inhibited bipolar cell ICaand produced a negative shift in the current/voltage relationship. Thus, sensitivity to Cl−may be a more general property of L-type Ca2+channel subtypes that mediate sustained neurotransmission.