Alger B E, Sim J A, Brown D A
Department of Pharmacology, University College London, UK.
Neurosci Lett. 1994 Feb 28;168(1-2):23-8. doi: 10.1016/0304-3940(94)90407-3.
Whole-cell voltage- and patch-clamp techniques were used to record the calcium-dependent component of ImAHP and correlated single-channel activity in postnatal cultured rat hippocampal neurons. The Ca-dependent ImAHP was elicited by voltage steps to + 10 mV from a holding potential of -50 mV in the whole-cell mode. In cell-attached patches, single currents of approximately 2 pA were observed following spontaneous action currents. The duration of ensemble-averaged single-channel activity was very similar to that of the whole-cell ImAHP, approximately 100 ms. Both whole-cell current and single-channel activity could be blocked by bath-applied cadmium, 200 microM. Vigorous channel activity was evoked by bursts of action potentials that are known to elicit Ca-dependent AHPs. We conclude that this channel is a candidate for mediating ImAHP.
采用全细胞电压钳和膜片钳技术记录出生后培养的大鼠海马神经元中依赖钙的内向超极化电流（ImAHP）成分及相关单通道活性。在全细胞模式下，通过将电压从 -50 mV 的钳制电位阶跃到 +10 mV 来诱发依赖钙的 ImAHP。在细胞贴附式膜片中，在自发动作电流后观察到约 2 pA 的单电流。整体平均单通道活性的持续时间与全细胞 ImAHP 的持续时间非常相似，约为 100 ms。全细胞电流和单通道活性均可被浴加 200 μM 的镉阻断。已知引发依赖钙的动作后电位的动作电位爆发可诱发强烈的通道活性。我们得出结论，该通道是介导 ImAHP 的候选通道。
