牛蛙离体交感神经元中钙依赖性超极化后电位

Calcium-dependent after-hyperpolarization in dissociated bullfrog sympathetic neurons.

作者信息

Tokimasa T

机构信息

Department of Physiology, Tokai University Medical School, Bohseidai, Isehara, Japan.

出版信息

Neurosci Lett. 1996 Oct 25;218(1):49-52. doi: 10.1016/0304-3940(96)13122-0.

DOI:10.1016/0304-3940(96)13122-0

PMID:8939478

Abstract

Whole-cell recordings were made from dissociated bullfrog sympathetic neurons. Tetraethylammonium (30 mM) and apamin (100 nM) were added to the superfusate to eliminate the known calcium-activated potassium currents termed Ic and IAHP. Under these conditions, the action potential carried by calcium ions was followed by a prolonged (10-60 s) after-hyperpolarization. A current component (IAC) underlying the after-hyperpolarization was eliminated by barium (2 mM) and showed voltage-dependence identical to that of a M-type potassium current. I concluded that the after-hyperpolarization is caused not only by IAHP but also by the calcium-dependent potentiation of M-current.

摘要

对分离的牛蛙交感神经元进行全细胞记录。向灌流液中加入四乙铵（30 mM）和蜂毒明肽（100 nM），以消除已知的钙激活钾电流，即Ic和IAHP。在这些条件下，由钙离子携带的动作电位之后是一个延长的（10 - 60秒）超极化后电位。超极化后电位的一个电流成分（IAC）被钡（2 mM）消除，并且显示出与M型钾电流相同的电压依赖性。我得出结论，超极化后电位不仅由IAHP引起，还由M电流的钙依赖性增强引起。