Photolytic Manipulation of [Ca2+]iReveals Slow Kinetics of Potassium Channels Underlying the Afterhyperpolarization in Hipppocampal Pyramidal Neurons
Photolytic Manipulation of [Ca2+]iReveals Slow Kinetics of Potassium Channels Underlying the Afterhyperpolarization in Hipppocampal Pyramidal Neurons
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[Ca2]i 的光解操纵揭示了海马锥体神经元后超极化背后的钾通道缓慢动力学
DOI：
10.1523/jneurosci.19-10-03657.1999
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
J. Clements
中科院分区：
文献类型：
--
作者：
P. Sah;J. Clements
钾通道的身份背后的缓慢，apamin不敏感的组件的后超极化电流（sIAHP）仍然未知。我们研究了sIAHP在CA 1锥体神经元使用同时全细胞记录，钙荧光成像，和闪光光解的笼化合物。胞内钙离子浓度（[Ca 2 +]i）峰值早于sIAHP，且衰减快于sIAHP。用低浓度的钙螯合剂EGTA加载细胞减缓了sIAHP的激活和衰减。在EGTA的存在下，细胞内钙衰减有两个时间常数。当[Ca ~（2+）]i在DM-Nitrophen光解后迅速增加时，apamin敏感和apamin不敏感的外向电流都被激活。apamin敏感电流激活迅速（<20毫秒），而apamin不敏感电流激活较慢（180毫秒）。通过应用5-羟色胺和卡巴胆碱降低了apamin不敏感电流，证实其由sIAHP通道引起。当[Ca 2 +]i通过光解重氮-2迅速降低时，sIAHP的衰减与对照相似（1.7秒）。所有结果都可以通过钙门控的模型钾通道再现，这表明sIAHP的基础通道具有固有的慢动力学，因为它们对钙的高亲和力。
The identity of the potassium channel underlying the slow, apamin-insensitive component of the afterhyperpolarization current (sIAHP) remains unknown. We studied sIAHP in CA1 pyramidal neurons using simultaneous whole-cell recording, calcium fluorescence imaging, and flash photolysis of caged compounds. Intracellular calcium concentration ([Ca2+]i) peaked earlier and decayed more rapidly than sIAHP. Loading cells with low concentrations of the calcium chelator EGTA slowed the activation and decay of sIAHP. In the presence of EGTA, intracellular calcium decayed with two time constants. When [Ca2+]i was increased rapidly after photolysis of DM-Nitrophen, both apamin-sensitive and apamin-insensitive outward currents were activated. The apamin-sensitive current activated rapidly (<20 msec), whereas the apamin-insensitive current activated more slowly (180 msec). The apamin-insensitive current was reduced by application of serotonin and carbachol, confirming that it was caused by sIAHP channels. When [Ca2+]i was decreased rapidly via photolysis of diazo-2, the decay of sIAHPwas similar to control (1.7 sec). All results could be reproduced by a model potassium channel gated by calcium, suggesting that the channels underlying sIAHP have intrinsically slow kinetics because of their high affinity for calcium.
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影响因子：
4
作者：
Zucker,RS
通讯作者：
Zucker,RS
影响因子：
2.5
作者：
K. Moore;A. Cohen;J. Kao;D. Weinreich
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K. Moore;A. Cohen;J. Kao;D. Weinreich
DOI：
10.1073/pnas.84.10.3496
发表时间：
1987-05-01
影响因子：
11.1
作者：
GURNEY, AM;TSIEN, RY;LESTER, HA
通讯作者：
LESTER, HA
猫感觉运动皮层神经元中的钙依赖性钾电流。
影响因子：
2.5
作者：
Schwindt,PC;Spain,WJ;Crill,WE
通讯作者：
Crill,WE
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DOI：
10.1152/jn.1997.78.2.825
发表时间：
1997
期刊：
Journal of neurophysiology.
影响因子：
--
作者：
Lasser-Ross,N;Ross,WN;Yarom,Y
通讯作者：
Yarom,Y