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Electrophysiological correspondence between Kv4.2 current and transient outward potassium current in the cultured rat hippocampal neuron

Jin Hongwei, Zhang Wei, Qu Lintao, Wang Xiaoliang

Institute of Materia Medica,Chinese Academy of Medical Science & Peking Union Medical College.Beijing 100050

Abstract

The results showed that I_(A) in cultured rat hippocampal neurons and Kv4.2 expressed in HEK293 cells both displayed "A"-type current properties. The activation curves of I_(A) and Kv4.2 were better fitted by simple Boltzmann function with V_(1/2)-10.0±3.3mV, k 13.9±2.6 mV for I_(A) and V_(1/2)-9.7±4.1 mV, k 15.8±5.7 mV for Kv4.2, respectively. The steady-state inactivation curves of I_(A) had a midopoint of -93.0±11.4mV and a slope of 9.0±1.5 mV. The voltage-dependence of inactivation for Kv4.2 exhibited midpoint and slope values of -59.4±12.2mV and 8.0±3.1 mV, respectively. The time constants (#tau#) of recovery from inactivation of I_(A) and Kv4.2 were 27.9±14.1 ms and 172.8±14.1 ms and 172.8±10.0 ms, respectively. These results suggest that Kv4.2 is probably a major isoform contributing to I_(A) in hippocampus neurons.

Key words: Transfection;Potassium channels;Kv4.2;Hippocampus neuron;Patch;Clamp techniques

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Citing This Article：

Jin Hongwei, Zhang Wei, Qu Lintao, Wang Xiaoliang. Electrophysiological correspondence between Kv4.2 current and transient outward potassium current in the cultured rat hippocampal neuron. Acta Physiol Sin 2003; 55 (6): (in Chinese with English abstract).