Characteristics of transient outward potassium channel exposed to 3 mT static magnetic field

Abstract

Acutely isolated mouse hippocampal CA3 pyramidal neurons were exposed to 3 mT static magnetic field, and the characteristics of transient outward K⁺ channel were studied using the whole-cell patch-clamp technique. The experiment revealed that the amplitude of transient outward potassium channel current was reduced. The maximum activated current densities of control group and exposure group were 163.62±20.68 pA/pF and 98.74±16.57 pA/pF(n=12, P<0.01)respectively. The static magnetic field exposure affected the activation and inactivation process of transient outward potassium channel current. Due to the magnetic field exposure, the halfactivation voltage of the activation curves changed from 5.59±1.96 mV to 27.87±7.24 mV(n=12, P<0.05), and the slope factor changed from 19.43±2.11 mV to 25.87±4.22 mV(n=12, P<0.05). The half-inactivation voltage of the inactivation curves also changed from −56.09±0.89 mV to −57.16±1.10 mV(n=12, P>0.05)and the slope factor of the inactivation curves from 8.69±0.80 mV to 10.87±1.02 mV(n=12, P<0.05). The results show that the static magnetic field can change the characteristics of transient outward K⁺ channel, and affect the physiological functions of neurons.

Keywords

transient outward potassium channel current / patch-clamp technique / static magnetic field / biological effect / neurons

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