摘要
利用波长650 nm,功率5 mW的半导体激光器照射急性分离的大鼠海马CA3区锥体神经细胞,应用全细胞膜片钳技术研究其延迟整流钾通道的电流特性。实验发现,弱激光对延迟整流钾电流IK有抑制作用,且抑制呈时间依赖性,5min激光抑制作用达到稳定,抑制百分比为34.54%±3.22%(统计样本数n=15);弱激光对IK的抑制作用还具有电压依赖性和可逆性,对照组、照射组和恢复组最大激活电流密度分别为429.78±41.40 pA/pF,283.26±39.62 pA/pF(n=10,t检验中P<0.01)和397.22±36.81 pA/pF(n=10,P>0.05);激光作用可显著地影响IK的激活过程,对照组和照射组半数激活电压分别为5.74±1.56 mV和20.98±8.85 mV(n=10,P<0.01),斜率因子分别为16.51±6.67 mV和17.44±5.19 mV(n=10,P>0.05)。结果表明,弱激光作用海马神经细胞可以改变其延迟整流钾通道特性,从而影响动作电位复极化过程,调节神经细胞的生理功能,有利于受损神经元的恢复和再生。
Acutely isolated rat hippocampal CA3 pyramidal neurons were irradiated with a semiconductor laser of 650 nm wavelengh and 5 mW power, and properties of delayed rectifier potassium (K^+ ) channel were studied using the whole-cell patch clamp technique. The experiment indicated that low level laser reversibly reduced the amplitudes of IK in a time-dependent and voltage-dependent manner. The percentage of inhibition was up to 34.54%±3.22% (n = 15) in irradiating 5 min. The maximum activated current densities of control group, irradiation group and restoration group respectively were 429.78±41.40 pA/pF, 283.26±39.62 pA/pF (n= 10, P〈0.01) and 397.22±36.81 pA/pF (n = 10, P 〉 0.05). Laser irradiation significantly affected the activation process of IK. The halfactivation voltage and the slope factor of the activation curves were also changed by the laser's exposure. The half- activation voltages of control group and irradiation group were 5.74±1.56 mV and 20.98±8.85 mV (n = 10, P 〈 0.01) respectively, and the slope factors were 16. 51±6. 67 mV and 17. 44±5. 19 mV (n = 10, P 〉 0.05) respectively. The results show that low level laser can change the properties of delayed rectifier K+ channel. Therefore, repolarization process of action potential is affected. Further, physiological functions of neurons are adjusted, which might contribute to the restoration and regeneration of injured neurons.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2006年第9期1288-1293,共6页
Chinese Journal of Lasers
关键词
医用光学与生物技术
生物刺激效应
延迟整流钾电流
膜片钳技术
弱激光照射
medical optics and biotechnology
biologic effect
delayed rectifier potassium current
patch clamptechnique
low level laser irradiation