【摘要】 本文以螯虾细小神经轴突为标本,成功地应用双玻璃微电极进行细胞内刺激与电活动的记录。观察了细小神经轴突膜电生理和物理特性参数。钾离子通道特异性阻滞剂4—氨基吡啶,使Weiss式中常数b值显著减少;a值无明显变化;膜静息电位去极化;阈电位水平上移;动作电位幅值、锋电位时程、膜电阻和膜时间常数均有显著意义的增加。结果提示:4—氨基吡啶可提高膜的应激性,对神经膜兴奋性无明显影响;生物膜应激性及膜电阻的变化与钾通道的活动状态有密切关系。更多还原

【Abstract】 Intracellular stimulating and recording method was used by two glass microelectrodes on crayfish small axon. Physiologic and physical parameters of small nerve fiber were measured. 4—aminopyridine (4-AP). a selective inhibitor of the potassium channel,made"b" (an irritability index,a constant in Weiss’s formula) decreased(p<0. 01) and "a" (an excitability index,another constant in Weiss’s formula)unchanged ,the resting potential depolarized (P<0. 01), the threshold potential level raised (P<0.05),the membrane resistance and membrane time constant increased significantly. The results suggested that 4-AP can increase membrane irritability , but not affect the membrane excitability; the changes of membrane irritability and membrane resistance were related to the inhibition and activation of potassium channel.更多还原