摘要
目的：研究引导电极之间、引导电极与刺激电极之间的距离对蟾蜍坐骨神经干动作电位波形记录的影响，阐明“两相波形不对称”这一现象蕴含的生理机制。方法：制备坐骨神经干标本，采取麻醉阻滞单相动作电位记录法、双相动作电位记录法、单／双相动作电位记录对比法，观察刺激电极间位置以及引导电极与刺激电极间位置对神经干复合动作电位的波形、幅度和时程的影响。结果：①刺激电极与引导电极间距离对单相动作电位波形的影响：通过单相动作电位记录，当刺激电极与引导电极间距离在3．0～5．5cm范围内逐渐增大时，波幅呈降低趋势，时程呈增大趋势。②引导电极间距离对双相动作电位波形的影响：通过双相动作电位记录，当两个引导电极间距离在0．1～2．0cm范围内逐渐增大时，负相、正相波波幅均显著升高，两电极间距〉2cm范围内逐渐增大时，负相波波幅与时程相对稳定，正相波波幅逐渐减小而时程逐渐增大。③通过单／双相动作电位对比记录同一位置的动作电位波形进行比较：当两引导电极间距〈2．0cm时，两种方法记录到的动作电位幅度有显著差别（P〈0．05），且单相动作电位幅度显著大于双相动作电位；当两引导电极间距〉2cm时，两种方法记录到的动作电位幅度和时程没有明显差别（P〉0．05）。结论：当两引导电极间距较小时，影响动作电位波形的主要因素是两引导电极之间的距离大小决定的“周期效应”，即间距在兴奋区域波波长内的两个引导电极引导出的电位差较兴奋区域波波长外的两个引导电极间的电位差有明显差别。当两引导电极间距较大时，影响动作电位波形的主要因素为引导电极与刺激电极之间的距离大小决定的“迁延效应”，即传播过程中，众多神经纤维动作电位叠加形成的神经干复�
Objective： To explore the effect of the electrode distance between stimulating（S） and guiding（R） electrodes and between the R electrodes on the sciatic nerve action potential waveform＇s re- cording and clarify the mechanism of ＂asymmetric two-phase waveform＂. Methods： Sciatic nerve-trunk specimens were made,to observe the waveforms, amplitude, and duration of nerve-trunk action potential waveforms. Through the recordings of anesthetic block monophasic action potentiai, biphasie action po- tential and the contrastive mono/biphasic action potential. Results： In monophasic recording, the ampli- tude decreases and the duration increases with the disance between S and R-- increased from 3.0 cm to 5.5 cm. In biphasic recordings, the amplitude of both negative and positive negative phase waves had the tendency to improve with the distance between R-- and R2- increasing from 0.1 cm to 2.0 cm. When that spacing was larger than 2 cm, the amplitude and duration of negative phase waves were relatively stable,while the amplitude of positive phase wave reduced and the duration increased gradually. In mono/ biphasic contrastive recordings, with the distance between Rz- and R2 ~ within 2.0 cm, the amplitude of two recording ways had significant difference （P^0.05）, and amplitude of monophasic potential ex- ceededed that of biphasic action potential. When the distance between R2 q- and R2 was more than 2 cm, the amplitude of two recording ways had no significant difference（P~〉0.05）. Conelusion..Within a certain range,＂the Cycle Effect＂ of the guiding electrodes＇ interaction between R and R-＋- is the main mecha nism of ＂asymmetric two-phase waveform＂, thus increasing the distance between R-- and R--can in- crease the amplitude of biphasic action potential; in a larger range, the main mechanism changes to ＂The Time Delay Effect＂ of the distance between S and R. Due to a fixed position of R , while the amplitude and duration of the negative phase wave are stable,in order to increase the
出处
《癫痫与神经电生理学杂志》
2014年第1期9-15,共7页
Journal of Epileptology and Electroneurophysiology(China)
关键词
神经干
动作电位
刺激电极
引导电极
位置
nerve trunk
action potential
stimulating electrode
guiding electrode
position
