Afterhyperpolarization鈥揻iring rate relation of turtle spinal neurons

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• 作者：E. K. Stauffer P>A1 ; D. G. Stuart P>A2 ; J. C. McDonagh P>A3 ; T. G. Hornby P>A4 ; R. M. Reinking P>A5
• 关键词：Afterhyperpolarization ; Current鈥揻requency relation ; Motoneuron ; Interneuron ; Turtle spinal cord
• 刊名：Journal of Comparative Physiology A ; Sensory ; Neural ; and Behavioral Physiology
• 出版时间：February 2005
• 出版年：2005
• 期刊代码：127_0340-7594
• 类别：bio
• 卷：191
• 期：2
• 页码：135-146
• 数据来源：sp

摘要

This study addressed the afterhyperploarization鈥揻iring rate relationship of unanesthetized turtle spinal motoneurons and interneurons. The afterhyperploarization of their solitary action potential at rheobase was compared to that during the cells鈥?minimum and maximum firing rates. Like previous mammalian findings, afterhyperpolarization duration and area at rheobase were 32 and 19%less for high- versus low-threshold motoneurons. Contrariwise, maximum firing rate was two times less for the high-threshold group. Other new findings were that for high- versus low-threshold interneurons, afterhyperpolarization duration and area were 25 and 95%less, and maximum firing rate 21%higher for the high-threshold group. For combined motoneurons versus interneurons, there were no differences in afterhyperpolarization duration and area at rheobase, whereas maximum firing rate was 265%higher for the interneurons. For high-threshold motoneurons alone, there were significant associations between minimum firing rate and afterhyperpolarization duration and area measured at rheobase. In summary, this study showed that (1) the afterhyperploarization values of both turtle spinal motoneurons and interneurons at rheobase provided little indication of their corresponding values at the cells鈥?minimum and maximum firing states, and (2) the evolution of afterhyperploarization from rheobase to maximum firing state differed both qualitatively and quantitatively for motoneurons versus interneurons.